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ISBN-13: 978 1 4160 2443 9 ISBN-10: 1 4160 2443 3 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data A catalog record for this book is available from the Library of Congress
Notice Medical knowledge is constantly changing. Standard safety precautions must be followed, but as new research and clinical experience broaden our knowledge, changes in treatment and drug therapy may become necessary or appropriate. Readers are advised to check the most current product information provided by the manufacturer of each drug to be administered to verify the recommended dose, the method and duration of administration, and contraindications. It is the responsibility of the practitioner, relying on experience and knowledge of the patient, to determine dosages and the best treatment for each individual patient. Neither the Publisher nor the editors or contributors assume any liability for any injury and/or damage to persons or property arising from this publication. The Publisher Printed in China Last digit is the print number: 9 8 7 6 5 4 3 2 1
Commissioning Editor: Susan Pioli Project Development Manager: Cecilia Murphy Project Manager: Glenys Norquay Design Manager: Jayne Jones Illustration Manager: Gillian Murray Illustrator: Jenni Miller and Cactus Marketing Manager(s) (UK/USA): Verity Kerkhoff /Matthew Latuchie
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Preface Sports medicine is a rapidly evolving interdisciplinary field that has benefited from recent increases in scientific and clinical knowledge in many medical specialties, including physiology, nutrition, primary care, orthopedics, and rehabilitation. This book is unique in that it is a comprehensive sports medicine text that specifically focuses on a rehabilitation approach. Many sports medicine books limit their content to a specific discipline such as exercise physiology, sports training, or sports injuries. We have taken a different approach and present to the sports medicine practitioner a wide variety of topics in three major areas of the field: basic principles of conditioning and medical care of the athlete, a comprehensive discussion of rehabilitation principles and interventions, and a general (non-surgically oriented) discussion of sports injuries by anatomical area. After reading this book, sports medicine practitioners will understand the scientific basis of sports conditioning and performance, identify the most important medical issues confronting the athlete, recognize the principles of rehabilitation for the injured athlete, and know the most common therapeutic principles of sports injuries in various anatomical areas and sports. The practice of sports medicine around the world is not uniform and significant variability exists among sports medicine centers and models of care in various countries, even among countries in geographical proximity. We have assembled experts from several continents and countries to reflect this diversity and to make sure that different points of view are represented in the discussion. We, as the editors, would like to thank all of our colleagues around the world for their interest in and contribution to this project. It would be hard to find another discipline or medical specialty with more international flavor than sports medicine. The international nature of sports competition requires that sports medicine practitioners understand the special needs of the traveling athlete in areas such as nutrition, environmental factors, doping control, and many others. These and related topics are discussed in detail in the book. The practice of sports medicine requires, by definition, a team of professionals with training and expertise in various health-related fields. This book is intended for all medical and non-medical professionals who are members of the sports medicine team, especially the non-surgical medical specialists. The sports medicine practitioner in general and the team physician in particular must have broad knowledge and understanding of a wide variety of scientific and medical issues that could result in deteriorating athletic performance and serious health complications. The relationship of these medical conditions and sports training programs must be recognized and understood. Thus, chapters in Section 1 include principles of conditioning as well as important primary care problems of the athlete and exercise enthusiasts. The incidence of injuries in many sports has increased with the intensity of the training and competition. Further, the goal of many athletes of all ages after injury is to return to competition as fast as possible. Therefore, rehabilitation has become an important area of research and practice in sports medicine. We recognize these developments in Section 2 of the book with a combination of classical and sports-oriented rehabilitation. Finally, although Section 3 has been dedicated to sports injuries, the book is not a treatise on the surgical management of the injured athlete. However, it may be useful to surgeons who serve as team physicians. We sincerely hope this book will help the established sports medicine specialist practice excellent sports medicine as well as motivate the beginner to dedicate further study to sports medicine. Sincerely, Walter R. Frontera Stanley A. Herring Lyle J. Micheli Julie K. Silver Timothy P. Young
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List of Contributors Julia Alleyne MD CCFP Dip Sport Med FACSM Medical Director, Sport C.A.R.E. Women’s College Hospital Assistant Clinical Professor Department of Family and Community Medicine University of Toronto Toronto, Ontario Eduardo Amy MD Assistant Professor Sports Injuries Unit PR Olympic Training Center University of Puerto Rico San Juan, Puerto Rico Joseph F. Audette MA MD Instructor Department of Physical Medicine and Rehabilitation Harvard Medical School Boston, MA Norbert Bachl MD Professor Department of Sports and Exercise Physiology Institute of Sports Science University of Vienna Vienna Allison Bailey MD Instructor Department of Physical Medicine and Rehabilitation Harvard Medical School Boston, MA Ramon Baron MD Professor Department of Sports and Exercise Physiology Institute of Sports Science University of Vienna Vienna Deborah A. Berrgfeld MD Attending Physician Buffalo Spine and Sports Institute, PC Buffalo, NY Joanne Borg-Stein MD Assistant Professor of Physical Medicine and Rehabilitation Harvard Medical School Medical Director Spaulding-Wellesley Rehabilitation Center Wellesley, MA
Andrea Burry MSc MD Resident Family Medicine Department Women’s College Hospital Toronto, Ontario Robert C. Cantu MA MD FACS FACSM Chairman, Department of Surgery Chief, Neurosurgery Service Emerson Hospital Concord, MA Robert V. Cantu MD Assistant Professor of Orthopaedic Surgery Department of Orthopaedic Surgery Dartmouth-Hitchcock Medical Center Lebanon, NH
Wayne E. Derman MBChB PhD FACSM Associate Professor Sports Science and Sports Medicine University of Cape Town Director, Chronic Disease Rehabilitation Programme Sports Science Institute of South Africa Cape Town Eduardo H. De Rose MD PhD Professor of Medicine Porto Alegre Pierre A. d’Hemecourt MD FACSM Director Primary Care Sports Medicine Children’s Hospital Boston Boston, MA
Kai-Ming Chan MBBS MC CH(Orth) FRCS(G) FRCS(E) Chair, Professor, and Chief of Service Department of Orthopaedics and Traumatology The Chinese University of Hong Kong Prince of Wales Hospital Shatin, Hong Kong
Sheila A. Dugan MD Assistant Professor Department of Physical Medicine & Rehabilitation Rush Medical College Chicago, IL
David S. Chang MD Orthopaedic Surgeon Sports Medicine Bay Area Sports Orthopaedics San Francisco, CA
Brandon E. Earp MD Instructor Department of Orthopaedic Surgery Harvard Medical School Boston, MA
Joseph Jeremy Hsi-Tse Chang MBChB Resident Department of Orthopaedics and Traumatology The Chinese University of Hong Kong Prince of Wales Hospital Shatin, Hong Kong
Emin Ergen MD PhD Professor of Sports Medicine Department of Sports Medicine Ankara University School of Medicine Ankara
Gian Corrado MD Clinical Lecturer Department of Emergency Medicine University of Michigan Ann Arbor, MI José Correa MD Assistant Professor Director of Primary Unit PR Olympic Training Center University of Puerto Rico San Juan, Puerto Rico David M. Crandell MD Instructor Department of Physical Medicine & Rehabilitation Spaulding Rehabilitation Hospital Boston, MA
Federrica Fagnani BSc Technician Sports Medicine Laboratory Department of Health Sciences University Institute of Movement Sciences (IUSM) Rome Karl B. Fields MD CAQ Director Moses Cone Family Medicine Residency and Primary Care Sports Medicine Fellowship Moses Cone Family Medicine Greensboro, NC
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Walter R. Frontera MD PhD Dean and Professor of Physical Medicine and Rehabilitation University of Puerto Rico School of Medicine Puerto Rico Lecturer (and former Professor and Chair) Department of Physical Medicine and Rehabilitation Harvard Medical School/Spaulding Rehabilitation Hospital Boston, MA
Johns Hopkins Medical Institution Baltimore, MD Ted A. Lennard MD Clinical Assistant Professor Department of Physical Medicine and Rehabilitation University of Arkansas for Medical Sciences Staff Physician Springfield Neurological and Spine Institute Springfield, MO
Peter Gerbino MD Assistant in Orthopedic Surgery Division of Sports Medicine Department of Orthopedic Surgery Children’s Hospital Boston Instructor in Orthopedics Harvard Medical School Boston, MA
Bert R. Mandelbaum MD Orthopaedic Surgeon Director, Santa Monica Orthopaedic and Sports Medicine Orthopaedic Research and Education Foundation and Fellowship Santa Monica, CA
Arrigo Giombini MD Medical Doctor Physiotherapy and Rehabilitation Department Sports Medicine Unit University Institute of Movement Sciences (IUSM) Rome
Julio A. Martinez-Silvestrini MD Assistant Clinical Professor, Tufts University School of Medicine Staff Physiatrist, Division of Physical Medicine & Rehabilitation Baystate Medical Education and Research Foundation Springfield, MA
Stanley A. Herring MD Medical Director of Spine Care Clinical Professor Departments of Rehabilitation Medicine, Orthopaedics and Sports Medicine, and Neurological Surgery University of Washington Team Physician, Seattle Seahawks Team Physician, Seattle Mariners Seattle, WA Jeff Hym man BSc MD FRCPC Assistant Professor of Pediatrics Children’s Clinic Winnipeg, Manitoba Robert Kennedy MD Associate Director Sports Medicine Department Saint Joseph’s Regional Medical Center Mishawaka, IN W. Ben Kibler MD FACSM Medical Director Lexington Clinic Sports Medicine Center Lexington, KY Mininder S. Kocher MD MPH Associate Director Division of Sports Medicine Children’s Hospital Boston Assistant Professor of Orthopaedic Surgery Harvard Medical School Boston, MA Brian J. Krabak MD MBA Assistant Professor of Physical Medicine & Rehabilitation Assistant Professor of Orthopaedic Surgery
Lyle e J. Micheli MD O’Donnell Family Professor of Orthopaedic Sports Medicine Harvard Medical School Boston, MA William Micheo MD Chairman & Professor Department of Physical Medicine, Rehabilitation & Sports Medicine University of Puerto Rico School of Medicine San Juan, Puerto Rico
Mark R. Proctor MD Assistant Professor in Surgery Department of Neurosurgery Children’s Hospital Boston Harvard Medical School Boston, MA Thomas D. Rizzo Jr MD Consultant Department of Physical Medicine & Rehabilitation Mayo Clinic Jacksonville, FL Assistant Professor of Physical Medicine and Rehabilitation Mayo Clinic College of Medicine Rochester, MN Roy J. Shephard PhD MD (Lond) DPE Professor Emeritus of Applied Physiology University of Toronto Toronto, Ontario Juliie K. Silver MD Assistant Professor Department of Physical Medicine and Rehabilitation Harvard Medical School Attending Physician Spaulding Rehabilitation Hospital Associate in Physiatry Massachusetts General and Brigham and Women’s Hospital Boston, MA Stephen M. Simons MD FACSM Director of Sports Medicine Saint Joseph’s Regional Medical Center South Bend, IN
Jason H. Nielson MD Pediatric and Adolescent Sports Medicine Children’s Bone and Spine Surgery Las Vegas, NV
Gerhard Smekal MD Professor Department of Sports and Exercise Physiology Institute of Sports Science University of Vienna Vienna
Attilio Parisi MD Professor of Nutrition Sports Medicine Unit University Institute of Movement Sciences (IUSM) Rome
Jennifer L. Solomon MD Clinical Instructor of Physical Medicine and Rehabilitation Weill Medical College Cornell University New York, NY
Fabio Pigozzi MD Professor of Sports Medicine Head, Sports Medicine Unit University Institute of Movement Sciences (IUSM) Rome
Christoph her J. Standaert MD Clinical Assistant Professor Departments of Rehabilitation Medicine, Orthopaedics and Sports Medicine, and Neurological Surgery University of Washington Medical Center Seattle, WA
Joe el M. Press MD Medical Director Spine and Sports Rehabilitation Center Rehabilitation Institute of Chicago Chicago, IL
Rachael Tucker MBChB Research Associate Division of Sports Medicine Children’s Hospital Boston Boston, MA
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Bülent Ulkar MD PhD Associate Professor Department of Sports Medicine Ankara University School of Medicine Ankara
Peter M. Waters MD Professor of Orthopedic Surgery Department of Orthopedic Surgery Harvard Medical School Boston, MA
Fiona Chui-Yan Wong MBChB Resident Department of Orthopaedics and Traumatology The Chinese University of Hong Kong Shatin, Hong Kong
Brandee Waite MD Assistant Professor of Physical Medicine and Rehabilitation University of California – Davis Medical Center Sacramento, CA
Jennifer M. Weiss MD Assistant Professor of Clinical Orthopaedics Department of Pediatric Orthopedics Keck School of Medicine of USC Children’s Hospital Los Angeles Los Angeles, CA
Merrilee Zetaruk MD FRCPC Dip Spo ort Med Associate Professor Department of Pediatrics and Child Health University of Manitoba Winnipeg, Manitoba
Katherine M. Walker MD CAQ Assistant Director, Sports Medicine Fellowship Sports Medicine and Injury Center Cabarrus Family Medicine Concord, NC
Anton Wicker MD PhD MS Head of Department Physical Medicine and Rehabilitation Paracelsus University Salzburg Salzburg
Jerrad Zimmerman MD Medical Director of Sports Medicine Carle Clinic University of Illinois Team Physician Urbana, IL
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Dedication We dedicate this book to the sports medicine providers whose knowledge and dedication help to ensure optimal health and performance in the athletes they treat.
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CHAPTER
1
An Overview of Sports Medicine Walter R. Frontera
INTRODUCTION The purpose of this chapter is to present an overview of the scientific and clinical discipline known as sports medicine. In a diverse world like ours, it is not surprising to see that there is no single definition of sports medicine that is accepted by all interested in the field. Clearly, discussions about sports medicine include the positive and negative consequences of acute and chronic exercise and physical activity, sports performance and the health implications of an active lifestyle. Yet, these elements have not been assembled in a statement that is universally accepted. Different authors and professional groups throughout the world have their own conceptual and practical definitions of sports medicine. This heterogeneity may explain why clinical sports medicine programs around the world vary in the nature and scope of their services. Also, educational and training programs in sports medicine do not have a common curriculum and educational experiences vary from region to region. Sports medicine is sometimes seen as the primary field of interest and sometimes as a sub-specialty within another field, such as cardiology, orthopedics or rehabilitation. It could be argued that sports medicine has been divided into sub-specialties such as the treatment and rehabilitation of sports injuries, the medical care of the athlete, and exercise medicine for public health. Finally, research in sports medicine covers a wide spectrum of topics and includes an assortment of scientists working in overlapping but distinct areas. Some examples of research topics that can be classified under the umbrella of sports medicine are the genetic determinants of aerobic performance, the molecular mechanism of force production in skeletal muscle, the optimal prescription of exercise for the primary prevention of chronic and degenerative diseases, the surgical technique most appropriate for the reconstruction of the anterior cruciate ligament (ACL) of the knee, and the types of mental training that will enhance performance in specific events such as archery. The wide variety of research questions makes sports medicine an exciting field of study for many. In fact, some researchers whose background is not in sports medicine may use experimental models including exercise to answer ques-
tions relevant to other medical specialties. In other words, they use exercise as a technique to study a biological phenomenon unrelated to sports performance. There is little doubt that a consensus with regards to the definition of sports medicine has not been achieved. Thus, for the purpose of this chapter it may be more relevant and productive to describe sports medicine as it is perceived and practiced around the world and to comment on the various approaches that have resulted from local or regional interests and beliefs. It is not the intention of the author to propose a definition of sports medicine but rather to describe the subject matter. This book is an attempt to assemble the knowledge in the field of sports medicine in a single source, with an emphasis on the medical and rehabilitative aspects.
ORGANIZED SPORTS MEDICINE Modern sports medicine, as we know it, has been around for decades. During the last 100 years, many countries have established national associations for sports medicine practitioners. For example, the German Society of Sports Medicine was established in 1912 and the French Society of Sports Medicine in 1921. In the Americas, national sports medicine associations were founded in Uruguay in 1941, in the US in 1954 and in Chile in 1955. Several international groups have also been established including the International Federation of Sports Medicine (1928), the Pan American Confederation of Sports Medicine (1976), the European Federation of Sports Medicine Associations (1997) and the Asian Federation of Sports Medicine (1990). The basis for the foundation of these groups, the professional background of their members, and the scientific and clinical emphasis of each vary widely. One way of illustrating the different views of sports medicine around the world is to examine the institutional organization and affiliation of sports medicine practitioners and clinics. In some countries, sports medicine services and clinics are fully integrated within academic departments in a medical school or in an academic health center; either as an independent department or as a section or division of another department. In
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these countries, sports medicine is included in the medical school curriculum and there is significant research activity. Physicians in those centers work with sports teams but their primary affiliation is with the academic institution. In other countries, sports medicine services are an integral part of a university faculty of sports science or physical education. Medical doctors are included and actively participate in educational and research programs but the structure is outside of a medical school or academic health center. In yet a third model, in other countries, the main sports medicine service or clinic is part of the National Sports Institute or Sports Ministry, loosely affiliated with an academic institution. In this case, it is the government or the sports federations that provide most of the support needed by the sports medicine service. The sports medicine physician is an employee of the government or sports club and the emphasis is dictated by the immediate health needs of the athletes and not by academic considerations. Finally, there are also large numbers of practitioners who provide services as private doctors, some without formal training but with an interest in sports and the medical needs of the competitive athletes. The latter is an example of sports medicine services offered outside of a system.
KNOWLEDGE BASE All sports medicine practitioners benefit from the knowledge generated by research in many basic and applied sciences. Some of this knowledge is not unique to the field of sports medicine and serves as the foundation for the practice of many health-related professions and medical specialties. When applied to the physically active individual and/or to the competitive athlete, this knowledge becomes part of the foundation of sports medicine. On the other hand, there is a body of knowledge that has accumulated over the last few decades that is unique to sports medicine. It has emerged from investigations designed to address specific questions related to the limits of human performance, the health benefits of regular physical activity and the healthcare needs of the physically active population. In these investigations, exercise has been the central proposition. Many scientific disciplines contribute to the knowledge base in sports medicine. Physiology and nutrition constitute the foundation that successful training programs are built upon. Sports performance cannot be thoroughly understood or enhanced without the sound application of exercise physiology principles and the optimal combination of fluids and nutrition with training loads. In addition, an in-depth understanding of the physiological responses to acute and chronic exercise can guide the development of preventive exercise programs for the general population and the rehabilitation interventions for patients with acute injuries and chronic diseases. Indeed, from the point of view of public health, one of the most important contributions made by sports medicine to society is the generation of new knowledge supporting the hypothesis that an active lifestyle contributes to the primary or secondary prevention of common chronic illnesses such as heart disease, diabetes, osteoporosis and hypertension.
Research on the psychological and biological bases of human behavior and emotions provide the framework for the mental preparation needed by the high-performance athlete and for the study of benefits of physical activity and exercise on mental health. The fundamental sciences such as physics and mathematics contribute to the understanding of the effects and benefits of therapeutic modalities such as cold and ultrasound used in the rehabilitation of sports-related injuries. Chemistry and pharmacology explain the appropriate use and effectiveness of the pharmacological agents in the treatment of pain and inflammation and serve to study the interaction between the metabolic changes associated with physical activity and drug metabolism. Pharmacological principles are equally relevant to the anti-doping efforts and the safe use of exercise training in patients who are taking drugs for therapeutic reasons. Substantial knowledge of the anatomy and biomechanics of the musculoskeletal system is essential in the development of proper training and performance techniques for successful sport participation. This knowledge is also fundamental in the development of therapeutic and surgical techniques for the treatment of injuries such as ligamentous tears and muscletendon strains. Clinical research has also contributed significantly to strengthening the science underlying the practice of sports medicine. Research into the optimal training techniques has helped develop recommendations for the elite athlete as well as the general public. Clinical trials of pharmacological, rehabilitative and surgical interventions have contributed enormously to the development of therapeutic protocols for injured athletes. In fact, the results of clinical research in sports medicine have now been used in the development of therapeutic interventions for the non-active individual.
PRACTICAL AND OPERATIONAL DEFINITIONS The content of study in sports medicine has evolved significantly during the last 50 years. In an editorial for the Journal of Sports Medicine and Physical Fitness published in 1977, Professor Giuseppe La Cava, President of the FIMS 1968– 1976, described sports medicine as the application of medical knowledge to sport with the aim of preserving the health of the athlete while improving his or her performance. La Cava included sports biotypology, physiopathology, medical evaluation, traumatology, hygiene and therapeutics as the main elements of sports medicine.1 Absent from this definition is the application of sports medicine to those who are not actively involved in sports. In 1988, Professor Wildor Hollmann, FIMS president 1986–1994, summarized the main aspects or sports medicine as follows: medical treatment of injuries and illnesses; medical examination before starting a sport to detect any damage that could be worsened by the sport; medical performance investigation to assess the performance capacity of the heart, circulation, respiration, metabolism and the skeletal musculature; performance diagnosis specific to the type of sport; medical advice on lifestyle and nutrition; medical assistance in developing optimal
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training methods; and scientifically based control of training.2 This definition is more inclusive and shows the evolution in the knowledge that took place during the 1980s and 1990s. More recently, many authors have expanded the nature of the clinical activities included in sports medicine. For example, according to Brukner and Khan (1993),3 clinical sports medicine includes management of medical problems associated with physical activity and exercise; the role of exercise in the treatment and rehabilitation of chronic disease states; performance enhancement through various interventions such as physiological training, and nutritional alterations; prevention, diagnosis, treatment and rehabilitation of sports injuries; special and specific needs of the pediatric, female and older populations of physically active people; healthcare needs of the traveling sports team; and the use and abuse of substances prohibited in sports (doping). This definition expands the frontiers of sports medicine and includes topics that were not previously thought to be within its domain. Thus, the evolution of the definition shows that sports medicine has become more inclusive of the non-elite athlete and the general public and more interested in topics other than the limits of human performance in competitive sports.
A PERSONAL VIEW It is clear that sports medicine includes a wide variety of themes and topics and that sports medicine practitioners must be familiar with many basic applied sciences as well as with broadly diverse medical and clinical disciplines. Sports medicine can be briefly and accurately defined as the study of the interrelationship between physical activity and health. In this context, physical activity includes daily and occupational activities, structured exercise training for the non-competitive athlete, and sports participation. This definition considers not only the study of the benefits of physical activity but also the deleterious effects of its absence since it is known that inactivity and deconditioning have negative consequences on human health and performance. Further, the fact that excessive activity, inappropriate training loads and techniques, and movements that test the limits of the musculoskeletal system may lead to injury and disease is also recognized. Health must be defined (in accordance with the World Health Organization) as a state of physical, psychological and social well-being, not only the absence of disease. Sports medicine is based on the reciprocal relationship between physical activity (in all forms) and health. In other words, in order to achieve health it is not only important but a requirement to participate in regular physical activity, exercise training and/or sports. This concept applies to the general public as well as to the competitive athlete. Optimal performance is not possible without optimal health. The converse idea is equally important: a state of optimal health can only be achieved by means of appropriate levels of physical activity, exercise, or sport participation. Physical activity, exercise, and sport participation contribute significantly to the prevention of chronic disease and the enhancement of physical and psychological functional
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capacity. Thus, it is clear that the sports medicine practitioner must be an advocate for both health for sports and sports for health. It could be argued that those who benefit from sports medicine services have one thing in common: they are physically active. The practice of sports medicine is not limited by age, gender, or the interest of the practitioner in one organ or system of the human body. Although specialists may develop particular skills and interests in one area, it is the need for a holistic and comprehensive approach that characterizes sports medicine. An interest in the consequences of physical activity, exercise, and sports is the fundamental stimulus of the sports medicine practitioner.
THE SPORTS MEDICINE TEAM Sports medicine is one of those professional disciplines in which the team approach is synonymous with the standard of care. The team is interdisciplinary in nature and the leader or coordinator of the team’s efforts is a physician. The medical leader of the team can be a sports medicine specialist, an orthopedic surgeon, a physiatrist (specialist in physical medicine and rehabilitation), a specialist in internal medicine, a pediatrician, or a physician with experience working with physically active people and athletes. Frequently, the athlete/patient interacts with any or all members of the healthcare team. Members of the sports medicine team may include, but are not limited to, athletic trainers, physiotherapists, nutritionist/dieticians, dentists and psychologists. The interdisciplinary nature of the sports medicine approach is not limited to the competitive athlete and is also applicable to the care of physically active individuals. In addition to the athlete/patient, other persons may be active participants in the delivery of healthcare services. In the case of a competitive athlete, the coach or manager should be included in important discussions and decisions made about the ability of the athlete to train or compete with the team. The planning of sports medical services as well as the implementation of many medical clinical interventions require, with the consent of the patient/athlete, the active participation of the coach, e.g. the treatment of a sports injury may require a reduction in the training load. Compliance with this recommendation is enhanced if the coach understands the rationale for the action. Further, the managers or administrators of sports teams or delegations should be aware of the nature of the health problem because their decisions directly affect the ability of the healthcare team to maintain the health status and enhance the performance of the athlete.
SPORTS MEDICINE IN DIFFERENT COUNTRIES In some countries such as Brazil, Cuba, Mexico, Italy, Germany, Spain and Uruguay, sports medicine is a recognized medical specialty. Formal postgraduate training has been instituted in various medical schools and universities, and sports medicine is recognized by the national medical society as a distinct field of
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interest within medicine. Education in sports medicine in these countries emphasizes the medical and physiological control of the athlete as well as the many other non-orthopedic aspects of sports medicine. In other countries, such as Canada, Switzerland and the US, sports medicine is not recognized as a specialty and training is available in the form of fellowships for physicians who have completed a primary medical specialty (for example, orthopedic surgery, physical medicine and rehabilitation, internal medicine, emergency medicine, or family medicine). However, the scope of some of these fellowships is at times limited to a particular area of sports medicine such as the diagnosis and treatment of sports-related injuries. In many other countries, where neither a residency nor a fellowship is available, physicians complete their professional training and acquire knowledge and expertise in sports medicine by participating in courses, attending seminars and working with physically active people and competitive athletes.
THINGS THAT MAKE SPORTS MEDICINE SPECIAL An interesting challenge in the practice of sports medicine is the nature of the patient and the interrelationship between the disease and the environment. The underlying mechanism of injury or medical problem must be fully understood because the patient/athlete’s objective is to return to the activity that caused the problem. Avoiding the activity associated with the injury or medical problem, except in life-threatening situa-
tions, is not an option; the sports medicine team must do everything possible to correct the fundamental problem to avoid re-injury or chronic disease. Although rest and even immobilization might be needed, it is almost never accepted without complaint. This is one reason why rehabilitation is needed to enhance the performance of the athlete, not only in daily activities but most importantly in the sports activities to which the patient/athlete will return.
A BROADENING SCOPE It is important to highlight the fact that the current international perspective of sports medicine is no longer limited to the elite athlete. Sports medicine has evolved from both the philosophical and clinical perspectives. The application of the sports medicine principles to the general population has become as important (some say more important) as the use of sports medicine knowledge to maintain health and enhance performance in competitive athletes. Furthermore, the use of exercise and physical activity in the prevention, treatment and rehabilitation of some chronic diseases is now considered as effective as more traditional interventions such as the use of pharmacological agents. The importance of exercise and physical activity should be obvious if we consider that in many countries, chronic diseases are the most frequent causes of morbidity and mortality, the prevalence of disability resulting from such diseases is on the rise, and the aging population will experience functional loss and disability.
REFERENCES 1 2
La Cava G. What is sports medicine: Definition and tasks. J Sports Med Phys Fitness 1977; 17:1–3. Hollmann W. The definition and scope of sports medicine. In: Dirix A, Knuttgen HG, Tittel K, eds. The Olympic book of sports medicine. Oxford: Blackwell Scientific; 1988:xi–xii.
3
Brukner P, Khan K. Clinical sports medicine. New York: McGraw Hill; 1993:3–7.
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2
Principles of Exercise Physiology and Conditioning Norbert Bachl, Ramon Baron and Gerhard Smekal
METABOLISM DURING EXERCISE Box 2.1: Key Points Metabolism during exercise The human organism can rely on three basic energy sources: • ATP-PCr system (‘high energy phosphates’): primarily for high intensive (‘all-out’) activities lasting for seconds (3–7 s). • Glycolysis: anaerobic energy provision from carbohydrates; primarily intensive (‘all-out’) activities lasting 40 s to 3 min. • Oxidative system: Oxidation from carbohydrates, fats and proteins; primarily at rest and during lower (more fat oxidation) or higher (more carbohydrates oxidation), intensive endurance events.
The principles of exercise physiology are based on an understanding of the production and use of energy in biological systems. In every cell, the hydrolysis of adenosine triphosphate (ATP) is the immediate energy source for almost all energyrequiring processes. ATP + H2O → ADP + Pi + energy As the store of ATP in the cells is limited, ATP must therefore be continuously replenished. This occurs through aerobic and anaerobic processes in a way that energy rich substances (carbohydrates, fat, proteins and phosphocreatine) are transformed into compounds like H2O, CO2, lactate and creatine, by sequences of different chemical reactions. During these processes, part of the change in free energy is used for the resynthesis of ATP. This ATP-ADP-ATP cycle (ADP, adenosine diphosphate) can be considered as the basic mechanism of energy metabolism in all cells and constitutes an intermediate between energy consumption and utilization processes.1 Because of the large variation in energy turnover, the skeletal muscle is a unique tissue. The transition from rest to exercise requires an increase in the energy demand and therefore the rate of ATP utilization can increase more than 150
times. This would lead to the utilization of all the ATP stored in the muscles in about 2 to 3 s. However, to guarantee cellular homeostasis and keep the muscular filaments contracting, it is important to maintain a constant muscle ATP concentration, meaning that the rate of ATP regeneration must equal the rate of ATP utilization. This requires different supplying systems of fuel and oxygen as well as the control of the energetic processes involving both feed-forward and feedback mechanisms.1
Anaerobic processes of ATP generation During muscle contraction, ATP is the direct connecting link between fibre shortening (or lengthening), force development and metabolism. In this process, the ATP turnover in muscle is most significantly determined by the quantity of calcium released from the transverse tubular system. The most important regulatory enzymes responsible for energy release from ATP are ATPase like actomyosin-ATPase, Na+/K+-ATPase and sarcoplasmatic reticulum Ca2+-ATPase which, in turn, are activated by calcium. The maximum quantity of ATP that can be hydrolyzed during a single contraction depends on the myosin isoenzyme pattern and, therefore, on the type of muscle fibre. In addition, muscles contain phosphocreatine (PCr), which is another high-energy phosphate compound and stored in muscle tissue at a concentration three times that of ATP. Because of the small quantity of ATP available in the cell, the breakdown to ADP immediately stimulates the breakdown of PCr to provide energy for ATP resynthesis. This reaction is catalyzed by the enzyme creatine kinase (CK): ADP + PCr + H+
ATP + creatine
In other words, a fall in the ATP concentration is buffered by PCr, and therefore the ATP concentration in the muscle remains nearly constant at a high level during physical exercise. Even under extreme physical strain leading to exhaustion, the ATP concentration rarely falls below 50% of the baseline value.2 The ‘high energy phosphate’ system, however, is limited by the fact that the quantity of releasable phosphate for the energy-production from the high-energy phosphates (PCr and
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ATP) during high intensive work is drastically reduced. During short-term intensive physical exercise followed by longer phases of regeneration, or during low-intensity physical loads, high-energy phosphates are mainly re-phosphorylated by the oxidative pathway. The capacity for resynthesis depends on the oxidative capacity of the respective system.3 In contrast, at highly intensive physical loads of longer duration, the PCr concentration drops rapidly and drastically. In this case, the resynthesis occurs through the anaerobic energy provision from carbohydrates, which leads to the production of lactic acid, a process named anaerobic glycolysis, because this process does not require oxygen. Glycolysis from glycogen: 3 ADP + 3 Pi + glycosyl unit → 3 ATP + 2 lactate + 2H+ An increase in pyruvate, NADH/NAD+ ratio or H+ are metabolic changes that will promote lactate formation. Oxygen deficiency, increased recruitment of fast twitch fibers and low aerobic conditions in the exercising muscle are conditions for this metabolic imbalance. NADH + H+ can be re-oxidized only by the reduction of pyruvate, catalyzed by lactate dehydrogenase (LDH). Lactic acid is produced in this process. The process of NADH − H+ re-oxidation through pyruvate is a very uneconomical interference because only three moles of ATP are obtained from the degradation per mole glycosyl unit, whereas 36 moles/38 moles of ATP can be formed during complete oxidation.4 Glycogen phosphorylase plays a key role in anaerobic glycolysis. It breaks down the muscle glycogen and is regulated by Ca2+ released from the transverse tubular system through the enzyme phosphorylase-kinase. Generally, the reduced Ca2+ release from the tubular system during cumulative fatigue is an indication of the importance of Ca2+ in muscle fatigue. Also the enzyme phosphofructokinase, which catalyzes the transformation of fructose 6-phosphate to fructose 1.6diphosphate in the cytoplasm of the muscle cell, appears to play a decisive role in anaerobic glycolysis in the sense that it is inhibited by the sinking pH value due to the lactic acid production and thus limiting the anaerobic glycolysis. In fact, H+ ion concentrations influence glycolysis and the PCr concentration during physical exercise.3,5 A high H+ concentration reduces the PCr level through the enzyme creatine kinase. Furthermore, local acidosis in the working muscles appears to further reduce the formation of cross-bridges between the myosin heads and the actin molecules of muscle fibers. In this context, it should be mentioned that a metabolic acidosis is not an absolute prerequisite for muscle fatigue because patients with a congenital glycogen phosphorylase deficiency (McArdle’s disease) are prone to early fatigue despite the fact that they have no lactate acidosis.6 During high intensive exercise, lactic acid can be accumulated for two reasons. As a result of the extremely high glycolysis rate which occurs under intensive physical strain, pyruvate is formed in such large quantities that it cannot be utilized by the mitochondria. In addition, the reduced NADH + H+ occurring in the cytoplasm of muscle cells during glycolysis cannot be re-oxidized at a sufficient rate by the mitochondrial membrane. When very intensive exercise continues to persist,
Lactate (mmoI/I)
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Anaerobic threshold Aerobic threshold
Work rate Fatty acids
Carbohydrates
Figure 2.1 Model of the lactate performance curve and the energy supply during increasing work load.
which requires continued anaerobic energy production, the buffer capacity of the organism is exceeded and lactic acid accumulates. Based on these theoretical considerations, the concentration of lactic acid in muscle and blood serves as a reference point for the interaction of the aerobic–anaerobic metabolism under physical strain. Therefore, lactate can be used as one of the most important parameters to determine endurance performance and also to optimize the training processes (Fig. 2.1). This can be recognized by plotting the blood lactate concentrations versus VO2 (l × min−1; ml × kg × min−1) during an exercise test with increasing work loads. During the first minutes or even first load steps, the blood lactate concentration as an indirect measure of the lactic acid produced in the exercising muscles remains stable because the energy demand, meaning the ATP-resynthesis rate is met by oxidation of fats and carbohydrates. Although at the beginning of the exercise or when increasing the workload step by step, lactate will be produced in the working muscles because of the delay of the cardio-respiratory supplying reactions, lactate will be metabolized within the muscles and will not be carried to other compartments like blood, a process which is called ‘cell to cell shuttle’. From a certain point, when the exercise intensity is higher, fast twitch muscle fibers which have a lower oxidative potential and therefore produce more lactate have to be activated and therefore lactate in the exercising muscles is formed and the blood lactate concentration will increase. This point, which is called the aerobic threshold or first lactate turn point is the beginning of a so-called ‘mixed aerobic-anaerobic metabolism’. With increasing intensity a second deflection point can be observed, when more lactate in the exercising muscle will be produced than can be buffered or even removed. From this point called the anaerobic threshold or respiratory compensation threshold, or the second lactate turn point, lactate production increases rapidly, will be accumulated and finally leads to the end of the exercise. If one contrasts the so called ‘lactate-performance-curve’ of an untrained person, a marathon runner and a 400-m runner, the differences in the interaction of the aerobic–anaerobic metabolism can easily be seen. The untrained person shows a very rapid
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400 m runner
22 20 18 16 14 12 10 8 6 4 2 0
220 200 180 160 140 120 100 80 60 40 20 0 4
6
8
10
12
14
16
have been reported in endurance-trained female and male athletes, respectively.
Marathon runner
18
20
22
Oxidation of carbohydrate Heart rate
Lactate (mmoI/I)
Untrained
9
24
km/h Figure 2.2 Lactate-performance curves and heart rate performance curves of three different trained individuals.
increase and accumulation of the blood lactate concentration from the resting value. In contrast, in the endurance-trained marathon runner, the lactate level remains low with increasing workloads, which is the result of the aerobic adaptations by the endurance training. That means that both – the first and the second lactate turn points – occur at a higher percentage of the athlete’s maximal aerobic power. On the other hand, the production rate of lactic acid and resistance against lactate accumulation is decreased. In contrast, the 400-m runner shows an earlier increase of the lactate production because of the specific metabolic adaptations resulting from anaerobic training. Furthermore, the increase of the blood lactate concentration over the anaerobic threshold (second lactate turn point) is longer and more flat, showing that the muscle cells can tolerate the acidification resulting from increasing lactate accumulation better as a consequence of the anaerobic training (Fig. 2.2).7
The first step in the oxidation of carbohydrates is the anaerobic breakdown of muscle glycogen and blood glucose to pyruvate. In the presence of oxygen, pyruvate – the end product of glycolysis – is converted into acetyl-coenzyme A (acetyl-CoA), which enters the Krebs Cycle (citric-acid cycle). The Krebs Cycle is a complex series of chemical reactions that breaks down these substrates into carbon dioxide and hydrogen and forming two ATPs. In addition, six molecules of reduced nicotinamide-adenine-dinucleotide (NADH) and two molecules of reduced flavin-adenine-dinucleotide (FADH 2) are also produced from the glucose molecule, which carry the hydrogen atoms into the electron transport chain where they are used to re-phosphorylate ADP to ATP (oxidative phosphorylation). The complete oxidation of one glucose molecule in skeletal muscle results in a net yield of about 36 or 38 ATPs depending on which shuttle system is used to transport NADH to the mitochondria (Fig. 2.3).8
Oxidation of fat Fat can only be metabolized in the presence of oxygen. The triglycerides are stored in fat cells and within the skeletal muscles and serve as a major energy source for fat oxidation.
LIPIDS
CARBOHYDRATES
PROTEINS
Fatty acids + Glycerol
Glucose/Glycogen
Amino acids
Beta oxidation
Glycolysis
Deamination
Aerobic processes of ATP generation In contrast to the anaerobic energy system which provides energy at a high liberation rate but with limited supply, muscles need a continuous supply of energy at rest and during long duration but low intensive activities. This is provided by the oxidative (aerobic) system which has a lower energy liberation rate but a tremendous energy yielding capacity. Aerobic production of ATP occurs in the mitochondria and involves the interaction of the citric acid cycle (Krebs Cycle) and the electron transport chain. Oxygen serves as the final hydrogen acceptor at the end of the electron transport chain. The term maximal aerobic power (VO2max, VO2peak) reflects the amount of ATP which can be produced aerobically and therefore the rate at which oxygen can be transported by the cardiorespiratory system to the active muscles. From resting metabolism (3.5 ml/kg per min) the aerobic power production can be increased up to peak values of 35–38 ml/kg per min and 42–45 ml/kg per min in untrained women and men, respectively. Values of 72–76 ml/kg per min and 85–90 ml/kg per min
Pyruvate Acetyl-CoA
Anaerobic Fatty acids
Lactate Oxalacetate
Succinate
Krebs-cycle α-Ketogluturate
CO2
Citrate
H+ O2
Aerobic
Electron transport chain NAD+>>NADH2 2 Fe3+>>2 Fe2+ FAD>>FADH2 cyt b, cyt b, cyt c, cyt a, cyt a3 ADP + P >> ATP +O2 = H2O
H2O Figure 2.3 ‘Flow sheet’ for energy yielding processes from lipids, carbohydrates and proteins. (Redrawn from Smekal 2004.8)
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For this to happen, the triglycerides are broken down by lipases to their basic units of one molecule of glycerol and three molecules of free fatty acids (lipolysis). After having entered the mitochondria, the free fatty acids undergo a series of reactions in which they are converted to acetylcoenzyme A, a process called beta-oxidation. From this point, the fat metabolism then follows the same pathway as the carbohydrate metabolism when acetyl coenzyme A enters the Krebs Cycle and the electron transport chain. While the ATPamount produced varies depending on the oxidation of different fatty acids, the complete oxidation of one (18-carbon) triglyceride molecule results in a total energy yield of about 460 ATPs. Although triglyceride oxidation provides more energy production per gram than carbohydrates, the oxidation of fat requires more oxygen, meaning that fat mostly is oxidized at rest or during moderate exercise when oxygen delivery is not limited by the oxygen transport system. At rest, e.g. the ratio of ATP-production is up to 70% of fat and 30% from carbohydrates, whereas during high intensity exercise, the majority of energy or even the total energy comes from carbohydrates.
Oxidation of proteins Oxidation of proteins is also utilized to obtain energy at rest as well as during physical exercise.9 Several amino acids (especially leucine, isoleucine, alanine and valine) contribute to the production of energy. The access to amino acids increases in proportion to the load intensity of any physical activity, but the proportion of energy provided by amino acids during physical exercise appears to be limited to about 10%. However, of practical significance is the fact that amino acids are oxidized in greater quantities when the caloric supply is insufficient and also in the presence of a carbohydrate deficiency. This leads to catabolic states (degradation of functional proteins) and loss of nitrogen. The degradation of functional proteins is problematic because muscles are affected by this phenomenon, which obviously has a detrimental effect on performance capacity.10
Power and capacity of energy yielding processes An important approach to a better understanding of energy demand and energy supply during physical activity and sports is the question as to which substrates are utilized for the production of energy at specific intensities. An important factor in the selection of the substrate is the rate at which energy can be released from the respective substrate, i.e. the maximum achievable release of energy per time unit. Therefore, the maximal intensity of the exercise is limited by the (combined) maximal power of the energetic processes. The ‘high energy phosphates-system’ provides the highest rate of energy liberation, but its capacity is limited to only 3–7 s and therefore needs to be replenished constantly providing other processes for ATP resynthesis on a lower energy liberation rate, the glycolytic (anaerobic) and the oxidative combustion of fuels.
Table 2.1 Power and Capacity of Energy Yielding Processes in Human Muscle Power (mol ATP/min) Pcr Lactate CHOox FFAox
2.5 1.9 1.1 0.6
Capacity (mol/ATP) 0.37 0.94 59 Not limited
Pcr, phosphocreatine; CHOox, carbohydrate oxidation; FFAox, free fatty acid oxidation. For details, see Henriksson and Sahlin 2002.1
The glycolytic pathway can provide energy rapidly because of the high concentration of glycolytic enzymes and the speed of the chemical reactions involved. However, glycolysis cannot supply as much energy per second as the ATP-PC system. At high intensity exercise, the highest energy liberation from glycolysis occurs during the first 10–15s because acidification of muscle fibers reduces the breakdown-rate of glucose and glycogen. This impairs glycolytic enzyme function and decreases the fiber’s calcium binding capacity and thus muscle contraction. This causes an increase of the muscle lactate up to more than 25–30 mmol/kg wt, and later one of blood lactate up to 18–25 mmol/l (Table 2.1).1 The muscle cells capacity for anaerobic glycolysis during maximal physical activity is for a period of approximately 1–3 min (shorter or longer depending on the intensity). Activities such as the 200-m free-style swim, 400-m sprint and strength-training activities with short rest periods between sets (e.g. 30 s) rely primarily on glycolysis for energy liberation. Anaerobic systems also contribute to energy production at the beginning of less intense exercise, when oxygen uptake kinetics lag behind the total energy demand placed on the system. Stored carbohydrates supply the body with a rapidly available form of energy with 1 g of carbohydrate yielding approximately 4.1 kcal (17.1 kJ) of energy. Under resting conditions, muscle and liver take up glucose and convert it into a storage form of carbohydrate, called glycogen, which is, when needed as an energy source, broken down into glucose and can be metabolized to generate ATP anaerobically and aerobically. The carbohydrate stores of the human organism are limited. They are composed of the circulating glucose in blood, and carbohydrates which are stored in the form of glycogen in the muscle and liver. The quantity of carbohydrates which can be stored in the form of glycogen in the skeletal muscles depends on a number of factors (e.g. nutrition, the state of training, muscle mass, the composition of muscle fibers and several other factors). Therefore, published data about the quantity of stored glycogen in the entire musculature vary between 1000 and 1900 kcal or even slightly more in trained athletes after carbohydrate loading. Taking into consideration that the muscles needed for physical exercise (e.g. the marathon run or biking) only constitute a part of the entire muscle mass, the carbohydrate reserves of the working musculature must obviously be regarded as an important limiting factor during physical strain of long duration and/or high
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Metabolism during exercise
Body Stores for Fuels and Energy a Grams
Fat
Untrained Trained Untrained Trained Carbohydrates Liver glycogen Muscle glycogen Glucose in body fluids Total Fats
~80 ~250 ~15 ~345
~120 ~400 ~18 ~538
~328 ~1025 ~62 ~1415
~492 ~1640 ~74 ~2206
Subcutaneous Intramuscular Total Amino acids Proteins
8000 50 8050 100 6000
6000 300 6300 110 7000
74 000 465 74 465 410 –
55 880 2790 58 670 451 –
a Estimates
Carbohydrates
Total
kcal Energy supply (kcal/h)
Table 2.2
11
24
based on body size of 70kg and 12% body fat (male).
intensity. The liver also has a storage pool of about 60–80 to a maximum 120 g of glycogen, corresponding to an energy reserve of about 240 to a maximum of 490 kcal.8 It is important to mention that hepatic glycogen has another important function: it maintains the supply of blood sugar to the brain, which is also important during exercise of high intensity or long duration (Table 2.2). Carbohydrates are used preferentially as energy fuel at the beginning of exercise and during high intensive loads requiring more than 70% of the maximum oxygen uptake. Compared with the anaerobic energy breakdown, the rate of energy liberation with the oxidation of carbohydrates is about one half and its capacity depends on the amount of glycogen stored in the muscles and in the liver. Without any substitution of carbohydrates during a long duration exercise, carbohydrate capacity allows endurance exercise for about 60–90 (120) min depending on the involved muscular system and the intensity of the physical activity. Because muscle glycogen stores are limited and can become depleted during longer lasting vigorous exercise, an adequate diet especially for endurance exercise must contain a reasonable amount of carbohydrates, which enhance glycogen synthesis and also glycogen stores in muscles and liver.11 Fats are stored well in the organism but oxidized rather slowly. In order to utilize fat from fat deposits as a source of energy, they must be mobilized and transported to the muscle cell in the blood in the form of free fatty acids, bound to albumin. However, fats are also present within the muscle in the form of fat cells between muscle cells, and in the form of droplets inside muscle cells. At low intensities, a large portion of the energy is provided by fat metabolism – mainly by the free fatty acids in plasma. If the intensity of physical activity is increased further, intramuscular fats and carbohydrates are utilized in greater measure to fulfill the energy requirements. Fat oxidation does not increase at higher load intensities, but it is rather markedly reduced. A large body of data shows that the limitation is particularly within the mitochondria. This is also evidenced by the fact that the oxidation of intramuscular fats seems to occur in an incomplete fashion. The most likely theory
32
40
48
56
64
72
80
88
96
100
% VO2max Figure 2.4 Total energy supply and relation of fat and carbohydrates during incremental workload. (Estimated from data by Achten and Jeukendrup 2003.12)
at the present time points to a blockade of the transport of long-chain fatty acids through the inner mitochondrial membrane when the rate of glycolysis is high (high intensity load). However, it is evident that in the presence of a markedly increased oxidative capacity of mitochondria, which is found in persons who have undergone endurance training, larger quantities of metabolites resulting from beta-oxidation can be oxidized. In other words, at the same load intensity, less metabolites are formed during glycolysis – which, in turn, has a positive effect on fat oxidation (Fig. 2.4).12 As discussed earlier, even in persons with a very good endurance performance, the energy flow rate from fat is limited. If one assumes that the energy requirements for various sports increase with the load intensity, carbohydrates must be utilized to an increasing extent to provide the required energy, because energy flow rates from carbohydrates markedly exceed those that could possibly result from fat.13,14 An increased carbohydrate utilization reduces the glycogen stores in muscles and liver, which are, as mentioned earlier, limited. Therefore when discussing carbohydrates and fat depots, it is important to mention that dietetic measures can increase the carbohydrate reserves in muscle a few days prior to the actual physical activity.15 Carbohydrates should also be ingested a few hours before the physical activity in order to optimize and restore the carbohydrate reserves in the muscle and liver.11 A major reason for this is the fact that the energy production from exogenously supplied carbohydrates during physical strain, even when supplied at optimum concentrations, is relatively low.16 Therefore the body’s fats constitute by far the largest energy depot in the human organism and ensure a constant resynthesis of high-energy phosphates. Fat is also the most efficient depot substrate in the organism because 1 g of fat contains more than double the quantity of energy compared with the other two substrate groups (carbohydrates and proteins). One gram of fat contains 9.3 kcal. In contrast, carbohydrates and proteins contain only 4.1kcal/g. In other words, a man weighing 80kg, with a body fat content of 15% has 12 kg of fat in his body and a total energy store of about 110 000 kcal. This is supplemented by the quantity of fatty compounds stored within the muscle (as described earlier). In practice, this means that a normally nourished individual is equipped with a large energy depot which he/she can utilize if necessary. The problem, however, is that because of the
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limited energy flow per time unit during intensive physical strain, this large depot can be accessed only to a limited (slow) extent. Thus, in intensive physical activity or training, one again is dependent on carbohydrates.
CONDITIONING In sports, training is defined as the preparation of sportsmen for the highest levels of performance. Sports training is the physical, technical, intellectual, psychological and moral preparation of an athlete by means of physical exercise, i.e. by applying workloads.17 Training involves an organized sequence of exercises that stimulates improvements, or adaptations, in anatomy and physiology. These adaptations require adherence to carefully designed training programs with attention focused on factors such as frequency, intensity, type of training, time or duration (FITT) and rest intervals. The development of effective training programs requires an understanding of fundamental training principles, specific types of training and individual goals. Optimizing training requires knowledge of such principles as specificity, overload, progression, recovery, diminishing returns, supercompensation, reversibility, tapering, periodization, de-training and overtraining. Therefore, principles of training include all methodologies and mechanisms of manipulating training variables which enhance physical performance and have to be applied to the training process of elite athletes as well as untrained persons and patients in the rehabilitation.
IMPORTANT PRINCIPLES OF TRAINING Box 2.2: Key Points
• • • • • • •
Specificity Overload Progression Supercompensation Reversibility principle and detraining Tapering Periodization
Specificity Specificity implies that the body’s acute and chronic responses and adaptations to exercise training are metabolically and biomechanically specific to the type of exercise performed and the muscle groups involved. Thus, the specificity principle has implications for anatomy, neuromuscular recruitment, motor skill patterns, cardiorespiratory function and muscle energy metabolism. Different activities, depending on their duration and intensities require the activation of specific energy sys-
tems. In many cases, all three energy-transfer systems – the ATP-CP system, the glycolytic system and the aerobic system – operate at different times during exercise. Activities of short duration lasting about 6s rely mainly on the breakdown of the ‘high energy phosphates-system’. Therefore, athletes such as sprinters or weightlifters, have to improve primarily the capacity of this energy-transfer system. When a muscle performs endurance exercise such as cycling or running lasting 1 h, the activities rely heavily on the aerobic system and the athletes have to improve the capacity of the aerobic system. Therefore, when designing a training program, it is important to know the specific metabolic profile of a sport or activity and to consider the relative contributions of the aerobic and anaerobic energy pathways to sports performance. In the context of the specificity principle, the principle of individual differences plays an additional important role.
The principle of individual differences This principle refers to the concept that individuals respond differently to the same training stimulus. The variability of the training response may be influenced by such factors as pre-training status, fitness level, genetic predisposition and gender.18 For example, athletes who are less conditioned make greater gains than those who begin the training program at a higher level of fitness. After several months of training, sedentary adults may improve their aerobic fitness by more than 50%, whereas conditioned athletes may improve by only 3% over the same period of time. At the end however, the athlete has a higher level of fitness. Therefore, even though they have the same goals they may not reach them by the same means.19 Because we cannot expect, that all people will response to exercise in the same manner, a proper training program should be modified to take individual differences into account.
Overload principle The principle of overload is based on the need to train the body at a level beyond that at which it normally performs. Therefore, overload should be a training stimulus, sufficient for chronic adaptations to occur. The amount of overload necessary to elicit a training response depends on the training state of the individual. An untrained individual needs very little overload stimulus to improve his performance. In contrast, to maximize muscular strength in athletes, the muscle needs to be stimulated with a resistance of relatively high intensity. Exercise frequency, duration and intensity are the variables most often manipulated to provide overload to the systems of the body with specific consideration given to the mode of exercise.16 As an example, for endurance exercise a minimal overload training stimulus is attained at exercise intensity corresponding to 50% VO2max, 70% of maximum heart rate, or 60% of the heart rate reserve.
Plateaux in performance improvement With regard to the experience that some individuals appear more ‘trainable’ than others or even reach a plateau in their
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Physical performance Physical performance
Time Figure 2.6 Load increments according to the overload principle. Duration of training Figure 2.5 Theoretical training curve and ceiling effect.
Supercompensation
performance improvement the principle of diminishing returns states that performance gains are related to the level of training experience of the individual. Untrained people will experience large gains in performance after a relatively short period of time. In contrast, athletes who have trained for several years will make small performance gains over a long period of time. At the onset of a training program, rapid gains are made. As training duration continues, the rate of plateau appears to be reached. This plateau may be considered a genetic ceiling (Fig. 2.5).18
Progression As an athlete adapts to a training stimulus, the exercise load (i.e. intensity, duration and/or frequency) must be increased so that improvements will continue. The training program can be progressed by, for example, increasing the load lifted, training frequency, quality and quantity of drills, or exercise stimulus. However, too great an overload may overstress the physiological systems and increase the risk of sports-related overuse injuries and exercise burnout. The training concept that provides an adequate overload stimulus without overstressing the body is optimal. From the initiation stage to the elite performance stage, workload in training must increase gradually according to each athlete’s physiological and psychological abilities. Physiologically, training gradually increases the body’s functional efficiency, increasing its work performance (Fig. 2.6).20
Time
Fatigue
Recovery
Figure 2.7 Stimulus-fatigue-recovery-adaptation. (Based on Yakovlev 1967.21)
This concept is not limited to a single exercise response but may be observed over a longer period producing training adaptations.22 There are a number of observations that support this concept. For example: Verkoshansky23,24 noted that a unidirectional concentrated load of strength or strengthendurance training for several weeks could result in a diminished speed–strength (power) capability among track and field athletes. Upon returning to normal training, increased performance can often be observed, sometimes beyond baseline values. Verkoshansky23,24 suggested that these results may be explained by the SFRA concept. Similar results have been observed among junior weightlifters after a planned high volume over-reaching phase; these results among weightlifters appear to be at least partially linked to alterations in anabolic/ catabolic hormones.25,26
Reversibility principle and detraining Supercompensation The amount of recovery required after a training session is directly related to the magnitude and duration of the exercise stress. Stimulus-fatigue-recovery-adaptation (SFRA): Conceptually, an appropriate stimulus will result in some level of fatigue, recovery and adaptation such that performance can be eventually improved. This phenomenon is called supercompensation (Fig. 2.7).21
Adaptations to regular physical activities begin to return to pretraining values when the training stimulus is removed. An extreme example of reversibility and detraining occurs during bed rest.27 Under this condition, VO2max decreased by 27% in 21 days. A decrease in VO2max has also been shown for prolonged periods where no training has occurred. Decrements in VO2max resulting from training cessation initially result from reductions in plasma volume28 and then from marked reductions in muscle mitochondrial enzyme activity.29–31 In contrast, no reduction in glycolytic enzyme activities has been shown
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during detraining. The metabolic causes of decreased performance during strength or power-related training are minimal. This means that training induced gains in strength and muscle power seem to diminish at a slower pace compared with gains in aerobic endurance.
Detraining/retraining It is evident that both low–moderate and highly-trained individuals who are detrained have a more rapid rate of gains after a return to training. Previous training does not alter the rate of training improvements from aerobic exercise after a period of 2–7 weeks of detraining. The slogan ‘If you don’t use it, you lose it’ is the main tenet of reversibility. After time off caused by injury, all athletes know that they cannot pick up exactly where they left off. Unfortunately, the body seems to lose muscle much more quickly than it is gained. A general proportion is 3:1. Missing 1 week of training requires 3 weeks to return to the same level.
Regularity and recovery Performance enhancement requires a balance between overload and recovery. Too much overload and/or too little rest may result in over-reaching and over-training and therefore reduced physical performance. This causes a state of physical, chemical and mental imbalance (Fig. 2.8).32 Therefore, recovery is one of the most important principles of training, because during the recovery sessions, the adaptations to training take place. Recovery sessions may not necessarily mean complete rest. Periods of training with lower intensity will guarantee an adaptation without increasing stress. These periods are excellent opportunities for training on technique and tactics.
Tedium Contemporary training requires many hours of work from the athlete. The volume and intensity of training are continuously increasing, and exercises are repeated numerous times. Under these conditions, boredom and monotony can become obstacles to motivation and improvement.33 The sessions should be different and enjoyable. When boredom sets in, it is very difficult to motivate people to improve their fitness.
Tapering Tapering is defined as: ‘a progressive nonlinear reduction of the training load during a variable period of time, in an attempt to reduce the physiological and psychological stress of daily training and optimize sports performance’.34 Peak performance requires maximal physiological stress tolerance. After periods of intensive training, the athlete’s exercise tolerance and performance capacity may start to decrease. Coaches may therefore reduce the training volume and intensity after a ‘hard training period’ before the next training cycle or major competition. This practice is referred to as tapering. Costill et al.35 showed, that the taper does not decrease conditioning, but actually can increase muscle power, improve psychological states and improve performance. Therefore, athletes should not fear to reduce their training volume for several days in a long-term training program and before an athletic competition. The length of a tapering period and the training programs depends on the specific sport, the purpose of the taper, the specific period in a training year and individual needs.
Designing a training program Based on the knowledge of the model of supercompensation, an effective sports training program must include an exercise prescription specifically developed for the individual athlete. This requires manipulation of the four primary program design variables (Table 2.3).36 The optimal way to develop an adequate training program is to have the factors related to the sports performance evaluated and use that information to generate a training program specific to the athlete.
Training frequency Training frequency refers to the number of training sessions conducted per day or per week. The frequency of training sessions will depend on an interaction of exercise intensity and duration, the training status of the athlete and the specific sport season. Recovery from individual training sessions is essential if the athlete is to derive maximum benefit from the subsequent training session. Whereas an Olympic athlete has to train twice a day, it is enough for recreational sportsmen and women to train three times a week. Training intensity Important for training adaptations in the body is the interaction of training intensity and duration. Generally, the higher the exercise intensity, the shorter the exercise duration. All biological adaptations are specific to the intensity, or effort expended during a training session.
Physical performance
Table 2.3
Time Figure 2.8 If the recovery is too short, the performance trend is negative. (Based on Kipke 1985.32)
F I T T
Training Program Design Variables (FITT)
Frequency of training Intensity of training Type of exercise mode Time of exercise duration
Based on Potteiger 2000.33
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Typically, the training year is divided into phases that include the off-season, pre-season, in-season, and post-season (Fig. 2.9).
Sprinting requires a high percentage of high intensity training; marathon, triathlon or 24 h running need more training sessions of long duration and low intensity.
Preparatory/pre-season The priority of pre-season training is to maintain a base of cardiorespiratory fitness. Initially, the training program should be composed of long-duration and low-intensity workouts. Periodic increases in exercise intensity occur when an athlete has adapted to the training stimulus and requires additional overload for continued improvements. During the preseason, the athlete should focus on increasing training intensity, maintaining or reducing training duration and incorporating all types of training into the program. Workload and type of training (e.g. endurance, strength, flexibility, speed) vary according to each athletes physiological abilities. The strengths and weakness of the individual athlete should determine the amount and frequency of each type of training (see Tapering).
Exercise mode: type The exercise mode refers to the specific physical activity performed by the athlete: cycling, rowing, playing basketball, etc. To improve performance, the athlete should select activities that mimic the movement pattern employed in competition as closely as possible.
Exercise duration: time Exercise duration refers to the length of time the training session is conducted. The duration of a training session is often influenced by the exercise intensity: the longer the exercise duration, the lower the exercise intensity (see Training intensity).
Periodization Because fatigue is a natural consequence of training (especially with high volume-loads) – and adaptations are primarily manifested during subsequent unloading periods – fatigue management is exceptionally important in producing an adequate program. To promote long-term training and performance improvements, the coaches should include variations in training variables organized in planned periods or cycles within an overall program.37 This program-design strategy is called periodization. The concept of periodization was proposed in the 1960s by Russian physiologist Matveyev.38
Competitive The in-season training program needs to be designed to include competition or race days in the training schedule. Low-intensity and short-duration training days should precede schedule competitions so the athlete is fully recovered and rested. Transition/Post-season During the active rest period, the main focus should be on recovering from the previous competition season. Low-training duration and intensity are typical for this active rest phase, but enough overall exercise or activity should be performed to maintain a sufficient level of cardiorespiratory fitness, muscular strength and lean body mass (Fig. 2.10, Table 2.4).38,39
Macrocycle The largest division typically constitutes an entire training year but may also be a period of many months up to 4 years (for Olympic athletes).
Volume (quantity)
A 12 month plan MacroPreseason cycles
Competitive
Postseason
Intensity (quality)
Mesocycles Microcycles
Preseason
Figure 2.9 A schematic illustration of the division of the annual training plan into macrocycles, mesocycles and microcycles.
Table 2.4
Transition
Competitive
Postseason
Figure 2.10 Matveyev’s model of periodization (1965). (Redrawn from Matveyev 1965.38)
Model of Periodization, Sample for Macrocycle, Weight Training
Macrocycle
General Conditioning
Strength
Power
Maintenance
Active Recovery
Sets Reps Intensity Volume
3–4 7–10 Low-moderate High
3–4 5–9 High Moderate
2–3 3–5 High Low
1–2 6–10 Moderate Moderate
1 10–12 Low Moderate
Based on Rhea et al. 2002.36
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60−70% 50−60% 40−50%
50%
Cycle 1
Cycle 2
Cycle 3
Figure 2.11 Percent increase of training load for a 4-week cycle.
Mesocycle This divides the macrocycle into two or more periods, each lasting several weeks to several months; the number depends on the goals of the athlete and the number of competitions. Figure 2.11 illustrates a hypothetical load increment over 4 weeks. The training load increases from step to step by approximately 10%, except in the regeneration week, when it decreases by 20%. The load per step refers to the training program for 1 day, which the athlete must repeat two or three times, depending on the number of training sessions per week (Fig. 2.12).33
Microcycle Each mesocycle is divided into two or more microcycles that are typically 1-week long but could last for up to 4 weeks, depending on the program. A microcycle is a weekly training program. It is probably the most important planning tool. Throughout the annual plan, the nature and dynamics of microcycles change according to the phase of training, the training objectives, and the physiological and psychological demands.33
FUNDAMENTALS OF FITNESS TRAINING Box 2.3: Key Points
• • •
Training works by altering homeostasis.
•
Principles of training represent an evidence-based understanding of how training works.
•
Optimization of performance trend line by exercising at the optimal training: • intensity • duration • frequency • type of training.
Adaptations occur during recovery. Optimization of training and recovery govern progression in a conditioning program.
Although there is consensus on the importance of the relation between physical activity and health and well-being, the specific dose of physical activity necessary for good health remains unclear.40 How much, what type, how often, what intensity and how long the physical activity dose should be and how this dose should be quantified and disseminated has led to the promulgation of numerous different public health and clinical recommendations.41
Cumulative effect
Time
Figure 2.12 Cumulative effect of multiple training sessions.
The Centers for Disease Control and Prevention and American College of Sports Medicine (CDC/ACSM) developed guidelines for moderate and vigorous activity based on an accumulation of epidemiological research over the past several decades.42,43 The recommended level of moderate activity (MACT) is at least 30 min of moderate-intensity physical activity each day.43 For individual training, the President’s Council on Physical Fitness and Sports44 published ‘Fitness Fundamentals – Guidelines for Personal Exercise Program’, including basics for fitness training: ‘Each workout should begin with a warm-up and end with a cool-down. As a general rule, the workouts have to be spread throughout the week and consecutive days of hard exercise should be avoided. In general, the amount of activity necessary for the average healthy person to maintain a minimum level of overall fitness is as follows: WARM-UP: 5–10 minutes of exercise such as walking, slow jogging, knee lifts, arm circles or trunk rotations. MUSCULAR STRENGTH: a minimum of two 20-minute sessions per week that include exercises for all the major muscle groups. Lifting weights is the most effective way to increase strength. MUSCULAR ENDURANCE: at least three 30-minute sessions each week that include exercises such as pushups, situps, pullups, and weight training for all the major muscle groups. CARDIO-RESPIRATORY ENDURANCE: at least five 30minute bouts of continuous aerobic (activity requiring oxygen) rhythmic exercise each week, e.g. walking, jogging, swimming, cycling, rowing, cross-country skiing. FLEXIBILITY: 10–12 minutes of daily stretching exercises performed slowly, without a bouncing motion. This can be included after a warm-up or during a cool-down. COOL-DOWN: a minimum of 5–10 minutes of slow walking, low-level exercise, combined with stretching’.
STRUCTURAL AND FUNCTIONAL ADAPTATION OF CARDIOVASCULAR SYSTEM, RESPIRATORY SYSTEM AND SKELETAL MUSCLE TO TRAINING The cardiovascular system Long-term regular training causes favorable hemodynamic changes which are associated with structural and functional adaptations. These adaptations are generally described as
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‘athlete’s heart’. From the hemodynamic point of view, sports might be divided into different types (although these types never appear in an ‘isolated’ form: (1) Endurance sports such as long-distance running, cross-country skiing, in which cardiac output is increased during exercise. (2) Strength sports, such as weightlifting and wrestling are associated with pressure load by a more pronounced increase of blood pressure and only slight increase in cardiac output caused by an enhanced heart frequency. (3) Sports with different combinations, for example rowing, canoeing and cycling. Over a long time, it has been accepted that endurance sports are characterized by a ventricular cavity enlargement, whereas strength sports lead to an increase in wall thickness.
Sports with a high endurance component Several previous studies45–48 reject the hypothesis that only left ventricular diameters increase as a result of dynamic endurance training. Data from these investigations show that in dynamic sports, such as long-distance running, athletes had not only larger left ventricular diameters and left ventricular mass but also significantly higher left ventricular wall thickness compared with controls.48 Scharhag et al.48 documented not only an increase in left ventricular inner diameter but also significant higher posterior wall thickness and interventricular septal thickness. In a meta-analysis, Fagard45 compared the echocardiographic parameters of runners and strength athletes with those of control groups, where all groups were matched for age and body surface area. They showed increased left ventricular end-diastolic diameters, increased left ventricular end-systolic wall thickness and increased relative left ventricular wall thickness (synonym: ‘hypertrophic index’ = ratio between left ventricular wall thickness plus interventricular septal thickness and left ventricular internal diameter) for both, runners and strength athletes versus the control group. The runners showed a larger increase in left ventricular end-diastolic diameter and in left ventricular end-systolic wall thickness. Only the relative left ventricular wall thickness of runners was lower than that of strength athletes. The data of enhanced left ventricular enddiastolic diameters of endurance athletes in comparison with strength athletes has been confirmed by another metaanalysis.46 In contrast to the results of Fagard, the left ventricular wall thickness was higher in strength athletes. But in this investigation, anthropometric data were not considered so that it cannot be excluded that body size might have influenced these results. Heart enlargement (increase in diameter and wall thickness) in endurance athletes seem to have two main explanations: (1) training regimes of endurance athletes are not exclusively ‘dynamic’ because in endurance sports, training schedules often include elements of strength training; (2) in ‘dynamic’ sports, load on the heart is not exclusively that of volume, since blood pressure also increases in endurance events although to a lesser extent than during strength events. Previous studies using echocardiographic techniques often refer to the left ventricle because echocardiographic measures of the right ventricle are topographically complicated by the lung. Using the technique of magnetic resonance imaging (MRI), it has been shown48 that regular and extensive endurance training results in similar changes in left ventricular and right ventricular mass, volume and function. Therefore, it can be concluded that regular and extensive endurance train-
17
ing results in a balanced enlarged heart with similar changes in both ventricles. Similar to muscle cells of peripheral muscles the above described structural changes of the heart are accompanied by ultrastructural and metabolic cellular adaptations resulting in an increased ‘aerobic capacity’ of heart muscle cells.49 Many studies investigating ventricular systolic function are based on the extent and velocity of fiber shortening, ventricular ejection fraction and the velocity of circumferential shortening. In concluding data from literature there is evidence that the ventricular emptying time is somewhat faster in endurancetrained individuals in comparison with untrained.50,51 But the systolic function during dynamic exercise is usually similar in the group of endurance athletes and untrained controls.45,46,48 The high stroke volumes observed in endurance-trained athletes are predominantly caused by higher end-diastolic volumes. In this context, it should be mentioned, that during incremental exercise, untrained individuals show a ‘plateau’ of stroke volume at submaximal heart rates. This phenomenon has been explained by an inadequate filling of ventricles when diastolic periods get shorter at higher heart rates. Comparing trained and untrained individuals, it has been demonstrated,50 that at high heart rates and work rates not only the ventricular emptying but also the ventricular filling of trained subjects were significant faster in the trained group. Furthermore, these changes in hemodynamic function were much more pronounced during the filling phase than during the emptying phase.50 The enhanced left ventricular diastolic function of athletes is also documented by measures of transmitral flow velocity, showing enhanced early diastolic ventricular filling (increase of ‘passive mitral blood’ flow).46,52,53 These changes are accompanied by progressively increasing stroke volumes with increasing exercise intensity and heart rates.50 Therefore, the high stroke volumes corresponding to high end-diastolic volumes observed in athletes during dynamic exercise are not only caused by structural but also by functional changes. Structural and functional adaptations result in changes in the physiological behavior of a trained heart when compared with an untrained one: higher maximal performance, higher cardiac output and a lower heart frequency at rest and at submaximal loads. Cardiac output at sub-maximal loads is similar between trained and untrained subjects. But long-term endurance training decreases sub-maximal exercise heart rate by reducing sympathetic and increasing parasympathetic activity in trained subjects.54 Therefore at sub-maximal loads, cardiac output of trained athletes is reached by higher stroke volumes and lower heart rate. These structural and functional changes are accompanied by adaptations of the central nervous system, adaptations of the coronary vascular system and adaptations of peripheral vessels (e.g. the common femoral artery).
Sports with high strength component Resistance exercise is associated with very high arterial pressure. This condition supported the ‘old’ theory of a ‘concentric hypertrophy’ caused by ‘static exercise’ with an increase in wall thickness without any increase in ventricular diameters. But this theory is not tenable considering current literature.45,46,55 It has been demonstrated that in strength athletes not only the left ventricular wall thickness was increased
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(in comparison with controls), but also the left ventricular diameter. A study presented by Fagard45 compared runners and strength athletes with that of controls, where all data were adjusted to age and body surface. It was shown that the percentage of increase in left ventricular wall thickness compared with controls was even lower in strength athletes than that of runners and much lower than that of cyclists. In the study of Pluim et al.46 the posterior wall thickness of strength athletes was only slightly higher than that of endurance athletes and equal with that of athletes performing ‘combined sports’ but as mentioned above in this case, the anthropometric data were not considered. However, this kind of adaptation caused by resistance exercise is reasonable considering that (1) heart rate and cardiac output do not remain unchanged during strength training; (2) pressure overload is limited by relatively short duration of resistance training when compared with endurance training and (3) training regimes and sports activities of strength athletes are often not only static but also dynamic. It should also be mentioned that echocardiographic data of elite strength athletes (e.g. weightlifters, shot putters) have to be considered with caution due to the potential influence of anabolic steroids. This assumption is confirmed by data including anabolic-free weightlifters, anabolic-free bodybuilders and bodybuilders using anabolic steroids.56 Comparing these athletes, the authors found a significant increase in the hypertrophic index in doped bodybuilders when compared with bodybuilders and weightlifters not practicing doping.
Sports with different combinations of endurance and strength This category of sports (e.g. rowing, canoeing, cycling, judo) involve elements of both dynamic and static exercise. Therefore, on one hand, mean arterial blood pressure is often increased over 200 mmHg for longer periods. On the other hand, this pressure load is also combined with an extreme volume load. This basic pre-requisite may explain why the largest increases in left ventricular internal dimension, left ventricular mass and left ventricular wall thickness are found in cyclists and rowers.45,46,55 Fagard45 documented the highest increase in left ventricular wall thickness, relative left ventricular wall thickness and left ventricular mass in cyclists when compared with runners, strength athletes and controls all adjusted in age and body size. In their meta-analysis, Pluim et al.46 found the highest mean values for left ventricular left ventricular internal dimension, left ventricular dimensions and left ventricular muscle mass in athletes with combined load profiles compared to runners and strength athletes. Pelliccia et al.55 measured left ventricular dimensions in 947 elite, male, highly-trained athletes who participated in a wide variety of sports. Only in 16 of the 947 athletes was an end-diastolic wall thicknesses identified 13 mm (normally a borderline for the diagnosis of hypertrophic cardiomyopathy). Fifteen of them were rowers or canoeists and one was a cyclist. It should not be forgotten that dimensions are also influenced by anthropometric dimensions. However, there is evidence that the propensity for developing an athlete’s heart is partly genetically determined. Already in the 21st century, longitudinal training studies on identical twins have supported this theory. There is also indication that
the ACE-gene (angiotensin-I-converting enzyme) – and probably others – has an effect to heart hypertrophy caused by training. It has been shown that individuals with the DD genotype of ACE-gene show a significantly increased left ventricular mass in response to physical training.57
The respiratory system It is commonly accepted that during exercise, the structural capacity of the ‘untrained’ lung concerning large diffusion surface area, short alveolar-capillary diffusion distance, substantial ventilatory capacity exceeds the demand of pulmonary O2 and CO2 transport in healthy humans at sea level. Certainly the lung adapts to regular training with an increase in maximal voluntary ventilation.58 These functional adaptations caused by endurance training are accompanied by improvement of oxidative capacity of inspiratory muscles and can be (in part) attributed to a higher mitochondrial enzyme activity of inspiratory muscles. Training also reduces the cross-sectional area of inspiratory muscles – a structural change that reduces the distance for diffusion of gases, metabolites and substrates. It is clear however, that lung diffusion surface, airways and respiratory muscles do not adapt to the same extent as other links in the oxygen transport and utilization system. Therefore, the suggestion of an ‘overbuilt’ lung has to be re-assessed in the light of high aerobic capacities of extremely endurance-trained individuals. Two main causes have been described, which may contribute in limiting the aerobic capacity via respiratory system during very hard or maximal exercise: the fatigue of diaphragm,59 and the so-called ‘exercise induced arterial hypoxemia’ (EIAH).59 Concerning the fatigue of the diaphragm it has been suggested that this effect is caused by a competitive relationship between working skeletal muscles and respiratory muscles for limited cardiac output, thus redistributing cardiac output to working limb muscles and depriving the diaphragm of adequate blood flow.59 However, it has been shown that alveolar ventilation is not compromised despite diaphragm fatigue59 – presumably because accessory respiratory muscles are recruited.59 EIAH is a phenomenon of arterial O2 desaturation of 3–15% below resting levels during very heavy and maximal exercise. It has been reported most frequently in fit young individuals (sedentary individuals do not experience EIAH). Until now, the causal mechanism, which favor the development of EIAH is uncertain. With regard to the respiratory system, it can be stated that: (1) the lung adapts to regular training but to a lesser extent than other systems linked to oxygen transport and utilization system and (2) the contribution of the respiratory system to the limitations of aerobic capacity is (if even present) probably very small. The cause for limitation of aerobic capacity is probably in other systems such as cardiac output, peripheral vessels, such as the common femoral artery, limb blood flow and mitochondrial function and structure of working muscle cells.
The skeletal muscle Adaptation to endurance training Endurance training performed on a regular basis induces extensive alterations in the metabolic characteristics of exercis-
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ing skeletal muscles. These adaptations are accompanied by pronounced changes in energy delivery and utilization. After long-lasting endurance training, exercise at a given intensity results in an enhanced fat oxidation.60–63 At given exercise loads, muscle glycogen depletion is also prevented after training due to a shift from anaerobic utilization of carbohydrates to an enhanced carbohydrate oxidation and due to an increase in fat oxidation.62,63 From the late 1960s, a wealth of data on exercise induced ultrastructural changes in skeletal muscle has become available. Since that time it has been frequently demonstrated that endurance training increases both size and number of mitochondria.64 This increase in mitochondrial surface area observed in trained skeletal muscle seems to stand for an increased capacity to exchange substrates, oxygen, and carbon dioxide between mitochondrion and cytoplasm.64 Training adaptations of the mitochondrial system have been shown to include increases in mitochondrial enzyme activities.63 The observation that a training-induced increase in mitochondrial enzyme activity was accompanied by an increase in oxidative capacity during exercise61,63 as well as the finding of a coincidental increase of mitochondrial ATP production rates and mitochondrial enzyme activity following longer periods of endurance training,65 support the theory that the mitochondrial enzymes are decisively involved in the shift from carbohydrates to fatty acids during sub-maximal exercise observed in trained skeletal muscle. This assumption is also indirectly supported by the observation that oxidative Type I fibers contain considerably higher mitochondrial activity of oxidative enzymes than Type II fibers. There is also common agreement in the literature about the importance of mitochondrial ultrastructural and metabolic adaptations for a training-induced increase in fat utilization of skeletal muscle during prolonged sub-maximal exercise. Recent investigations conducted in isolated mitochondria of skeletal muscle support this theory by clearly demonstrating an increase in mitochondrial ATP production rates, mitochondrial fat oxidation rates and increased muscle oxidative power as a result of training.65,66 However, these findings support a model of a greater ‘pull’ by the mitochondria60 of endurance-trained skeletal muscle compared with their untrained counterparts. The findings of a substrate flux to the mitochondrion (caused by an increased mitochondrial surface area) and of an oxidative utilization rate (caused by an increased activity of mitochondrial oxidative enzymes in mitochondria) in skeletal muscle are in agreement with the observation of larger intramuscular fat stores of endurance-trained muscle cells. 67 Intramuscular triglycerides (IMTG) which are mainly stored in the form of lipid droplets in the cytoplasm of muscle cells are supposed to contribute to the energy supply of exercising muscles. Because these intramyocellular droplets are located close to muscle mitochondria,68 the transit time of fatty acids hydrolyzed from droplets to the outer mitochondrial membrane is very short and therefore these fatty acids seem to be readily available for oxidation during exercise. Utilizing 1H nuclear magnetic resonance spectroscopy it has been shown that the IMTG content of working muscles decreases after prolonged sub-maximal exercise.69 This observation is in agreement with findings showing that higher IMTG content is found in Type-I muscle fibers
19
than in Type II fibers.70 However, the higher relative contact surface area between the intracellular lipid droplets and the outer mitochondrial membrane of the trained skeletal muscle has also been interpreted as an adaptive mechanism of trained skeletal muscle to increase fatty acids turnover. It is important to be aware that oxidative processes are dependent on the microvascular supply of skeletal muscle. Based on available data it has been hypothesized that capillary surface per muscle fiber expressed as capillary to fiber ratio is linked with the mitochondrial volume.71 These differences in oxygen (and substrate) supply to skeletal muscle seem to be matched by differences in the amount of mitochondrial structure.71 However, there is clear evidence indicating that capillarization of human and animal skeletal muscle increases as a result of training, prolonging the transit time of red blood cells that pass through the capillaries into the mitochondrion of muscle cells.
Adaptation to strength training It is also generally accepted that strength training is beneficial to improve athletic performance, enhance general health and fitness and rehabilitate after injury. Resistance training results in adaptations of many physiological systems such as the muscle, the endocrine system and the neuronal control. These adaptations contribute to changes of muscular strength, power, local muscular endurance, speed, balance, coordination, jumping ability, flexibility and the corresponding measures of motor performance.72,73 However, these adaptations depend on the muscle actions used (mode of exercise, intensity, volume, number of sets and rest periods between sets). This summary is focused on strength, power, muscle hypertrophy and muscular endurance. Training to maximize muscular strength for sports performance is normally carried out with 100% of one repetition maximum (1 RM) down to 80% 1 RM, whereas a variety of loads within this range seems to be most conductive.73 Regularly performing this kind of training alters human fiber type profile. The main adaptation to training near maximal loads is a conversion of IIB fibers to IIA.72,74 This finding is in agreement with the observation of increased IIa myosin heavy chain isoforms (MHC) and decreasing IIb MHC.75 Concerning hypertrophy, it has been shown that bodybuilders are different with respect to percentage of cross-sectional area (CSA) fiber type when compared with weightlifters. While weightlifters show a preferential hypertrophy of type II fibers, the bodybuilders obviously succeed in increasing size of both, type I and type II fibers.72,74 This difference seems to be caused by extremely high loads (= 90% 1 RM) routinely used by weightlifters during training, while bodybuilders spend considerable more time using loads = 80% 1 RM with a higher number of repetitions. However, based on data in literature, there is some evidence that there may be a ‘threshold’ for optimal growth of muscles at about 80% 1 RM.72 Furthermore, proceeding from the assumption of a ‘hypertrophy threshold’ of 80% 1 RM it is also evident, that higher volumes (higher amount of repetitions) can be reached at 80% 1 RM when compared with 100% 1 RM. Additionally, there is also some evidence that hypertrophic response is not optimal when using only sets of 100% 1RM.76
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Concerning structural adaptations caused by high load/low repetition resistance training, the following observations have been made: (1) Elite weightlifters show a similar number of capillaries per muscle fiber when compared with untrained subjects. However, there is a decrease in capillaries per unit muscle area due to an increase in muscle fiber size.77,78 In contrast to weightlifters, bodybuilders often show a slight increase in capillaries per muscle fiber with a similar number of capillaries per unit muscle area in comparison with untrained persons.78,79 (2) Mitochondrial density has been found similar or even slightly decreased80,81 as result of high load resistance training. (3) High load resistance training does not enhance the activity of enzymes associated with aerobic energy production.82 Weightlifters normally show similar or even slightly decreased activities of ‘aerobic’ enzymes than untrained persons. However, higher activities of citrate synthetase and 3-hydroxyacyl-CoA dehydrogenase (HAD) has been demonstrated in bodybuilders when compared with weightlifters.78 These differences between weightlifters and bodybuilders seem to be caused by differences in training regimes with regard to higher number of repetitions in body building. (4) Concerning the high energy phosphate metabo-
lism, some83,84 investigators found an improvement of fast ATP restoration caused by higher activities of several enzymes like ATPase, creatine kinase or myokinase as a result of high load resistance training. These changes seem to contribute to the higher contractility, power and speed observed as a result of high load resistance training. (5) Evaluating the effects of high load resistance training to anaerobic glycolytic metabolism data presented in literature are inconsistent. Several investigations demonstrate that ‘anaerobic’ enzymes like phosphofructokinase or lactate dehydrogenase are unaffected by high load resistance training.81,84,85 These findings are contrasted by other data showing a slightly higher activity of ‘anaerobic’ enzymes like lactate dehydrogenase in strengthtrained athletes than untrained subjects.83 Local muscular endurance can be trained with a special regime of resistance training. This kind of training consists of low to moderate intense training with high repetitions and short recovery between the sets. This kind of training is designed to increase muscular endurance capacity of specific muscle groups with all its structural and functional adaptations such as mitochondrial and capillary density, fiber type transition and buffering capacity.
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Rhea MR, Ball SD, Phillips WT, Burkett LN. A comparison of linear and daily undulating periodized programs with equated volume and intensity for strength. J Strength Cond Res 2002; 16:250–255. Kesaniemi YK, Danforth E Jr, Jensen MD, Kopelman PG, Lefebvre P, Reeder BA. Doseresponse issues concerning physical activity and health: an evidence-based symposium. Med Sci Sports Exerc 2001; 33:351–358. Blair S, LaMonte MJ, Nichaman MZ. The evolution of physical activity recommendations: how much is enough? Am J Clin Nutr 2004; 79 (Suppl):913–920. American College of Sports Medicine Position Stand. The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults. Med Sci Sports Exerc 1998; 30:975–991. Pate RR, Pratt M, Blair SN, et al. Physical activity and public health: a recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA 1995; 273:402–407. President’s Council on Physical Fitness and Sports. Fitness fundamentals – Guidelines for personal exercise programs. Online. Available: http://fitness.gov/fitness.pdf 19 July 2003. Fagard RH. Athlete’s heart: a meta-analysis of the echocardiographic experience. Int J Sports Med 1996; 17:140–144. Pluim BM, Zwinderman AH, van der Laarse A, van der Wall EE. The athlete’s heart. A meta-analysis of cardiac structure and function. Circulation 2000; 101:336–344. Spirito P, Pelliccia A, Proschan MA, et al. Morphology of the ‘athlete’s heart’ assessed by echocardiography in 947 elite athletes representing 27 sports. Am J Cardiol 1994; 74:802–806. Scharhag J, Schneider G, Urhausen A, Rochette V, Kramann B, Kindermann W. Athlete’s heart: right and left ventricular mass and function in male endurance athletes and untrained individuals determined by magnetic resonance imaging. J Am Coll Cardiol 2002; 20:1856–1863. Moore RL. Cellular adaptations of the heart muscle to exercise training. Ann Med 1998; 30:46–53. Gledhill N, Cox D, Jamnik R. Endurance athletes’ stroke volume does not plateau: major advantage is diastolic function. Med Sci Sports Exerc 1994; 26:1116–1221. Ferguson S, Gledhill N, Jamnik VK, Wiebe C, Payne N. Cardiac performance in endurance-trained and moderately active young women. Med Sci Sports Exerc 2001; 33:1114–1119. Di Bello V, Santoro G, Talarico L, et al. Left ventricular function during exercise in athletes and in sedentary men. Med Sci Sports Exerc 1996; 28:190–196. Stork T, Mockel M, Muller R, Eichstadt H, Hochrein H. Left ventricular filling behaviour in ultra endurance and amateur athletes: a stress Doppler-echo study. Int J Sports Med 1992; 13:600–604. Carter JB, Banister EW, Blaber AP. Effect of endurance exercise on autonomic control of heart rate. Sports Med 2003; 33:33–46. Pelliccia A, Maron BJ, Spataro A, Proschan MA, Spirito P. The upper limit of physiologic cardiac hypertrophy in highly trained elite athletes. N Engl J Med 1991; 324:295–301. Urhausen A, Kindermann W. Sports-specific adaptations and differentiation of the athlete’s heart. Sports Med 1999; 28:237–244. Fatini C, Guazzelli R, Manetti P, et al. RAS genes influence exercise-induced left ventricular hypertrophy: an elite athletes study. Med Sci Sports Exerc 2000; 32:1868–1872. O’Kroy JA, Coast JR. Effects of flow and resistive training on respiratory muscle endurance and strength. Respiration 1993; 60:279–283. Dempsey JA, Sheel AW, Haverkamp HC, Babcock MA, Harms CA. Pulmonary system limitations. Can J Appl Physiol 2003; 28 (Suppl):2–4. Coggan AR, Raguso CA, Gastaldelli A, Sidossis LS, Yeckel CW. Fat metabolism during high-intensity exercise in endurance-trained and untrained men. Metabolism 2000; 49:122–128. Hurley BF, Nemeth PM, Martin WH 3rd, Hagberg JM, Dalsky GP, Holloszy JO. Muscle triglyceride utilization during exercise: effect of training. J Appl Physiol 1986; 60:562–567. Martin WH 3rd, Dalsky GP, Hurley BF, et al. Effect of endurance training on plasma free fatty acid turnover and oxidation during exercise. Am J Physiol 1993; 265:708–714. Phillips SM, Green HJ, Tarnopolsky MA, Heigenhauser GF, Hill RE, Grant SM. Effects of training duration on substrate turnover and oxidation during exercise. J Appl Physiol 1996; 81:2182–2191.
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Hoppeler H, Howald H, Conley K, Lindstedt SL, Claassen H, Vock P, Weibel ER. Endurance training in humans: aerobic capacity and structure of skeletal muscle. J Appl Physiol 1985; 59:320–327. Starritt EC, Angus D, Hargreaves M. Effect of short-term training on mitochondrial ATP production rate in human skeletal muscle. J Appl Physiol 1999; 86:450–454. Tonkonogi M, Walsh B, Svensson M, Sahlin K. Mitochondrial function and antioxidative defence in human muscle: effects of endurance training and oxidative stress. J Physiol 2000; 15:379–388. Howald H, Boesch C, Kreis R, Matter S, Billeter R, Essen-Gustavsson B, Hoppeler H. Content of intramyocellular lipids derived by electron microscopy, biochemical assays, and (1)H-MR spectroscopy. J Appl Physiol 2002; 92:2264–2272. Vock R, Weibel ER, Hoppeler H, Ordway G, Weber JM, Taylor CR. Design of the oxygen and substrate pathways. V. Structural basis of vascular substrate supply to muscle cells. J Exp Biol 1996; 199:1675–1688. Brechtel K, Niess AM, Machann J, et al. Utilisation of intramyocellular lipids (IMCLs) during exercise as assessed by proton magnetic resonance spectroscopy (1H-MRS). Horm Metab Res 2001; 33:63–66. Hwang JH, Pan JW, Heydari S, Hetherington HP, Stein DT. Regional differences in intramyocellular lipids in humans observed by in vivo 1H-MR spectroscopic imaging. J Appl Physiol 2001; 90:1267–1274. Hoppeler H, Weibel ER. Structural and functional limits for oxygen supply to muscle. Acta Physiol Scand 2000; 168:445–456. Fry AC. The role of resistance exercise intensity on muscle fibre adaptations. Sports Med 2004; 34:663–679. Kraemer WJ, Adams K, Cafarelli E, et al. American College of Sports Medicine. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Med Sci Sports Exerc 2002; 34:364–380. Campos GE, Luecke TJ, Wendeln HK, et al. Muscular adaptations in response to three different resistance-training regimens: specificity of repetition maximum training zones. Eur J Appl Physiol 2002; 88:50–60. Hikida RS, Staron RS, Hagerman FC, Walsh S, Kaiser E, Shell S, Hervey S. Effects of high-intensity resistance training on untrained older men. II. Muscle fiber characteristics and nucleo-cytoplasmic relationships. J Gerontol A Biol Sci Med Sci 2000; 55:347–354. Hakkinen K, Pakarinen A. Acute hormonal responses to two different fatiguing heavyresistance protocols in male athletes. J Appl Physiol 1993; 74:882–887. Kadi F, Eriksson A, Holmner S, Butler-Browne GS, Thornell LE. Cellular adaptation of the trapezius muscle in strength-trained athletes. Histochem Cell Biol 1999; 111:189–195. Tesch PA, Alkner BA. Acute and chronic muscle metabolic adaptations to strength training. In: Komi PV, ed. Strength and power in sport. Oxford: Blackwell Science; 2003:265–280. Schantz PG, Kallman M. NADH shuttle enzymes and cytochrome b5 reductase in human skeletal muscle: effect of strength training. J Appl Physiol 1989; 67:123–127. Chilibeck PD, Syrotuik DG, Bell GJ. The effect of strength training on estimates of mitochondrial density and distribution throughout muscle fibers. Eur J Appl Physiol Occup Physiol 1999; 80:604–609. Wang N, Hikida RS, Staron RS, Simoneau JA. Muscle fiber types of women after resistance training – quantitative ultrastructure and enzyme activity. Pflugers Arch 1993; 424:494–502. Green H, Goreham C, Ouyang J, Ball-Burnett M, Ranney D. Regulation of fiber size, oxidative potential, and capillarization in human muscle by resistance exercise. Am J Physiol 1999; 276:591–596. Tesch PA, Thorsson A, Essen-Gustavsson B. Enzyme activities of FT and ST muscle fibers in heavy-resistance trained athletes. J Appl Physiol 1989; 67:83–87. Komi PV, Karlsson J, Tesch PA, Suorninen H, Heikkinen E. Effects of heavy resistance and explosive-type strength training methods on mechanical, functional and metabolic aspects of performance. In: Komi PV, ed. Exercise and sport biology: International series on sports sciences. Vol. 12. Champaign, IL: Human Kinetics; 1982:90–102. Bishop D, Jenkins DG, Mackinnon LT, McEniery M, Carey MF. The effects of strength training on endurance performance and muscle characteristics. Med Sci Sports Exerc 1999; 31:886–891.
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CHAPTER
3
The Role of Diet and Nutritional Supplements Fabio Pigozzi, Arrigo Giombini, Federica Fagnani and Attilio Parisi
INTRODUCTION In modern sports, nutritional strategies may have their biggest influence on performance by supporting intensive sports activity and thus promoting adaptations to training that will lead to enhanced performance.
Box 3.1: Key Points 1
Carbohydrate supplementation during exercise is an effective means of improving performance in endurance sports. This can be accomplished without significantly modifying an athlete’s normal training protocol or diet.
2
An adequate protein intake can help an individual who is active in aerobic or resistance training to reach his/her potential by preserving muscle tissue and possibly enhancing recovery after strenuous exercise.
3
For the athlete with very high levels of energy expenditure during training, the exercise intensity will inevitably be reduced to a level where fatty acids provide a large part of the energy supply and become an important dietary component.
4
Of special significance in the metabolic mixture are the micronutrients, the small quantities of vitamins and minerals that play highly specific roles in facilitating energy transfer and tissue synthesis. These nutrients can be obtained by consuming wellbalanced meals.
5
Minerals function primarily in metabolism where they serve as important parts of enzymes. Sweat loss during exercise usually does not increase the minerals requirements above recommended values.
6
The use of supplements and ergogenic aids represents a controversial area of sports medicine worldwide. The clinician has to be well informed in the more popular supplements and drugs reputed to be ergogenic in order to distinguish fact from fiction.
The foods that an athlete chooses can make the difference between success and failure. A correct food choice will not make a champion out of the athlete who is not talented or motivated but a scanty or inadequate diet can prevent the
talented athlete from making it to the top. The goals for adequate nutrition for athletes should include: maintaining energy supply to the working muscles, supporting tissue adaptation, growth and repair, and promoting immune function. In competition, all important and worthy goals must be met, but the requirements and the strategies adopted will greatly vary depending on the nature of the event. The purpose for the nutritionist involved in competitive sport is to identify first the nutritional goals of the athlete and then to translate them into dietary strategies, taking into account the individual needs. This general consideration is applied to all sports, but the strategies utilized may be very different because of the different demands of training and competition. Any form of sport activity will increase the rate of energy expenditure, and for this reason, energy intake must be increased accordingly; also considering that the energy demands of sportsmen and women in training vary depending primarily on body mass and training load.
MACRONUTRIENTS Role of carbohydrates Relative to fat or protein, the carbohydrate stores of the body are quite limited: 300–500 g of glycogen are stored in skeletal muscle; 60–100 g are stored in the liver and an additional 15–20 g of glucose is stored in blood and extracellular space.1 The rate of blood glucose and muscle glycogen use is dependent on both the intensity and duration of exercise. It is also influenced by the availability of other fuel sources, mainly plasma free fatty acids. If carbohydrate stores were the only fuel source available during exercise, they would provide only enough energy to complete a 32 km run.1 When the exercise intensity increases linearly, muscle glycogen use increases exponentially. Saltin and Gollnick2 found that the rate of muscle glycogen use was 0.7, 1.4, and 3.4 mmol/kg per min at exercise intensity of 50%, 75% and 100% of VO2max, respectively.2 However, the rate of glycogenolysis is also dependent on the muscle glycogen concentration, the greater the initial muscle glycogen concentration, the faster the rate of glycogenolysis.
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Similar to the situation with muscle glycogen utilization, a linear increase in exercise intensity results in an exponential increase in muscle glucose uptake.3 Björkman and Wahren reported that after 40 min of exercise at an intensity of 25% and 75% VO2max, leg glucose uptake was 0.4 mmol/min and 1.8 mmol/min, respectively.1 This increase in muscle glucose uptake seems to partially offset the decrease in glycogenolysis that accompanies a decrease in the muscle glycogen concentration.4 Recovery of the muscle and liver glycogen stores after exercise is a rather slow process, and complete recovery may not be achieved until 24–48 h after the end of an exercise bout. The rate of glycogen resynthesis after exercise is determined largely by the amount of carbohydrates supplied in the diet. The amount of carbohydrates consumed is of far greater importance for this process than the type of carbohydrates. Carbohydrate loading is a practice used to maximize glycogen storage before competition. This can be accomplished without significantly modifying an athlete’s normal training protocol or diet. Sherman and collaborators have recommended that the muscle glycogen stores first be depleted with a hard exercise bout, 7 days before competition.3 This is followed by a normal 6-day training taper. During the first 3 days of the taper, a mixed diet composed of 45–50% carbohydrate is consumed. During the last 3 days of the taper, the carbohydrate content of the diet should be increased to 70%. A high-carbohydrate meal may also be consumed 4 h before competition, providing an additional supply of carbohydrate without substantially altering the normal exercise hormonal and metabolic milieu.5 Supplements taken less than 4 h before competition could result in hypoglycemia and an increased reliance on muscle glycogen; however, if supplementation is continued throughout exercise, this should not present a problem as long as the supplement is readily digestible. Carbohydrate supplementation during exercise is an effective means of improving endurance performance. The major objective of supplementation during exercise is to prevent hypoglycemia. Some authors recommend the consumption of 30–60 g of carbohydrate per hour. The means by which this is provided depend on the type, intensity, duration of the exercise, and the environmental condition under which the exercise is performed. For hot, humid conditions in which dehydration is a concern, liquid supplements composed of 5–6% carbohydrate every 15–20 min is optimal. Dehydration becomes a definite risk during cold weather exercise because colder air contains less moisture than air at warmer temperature and cold stress stimulates the body to increase urine production causing a considerable body fluid loss; for this reason, liquid supplements are suggested during prolonged exercise in cold weather. For the rapid restoration of muscle glycogen, some authors recommend that 1.0–1.5 g carbohydrate/kg body weight be consumed immediately after exercise. Continuation of supplementation every 2 h, or smaller amounts taken more frequently, will maintain a maximal rate of storage 6 h after exercise. Supplements composed of glucose or glucose polymers are more effective than fructose for the restoration of muscle glycogen; however, the addition of some fructose to the sup-
plement is recommended because fructose is more effective than glucose in the restoration of liver glycogen. The addition of protein to the supplement may also be of benefit because it increases the pancreatic insulin response and rate of muscle glycogen synthesis. We think, in conclusion, that there is enough evidence to support the theory that adequate carbohydrate intake is important for the restoration of muscle glycogen stores, and that other dietary strategies related to the timing of intake, type of carbohydrate source or addition of other nutrients may either directly enhance the rate of glycogen-storage recovery or improve the practical achievement of carbohydrate intake targets.
Role of proteins Humans need dietary protein to provide the essential amino acids that our body cannot synthesize but that are needed in the production of important proteins in the body. Therefore, all humans need to consume a certain proportion of nine essential amino acids including histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. Our total nitrogen need is in excess of that required for the essential amino acids and the body can use this additional nitrogen to synthesize non-essential amino acids needed for protein synthesis. Most athletes consume more than enough protein in their daily diets. Van Erp-Baart et al. found that protein intake in high-level athletes was highly related to energy intake.6 Thus, athletes in high-energy-expenditure sports and male athletes were the highest consumers of protein. The highest protein intakes were found in male cyclists in the Tour de France, at approximately 3 g/kg per day (Fig. 3.1). Male bodybuilders consumed approximately 2.5 g/kg per day, whereas female bodybuilders reported diets with approximately 2.0 g/kg per day. Female hockey, volleyball and handball players had the lowest average protein intake, at about 1.0–1.2 g/kg per day. Thus, all of the athletic groups as a whole were consuming a quantity of protein greater than the US recommended dietary allowance (RDA), but some individuals, particularly the lowenergy consumers, may have consumed less than this recommended level. Both muscle protein synthesis and degradation are increased as a result of resistance exercise, with more of an increase in synthesis resulting in net increase of body protein. Scientific evidence shows that protein intake in the range of 1.2–1.8 g/kg per day is optimal for maintaining body protein and allowing maximal muscle protein synthesis.7 Novice athletes starting a resistance-training program should use the upper end of this range. Long-term consumption of protein at higher levels than this range has not been shown to have any benefit. Preliminary research suggests that consumption of carbohydrate with protein mixtures after resistance exercise may enhance protein increase and metabolic recovery. Resistance exercise is required to stimulate muscle protein synthesis and in the end, muscle hypertrophy. Thus, underweight patients who ask whether protein supplements would help them gain weight should be advised to begin resistance
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tributes to the development of kidney disorders. Although there is little experimental evidence to support this concern, it would be advisable to limit protein intake to less than 2 g/kg. Protein intake greater than 2 g/kg has not been shown to be beneficial and may have negative effects on overall dietary quality, excluding high carbohydrate and other nutrient dense foods from the diet. It is the authors’ opinion that an adequate protein intake, in the range of 1.2–1.8 g/kg, can help an individual who is active in aerobic or resistance training to reach his potential by preserving muscle tissue and possibly enhancing recovery after strenuous exercise. Protein catabolism during exercise becomes pronounced when carbohydrate reserves deplete. The amino-acid alanine plays a key role in providing carbohydrate fuel during prolonged exercise via gluconeogenesis. During strenuous exercise of long duration, the alanine-glucose cycle accounts for up to 10–15% of the total amount of energy expenditure.
Role of fats
Figure 3.1 The highest protein intakes were found in male cyclists in the tour the France. (From Van Erp-Baart et al. 1989,6 with permission.)
training in addition to increasing their energy intake. Additional dietary energy, required for protein synthesis to occur, is probably the most important dietary change they can make because they are likely consuming enough protein in their typical diets. Although the majority of individuals already consume the recommended amount of protein in their daily diets, there are high-risk groups for low protein intake such as women, people who are dieting for weight loss and elderly individuals. A safe minimal competitive body weight should be established for female gymnasts, many of whom use disordered eating behaviors to achieve weight loss. For female gymnasts, the minimal body weight should contain no less than 12–14% body fat. They can decrease the intake of calories by reducing dietary lipid, protein and carbohydrate, but should not totally eliminate any one of these three, consuming at least 1500 cal/day to prevent vitamin and mineral deficiencies. The low energy intake associated with these groups is more likely to result in a low protein intake. Any individuals thought to be at risk should be asked to keep a food record for 3 days and receive counseling concerning low-fat sources of protein, such as lean meats, low-fat or non-fat dairy products, fish and legumes. A common question could be whether there is any risk in consuming a high protein diet. A high protein diet is known to be detrimental in individuals with kidney and liver disease. It has been suggested that a chronically high protein diet con-
If carbohydrates are not available or available only in a limited amount, the intensity of the exercise must be reduced to a level where the greater part of the energy requirement can be met by fat oxidation.8 For the athlete with very high levels of energy expenditure in training, the exercise intensity will inevitably be reduced to a level where fatty acid oxidation will make a substantial contribution to energy supply and fat will provide an important energy source in the diet. Marathon and triathlon are examples of sports that depend on fat oxidation (Fig. 3.2). Plasma triacylglycerols (TGs), free fatty acids (FFAs) and muscle triacylglycerols (TG) are oxidizable lipid fuel sources for skeletal muscle metabolism during prolonged exercise. Plasma FFAs are a major fuel oxidized by skeletal muscle, and their rate of use by muscle depends on several factors, including their plasma concentration, transport from plasma to the mitochondria, and intracellular metabolism. Mobilization of FFAs from adipose tissue is the first step in FFA metabolism, and it depends on the rate of adipose tissue lipolysis. Adipose tissue lipolysis increases with exercise duration and intensity up to approximately 60–65% of VO2max.8 Evidence suggests that FFAs are transported from plasma to the mitochondria by FFA carrier proteins that include the plasma membrane and cytosolic plasma membrane fatty acid-binding protein (FABPPM) and cytoplasmic fatty acidbinding protein (FABPc). Plasma FFA use can also be regulated at the mitochondrial transport step by changes in the activity of carnitine palmitoyltransferase (CPT-1).9,10 Although results from biopsy and tracer studies indicate that muscle TG contribute to skeletal muscle oxidative metabolism during exercise, their exact contribution is difficult to ascertain in quantitative terms.11 Dietary strategies can modulate substrate use during exercise and can potentially affect exercise performance. High carbohydrate availability before exercise is associated with an increase in blood glucose and plasma insulin concentrations which can, in the end, decrease the rate of adipose tissue
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Figure 3.2 Marathon is an example of sport that depends on fat oxidation.
lipolysis and the availability of plasma FFAs. Increased glucose flux has also been shown to decrease lipid oxidation by directly inhibiting the transport of FFAs across the mitochondrial membranes. High lipid availability can be altered by short-term or long-term exposure to high-fat diets. The value of feeding a high-fat diet in preparation for competition is still a matter of considerable debate. There is evidence both for and against the hypothesis that training on a high-fat diet a few weeks before competition can improve performance by promoting fat utilization and sparing glycogen stores. It is likely that differences in diet composition exercise models, and in the training status of athletes, make comparisons between studies very difficult.
MICRONUTRIENTS Vitamins Of special significance in the metabolic mixture are the micronutrients, the small quantity of vitamins and minerals that play highly specific roles in facilitating energy transfer and tissue synthesis. For example, the body requires, each year, only about 350 g (12 oz) of vitamins from the 820 kg (1820 lb) of food consumed by the average adult.5 Some 13 different vitamins have been isolated, analyzed, classified and synthesized, and have established recommended dietary allowance (RDA) levels. Vitamins are classified as either fat-soluble or water-soluble. The fat-soluble vitamins are vitamins A, D, E and K; the water-soluble vitamins are vitamin C and the B-complex vitamins (based on their common source distribution and common functional relationships): pyridoxine (B6), thiamine (B1), riboflavin (B2), niacin (nicotinic acid), pantothenic acid, biotin, folic acid (folacin or folate, its active form in the body) and cobalamin (B12).
Fat-soluble vitamins Because fat-soluble vitamins dissolve and store in the body’s fatty tissues, they need not be ingested daily. In fact, years may elapse before symptoms of a fat-soluble vitamin insufficiency become evident. The liver stores vitamins A and D, whereas vitamin E is distributed throughout the body’s fatty tissues. Vitamin K is stored only in small amounts, mainly in the liver. Dietary lipid provides the source of fat-soluble vitamins; these vitamins, transported as part of lipoproteins in the lymph, travel to the liver for dispersion to various body tissues. Fat-soluble vitamins should not be consumed in excess without medical supervision. There is no evidence that daily supplementation above the recommended level of fat-soluble vitamins can be beneficial for sports performance. However, a daily moderate to large excess of vitamin A and D can produce serious toxic effects. For example, an excess of vitamin A in adults can cause nausea, headache, drowsiness, loss of hair, diarrhea and loss of calcium from bones; kidney damage can result from an excess of vitamin D.
Water-soluble vitamins The water-soluble vitamins act largely as coenzymes, with small molecules combining with a larger protein compound (apoenzyme) to form an active enzyme that accelerates the interconversion of chemical compounds. Coenzymes participate directly in chemical reactions; when the reaction runs its course, coenzymes remain intact and participate in additional reactions. Water-soluble vitamins, similar to their fat-soluble counterparts, consist of carbon, hydrogen and oxygen atoms. They also contain nitrogen and metal ions including iron, molybdenum, copper, sulphur and cobalt. Because of their solubility in water, water-soluble vitamins disperse in the body fluids without being stored to any
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appreciable extent. Sweating, even during strenuous physical activity, produces negligible losses of water-soluble vitamins. An excess intake of water-soluble vitamins becomes voided in the urine. Water-soluble vitamins probably exert their influence for 8–14 h after ingestion, then their effectiveness begins to decrease. For maximum benefit, for example, vitamin C supplements should be consumed at least every 12 h. Although vitamins contain no useful energy for the body, they do serve as essential links and regulators in metabolic reactions that release energy production from food. Vitamins also control the processes of tissue synthesis and aid in protecting the integrity of the cells’ plasma membrane. The vitamin needs of athletes do not exceed those of sedentary counterparts. Well-balanced meals provide an adequate quantity of all vitamins, regardless of age and physical activity level. Indeed, individuals who expend considerable energy exercising do not need to consume special foods or supplements that increase the vitamin content above recommended levels. In addition, at high levels of daily physical activity, food intake is generally increased in order to sustain the added energy requirements of exercise. Additional food through a variety of nutritious meals proportionately increases vitamins intake. Different athletic groups receive relatively low intakes of vitamins B1 and B6.12–14 Adequate intake of these two vitamins occurs if the daily diet contains fresh fruit, grains and uncooked or steamed vegetables. Individuals on meatless diets should consume a small amount of milk, milk products, or eggs because vitamin B12 exists only in foods of animal origin.
Antioxidants role of specific vitamins Although regular physical activity is known to have many beneficial effects, it results in an increased production of radicals and other forms of reactive oxygen species (ROS).15–18 In fact, evidence exists to implicate ROS as an underlying cause in exercise-induced disturbances in muscle homeostasis (e.g. redox status), which could result in muscle fatigue or injury.19,20,21 Muscle cells contain complex cellular defense mechanisms to minimize the risk for oxidative injury. Two major classes of endogenous protective mechanisms work together to reduce the harmful effects of oxidants in the cell: enzymatic and non-enzymatic antioxidants. Key antioxidant enzymes include superoxide dismutase, glutathione peroxidase and catalase. These enzymes are responsible for removing superoxide radicals, hydrogen peroxide or organic hydroperoxides and hydrogen peroxide, respectively. Important non-enzymatic antioxidants include vitamins E and C, beta-carotene, GSH, uric acid, ubiquinone and bilirubin. Vitamin E, beta-carotene and ubiquinone are located in the lipid regions of the cell, whereas uric acid, GSH and bilirubin are in water compartments of the cell. To date, limited reports have examined the effects of antioxidant supplementation on muscular performance in humans. Furthermore, many of these studies suffer experimental design weaknesses, and most studies have investigated the effects of a single antioxidant rather than investigating the combined effects of both lipid-soluble and water soluble antioxidants. So far, the most widely studied antioxidant vitamin is vitamin E,
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whereas few studies have examined the effects of other antioxidants on human performance.22 Although several studies have indicated that supplementation with vitamin E and vitamin C23 decreases exercise-induced oxidative stress in humans, little evidence shows that antioxidant supplementation can improve human performance. One well-designed study has reported an improvement in human performance following supplementation with antioxidants. In this study, Reid et al. administered 150 mg of Nacetylcysteine to human subjects and measured muscular fatigue during low-frequency electrical stimulation. Results revealed an improvement in muscular endurance following treatment with this antioxidant.24 To date, limited evidence shows that dietary supplementation with antioxidants improves human exercise performance. However, because of the paucity of research on this topic, many additional studies are required before a firm conclusion can be reached about the effects of antioxidant treatment on human exercise performance. Future studies should examine the potential synergistic effects of several different antioxidants on human performance.
Nutrition and immune function A fundamental characteristic of the immune system is that it involves multiple functionally different cell types which permit a large variety of defense mechanisms. A heavy schedule of training and competition can lead to immune impairment in athletes, which is associated with an increased susceptibility to infections, particularly upper respiratory tract infections (URTI).25 This exercise-induced immune dysfunction seems to be mostly due to the immunosuppressive actions of stress hormones such as adrenaline and cortisol. Nutritional deficiencies can also impair immune function and there is a vast body of evidence that many infections are increased in prevalence by specific nutritional deficiencies.25
Dietary immunostimulants β-Carotene (pro-vitamin A) acts both as an antioxidant and an immunostimulant, increasing the number of T-helper cells in healthy humans and stimulating natural killer cell activity when added in vitro to human lymphatic cultures.26 Furthermore, elderly men who had been taking β-carotene supplements (50 mg on alternate days) for 10–12 years were reported to have significantly higher natural killer cell activity than elderly men on placebo.26 However, supplementing runners with β-carotene was not found to have a significant effect on the incidence of URTI after a 90-km ultramarathon.27 Several herbal preparations are reputed to have immunostimulatory effects, and consumption of products containing Echinacea purpurea is widespread among athletes. However, few controlled studies have examined the effects of dietary immunostimulants on exercise-induced changes in immune function. In one recent double-blind, placebo-controlled study, the effect of a daily oral pre-treatment for 28 days with pressed juice of E. purpurea was investigated in 42 triathletes before and after a sprint triathlon. A sub-group was also treated with magnesium as a reference for supplementation with a
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micronutrient important for optimal muscular function. The most important finding was that during the 28-days pretreatment period, none of the athletes in the Echinacea group felt ill, compared with three individuals in the magnesium group and four in the placebo group.28 Pre-treatment with Echinacea appeared to reduce the release of soluble IL-2 receptor before and after the race and increased the exerciseinduced rise in IL-6. Probiotics are food supplements that contain ‘friendly’ gut bacteria. There is now a reasonable body of evidence that regular consumption of probiotics can modify the population of the gut microflora and influence immune function. 25 Some studies have shown that probiotic intake can improve rates of recovery from rotavirus diarrhea, increase resistance to enteric pathogens and promote anti-tumor activity. Furthermore, there is some evidence that probiotics may be effective in alleviating some allergic and respiratory disorders in young children. However, to date, there are no published studies of the effectiveness or safety of probiotic use in athletes.
Minerals Approximately 4% of the body’s mass (about 2 kg for a 50-kg woman), consist of a group of 22 mostly metallic elements, collectively called minerals. Minerals serve as constituents of enzymes, hormones and vitamins, and exist in combination with other chemicals (e.g. calcium phosphate in bone, iron in the heme of hemoglobin) or exist singularly (free calcium in body fluids). Minerals, essential to life, are classified into major (seven minerals required in amounts of more than 100 mg daily) or minor or trace minerals (14 minerals required in amounts of less than 100 mg daily). Mineral supplements, like vitamins, generally confer little benefit in terms of sports performance because these minerals are readily available in our food and water. Some supplementation may be necessary, however, in geographic regions where the soil or water supply lacks a particular mineral. While vitamins activate chemical processes without becoming part of the by-products of the reactions they catalyze, minerals often become incorporated within the structures and existing chemical in the body. Minerals provide structure in forming bones and teeth, activate numerous reactions that release energy during carbohydrate, fat and protein metabolism. In addition, minerals are essential for synthesizing biologic nutrients, such as glycogen from glucose, triglycerides from fatty acids, and glycerol and proteins from amino acids. The fine balance between catabolism and anabolism would be disrupted without the essential minerals. Minerals also form important components of hormones.
Iron Iron deficiency is one of the most prevalent nutrient deficiencies observed in female athletes.29 This high incidence of iron
deficiency is usually attributed to several factors. First, female athletes often have poor iron intake, which is usually attributed to a diet poor in foods high in heme iron, such as meat, fish and poultry. These diets have a low caloric content restricting energy intake. If energy intake is restricted, total daily iron intake will be lower unless a supplement is added to the diet. Second, many female athletes follow vegetarian diets, which provide no heme iron. Therefore, the bioavailability of the iron consumed is reduced. Finally, female athletes may have increased iron losses through menstrual blood and iron lost in sweat, feces and urine. Examination of the dietary iron intake of female athletes who do not take iron supplements shows large variations in iron intake, depending on when the data were collected. Studies published in the late 1980s and early 1990s typically reported the dietary iron intakes of female athletes to be less than the RDA of 15 mg/d28; however, recent studies report higher iron intakes in female athletes from the diet only.30 The increased prevalence of fortified foods in the typical US diet and the diets of athletes has increased the intake of many micronutrients, including iron; however, this increased intake of iron did not reduce the prevalence of iron deficiency in these athletes. The diagnosis of asiderotic anemia results from the hemachrome which shows the presence of microcythemia (with small red blood cells), with decrease in the values of sideremia and ferritin, while transferrin is normal or increased. Altered values in the long run can lead to a decrease in the hemoglobin. Reports of the incidence of poor iron status in active women are variable and often depend on the sport and the type of athlete examined. When ferritin concentrations are used as the assessment criteria (either 2000 m) will kill most bacteria and parasites. Chemical disinfection including the use of iodine and a neutralizer to make the water more palatable can be effective
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for a variety of pathogens, but will not kill Cryptosporidium. Finally, water filtration systems are available, but vary in regard to the process for which they filter out any pathogens. Reverse-osmosis filters or pore sizes less than 1 µm are designed to filter out such pathogens as Giardia or Cryptosporidium. Cultural and regional differences in foods and meals may also be an issue. The team should be aware if the regional diet is similar or comparable with their usual food. If exotic foods are unpalatable or nutritionally deficient, the athletes’ energy and performance may be negatively affected. Dairy products are not always pasteurized, including milk, butter, cheese and ice cream. Raw vegetables are easily contaminated during preparation and uncooked vegetables should be avoided. Fresh fruit should be avoided unless washed and peeled by the athlete. Street vendor food should be avoided as it has been associated with an increased risk of illness. Cooked food should be eaten immediately, as food allowed to sit around for hours will develop bacterial growth over time. It is wise to plan ahead for any potential nutritional issues specific to the region of travel. Prior knowledge of the lodging arrangements at the destination is also important. Accommodations can vary from country to country and will depend upon the event. Lodging with loud noises, excess light or rooms that allow smoking could be quite disruptive to the athletes’ rest. Depending upon the venue, accommodation may be a tent, local dormitories, hotels or villages specific for the athletic staff. Ascertain if there are private rooms or if sharing is expected. Be aware of the possibility of the room being used as a treatment room as well. In addition to accommodation details, the team physician should be aware of the medical treatment facilities at the event venue and in the local area. The team usually has its own medical bag with supplies (detailed in the next section). It helps to know if the venue has private treatment rooms or partitions. It is possible that healthcare may be expected for the opposing team, spectators, or venue employees. Find out if the event is scheduled to have paramedics standing by. If desired, local EMT providers can usually send a unit to be on standby if there is a need and it is requested in advance. Find out whether or not an ambulance is on-site, find out where the nearest hospital is, what emergency services are provided there and how patients can be transported in an emergency. For events in the wilderness, it is necessary to assess emergency evacuation routes including use of all-terrain vehicles or helicopter support, in cases where an athlete is severely injured and has limited access. Finally, a physician traveling internationally should understand the team’s health insurance and malpractice coverage. Every athlete and staff member should have health insurance coverage in case of an emergency. Many insurance plans will reimburse any expenses incurred during travel up to a certain amount. Supplemental health insurance may be helpful, especially if someone needs emergent evacuation from a particular site. Malpractice coverage will vary as well. Some institutions provide malpractice coverage throughout the world. Other plans may offer coverage restricted to the US. However, sometimes the supporting athletic organization will obtain supplemental malpractice coverage. You should check with the malpractice coverage organization to understand the full extent of coverage.
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Supplies for emergencies Preparation of supplies for emergencies during travel should also be established before a trip. The medical bag should be checked and fully stocked. The contents of the medical bag vary somewhat by team and event.1,2 Table 5.2 provides an example of standard supplies. However, the exact contents will depend upon the teams’ needs. Determine if the medical staff or athletic trainers will be responsible for checking, stocking and transporting the bag during travel and at the event. The bag should be precisely organized so that items are clearly labeled, easy to find and always kept in the same location within the case or bag (Fig. 5.1). In addition to planning what should be in the medical bag, the team physician should also know what should not be in the bag. For international travel, the physician should be aware of the local laws to avoid bringing illegal medications into a specific country. In Japan, it is illegal to bring stimulants such as pseudoephedrine or codeine into the country. While in the Middle East, a variety of narcotics may lead to an arrest. All prescription medication should be carried in its original bottle. In addition, a letter from a physician stating the nature and use of the medication is quite helpful. The United States Department of State website can provide a wealth of information regarding any potentially illegal substances while traveling to a specific country (http://travel.state.gov/travel). It is imperative that the physician be aware of which substances are banned by any governing bodies of the team’s sport. Some websites with current guidelines include the World Antidoping Agency (www.wada-ama.org), United States Olympic Committee (www.usoc.org), the International Association of Athletes Federation (www.iaaf.org/antidoping/downloads), or the National Collegiate Athletic Association (www.ncaa.org). The physician should periodically check the appropriate organization’s website, as substances and medications will change over time.
Team communication It is up to the head medical practitioner to assure that the rest of the team members are informed about medical and health travel issues. For local trips, this is not much of an issue. Long distance and international travel however, may present additional health challenges. Depending on the destination, issues of proper hydration, environmental and climatic conditions, and sanitation may warrant team education prior to travel. Personal safety reminders and education may be needed. Athletes should also be reminded about the potential risks of sexual activity and counseled to use judgment and protection. Cultural differences may necessitate education about appropriate public behavior and attire to avoid embarrassing, difficult, or dangerous public interactions.
Physician checklist There is much to be scheduled, checked, and planned prior to traveling with the team. Having a standard check list (Table 5.3) of tasks denoting a timeline (count-down to departure) can be very helpful. The successful team practitioner plans ahead and prepares for a trip in a timely manner to avoid last minute
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Table 5.2
Team Physician Medical Supplies: Bag Contents
I Airway management Bag valve mask Forceps Laryngoscope Straight and curved laryngoscope blades Extra batteries Extra bulbs ET tubes (sizes 6–9) Oral airways (sizes 5.5–12) 60 cc syringe 10 cc syringe No. 11 blade Cricothyroidotomy kit No. 14 intercath II I.V. kit Tourniquet Alcohol pads Angiocaths 14G, 21G, 18G Butterfly 19G, 21G, 23G Gauze Tape I.V. tubing sets I.V. fluid (LR, D51/2NS, NS) III Eye kit Eye shield Oval eye pads Cotton tipped applicator Eye solution Tape Fluorescein drops Tobramycin drops Proparacaine drops Cobalt blue light Mirror Pen light IV Suture and injection kit Syringes (3 cc, 5 cc, 10 cc) Marcaine Lidocaine Needles (16G, 18G, 22G, 25G) Alcohol pads Betadine swabs Needle holder, scissors, pick-ups Suture (3–0, 4–0, 5–0, 6–0) Antibiotic ointment Gauze Bandaids Tape Benzoin Steri-strips Sterile gloves V Wound care Betadine swabs Alcohol pads
Hibiclens or hydrogen peroxide Sterile water Tefla pads Duoderm Bioclusives Kling gauze Bandaids Topical antibiotic packets Benzoin Steri-strips Tape Skin glue VI Medications (depends upon region) Injectable Marcaine Lidocaine with/without epi Morphine Epi pen Phenergan Ketorolac (Toradol) Celestone Oral Acetaminophen (Tylenol) Ibuprofen or naproxen Ciprofloxacin Norfloxacin Azithromycin Benadryl Tylenol with codeine Albuterol inhaler Loperamide Phenergan Methylprednisolone Pepto-Bismol VII Physician diagnostic kit Tongue depressors Cotton-tipped applicator Latex and vinyl gloves Pen light Oto/ophthalmoscope Stethoscope Sphygmomanometer Reflex hammer Urine dip sticks Thermometers VIII Miscellaneous Cervical collar Pens Injury assessment forms Prescription pad Sharps container Biohazard bag
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Figure 5.1 (A) Medical cabinet for storage of supplies. (B) Medical backpack with organization of supplies into pouches.
A
B
problems. Some general topics to include on this list are checking on the venue, accommodations, required health precautions, emergency numbers/contacts, team education issues and the medical bag. In addition to a medical checklist, having a personal check list can help you to be fully prepared not only for the medical care duties, but also for the personal and fun aspects of the trip.
TRAVEL Traveling with a team for sporting competition can be both exciting and stressful. Questions related to air or road travel
are often directed to the medical personnel. Psychological and emotional issues related to travel and competitive stress affect team members and staff. Sports-related injuries, incidental
Box 5.2: Key Points ●
Traveling can have a physical and emotional impact on athletes and their performance.
●
Jet lag may impede performance and should be treated pro-actively as appropriate.
●
Maintain proper nutrition including hydration.
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Table 5.3
Physician Travel Preparation Checklist
Weeks prior to departure Review location logistics ˛ Venue medical facilities ˛ Accommodations ˛ Visas/Passports as appropriate ˛ Local hospitals/local contacts ˛ Secure any special medications ˛ Local weather patterns (temperature, humidity, sun exposure) assessing time needed for acclimatization Team health concerns ˛ Team immunizations ˛ Regional health concerns ˛ Emergency contact info Days prior to department Team health concerns ˛ Review medical supplies and secure items ˛ Review any medical precautions with athletes and staff ˛ Encourage hydration during travel Personal concerns ˛ Review personal medical supplies ˛ Review personal travel gear ˛ Passport
injuries and travel-related illnesses need to be dealt with in a timely fashion. In addition to the preparation discussed in the previous section, successful management of these issues requires knowledge and readiness to act.
Transportation-specific issues Different methods of travel share some common potential problems that can be simply avoided. More common problems include jet lag, dehydration and muscle cramping from immobility. Jet lag is a term used to describe a host of symptoms an individual feels after rapidly traversing several time zones. It is believed to occur when a person’s internal circadian rhythms and body clock are dyssynchronous with the environment after traveling across time zones.3 Symptom intensity increases the greater the disparity in time change between home and destination. Symptoms include general malaise, fatigue, insomnia, headaches and gastrointestinal upset. Approximately 0.5–1 day per time zone crossed is needed to reset circadian rhythms to local time, and is generally slower following eastward compared with westward travel.4 Exposure to the light/dark cycle at the destination is believed to be the major factor in resetting the circadian rhythms. Treatment options vary based on the individual’s preference but include altered sleeping times while traveling, prescribed medications and supplements. The use of medications includes short-acting zolpidem or melatonin. However, long-acting medications, such as diphenhydramine, should be avoided as they might lead to sedation of the athlete and a ‘hangover feeling’. There is some evidence that oral melatonin combined with appropriate light/dark entrainment and timely physical
exercise can decrease the time it takes to re-entrain to the local time zone.5,6 Various studies have attempted to assess the impact of time zone changes on athletic performance.7–9 A study of athletic performance following travel through multiple time zones has shown some athletes to have mood alterations, and decreased aerobic power, aerobic capacity and dynamic strength.8 However, another study showed mixed results for measures of muscle strength and muscular endurance.9 More studies are needed to support or refute the extent to which traveling through time zones affects athletic performance.7 Several studies have suggested existence of a ‘peak time’ for athletic performance related to the internal clock/circadian rhythms. Peak athletic performance has been hypothesized to occur in synchrony with peak circadian body temperatures from approximately 1800 to 2000 hours. It is also purported that the trough temperature (and athletic performance) occurs in the early morning, approximately 0400 to 0600 hours. The studies did not control for all of the multiple potential confounding factors (nutritional status, prior rest, environment and body temperature, among others) and thus cannot be considered conclusive.4 Studies examining the effect of time zone changes on performance in the National Football League and the National Basketball Association suggest that west coast teams traveling east display a winning advantage for night games, where east coast teams traveling west display a disadvantage.10–12 The studies propose that a possible factor is that the west coast teams are competing in sync with the circadian peak for athletic performance. Further studies are needed to be conclusive. However, the implication is that athletes do show some competitive advantage when competing in sync with circadian athletic peaks. This may be helpful information if a team has any choice of what time of day to compete when on the road. Hydration is another factor that affects performance and cramping. Long road trips in warm weather or flights with recirculated air can certainly lead to mild to moderate dehydration if travelers do not adequately replace water loss by drinking water or sports drinks en route. Alcohol intake only contributes to dehydration, especially on flights and should be strongly discouraged. In addition to proper hydration, team members should be reminded to eat at appropriate times during travel. Meals or per diem food funds should be provided to the athletes for car or bus trips. Airlines may provide a meal service, but this is becoming less available. Team staff should be prepared to keep the team properly fed or the athletes should be reminded to bring their own food. Finally, with prolonged transportation by bus, car, or airplane, athletes should be reminded to change position every hour or so to avoid a potential deep venous thrombosis and minimize cramping from immobility in the seated position. Prevention strategies include stopping every few hours at a rest stop (car or bus) or walking in the aisle (bus or airplane).
Common travel illnesses Traveler’s diarrhea The most common pathogens for traveler’s diarrhea include bacteria, viruses and parasites. The primary bacterial strains
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Box 5.3: Key Points ●
Prevention is the key to avoiding potential common illness.
●
Review the appropriate use of any medications to avoid doping restrictions.
●
Adequate acclimatization, rest and proper nutrition is crucial to avoiding illnesses related to temperature or altitude.
include Escherichia coli and Shigella, while viruses or parasites might include Giardia or Entameba. Symptoms will typically include watery diarrhea, nausea, vomiting, abdominal cramps and low-grade fever. Other rare symptoms include bright red blood in the diarrhea and dehydration with resultant fatigue. Fortunately, the symptoms are often mild and self-limiting. Symptoms will resolve in 1–4 days without antibiotics, but can be shortened to 12–24 h, with antibiotics.13 Though diarrhea, nausea and vomiting are self-limited, they can be distressing and negatively affect an athlete’s performance. Aggressive hydration with oral rehydration fluids including electrolyte supplement should be instituted and are essential to recovery. Athletes experiencing symptoms for more than 2–3 days or exhibiting signs including orthostasis, tachycardia or disorientation should receive intravenous fluid. Antimicrobial medications (Table 5.4) taken at the onset of the diarrhea will shorten the duration of the symptoms. Ciprofloxacin is typically used, though for more severe cases doxycycline or norfloxacin may be used. Combining loperamide, used to decrease the number of diarrheal stools, with ciprofloxacin, may shorten the recovery time. For very mild cases, bismuth subsalicylate will help with the symptoms but must be taken up to four times a day. Finally, preventive measures include avoidance of tap water, ice cubes and salads or fruit washed in local water.
Upper respiratory tract infections Upper respiratory tract infections are often quite common. Often, athletes will present with a cough, shortness of breath
Table 5.4 Antibiotic Azithromycin Ciprofloxacin Doxycycline
Common Medications for Traveling Prophylactic Treatment Dose Dose 500 mg 100 mg
Norfloxacin Sulfamethoxazole 1DS tab + Trimethoprim Medication Bismuth 2 tabs after subsalicylate each meal and at night Loperamide
1000mg once or 500 mg daily for 3 days 500 mg once or twice a day for trip 200 mg the first day and then 100mg twice a day for 3 days 400 mg twice a day for 3 days 2DS tabs once or 1DS daily for 3 days
2 tabs every 2–4 h as needed
4 mg once, then 2 mg after each loose stool, max 16 mg per day
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and decreased performance. Associated symptoms might include wheezing, fever or chills. They may be acquired with a change in the environment with an exposure to various strains of viruses. Often, the symptoms are self limiting and treated symptomatically. However, many standard medications are banned by the governing bodies of most athletic competitions, so care is needed when choosing treatments. Antihistamines, throat lozenges and nasal sprays can be helpful. Antiviral agents are not recommended. In the case of possible bacterial infection, antibiotics may be initiated. If there is concern about cross-infection with other athletes, the infected athlete should be isolated until their symptoms have improved.
Heat-related illnesses Traveling to different regions or countries may include a significant change in temperature from the departure city. Athletes competing in areas significantly warmer and more humid than their home have the potential to experience heatrelated illnesses as heat dissipation is altered. Risk factors include lack of acclimatization, dehydration, fatigue, alcohol and caffeine use, peer pressure and overmotivation.14 A 10-year study of American high school and college athletes revealed that 10% of deaths were caused by exertional heatstroke.15 Prevention includes proper hydration and acclimation to the environment. The clinical spectrum of heat-related illnesses ranges from mild heat cramps to heatstroke. The key to successful management is prevention and early recognition of the symptoms. Heat cramps refers to brief, intermittent cramping of large muscles after physical exertion. The symptoms can become quite painful causing the athlete to stop competition. Prevention includes proper hydration and perhaps, increased dietary salts. 16 Although the etiology is unclear, treatment will include rest in a cool environment and rehydration with an electrolyte solution. For severe cramps, intravenous fluids may be warranted and diazepam may help to relax the muscle.16 Athletes presenting with heat exhaustion will typically experience fatigue and decreased athletic performance. They may note associated headaches, dizziness, nausea and irritability. Similar to heat cramps, treatment will include cessation of the athletic activity and rest in a cool environment. A variety of cooling measures have been described including the use of ice packs or ice water immersion for temperatures greater than 40˚C.17 Oral hydration with an electrolyte solution should be attempted first prior to the initiation of intravenous fluids. Intravenous fluids should be initiated if the athlete has severe vomiting and becomes hemodynamically unstable. Heatstroke is a medical emergency and requires quick treatment to prevent death. It typically occurs with high core body temperatures of 41˚C, which leads to thermal injury of tissues. However, symptoms may be experienced with lower core body temperatures. Symptoms include mental status changes (coma, convulsions and confusion) and cessation of sweating in addition to severe hyperthermia. Treatment includes immediate aggressive cooling measures (ice water submersion), intravenous fluids and emergent transport to a hospital (Table 5.5).16
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Table 5.5
Heat-Related Illnesses
Type
Temperature
Heat cramps
36–38˚C
Heat syncope
36–38˚C
Heat exhaustion
37–40˚C
Heatstroke
>40˚C
Symptoms/Signs
Plan of Care
Symptoms: brief intermittent muscle cramping Signs: palpable muscle spasm Symptoms: syncope Signs: transient loss of consciousness Symptoms: fatigue, headache, dizziness, nausea, irritability and mild disorientation Signs: hypotension, tachycardia, confusion Symptoms: fatigue, nausea, profound mental status changes, visual disturbances, vomiting Signs: hypotension, arrhythmias, possible loss of sweating, hyperventilation, confusion or coma
Treatment: Rest, stretching, oral hydration ± salts Consider: i.v. fluids and Valium for severe cases Treatment: Rest, lie athlete supine with feet raises Monitor : ABCs, monitor temperature and vital signs Treatment: rest, cool environment, oral or i.v. fluids Monitor: ABCs, monitor temperature and vital signs, Treatment: rest, cool urgently (ice baths/water immersion, i.v. fluids Transport to emergency facility
ABCs, airway, breathing, circulation; i.v., intravenous.
Cold-related illnesses Similar to heat-related illnesses, athletes competing in areas significantly colder than their home have the potential to experience cold-related illnesses. Fortunately, the majority of the time, the symptoms are mild in nature and can be managed easily. Contributing factors include poor acclimatization, improper clothing, the time of exposure to cold temperatures, concurrent use of medications, dehydration, sleep deprivation and fatigue. Symptoms will include chills, nausea, fatigue and dizziness. With hypothermia (temperature less that 35˚C), athletes may experience tachypnea, altered consciousness and incoordination.18 Treatment of mild hypothermia requires immediate removal of the athlete from the cold environment. Removal of any wet clothing and slow passive re-warming with blankets is important. Hydration is essential and warm, sweet drinks should be considered if the athlete can take fluids orally. Caffeinated drinks should be avoided. For more severe hypothermia or associated frostbite, the athlete should be transported to a hospital for further care.
Altitude Acute mountain sickness (AMS) occurs when acclimatization to altitude lags significantly behind the ascent and is basically manifestation of hypoxia. The severity will depend upon multiple factors, including the altitude attained, rate of ascent, length of altitude exposure and level of exertion.19 AMS encompasses a spectrum of illness from mild to severe (including high altitude cerebral edema, or HACE). The diagnosis of early AMS is a throbbing, bitemporal or occipital headache, typically worse at night and upon awakening. The headache is usually associated with one or more of the following: gastrointestinal upset, fatigue, weakness, dizziness, light-headedness, confusion or insomnia. Dyspnea on exertion is common for AMS, but dyspnea at rest would suggest high altitude pulmonary edema (HAPE). Physical examination is quite varied depending upon the severity of the symptoms, but pulmonary rales and lack of increase urine output is not uncommon.20 In more severe HACE, the athlete will wish to be left alone, have difficulty performing activities of daily living and eventually may slip into a coma.
Treatment is based on early diagnosis and continued monitoring of systems. Symptoms will usually improve within 24–48 h, but worsening symptoms require a descent to lower altitude. Indications for immediate descent include pulmonary edema and neurologic changes. For mild AMS, the treatment consists of halting the ascent, rest, oral hydration and analgesics (acetaminophen, aspirin or ibuprofen) are helpful. Use of acetazolamide (125–250 mg twice a day orally) can speed acclimatization.21 Studies suggest that prophylactic acetazolamide 125–250 mg taken orally twice daily started 24 h prior to ascent is effective in decreasing symptoms of AMS.22
Skin rashes Dermatologic disorders are relatively common depending upon the sport. The most common disorders are due to infectious or inflammatory conditions. The following discussion is meant as an overview and specific details should be obtained from more focused articles. Infectious causes may be fungal, viral, bacterial or parasitic sources.23 Fungal (tinea), viral (herpes simplex) and bacteria (streptococci or staphylococci impetigo) infections are quite common, especially in wrestlers, football and basketball players. Infections may occur in areas of macerated skin from sweating, including the groin or feet. Environmental factors include competition in hot and humid climates, improper cleaning, prolonged equipment use without cleaning and close skin to skin contact. Prevention is extremely important, including educating athletes about the avoidance of towel or equipment sharing, proper hygiene, use of sandals in the shower and pharmacologic medication, as appropriate. Treatment options will depend upon the source of the infection but include the use of topical or oral antifungal medication (i.e. fluconazole), oral antiviral medications (i.e. famciclovir) and antibacterial medications (i.e. dicloxacillin or cephalexin), as appropriate. Athletes may need to wait 5–7 days or until any lesions are scabbed and dry before returning to competition. Common inflammatory conditions include contact dermatitis and urticaria. Contact dermatitis may be allergic or from contact with an irritating agent. Athletes may experience
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References
allergic reactions from equipment, medications or environmental exposures (plants or chemicals on the field). Athletes especially sensitive to latex, rubber products or adhesives should take special care to avoid such products. Outdoor competitions including exposure to new plants or poison ivy should be limited as much as possible. Treatment includes the use of topical corticosteroids and the avoidance of any offending products.24 Urticaria (or hives) may occur in both hot and cold climates. The erythematous plaques often resolve over 24 h and in response to the use of antihistamines. Corticosteroid medications are typically ineffective.
Sexually transmitted diseases (STDs) For some athletes, traveling to a new location is an exciting time to experience new things. Unfortunately, athletes may exhibit some high-risk behaviors that could lead to subsequent medical issues. Unsupervised athletes may partake in excessive drug and alcohol use or high risk sexual behavior. High school and college aged athletes are at increased risk for such behavior leading to morbidity or mortality. College athletes appear to consume more alcohol compared with their non-athletic peers.25 In addition, college athletes exhibit greater risky sexual behavior, including more sexual partners and less condom use, resulting in a greater number of diseases compared with their non-athletic peers.25 Unfortunately, substance abuse may lead to unprotected sexual activity and subsequent sexually transmitted diseases. Common diseases include chlamydia, gonorrhea, syphilis or HIV. Prevention is the key to avoiding such illnesses. The team physician should speak to all athletes about substance abuse and sexual activity prior to traveling. All athletes should be counseled about the potential risks and encouraged not to have random sexual encounters. They should be advised to use condoms during any sexual activities to prevent disease and pregnancy. During the recent Olympic Games, the Athlete Village
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Central Medical Clinic supplied athletes with condoms in the hope of preventing STDs. Treatment for sexually transmitted diseases will depend upon the source of infection. Common medications include azithromycin (chlamydia), acyclovir (herpes), penicillin (syphilis) or newer medications for HIV.
RETURNING HOME Arriving home does not quite signify the end of travel responsibility for the physician. Several issues should be resolved prior to the end of the trip. Any athlete or team member who needs follow-up care should be scheduled for an evaluation prior to their final dismissal. Speaking with the coaches, trainers and/or athletes will alert the physician to any lingering issues or questions. A member of the medical staff should assess which supplies have been used and all medical supplies should be re-stocked. Finally, the members of the team should provide input into what worked well for the team and identify any protocol that should be revised to ensure future success.
CONCLUSION The responsibilities of the team physician are vast and the schedule can be demanding. For the practitioner who chooses the role of traveling team physician, the difficulties and sacrifices are offset by the gratification of working with motivated athlete-patients. Providing medical care in the competitive sports venue is a competitive market itself among sports medicine physicians. Demonstration of effective planning, appropriate knowledge of pertinent issues, and the ability to maintain rapport with the team and staff will make you a sought-after team care provider.
REFERENCES 1 2 3 4 5 6
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Brukner P, Khan K, eds. Medical care of the sporting team. In: Clinical sports medicine. New York: McGraw-Hill; 1993:654–657. Buettner CM. The team physician’s bag. Clin Sports Med 1998; 17:365–373. O’Connor P, Morgan W. Athletic performance following rapid traversal of multiple time zones. Sports Med 1990; 10:20–30. Youngstedt SD, O’Connor PJ. The influence of air travel on athletic performance. Sports Med 1999; 28(3):197–207. Atkinson G, Drust B, Reilly T, et al. The relevance of melatonin to sports medicine and science. Sports Med 2003; 33:809–831. Cardinali D, Bortman G, Liotta G, et al. A multifactorial approach employing melatonin to accelerate resynchronization of sleep–wake cycle after a 12 time-zone westerly transmeridian flight in elite soccer athletes. J Pineal Res 2002; 32:41–46. Atkinson G, Reilly T. Circadian variation in sports performance. Sports Med 1996; 21:292–312. Hill DW, Hill CM, Fields KL, et al. Effects of jet lag on factors related to sports performance. Can J Appl Physiol 1993; 18:91–103. Wright JE, Vogel JA, Sampson JB, et al. Effects of travel across time zones (jet-lag) on exercise capacity and performance. Aviat Space Environ Med 1983; 54:132–137. Jehue R, Street D, Huizenga R. Effect of time zone and game time changes on team performance: national football league. Med Sci Sports Exerc 1993; 25:127–130. Smith R, Guilleminault C, Efron B. Circadian rhythms and enhanced athletic performance in the national football league. Sleep 1997; 20:362–365. Steenland K, Deddens J. Effect of travel and rest on performance of professional basketball players. Sleep 1997; 20:366–369. Brukner P, Khan K. Traveling with a team. In: Bruckner P, Khan K, eds. Clinical sports medicine. New York: McGraw-Hill; 1993:658–665.
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Epstein Y, Moran DS, Shapiro Y, et al. Exertional heat stroke: a case series. Med Sci Sports Exerc 1999; 31:224. Camp SP Van, Bloor CM, Mueller FO, et al. Nontraumatic sports death in high school and college athletes. Med Sci Sports Exerc 1995; 27:641–647. Eichner ER. Treatment of suspected heat illness. Int J Sports Med 1998; 19:150–153. Gaffin SL, Garnder J, Finn S. Current cooling method for exertional heatstroke. Ann Intern Med 2000; 132:678. Danzl DF. Accidental hypothermia. In: Auerbach P, ed. Wilderness medicine. St Louis, MO: Mosby; 2001:135–177. Roach RC, Maes D, Sandoval D, et al. Exercise exacerbates acute mountain sickness at simulated high altitude. J Appl Physiol 2000; 88:581–585. Hackett PH, Roach RC. High-altitude medicine. In: Auerbach P, ed. Wilderness medicine. St Louis, MO: Mosby; 2001:2–43. Grissom CK, Roach RC, Sarnquist FH, et al. Acetazolamide in the treatment of acute mountain sickness: Clinical efficacy and effect on gas exchange. Ann Intern Med 1992; 116:461–465. Carlsten C, Swenson ER, Ruoss S. A dose-response study of acetazolamide for acute mountain sickness prophylaxis in vacationing tourists at 12,000 feet (3630m). High Alt Med Biol 2004; 5:33–39. Adams BB. Dermatologic disorders of the athlete. Sports Med 2002; 32:309–321. Fischer AA. Sports-related cutaneous reactions: Part II: allergic contact dermatitis to sports equipment. Cutis 1999; 63:202–204. Nattiv A. Puffer J, Green G. Lifestyle and health risks of college athletes: a multi-center study. Clin J Sports Med 1997; 7:262–272.
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6
General Medical Problems of the Athlete Julia Alleyne and Andrea Burry
ANEMIA
Box 6.1: Key Points ●
Athletes with low hemoglobin may have a high plasma volume causing a dilutional effect and treatment is not necessary.
●
Check for true anemia through diet recall, detailed gastrointestinal and geni and blood analysis as it may reduce athletic performance.
●
Iron supplementation, dietary modifications and monitoring.
Overview and incidence Anemia, or low hemoglobin, is an important consideration in sport, as iron deficiency may adversely affect athletic performance. Anemia is generally defined as a hemoglobin concentration under 14 g/dl in a man or under 12 g/dl in a woman. Anemia is classically divided into three categories; microcytic, normocytic and macrocytic, based on the size of the RBC or the MCV. All of these categories of anemia are caused by specific conditions (Table 6.1). There are some important considerations to take into account when interpreting a low Hb value in athletes. Athletes often have a lower Hb concentration than the general sedentary public and therefore, what is an ‘abnormal’ laboratory Table 6.1
Categories of Anemia
Microcytic (MCV 95 fL)
Iron deficiency Thalassemia minor Lead poisoning Sideroblastic anemia
Chronic disease Hemolysis Rapid bleeding Malignancy
Folate deficiency B12 deficiency Hypothyroidism Liver disease Malignancy Drugs
Modified from Fields 1997.2 MCV, mean corpuscular volume (red blood cell size).
value may actually be ‘normal’ for the athletic population. Also, routine laboratory blood testing does not take into account the RBC mass. If the plasma blood volume is higher (as it may be in athletes) the Hb may be diluted and read as ‘low’, when in fact the red cell mass is normal.1 The three most common causes of anemia in athletes are iron-deficiency anemia, sports anemia or pseudoanemia and footstrike hemolysis. Iron deficiency anemia is a true anemia commonly found in athletes, especially females. Iron is incorporated into the formation of hemoglobin and is important in sports performance because of its role in oxygen transport. Inadequate iron intake, absorption or excessive loss limits the amount of iron available for this and other intracellular processes.2 Iron deficiency anemia is common in non-athletic populations and is likely the most common nutritional deficiency in the western world. The issue of whether iron deficiency is more common in athletes has always been a point of controversy. Large studies have shown that iron deficiency occurs in about 20% of menstruating women and 1–6% of postmenopausal women and men.3 Some studies have shown a higher prevalence of iron deficiency in female athletes than the general population, while others have failed to show a difference when compared with proper controls.4,5 This suggests that exercise itself is not a risk factor for the condition, but athletes may be more prone to developing it. Pseudoanemia, although not a true anemia, is the most common anemia in endurance athletes. As mentioned in earlier, endurance athletes tend to have lower Hb levels than the general population despite a normal red cell mass. This is due to an expansion of plasma volume and a subsequent dilutional effect. This ‘sports anemia’ due to dilution of RBCs is referred to as pseudoanemia and is an adaptation of exercise and does not seem to inhibit athletic performance. It is not a pathologic condition and it normalizes with training cessation in 3–5 days. The Hb level in a well-conditioned athlete may be 1–1.5 g/dl lower than the laboratory quoted ‘normal’. The physician looking after athletes must be able to recognize this as a pseudoanemia and exclude iron deficiency anemia. There is no treatment for pseudoanemia other than recognizing it as distinct from other pathological anemias.
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Footstrike hemolysis refers to the bursting of RBCs in the circulation, from the impact of footfalls.1 Rowing and swimming also have been shown to have similar intravascular hemolysis and hence, such destruction of RBCs may be due to exertion as opposed to the footstrike itself.6 This hemolysis is usually mild and rarely if ever drains iron stores and causes anemia. Diagnosis can be made when one has the combination of an elevated red cell volume, reticulocytosis and a low serum haptoglobin. Treatment revolves around lessening the foot impact, i.e. wearing well-cushioned shoes, attaining and maintaining an ideal weight and running on soft surfaces. It is unknown at this point how to treat hemolysis from non-impact sports, however, since it is so mild, treatment is rarely required.
Relation to sport The underlying development of iron deficiency anemia is either due to blood loss or poor iron intake through diet. Other sources have been suggested but do not appear to contribute to a clinically apparent anemia. Iron loss in sweat accounts for a very minimal amount. Similar studies (Fields 1997) have been done investigating iron loss from urine, the GI tract or from footstrike hemolysis; none of these appear to deplete iron stores in sufficient amounts to cause anemia.2 The main culprit then seems to be dietary in nature. Athletes, especially women, involved in sports such as long-distance running, ice skaters and gymnasts, through restrictive diets, consume too little iron to meet their daily needs. Vegetarian athletes are particularly at risk because the iron in vegetables and grains is not as readily absorbed as that in red meat.
Signs and symptoms Athletes with iron deficiency anemia may be asymptomatic, while others may experience muscle weakness, palpitations or shortness of breath. They usually seek medical attention because of fatigue or decreased performance.2 A complete history should be taken to rule out significant GI or GU sources, although this is uncommon in a younger population, it may be significant in older athletes.
Investigations Laboratory investigations should include a complete blood count, serum ferritin and total iron binding capacity.3 Findings of iron deficiency anemia will include microcytic, hypochromic RBCs, a serum ferritin less than 10 µg/l and a low iron saturation. Once diagnosis is made, the etiology of the deficiency must be established. Again, one must be astute to the fact that athletes may present with ‘non-athletic’ causes of anemia, so GI or GU related causes must be ruled out.
Management Treatment of iron deficiency anemia requires iron supplementation such as ferrous sulfate or gluconate in doses of 600 mg two to three times daily. Maintenance dosing is 600 mg once daily. Absorption is best when taken between meals and with
orange juice as ascorbic acid improves iron absorption. Iron rich foods, such as lean red meats should be incorporated into the diet. With dietary changes and iron supplementation, the athletes’ Hb should return to normal within a couple of months, and relief of symptoms may occur within days to weeks. Most recommend therapy for 6–12 months to fully replenish iron stores and some may require lifelong therapy especially if the cause of the deficiency is diet related.3
Summary Iron deficiency is a common problem with special significance for athletes due to the demands of their physical lifestyle. The cause appears to be primarily dietary in nature, however, other more serious causes must be taken into account. The diagnosis can be made quite easily with relatively non-invasive means and treatment in the form of a supplement can improve symptoms within weeks.
ASTHMA Box 6.2: Key Points ●
Exercise-induced asthma (EIA) is a common condition that affects athletes but may be underdiagnosed by 30%, due to its inconsistent presentation.
●
It is often triggered by dry, cold conditions.
●
History and physical exam may not reveal abnormalities; often a trial of pharmacotherapy and/or formal challenge testing is required.
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The most effective treatment for exercise-induced asthma is a shortacting beta-agonist given within 15 min of exercise.
●
When properly treated, exercise-induced asthma does not hinder athletic performance or one’s ability to perform in intense competition.
Overview and incidence Asthma is one of the most common chronic illnesses of young people, affecting between 5 and 15% of the North American population. Asthma is characterized by reversible airway obstruction caused by bronchial smooth muscle spasm, inflammation of the endobronchiole tree or both.7 Asthma has a significant impact on lifestyle; accounting for missed work or school days and limiting physical activities. Exercise-induced asthma (EIA) or exercise-induced bronchospasm (EIB) is a type of asthma that is characterized by a transient increase in airway resistance following intense physical exercise. It can be present with chronic asthma, but, most often is a separate disease. The signs and symptoms of EIA are similar, but not identical to those of chronic asthma and many athletes often go undiagnosed as a result. There are special diagnostic tests available to aid in diagnosis and a number of new therapies available to treat EIA. With proper diagnosis and treatment, athletes with EIA should be able to participate in any level of sports competition. While chronic asthma is primarily caused by inflammation due to a hyper-responsiveness of the airways to inhaled stimulants, the mechanism of EIA is not totally understood. There
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are two current theories (Storms 2003); the hyperosmolarity theory and the airway re-warming theory.8 The hyperosmolarity theory assumes that during exercise, water is lost from the airway surface leading to a hypertonic and hyperosmolar condition in the airway cell. This causes the release of inflammatory mediators like histamine, prostaglandins and leukotrienes that eventually lead to bronchoconstriction. The airway rewarming theory states that during exercise, hyperventilation causes cooling of the surface airway cells. Subsequently, following exercise, the ‘re-warming’ causes dilatation of small bronchiolar vessels around the airway, leading to airway lining hyperemia, fluid exudation into the submucosa of the airway wall from the blood vessel, mediator release and subsequent bronchoconstriction. EIA affects up to 35% of athletes and up to 90% of chronic asthmatics.9 There have been numerous studies showing a high prevalence of EIA in recreational and elite athletes. Vacek (1997) showed that the incidence of EIA in Canadian high school athletes was 13.2% as determined by a 15% decrease in peak expiratory flow rate on a Free Running Asthma Screening Test (FRAST).10 Interestingly, almost 30% of these cases were new diagnoses; indicating that symptoms often go unnoticed by the athlete. Kukafka et al. (1998) showed similar results in American high school athletes by the same challenge test and criteria.9 The prevalence of EIA in elite athletes is similarly high (Table 6.2). In the 1996 summer Olympic Games, 16.7% of the American athletes had a diagnosis of asthma.11 The events with the highest prevalence were cycling and mountain biking; none of the weightlifters or divers had a diagnosis of EIA and this may be related to the endurance component of the sport or the re-breathing that occurs with prolonged endurance. A similar study by the same authors showed that 22.4% of the athletes on the US team at the 1998 Winter Games had a previous diagnosis of asthma or used asthma medications or both.12 Nordic, cross-country and short-track skiing had the highest prevalence of EIA by previous diagnosis or current medication use at 60.7% in contrast with only one (2.8%) of the 36 athletes who participated in bobsled, biathlon, luge, and ski jumping. The incidence was 24% in athletes who participated in alpine, longtrack, figure skating, snowboarding and curling. This data is beneficial as it is one of the first studies to chronicle the winter sports, however, there was no actual clinical challenge testing done in the field of play. Taken together, these data suggest that asthma is quite common in athletes and is more prevalent than in the general population. Athletes whose sport is performed in cold weather or dry environments have a much higher incidence of EIA comTable 6.2
pared with those whose sport is performed in warm/humid conditions.
Relationship to sport Even though the prevalence of EIA in the elite athletic population is significantly greater than that of the general population, it does not appear to hinder performance. Several well-known elite and successful athletes have EIA. In the 1984 Olympics, 67 out of 597 US athletes had EIA and they accounted for 41 medals.7 Among the individuals with EIA who performed at the 1998 Winter Games, one team gold medal, one individual silver and one individual bronze medal were won.13 When properly treated, EIA does not hinder athletic performance and intense competition.
Signs and symptoms of EIA EIA is associated with airway obstruction and a decrease in forced expiratory volume at 1s (FEV1).8 Symptoms of EIA are varied and usually begin several minutes after the start of vigorous exercise and peaks after 5–10 min and can persist for 60–90 min before ending spontaneously.14 Some athletes complain of respiratory problems: coughing, wheezing, shortness of breath and/or chest pain during of after exercise, while others may complain of fatigue, stomach/intestinal aches and/or headaches (Table 6.3).8,15 The wide variety of symptoms makes diagnosis difficult as athletes may attribute their symptoms to their own lack of conditioning and not seek medical attention.8 It is important that everyone involved with the athletic population be astutely aware of the typical and atypical symptoms of EIA so that effective treatment can be sought. A thorough history and physical exam is the first step towards making a diagnosis of EIA, although in many cases it will not reveal any abnormalities. Pertinent questions to ask concern: a history of increased symptoms with triggers such as pollen or animal dander, cold air exposure and with certain sports known to have a higher incidence of EIA such as skating and cross-country skiing; a family history of asthma and personal history of allergic rhinitis or sinusitis also increase the likelihood of EIA. A full physical exam should be done with special attention paid to an ear, nose, throat and respiratory exam to assess any signs of nasal allergies, sinusitis, otitis or wheezing. Most patients with EIA will have a normal respiratory examination in the physician’s office.8 In someone with a normal physical exam, but in whom EIA is suspected by history, spirometry should be performed in the office. This can be normal in an athlete with EIA when done at
Incidence of EIA among Elite Athletes
Sport
(%)
Cross-country skiers Ice hockey players Speed skaters Figure skaters Cross-country runners
50 35 43 35 14
Adapted from Storms 2003.8 EIA, exercise-induced asthma.
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Table 6.3
Symptoms of EIA
Typical
Atypical
Cough: during/after exercise Wheezing Shortness of breath: during/after exercise
Stomach cramps Headache Feeling ‘out of shape’
Adapted from Storms 2003.8 EIA, exercise induced asthma.
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rest. If suspicion for EIA is still sufficiently high but there are no objective physical findings, a trial of pharmacotherapy could be initiated. If the response is less than expected, then formal PFTs or challenge testing would be appropriate next steps.14
Investigations Challenge testing is important for four reasons: (1) to confirm a diagnosis of EIA, (2) to screen athletes who participate in EIA prone sports, (3) for epidemiologic studies to evaluate prevalence of EIA and (4) for proof of EIA in competitive athletes to allow them to take anti-asthmatic medications.8 As of June 2001, the IOC requires clinical proof of EIA for all competitions since the number of athletes notifying the IOC of their need to take beta-agonists has increased over the past few years. In addition to written notification, the athlete must submit a detailed report of symptoms, medical records pertaining to their diagnosis of asthma and either a positive bronchodilator test, positive exercise challenge test in lab or field, or a positive methacholine challenge test. There are several tests one can perform to prove or disprove a diagnosis of asthma. The eucapnic voluntary hyperventilation (EVH) challenge has been used to assess EIA in athletes.15 It has also been recommended by the IOC for testing Olympic athletes. It involves breathing at a pre-determined rate, 60–85% of maximal ventilation rate (MVV). The respiration rate for the challenge is estimated by assuming MVV to be 35 times FEV1. EVH challenge is administered between pre and post-spirometry using a dry-air mixture of 4.5% CO2 to ensure eucapnia while protecting against a hyperventilationinduced hypocapnia. Any decrease in FEV1 is assumed to be positive for EIA. A field exercise challenge test versus a laboratory exercise challenge test can be beneficial diagnostically, as it is conducted in conditions representing the sport-specific temperature environment and the competition venue conditions. The methacholine inhalation challenge has been used to classify the severity of a patient’s asthma, however, most agree that that it is not specific to the bronchoconstriction associated with exercise.15
Management Non-pharmacologic The first advice to give an athlete with a recent diagnosis of EIA is to advise about others types of exercise that are less likely to produce symptoms. For those already competing in an asthmaprone sport, this is not practical, but, for a recreational athlete, may be quite feasible.8 Also, an adequate warm-up, at least 10 min prior to exercise has been shown to reduce the severity of EIA. One could also try covering the mouth and nose with a scarf or balaclava during cold weather.14
Pharmacologic The most effective treatment for EIA is a short-acting betaagonist within 15 min of exercise.8 If this is not adequate then Cromolyn (or other mast cell stabilizer) can be added to the beta-agonist. Cromolyn is an anti-inflammatory agent that
works with the beta-agonist to inhibit the early bronchospastic phase of EIA by inhibiting mast cell mediator release. Inhaled corticosteroids have been shown to be useful in EIA and are safe and effective when used in the recommended dosage. Another class of inhalers that may be worth trying are the anticholinergics. If the pre-exercise therapy is not effective, then daily antiasthmatic therapy should be added on top of the pre-exercise therapy. These daily medications can be used alone or in combination and include inhaled corticosteroids, leukotriene receptor antagonists, long-acting beta-agonists and theophyllines. Athletes with chronic persistent asthma can also be treated with the same daily controller medications in addition to the pre-exercise therapy medications. Although there is no evidence to confirm that inhaled beta2 agonists enhance performance in doses required to treat EIA, a documented history of asthma as identified by the IOC Medical Commission is required for these medications to be allowed in competition. Information on banned/approved substances can be found on the WADA website (www.wada-ama.org). These lists are subject to change and these sites should be contacted regularly to ensure that there will not be any problems during the competition.
Conclusion EIA is a common and treatable condition. One first should confirm the athlete does have EIA and not chronic asthma, as the treatments are slightly different and the risk of permanent lung damage from untreated chronic asthma is significant. In making the diagnosis, a through history and physical exam including forced FEV1 should be performed. A trial of inhaled β-agonist with/without anti-inflammatory agents can be tried if the diagnosis is unclear. If there is no improvement, formal pulmonary function testing should be performed to rule out any underlying lung pathology.
DIABETES
Box 6.3: Key Points ●
Divide meal planning into the pre-competition, competition and postcompetition phases.
●
Monitor consistently for disease complications.
●
Some athletes may be restricted from participation if they have signs of vascular insufficiency or unstable glucose levels.
Diabetes mellitus is a metabolic condition that affects the pancreas leading to abnormally high blood glucose levels due to deficiency in insulin production. This breaks down carbohydrates into glucose which requires insulin to be transported for cellular activity. When the insulin is impaired, the glucose levels rise in the circulating plasma and this can be harmful to exposed tissues in the eyes, nerves, renal tissue and cardiac
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system. There are three types of diabetes: Type I (formerly known as insulin-dependent diabetes), Type II (formerly known as non-insulin dependent diabetes) and gestational diabetes, occurring during pregnancy. Treatment revolves around nutrition, exercise and medication.
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1–2 CHO serving, 1 protein serving and 1 dairy or vegetable serving. Blood glucose should be done at 15 min post-competition and again at 30 min post the second meal.
Complications of diabetes in sport Competition nutrition There are a growing number of athletes with diabetes as sport and physical activity has become linked with health and treatment. There are no actual studies at this time identifying the overall incidence but the participation in sport of athletes with diabetes is not uncommon. Athletes with diabetes must be attuned to their blood glucose levels and their diet requirements during training and competitions. This becomes easier with the experience that the athlete has with the diabetes control.
Eating before training and competition Diabetic athletes should consume a carbohydrate based meal 3–6 h before exercise with a small snack closer to the event if needed. The recommended pre-event carbohydrate intake is 1g/kg body weight within the hour before exercise (toast with jam or juice) and up to 4g/kg body weight within 3–4 h before exercise (pancakes, bread or fruit). Additional carbohydrate intake about 20 min before an event may also be required by some; crackers, muffins, yogurt are good choices.16 Type I diabetics should also ensure that their blood glucose is between 4 and 8 mmol/l. Exercising with high blood sugar will disrupt normal metabolic control and result in poor performance.
Eating during training/competition Everyone needs carbohydrate (CHO) during exercise events that last longer than 60–90 min. Ingesting CHO during prolonged activity can improve performance by maintaining blood glucose later in exercise. Non-diabetic athletes have been shown to maintain blood glucose levels and perform better when given 1 g/kg of CHO at 20 min of exercise and 0.25 g/kg every 20 min thereafter, compared with athletes not given CHO.17 Diabetic athletes are more at risk of rapid hypoglycemia and as such, CHO feedings during exercise are extremely important. A minimum of 30–60 g of CHO (in solid or liquid form) should be consumed hourly, preferably at 15–30 min intervals. Appropriate adjustments of insulin doses are also needed to allow hepatic glycogenolysis to continue, therefore reducing the risk of hypoglycemia.17
Eating post-training/competition Nutrition in the post-competition phase should be viewed as replenishment for energy used and then preparation for the next competitive session. Replenishment should be gradual with monitored glucose levels and should include moderate levels of neutral fluids like water, tea and milk. It is advised that two small meals be consumed within the first 2.5h post-competition. Meals servings should include
There are several complications of exercise in the diabetic athlete, of which the diabetic as well as training personnel and other team members should be aware. These are mainly hypoglycemia, ketoacidosis as well as the complications of the diabetes itself that may be aggravated by exercise and sport.
Hypoglycemia Hypoglycemia is a fear of most diabetic athletes. The symptoms of hypoglycemia are similar to symptoms experienced during vigorous exercise; sweating, headache and tremulousness and are often difficult to distinguish. Uncorrected hypoglycemia can lead to confusion, loss of consciousness and even convulsions. The diabetic athlete should always carry some form of easily digestible carbohydrate (glucose tablets or glucose-electrolyte solution) and should take it at the first signs of hypoglycemia.18 Prevention of hypoglycemia requires rigorous blood sugar testing before, during and after exercise so that diet and insulin dosing can be adjusted accordingly. Most diabetics will require 15–30 g of glucose per half hour of training.
Diabetic ketoacidosis Exercise is contraindicated in diabetics with poor glucose control or medical instability, as it can lead to ketoacidosis in poorly-controlled diabetics and in those who commence exercise with an insulin deficiency. Exercise increases glucose levels through the release of counter-regulatory hormones. Therefore, athletes should be well-controlled prior to commencing a vigorous exercise program. Well-known complications of diabetes include autonomic and peripheral neuropathy, retinopathy and nephropathy. Autonomic neuropathy is a potential problem during exercise because of the impaired sympathetic and parasympathetic activity which can cause abnormal heart rate and blood pressure responses. Athletes with autonomic neuropathy are at high risk for sudden death and myocardial infarction during exercise. Therefore, high intensity activity should be avoided, swimming and stationary bicycling would be better activity choices. Peripheral neuropathy also causes a problem with sports that may be traumatic to the feet, like running. Non-weight bearing alternatives are suggested. Proper footwear should be worn at all times and feet should be inspected on a regular basis. Diabetics with evidence of retinopathy should avoid sports that increase blood pressure, in fact, systolic blood pressure should not be elevated greater than 170 mmHg.16 Weightlifting and other sports that cause significant increases in blood pressure can cause retinal hemorrhage and should be avoided. Activities such as swimming, cycling and walking would be more appropriate for these individuals.
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Contraindications to participation The benefits of exercise in both Type I and Type II diabetics have been firmly established. These mainly relate to better glycemic control, improvement of cardiovascular fitness as well as social and psychological well-being. However, an exercise program is not without risk in a diabetic patient and as such, there are a few absolute contraindications to participation in competitive exercise and/or sports. Even if a diabetic individual is unable to participate in competitive sports, some degree of exercise is possible. The physician should consult the Clinical Practice Recommendations published by the ADA for advice.18
DERMATOLOGY
Box 6.4: Key Points ●
Athletes such as wrestlers are more prone to infectious skin conditions due to the increased perspiration with skin contact among competitors causing a higher incidence of infections.
●
Many athletic organizations have specific criteria regarding participation in competition and dermatological infection. Most require proof of treatment for at least 2 days prior to the event and require complete coverage of infected lesions.
Poor blood glucose control New diabetes or those who are poorly controlled should not begin an exercise program or participate in a sport until they achieve metabolic control (Berg 2001). Exercising with lack of insulin in the blood can cause hyperglycemia and ketosis during exercise. Hypoglycemia is also a consequence of exercise and may occur during or after exercise. It can be related to too much insulin, too little food, too much exercise or a combination of factors. It can take some time before an athlete is comfortable with adjusted meals and insulin so that they avoid blood sugar extremes. Only when good control is demonstrated by target HbA1c and blood glucose monitoring, should competitive training be introduced.
Participation in physical exercise can be associated with a variety of skin problems from infections, mechanical trauma and environmental exposure. The diagnosis of specific skin conditions can be both interesting and challenging for the primary care sports medicine physician and requires some familiarity with common skin conditions associated with athletics. Some problems may require a referral to a dermatologist, but most can be successfully treated by a primary care physician who is educated in common athletic skin conditions.
Bacterial infections Impetigo
Poor cardiac reserve Diabetic patients are at significantly higher risk than the general population for cardiovascular disease and silent ischemia. An exercise ECG and/or other tests of circulation and exercise capacity should be administered to patients 40 years of age and older and those who have had diabetes for 25 years or more.19 The results of these tests should aid the decision making process about whether or not competitive exercise is safe.
Impetigo is a bacterial infection caused by staphylococcus or β-hemolytic streptococcus. It begins as an erythema, but can rapidly develop into blisters and honey-colored crusted lesions.20 It most commonly occurs on the face; however, it is very contagious and can spread rapidly to any part of the body. Diagnosis: Impetigo is diagnosed on its classical clinical appearance (Fig. 6.1). Athletes involved in skin contact sports such as wrestling and rugby are at highest risk of developing impetigo.
Peripheral vascular disease (PVD) This may be an area of concern in athletes involved with sport that causes foot/lower extremity trauma. Patients with vascular insufficiency or sensory neuropathy may incur injury to their feet without their knowledge. Diabetics with PVD have a slower rate of healing and an increased risk of infection. Certain sports are more traumatic to the foot and should be avoided, these include running, basketball, martial arts and diving. 19 Diabetic athletes should inspect their feet daily for wounds or callus development.
Retinopathy Strenuous activities such as contact sports, jumping, scuba diving and weight training are not recommended for patients with retinopathy because of the risk of hemorrhage.19 Limits may also need to be set on activity in other sports in diabetics with proliferative retinopathy.
Figure 6.1 Impetigo occurs most often on the face. (Reproduced from Bacterial Infections. In: Skin Disease: Diagnosis and Treatment. Habif TP (ed). Philadelphia: Mosby Inc 2005, pp. 137; with permission of Elsevier, copyright 2005.)
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Treatment: Oral and topical antibiotics are used to treat impetigo. Most frequently used are erythromycin, cloxacillin or first generation cephalosporins. Topical treatment works best when one uses warm water soaks to remove crusts before applying mupirocin four times a day for 7–10 days.20 Prevention: Impetigo is contagious and as such, many athletic organizations have restrictions for athletic participation. Most require an athlete to have 3 or more days of antibiotics and be free of new lesions for 2 days prior to competition. All lesions must be covered during practice or competition.
anti-viral therapy shortens the duration of the disease and significantly reduces viral shedding. Relief from symptoms may be obtained by using NSAIDs, and various creams for the pruritic reaction. Prevention: HSV is highly contagious; therefore, mats and other equipment must be thoroughly and frequently washed with viricidal solutions. The infected athlete much also be removed from participation for at least 5 days or until the lesions have crusted over. As an extra precautionary measure, even crusted over lesions should be covered.
Folliculitis
Verruca vulgaris (plantar warts)
Folliculitis is an infection of the hair follicles usually caused by staphylococcus aureus or can be caused by pseudomonas when it is contracted in whirlpools and hot tubs. Diagnosis: Inflammatory changes usually occur at the base of the hair follicle and can occur clinically as macules, papules or pustules.20 Areas usually affected are the skin under protective gear, i.e. shoulder pads and in particularly sweaty areas like the trunk and under arms. Deeper infections can occur and can lead to abscess formation (furuncle and carbuncles). Treatment: Most cases do well with anti-bacterial soaps, benzoyl peroxide, topical mupirocin as well as oral tetracycline or erythromycin. Severe cases that have developed into furuncles require drainage of the abscess. Prevention: As with impetigo, most organizations require athletes with folliculitis to have at least 3 days of antibiotics and be without new lesions for at least 2 days prior to competition.
Plantar warts are caused by infection with the human papilloma virus.20 They are common and extremely annoying to the athlete. Diagnosis: They are usually diagnosed by their appearance which is a well-circumscribed, firm, slightly elevated lesion.22 They interrupt normal skin lines and when pared down, they reveal black spots; remnants of thrombosed capillaries (Fig. 6.2). Prevention: Exposure to the virus in locker rooms and showers is the route of transmission. Therefore, wearing a sandal or an aquatic shoe in these environments should reduce the risk. Treatment: The best treatment is daily application of a salicylic acid. It is best applied at night after paring the wart. It may take up to 3 months for the wart to completely resolve. More aggressive therapies, such as cryotherapy are also useful; however, this can cause painful ulceration and hence impair mobility.
Hot tub folliculitis Hot tub folliculitis is caused by Pseudomonas aeruginosa, which is commonly found in hot tubs and whirlpools. The submerged part of the body develops erythematous papules and pustules. The condition is usually selflimiting. Treatment is supportive with antipruritics and/or 5% acetic acid compresses. If the athlete presents with systemic symptoms, one can administer a course of oral ciprofloxacin.21
Viral infections Cutaneous herpes simplex Herpes simplex viral infection type I (HSV-I) is the most common viral skin infection in athletes. HSV is transmitted by skin–skin contact and is commonly seen in wrestlers and as such is often referred to as Herpes gladiatorum.22 It is spread by contact with the athlete’s active lesion or contact with infectious secretions on the mat. Diagnosis: The diagnosis of HSV is usually clinical. The typical presentation is a prodrome of symptoms including pain, itching and burning in the area of contact before an eruption of multiple vesicles on an erythematous base.20 Confirmatory tests are also available and include a Tzanck smear of the base of the vesicle or a viral culture of a new lesion.22 Treatment: Treatment should begin as soon as the individual is experiencing symptoms. Acyclovir, 400 mg p.o., t.i.d.p.i.d. for 5–7 days, is usually the treatment of choice however, other anti-viral medications may also be useful.20 Using oral
Figure 6.2 Herpes gladiatorum is characterized by grouped vesicles on an erythematous base. (Reprinted from Kirnbauer R, Lenz P , Okun MM. Human Papillomavirus. In: Bolognia JL, Jorizzo JL, Rapini RP (eds). Dermatology. Mosby: Philadelphia 2003, pp. 1222, Fig 79.8; with permission of Elsevier, copyright 2003.)
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Fungal infections Tinea pedis (athlete’s foot) This infection causes an erythematous, scaly eruption on the plantar surface of the foot as well as fissures in the skin between the toes.20 Occasionally, these areas can become secondarily infected. The most common etiologic agent is the dermatophyte Trichophyton rubrum, also T. mentagrophytes and Epidermophyton floccosum.20 Diagnosis: Diagnosis is usually made by classic clinical appearance (Fig. 6.3). The differential includes eczema, contact dermatitis and psoriasis.20 If unsure, skin scrapings on a KOH will show fungal elements in positive cases, fungal cultures can also be used. Prevention: Warm, moist conditions support fungal growth. As a result, Tenia pedis is usually from shared surfaces, such as shower or locker room floors. One can avoid infection primarily by wearing shoes or sandals in these areas and by paying attention to proper foot hygiene. Natural fiber socks may also help to prevent infection by whisking the moisture away from the skin. Treatment: Tinea pedis is best treated with a topical antibiotic cream such as clotrimazole or nystatin 2–3 times a day. In addition, the affected areas should be washed often with soap and water and kept dry during athletic activities with talcum powders.
Tinea Cruris (jock itch) Tinea cruris is a similar process to tinea pedis and is caused by the same agents. All of the same preventative strategies suggested for tenia pedis will also work here. Poor hygiene may be a factor. Diagnosis: Similar to tinea pedis, there is a sharply delineated erythematous, scaly rash in the moist folds of the groin and inner thighs sparing the scrotum and penis.20 The athlete may experience pain and pruritus. The differential includes contact dermatitis, mechanical intertrigo, candida intertrigo and erythrasma. Treatment: Topical antibiotic creams will work here as in tenia pedis. Topical low-potency steroids may be useful in combination with the anti-fungal creams to lessen pruritus. The area should also be kept dry; this can be accomplished with talcum powder or another drying agent.
Figure 6.3 Tinea pedis. Infection involving the toes and interdigital spaces. (http://www.doctorfungus.org/ imageban/images/ init_images/381mike.jpg Courtesy of www.doctorfungus.org © 2005).
Tinea corporis (ringworm) Tinea corporis is a superficial infection of non-hairy skin (face, trunk, limbs). It occurs as an erythematous scaling ring with raised borders. It is very pruritic and contagious, especially among wrestlers.20 Diagnosis: Diagnosis is usually made on clinical appearance and/or by KOH prepared skin scrapings because this is a test a team physician can do in the office (Fig. 6.4). Treatment: Again topical antibiotic creams work best as with the other tinea infections. Extensive lesions should be treated with griseofulvin, 500 mg orally twice a day. All lesions should be covered with a pas-permeable membrane before a wrestler can compete so that spread is decreased.20
Subungual hematoma Subungual hematoma is often referred to as runner’s toe or tennis toe. It is a hemorrhage in the distal nail bed that results from the toe frequently pushing on the toebox of the shoe.20 These are most common in tennis and football and other such sports that require stopping and turning (Fig. 6.5). Most are painless, however, some may cause pain as pressure builds up in the closed space.22 Properly fitting footwear can prevent this injury as can keeping toenails trimmed regularly.23 In painful cases, drainage with a needle through the nail plate can reduce the pressure and the associated tenderness.23
Calluses Calluses are hyperkeratotic lesions that develop on the hands or feet as a result of prolonged friction or pressure. Hand cal-
Figure 6.4 Tinea corporis. In classic ringworm, lesions begin as flat scaly spots that develop a raised border which extends out at variable rates in all directions. The advancing scaly border may have raised papules or vesicles. (Reprinted from Sobera JO, Elewski BE. Fungal Diseases. In: Bolognia JL, Jorizzo JL, Rapini RP (eds). Dermatology. Philadelphia: Mosby 2005, pp. 1117, Fig 77.5A, with permission of Elsevier, copyright 2005.)
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1000 and 1400 hours is also suggested, but not always possible in training athletes. If sunburn does occur, treatment should include cool compresses and analgesics. Those that experience excessive sun exposure are also at risk for premature aging of the skin and skin cancers. All athletes with this history and especially those that are fair-skinned or who have had frequent sunburns, should have regular screenings for any ominous skin changes.
GASTROINTESTINAL IRRITATION
Box 6.5: Key Points Figure 6.5 Subungual hematoma and nail bed hemorrhages in a squash player. (From Tosti A, Pazzaglia M. Occupational nail disorders. In: Scher RK and Daniel III CR, eds. Nails: diagnosis, therapy, surgery. 3rd edn. New York: Elsevier; 2005: 210; Figs 18–20.)
luses are common in sports such as weightlifting. When calluses are on the feet they are usually over a bony prominence.20 Treatment is usually not necessary unless they are associated with pain. One can pare down the thickened skin and apply a salicylic acid plaster (40%). Prevention is always best and one should ensure that footwear/equipment is fitting properly. Donut pads can be used over susceptible bony prominences.
Blisters Blisters are fluid-filled bullae that occur as a result of a disruption of the dermal–epidermal junction due to friction. The areas most affected are the heel and ball of the foot, as well as the plantar surfaces of the great toes.24 Hands can also be affected in racquet sports and weightlifting. Treatment may be required when the blister is sufficiently large. In these cases, it is best to drain the fluid using a sterile needle and leave the overlying skin intact to act as protection to the underlying, unprotected skin.23 The drained blister should be covered with an occlusive pressure dressing to facilitate healing. Hydrocolloid or hydrogel dressings such as DuoDERM or Second Skin are helpful if the skin roof is lost.22 The area should be kept clean and an antibiotic ointment such as a Polysporin may also be applied to prevent infection. The hallmark of blister treatment is prevention. This includes wearing properly fitting shoes and appropriate socks and/or gloves made of synthetic materials that whisk moisture away as well as limiting certain ‘at risk’ behaviors, i.e. increasing intensity of exercise too quickly, or running in wet shoes.
●
Dietary analysis is a critical factor in the diagnosis and management of gastrointestinal disorders.
●
The relationship between anxiety and mood changes with gastrointestinal symptoms should be considered for accurate management.
●
Dietary changes should be attempted in practice and trial situations and not as a first attempt in competition.
Overview Gastrointestinal symptoms in sport are common and usually benign in nature but can certainly have a negative effect on training, performance and optimal preparation. Common symptoms associated with exercise include nausea, heartburn, loss of appetite, abdominal cramps, diarrhea and constipation. The cause of gastrointestinal symptoms may be related to reduced blood flow to the abdominal viscera, acidic changes in the upper tract and changes in the rate of gastric emptying and intestinal motility. Assessment should always include the elimination of pathological disorders such as gastric ulcers, inflammatory bowel disease, tumor and eating disorders.
Incidence Upper gastrointestinal symptoms such as heartburn, reflux, nausea and even vomiting are more common than lower gastrointestinal symptoms such as diarrhea, constipation, rectal bleeding and abdominal cramping. In patients with established gastric reflux, 20% indicate that exercise is a contributing factor. The incidence of occult bleeding can be high in endurance athletes especially runners and this may be further increased by the frequent use of aspirin and non-steroidal anti-inflammatories (Schwartz). The common abdominal ‘stitch’ is thought to be related to spasm of the diaphragm or possibly air-trapping in the colon.
Sunburn Training for triathlons, track and field, swimming and several other sports requires prolonged sun exposure and prevention of sunburn is paramount. This can be accomplished in ways similar to that of the general population, i.e. wearing protective clothing and application of sunscreens of at least SPF 15. Agents that contain cinnamates and benzophenones or Parsol 1789 are advisable.25 Avoiding the sun between the hours of
Relationship to sport The impact of exercise on the gastrointestinal system has been inconclusive and indicates that moderate exercise is usually well-tolerated and can benefit patients with inflammatory bowel disease, however high intensity exercise inhibits gastric emptying, interferes with gastrointestinal absorption, and
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causes many gastrointestinal symptoms, most notably gastrointestinal bleeding.26 Gastrointestinal hemorrhage of the stomach is the most frequently reported site in athletes and is most commonly identified in runners. The etiology is unknown but theories include a generalized ischemia to the area, direct trauma from the diaphragm and elevated adrenalin and cortisol levels. Gastroesophageal reflux (GER) in the athlete, increases with intensity of exercise, is more common with endurance sports, and worse with postprandial exercise.27
loss through reduced iron and ferritin stores. Hemo-occult blood stool testing may be helpful but the sensitivity is low on this test and so clinical history would still dictate further investigations. Stool samples for culture and sensitivity may also be useful to identify agents such as Campylobacter, salmonella or shigella. In addition, screening for absorptive deficiencies such as lactose intolerance is often helpful in long-term management.
Management Common presenting symptoms Upper gastrointestinal symptoms may be related to gastric reflux and produce symptoms such as heartburn, chest pain and nausea. Gastric emptying rate has been linked to the onset of gastroesophageal reflux (GER) symptoms especially in the initial stages of stomach fullness. Symptoms may be related to gastric hormonal levels, meal size, dietary fibre, acidity and athlete anxiety. In addition to a dietary intake history, the athlete should be questioned on potential changes in gastric vomiting, stool color and volume and rectal bleeding. ‘Runner’s Diarrhea’ is a term that applies to the urgency to defecate while running and this appears to be related to the intensity of the exercise and potential contributing anxiety. Athletes may have to stop their activity to empty their bowels and their stool may be more watery than usual but usually the color is unaltered. Infective diarrhea may be present when sport is combined with travel however, the diarrhea persists whether the athlete is active or not and is often associated with a stool color change. A general functional inquiry should include questions related to weight loss, malaise, fever and chills. Medication review should include the use of caffeine, alcohol, tobacco, antibiotics, NSAIDs and sport drinks.
Nutritional practices are the foundation of treatment and include avoidance of fat and high protein prior to competition. In certain illness specific conditions, dietary recommendations may include reduction of acid, and an increase of iron or calcium within meal planning. Fluids should be administered in small, frequent doses and may include some carbohydrates. Fibre should be reduced if diarrhea is present. Medications should be selected and tried in a practice setting to ensure their predicted response during competition. For upper gastrointestinal symptoms, antacids can be used 30 min prior to competition and H2 receptor antagonists such as ranitidine may be required on a daily basis (Table 6.4). Motility altering drugs are helpful for symptoms related to quick emptying of the gastrointestinal tract. For the upper gastrointestinal symptoms, prokinetic agents may improve the contractility of the esophageal sphincters. The careful use of antidiarrheal agents may be helpful short-term but are not recommended for ongoing long-term use, as they can depress the central nervous system. In the case of acute distress, hydration is essential to prevent any progression of stomach or bowel ischemia. There are many causes of diarrhea, most of which are infectious. The most common causative organisms are bacteria, such as E. coli, salmonella, shigella and Campylobacter. Parasites or protozoa such as Giardia lamblia, Entamoeba histolytica, Cyclospora and cryptosporidium occur much less
Signs on physical exam The athlete should always be evaluated for sites of gastrointestinal bleeding and potential bloating and fullness. Hydration status should be evaluated including vital signs, urine color and output and skin turgor. Orthostatic blood pressure can be assessed in the supine position and then after 5 min in the standing position. A decrease in systolic pressure of 20 points or any increase in heart rate of 20 beats can be indicative of dehydration. Abdominal palpation may reveal areas of tenderness, spasm, significant pain or a mass. Auscultation of the abdomen may reveal hyperactive or hypoactive bowel sounds requiring further investigation. Lastly, it is always helpful to palpate the thyroid gland and other key lymphatic glands for enlargement.
Table 6.4 Dosages Medical Condition
Medication
Treatment Dosage
Diarrhea
Loperamide HC
4 mg initially, then 2 mg following each loose bowel movement to a maximum of 8 mg/day Two oral tablets every 1–2 h, with a maximum of 16 tablets per day 150 mg twice daily
Bismuth subsalicylate Reflux symptoms
Investigations Investigations should include imaging of the gastrointestinal tract with barium contrast radiography, endoscopy and colonoscopy as indicated. Blood work may identify slow blood
Common Medications and Treatment
Nausea and vomiting
Histamine-2 blockers such as Ranitidine Esomeprazole magnesium Dimenhydrinate
20–40 mg once daily for maximum of 4 weeks 75–150 mg every 8 h to a maximum of 375 mg/day
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Infections
Table 6.5
Foods and Drugs that can Cause Diarrhea
Foods and Drugs
Ingredient Causing Diarrhea
Apple juice, pear juice, sugar-free gum, mints Apple juice, pear juice, grapes, honey, dates, nuts, figs, soft drinks (especially fruit flavors) Table sugar Milk, ice cream, yogurt, frozen yogurt, soft cheese, chocolate Antacids containing magnesium Coffee, tea, cola drinks, some over-the-counter headache remedies Fat-free potato chips, fat-free ice cream
Hexitol, sorbitol, mannitol Fructose Sucrose Lactose Magnesium Caffeine Olestra
Compiled from: Merck manual of diagnosis and therapy, Section 3. Gastrointestinal disorders, Ch. 27 Diarrhea and constipation. Online. Available: http://www.merck.com/ mrkshared/mmanual/tables/27tb1.jsp
frequently. Cholera, a bacteria, is a very rare cause of diarrhea among travelers. Sometimes, diarrhea is not due to infection, but can be attributed to lifestyle choices in alcohol or adjustment to food preparation and spicing (Table 6.5). Diarrhea may be mild with just some cramps and a few loose bowel movements per day, or be much more severe. The most important aspect of treatment is replenishment of lost fluids. This can be accomplished with flat carbonated drinks, electrolyte mixtures or clear juices. It is important to continue eating but to reduce your food choices to easily digestible carbohydrates such as rice, bread and bananas. Medications may be used for symptomatic relief and antibiotics can be required if fever, pus or additional symptoms occur.
INFECTIONS
Box 6.6: Key Points ●
Infection prevention is a key component of performance management including environmental assessment of travel.
●
Early detection improves successful outcomes considerably.
●
Containment of infectious spread is a priority in games management.
Overview Infections in sport are a concern to athletes and healthcare professionals alike as they require immediate attention for safe care of the ill athlete and rigorous infection control for the prevention of disease spread to healthy athletes. Athletes are often in close quarters for travel, meals and sleeping and this makes infection control procedures challenging. Many factors have contributed to the rise in athlete infections including the sharing of water bottles, the severity of blood-borne infections like HIV and the increasing international travel. Injuries in sport where blood products are exposed contain potential
71
threats to the attendees and a cause for concern with Games organizers.
Incidence Infections such as Hepatitis A, B and C are more common in young people and can be associated with travel and open wound blood exposure. HIV is a worldwide concern and it has affected the sport world with awareness and concern for all athletes. The Epstein–Barr virus causing infectious mononucleosis is very common among young people, contagious and can significantly interfere with an athletes training. Upper respiratory infections are common and often occur with travel due to airplane air circulation of infections and change in weather conditions. Upper respiratory infections are common infections and include pharyngitis, sinusitis, epiglottitis, laryngotracheitis and the common cold. Viruses play a significant role in the pathogenesis of many of these infections. Bacteria and other organisms also are responsible. Some 80% of upper respiratory infections are caused by viruses and are treated symptomatically for relief. Bacterial infections are usually associated with high fever temperatures and greenish nasal or phlegm discharge. When a viral infection has become prolonged over weeks, bacterial infections are common as a secondary onset.
Relationship to sport The key factors influencing the management of infections in sport include: 1 Safe athlete participation while infected 2 Infection control for others 3 Safe return to sport after infection. Common infections in athletes include upper respiratory infections often seen in endurance athletes, skin infections identified in contact sports and water-borne infections particular to water sports.
Common presenting symptoms The presence of fever, myalgia, tachycardia, fatigue and swollen glands signal that an infection is systemic and greater precautions must be taken to curtail sport participation. Infectious mononucleosis may display symptoms of fever, sore throat, headache, loss of appetite and nausea. Splenomegaly occurs in about 50% of affected cases and this peaks in about the second or third week of infection.
Signs on physical exam Assessment should include a complete physical examination including visualization of the ears, nose and throat and palpation of the glandular chains. Vital signs including temperature, heart rate, blood pressure and respiratory rate are key to managing the symptoms. In hepatitis, identification of jaundice in the conjunctiva, palms and abdomen can assist with the diagnosis. Palpation of the liver and spleen are essential.
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In mononucleosis, the patient may have an exudative pharyngitis with swollen cervical lymph nodes and a fever. Influenza may present with generalized fatigue, muscle weakness and non-specific tenderness of the abdomen.
Investigations The investigations of an infection should include the identification of the pathogen if possible. This may require a throat swab, stool sample or blood sample for antibody identification. Further blood work may identify the immune status of the athlete and titres can determine the acuteness of the infectious contact in some cases.
Management Management of infections require a sensible approach to containment. It must be determined whether the athlete is suffering from a single system infection like a localized skin infection or a sinus infection as opposed to a generalized systemic infection such at influenza, mononucleosis or hepatitis. The next question is to determine if the athlete is febrile or afebrile. Generally, an athlete with a localized infection who is afebrile will be able to continue training to 80% of maximum and is safe to enter competition. On the other hand, if an athlete is systemically ill, then he should refrain from training and competition. Re-integration to sport must be gradual and should resume only after all symptoms have subsided and general energy and appetite have resumed.
SPORT PSYCHIATRY This is an emerging area of sport management and not identical to sport psychology. Sport psychiatry encompasses the areas of emotional wellness and mood instability that often require intrapersonal counseling, medication and long-term cognitive-behavioral changes. Common diagnoses include generalized anxiety, depression and mood instability and eating disorders. Schizophrenia, although less common, has an increased incidence of new diagnosis in the youth and young adult age groups which coincides with the average age of competitive athletes. Athletes are not immune to social issues such as substance abuse, legal implications, gambling, financial stress and physical abuse and often may be susceptible due to lifestyle chaos. Athlete screening should include awareness and openness to emotional and social dysfunction. A reasonable approach for athlete disclosure of emotional problems includes a trusting relationship with an impartial member of the sports medical organization. Disclosure may occur when the athlete is ready or it may occur during crisis. The medical team should include mental health professionals who are on-call for such situations. Prevention of crisis can be managed with open educational sessions addressing the common problems of athlete mental health and useful strategies for dealing with issues. Medication may be warranted and should first be cleared with competition doping agencies in order to choose the best possible solutions.
REFERENCES 1 2 3 4 5 6
7
8 9
10 11 12 13
Eichner ER. Hematological problems in athletes. Principles and practice of primary care sports medicine. Philadelphia, PA: Lippincott Williams & Wilkins; 2001. Fields KB. The athlete with anemia. Malden, MA: Blackwell Science; 1997. Shaskey DJ, Green GA. Sports haematology. Sports Medicine 2000; 29:27–38. Balaban EP, Cox JV, Snell P, Vaughan RH, Frenkel EP. The frequency of anemia and iron deficiency in the runner. Med Sci Sports Exerc 1989; 21:643–648. Risser WL, Lee EJ, Poindexter HB, et al. Iron deficiency in female athletes: its prevalence and impact on performance. Med Sci Sports Exerc 1988; 20:116–121. Selby GB, Eichner ER. Endurance swimming, intravascular hemolysis, anemia, and iron depletion. New perspective on athlete’s anemia. Am J Med 1986; 81:791–794. Orenstein DM. The athlete with asthma or other pulmonary disease. Principles and practice of primary care sports medicine. Philadelphia, PA: Lippincott Williams & Wilkins; 2001. Storms WW. Review of exercise-induced asthma. Med Sci Sports Exerc 2003; 35:1464–1470. Kukafka DS, Lang DM, Porter S. et al. Exercise-induced bronchospasm in high school athletes via a free running test: incidence and epidemiology. Chest 1998; 114:1613–1622. Vacek L. Incidence of exercise-induced asthma in high school population in British Columbia. Allergy Asthma Proc 1997; 18:89–91. Weiler JM, Layton T, Hunt M. Asthma in United States Olympic athletes who participated in the 1996 Summer Games. J Allergy Clin Immunol 1998; 102:722–726. Weiler JM, Ryan EJ. Asthma in United States Olympic athletes who participated in the 1998 Olympic winter games. J Allergy Clin Immunol 2000; 106:267–271. Wilber RL, Rundell KW, Szmedra L, Jenkinson DM, Im, J, Drake SD. Incidence of exercise-induced bronchospasm in Olympic winter sport athletes. Med Sci Sports Exerc 2000; 32:732–737.
14 15 16 17 18 19 20 21 22 23 24 25 26 27
Sinha T, David AK. Recognition and management of exercise-induced bronchospasm. Am Fam Physician 2003; 67:769–774. Rundell KW, Jenkinson DM. Exercise-induced bronchospasm in the elite athlete. Sports Med 2002; 32:583–600. Brukner P, Khan K. Diabetes and exercise. Clinical sports medicine. 2nd edn. New York: McGraw-Hill; 2003. Franz MJ. Nutrition, physical activity and diabetes. Alexandria, VA: American Diabetes Association; 2002. American Diabetic Association. Standards of medical care in diabetes. Diabet Care 2005; 28:S4–S36. Berg K. The athlete with Type 1 diabetes. Philadelphia, PA: Lippincott Williams & Wilkins; 2001. Lillegard WA, Butcher JD, Fields KB. Dermatologic problems in athletes. Oxford: Blackwell Science; 1997. Freiman A, Barankin B, Elpern DJ. Sports dermatology part 2: swimming and other aquatic sports. Can Med Assoc J 2004; 171:1339–1341. Ramirez AM, Van Durme DJ. Dermatology. In: Birrer RB, Griesemer BA, Cataletto MB, eds. Philadelphia, PA: Lippincott Williams & Wilkins; 2002: Freiman A, Barankin B, Elpern DJ. Sports dermatology part 1: common dermatoses. Can Med Assoc J 2004; 171:851–853. Mellion MB, Sitorius MA, Butcher JD. Medical problems in athletes. Boca Raton: CRC; 1994. Helm TN, Bergfeld WF. Sports dermatology. Philadelphia, PA: Lippincott Williams & Wilkins; 2001. Bi L, Triadafilopoulos G. Exercise and gastrointestinal function and disease: an evidencebased review of risks and benefits. Clin Gastroenterol Hepatol 2003; 1:345–355. Parmelee-Peters K, Moeller JL. Gastroesophageal reflux in athletes. Curr Sports Med Rep 2004; 3:107–111.
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7
Special Considerations in the Pediatric and Adolescent Athlete David S. Chang, Bert R. Mandelbaum and Jennifer M. Weiss
INTRODUCTION In the modern age of television and video games, America’s youth is experiencing an alarming increase in the prevalence of overweight and obesity (defined as greater than 85th percentile and 95th percentile of body mass index (BMI), respectively). Unfortunately, this phenomenon is not regionalized to the US but rather poses an international problem. Published trends in Australia, Britain, Spain, Canada and the US all demonstrate overwhelming data of overweight and obesity of epidemic proportions. In Australia, from 1985–1997, the prevalence of overweight and obesity combined doubled and that of obesity alone tripled among youths (ages 7–15 years).1 In a region of Spain, the prevalence of overweight between the years 1985 and 1995 nearly doubled among boys and girls aged 6–7 years.2 In Canada, the prevalence of boys and girls (ages 7–13 years) classified as overweight was 33% and 26%, respectively.3 In 2000, data collected from the NHANES (National Health and Nutrition Examination Surveys) demonstrated the prevalence of overweight was 15.5% among adolescents aged 12–19 years, 15.3% among children aged 6–11 years, and 10.4% among children aged 2–5 years.4 From 1988–1994, the prevalence was 10.5%, 11.3% and 7.2%, respectively. According to data presented by the US Department of Health and Human Services, in the last two decades, overweight among children and teens has doubled. In 2000, one-quarter of US children watched 4 or more hours of television daily. In 2001, only 32% of students in grades 9 through 12 participated in daily school physical education; down from 42% in 1991. At the other end of the youth activity spectrum is the ever increasing popularity of team athletics, especially soccer and basketball. The multifaceted, positive influence of team sports and routine exercise on young athletes includes physical, psychological and social benefits. However, too much of a good thing can become harmful. More commonly, today’s young athlete participates not only in school teams but also in community club teams and tournament teams, thereby creating a ‘perpetual season’ without adequate rest periods. In addition, many youth athletes participate in multiple sports with overlapping seasons, effectively subjecting their developing bodies
to year-round physical stress with no off-season to recuperate. In essence, the American youth have been polarized to those who are inactive and those who are overly active, each with their own significant health risks.
BENEFITS OF SPORTS The spirit of the Olympic Games is embraced by the phrase ‘citius, altius, fortius’, which means ‘faster, higher, stronger’. Indeed, this spirit has permeated the arena of American youth athletics with substantial benefits. With routine exercise, children gain fitness, increase strength, reduce body fat, lower cholesterol and triglycerides. Certainly, sports and exercise provide a healthy antidote to the alarming epidemic of child overweight, obesity, and type II diabetes mellitus now observed in the US and internationally.5–7 Overweight and obesity in children, as in adults, can lead to numerous, significant medical comorbidities such as arterial hypertension, left ventricular hypertrophy, hyperlipidemia, non-alcoholic-steatohepatitis, sleep apnea syndrome, as well as orthopedic, psychological and social problems. A prospective, randomized trial involving 18 high schools assessed the impact of an educational program (ATHENA – Athletes Targeting Healthy Exercise and Nutrition Alternative) on student-athletes’ health and social behavior.8 A total of 928 students from 40 high school sports teams were enrolled in the study with a mean age of 15.4 years. ATHENA involved 8 weekly 45-min sessions incorporated into a team’s usual practice activities. Curriculum content was gender-specific, peer-led and explicitly scripted. Topics included sports nutrition, effective training, negative effects of drug use and other unhealthy behaviors on sports performance, media image of females, and prevention of depression. Athletes randomized to the ATHENA program reported lower use of diet pills and athletic-enhancing substances (amphetamines, anabolic steroids, and sport supplements). They engaged in fewer incidences of high-risk social behaviors such as riding with an alcohol-consuming driver, more seat-belt use and less new sexual activity. The authors concluded that team athletics at the high school level are natural vehicles to promote an educational
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program to promote healthy lifestyles, deter negative social and athletic behaviors, and minimize other health-harming behaviors. ‘Planet Health’, another school-based educational program not necessarily catering to student-athletes, focused on decreasing television viewing, decreasing consumption of high-fat foods, increasing fruit and vegetable intake, and increasing moderate and vigorous physical activity. This program reduced the prevalence of obesity among girls in intervention schools compared with controls but no difference was detected among boys.9 Team athletics and routine exercise benefit the young athlete psychologically. Vigorous aerobic activity and structured aerobic activity in adolescents and children was found to improve cardiovascular fitness and to increase self-esteem while reducing depression.10 Naturally, body appearance has a significant impact on self-esteem and self-confidence. A study of university students revealed that for females, BMI was the strongest positive predictor of body dissatisfaction and social physique anxiety.11 In middle school children, body dissatisfaction was prevalent, especially for females.12 In addition, body dissatisfaction was negatively related to fitness levels and BMI was positively related to body image measures. The authors suggest that early intervention to decrease body dissatisfaction in this age group is necessary. Indeed, early onset of obesity increases the risk of body dissatisfaction.13 Additionally, in a cohort of females 7–16 years, a correlation was established between social physique anxiety and a negative body image and risk for developing an eating disorder.14 Youth sports and exercise participation can help curtail the negative social consequences associated with overweight and obesity. Overweight women were found to have completed fewer years of school (0.3 years less), to be less likely married (20% less likely), to possess lower household incomes (US$6710 less per year), and to have higher rates of household poverty (10% higher) than non-overweight women, independent of their base-line socioeconomic status and aptitude-test scores.15 Likewise, overweight men were less likely to be married (11% less likely). In another study, obese girls (compared with normal weight girls) were less sociable, performed less well in school, and reported more emotional problems including suicide attempts.16 Obese and underweight boys also reported some adverse social and educational issues.
RISKS Box 7.1: Key Points • Physical overtraining • Psychological ‘burn out’ • Medical considerations
The modern-day, young athlete is faced with increased training, competition, pressure to succeed, and relatively shorter periods of rest and recovery – all of which contribute to potential disastrous consequences physically, physiologically,
and psychologically. Overtraining and extended seasons with inadequate rest periods lead to overuse injuries that now plague the young athlete. Physiologically, children and adolescents are not fully mature and may have difficulty with heat mal-adaptation and dehydration. Before puberty, body size, body composition, and physiology are similar between girls and boys. Adult women have a larger surface area-tomass ratio than men and may offer them an advantage in tolerating dry heat.17 Younger athletes are more prone to heat mal-adaptation due to their immature cardiovascular systems, especially in humid and extremely warm conditions.18 Symptoms can be avoided or minimized with pre-competition carbohydrate and glycogen loading, adequate hydration (before, during and after the event) and acclimatizing the young athletes to heat.19 The young athlete is often at high risk for psychological ‘burnout’. The athletes at the greatest risk are those who compete at high intensity year round, such as swimmers, gymnasts, soccer players, and dancers. As the pressure mounts for improved performance and successful outcomes, children may no longer enjoy playing and competing in their respective sports. Injuries and pain may be feigned, preventing the child to continue to fully participate in their sport. Effective and frequent communication among the young athlete, the parents, and the coaching staff is essential to recognize early signs of ‘burnout’ and to initiate interventional strategies to help the child. Athletic performance is psychologically affected by both intrapersonal (self-motivation, cognitive capacity and coping skills, affective orientation and mental training skills) and interpersonal (social support and the athlete–coach relationship) factors.20 Finding a balance of these intrapersonal and interpersonal factors is necessary for the young athlete to restore enjoyment in competition.
MEDICAL CONSIDERATIONS Exercise-induced bronchospasm, exercise-induced bronchoconstriction, and exercise-induced asthma (EIA) are synonymous terms that describe the phenomenon of transient airflow obstruction following physical exertion.21 The symptoms of EIA include shortness of breath, cough, chest tightness and wheezing. Bronchospasms may occur around 10–15 min after the initiation of exercise, peak at around 8–15 min after the conclusion of exercise, and resolve approximately 60 min later. Exercise-induced asthma (EIA) is largely underdiagnosed in the high school athletic population and affects up to 35% of athletes and 90% of asthmatics.22–24 Although questionnaires and health histories can readily identify at-risk athletes, the true challenge lies in reliably screening young athletes for EIA. In a 1998 study, 10% of high school American football athletes reported a history of treated asthma, but an additional 9% of the remaining athletes were identified as having EIA via the ‘free running test’.25 The authors concluded that a substantial rate of EIA existed in high school athletes, especially in the urban setting, and that active screening was necessary to identify these young athletes. The free running test proves to be a relatively reliable screening tool for EIA, whereas pre-participation physicals, and self-reporting questionnaires, and peak
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expiratory flow rates (PEFRs) are less reliable.26,27 PEFRs conducted in the laboratory setting still remain an important diagnostic tool.21 Traditional asthma medications are used to suppress EIA. Physical exertion does not produce a prolonged airway reaction as with an allergic response. Short-acting β-agonists are considered the first-line therapy and protect 80–95% of affected individuals. Non-pharmacological therapy can be employed to minimize symptoms. Approximately 40–50% of athletes with EIA experience a refractory period after exercise. Breathing warm, humidified air through the nose and trachea during rest may offer protection from symptoms that last up to 3 h.28 Certainly, physical fitness and aerobic conditioning can help mitigate symptoms but does not eliminate them.21 Sudden death is a rare but tragic occurrence in young athletes with the majority (85%) being attributable to cardiac causes.29 The prevalence of sudden death in the high school and college athletic population ranges between 1 in 100 000 and 1 in 300 000 resulting in approximately 50 sudden cardiac deaths per year among athletes.29,30 In a 1996 study by Maron et al., the median age of patient dying of cardiac causes was 17 years, with a range of 12–40 years.29 Some 90% of the cases were male. White athletes comprised 52% of the cases and black athletes 44%. Basketball and American football accounted for 68% of the sudden death cases. The majority of athletes (90%) succumbed during or immediately after a training session or competition, with 63% of deaths occurring between 1500 and 2100 hours. The most common cause of cardiac sudden death in the pediatric and adolescent athletic population is hypertrophic cardiomyopathy (36%) followed by congenital coronary artery anomalies (13%).29,31 Hypertrophic cardiomyopathy (HCM) is more prevalent in black athletes (48%) compared with white athletes (26%). Pre-participation medical examinations were found to be of limited value in detecting potential cardiac anomalies, identifying only 3% of affected athletes examined with risk factors. Twelve lead electrocardiogram (ECG) studies can identify patterns left ventricular hypertrophy and inverted T-waves in the inferior and precordial leads that are consistent with the athletic, conditioned heart. If these ECG changes are found in conjunction with left ventricular septal wall hypertrophy of greater than 13 mm, a diagnosis of HCM may be appropriate.30 Hypertrophic cardiomyopathy is inherited in an autosomal-dominant pattern with variable expression. The trait results in variable expression of the cardiac sarcomere leading to the disorganized cellular architecture of the left ventricle.30 Symptoms of HCM may include chest pain, shortness of breath, lightheadedness or syncope. Often, athletes with HCM report no symptoms and the first clinical presentation may be sudden cardiac death. A careful cardiac history during the pre-participation examination may help identify athletes at risk for familial transmission of HCM. Although ECG has been found to be a much more effective screening tool than cardiac history and physical examination in detecting cardiovascular abnormalities, the cost-effectiveness of routine ECG screening of adolescent athletes has not been demonstrated.30,32
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YOUNG ATHLETE RECOMMENDATIONS Box 7.2: Key Points • Initiation of sport • Common overuse injuries • Stress fractures • Injury prevention
For the young athlete, age of initiation to sport and exercise is an important consideration. Introduction to play should be gradual with a systematic progression to the various demands of the particular sport. ‘No pain, no gain’, the philosophy of the great 1960s American football coach, Vince Lombardi, is no longer applicable in modern youth sports. Overtraining and overplaying without scheduled cyclical rest phases can only lead to injury and burnout. Today, ‘less is more’ as successful athletes emphasize quality and diversity of training, rather than quantity and duration of training. Children cannot be approached as merely smaller-sized adults. Indeed, young athletes exhibit complex physical, physiological, and psychological differences based on their age and sex. Development of the elite athlete requires a systematic process of selection and progression of increasing levels of focus and competition. Sports, fitness, and exercise are essential for children at all stages for optimal physical, physiological, and psychological development.
Overuse injuries Not surprisingly, in recent decades, the sports medicine community is witnessing greater numbers of overuse stress injuries in young athletes. Heightened awareness and improved diagnostic means have also contributed to better recognition of these entities. Overuse injuries occur when repetitive, submaximal stress is subjected to normal tissue in the absence of adequate time for healing. In growing children, the problem is compounded when bony growth outstrips soft tissue adaptation, leading to increased propensity for injury. Most commonly, injury patterns are seen at musculoskeletal tissue junctional sites such as bone-ligament, bone-tendon or tendon-muscle. Clinical examples of these common overuse syndromes in youth are Osgood–Schlatter, Sinding–Larsen–Johansson, Sever’s apophysitis, and Panner’s disease.
Stress fractures Stress fractures are defined as mechanical failures of bone caused by repetitive mechanical loading beyond the tolerance of bone. In 1885, the Prussian physician Breithaupt first described stress fractures in the feet of marching soldiers. In 1897, these fractures were characterized on roentograms by Stechow. In 1905, the military surgeon Belcher first documented the fatigue fracture of the femoral neck.33 Even well into the twentieth century, our understanding of stress fractures came largely from the military literature. In 1987, Matheson et al.
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reported on 320 stress fractures in an athletic population and found that tibial and fibular stress fractures were more commonly associated with younger athletes while femoral and tarsal stress fractures were more commonly associated with older athletes.34 Similarly, Walker et al. reviewed 34 stress fractures in 32 skeletally immature patients and found that the most common site was the tibia (47%), followed by the fibula (21%) and the femur (12%).35 Nearly all patients healed with conservative treatment and were able to return to normal activity. A review of stress fractures in collegiate athletes at one institution revealed that the tibia (37%) was the most commonly involved bone but that the foot (44%) was the most commonly involved region.36 Stress injuries were more prevalent among women (1.9%) than men (1.1%), with female distance runners exhibiting the highest incidence (6.4%).36
Prevention ‘An ounce of prevention is worth a pound of cure’.
Female athletes in the intercollegiate and adult age groups have rates of anterior cruciate ligament (ACL) tears on the order of two to eight times higher than that of male athletes. Due to the recent significant increase in team athletic participation with female athletes at the high school and collegiate ranks, a 9-fold and 5-fold higher incidence of ACL tears compared with male athletes in the same cohort was discovered, respectively.37–39 A multitude of variables explain this discrepancy including anatomical, environmental, hormonal, and biomechanical risk factors. In 2000, a study was initiated with young female soccer athletes (ages 14–18 years) in Southern California, implementing a neuromuscular training program to determine its efficacy in reducing the incidence of ACL injuries (Table 7.1). That year, 1041 players from 52 teams were trained with the Performance Enhancement injury Prevention (PEP) program developed by the Santa Monica Orthopaedic and Sports Medicine Group. An additional 1905 players from 95 teams served as the age and skill matched control group. The control group reported 32 ACL tears (1.7 injuries/player/1000 exposures) compared with the PEP group with two ACL tears (0.2 injuries/player/ 1000 exposures).40 This resulted in an overall 88% reduction in ACL tears in the PEP group compared with an age and skillmatched control group for the 200 season.40 In 2001, 844 players from 45 teams were enrolled in the PEP group while 1913 players from 112 teams served as the non-randomized, age and skill-matched control. The control group reported 35 ACL tears (1.8 injuries/player/1000 exposures) compared with the PEP group with four ACL tears (0.47 injuries/player/1000 exposures). This resulted in an overall 74% reduction in ACL tears in the PEP group compared to an age and skill-matched control group for the 2001 season (Fig. 7.1).40 Subsequently, a collaborative study between Santa Monica Orthopaedics and Sports Medicine Group and the Center for Disease Control yielded a randomized controlled trail comparing the PEP program to control in NCAA Division I women’s soccer teams. A total of 61 teams with 1394 athletes completed the study (561 PEP, 833 control). ACL injuries totaled seven in the PEP group (0.15 injuries/player/1000 exposures) compared
Table 7.1 Program
Prevent Injury and Enhance Performance
Exercise 1. Warm-up Jog line to line Shuttle run Backward running 2. Stretching Calf stretch Quadriceps stretch Hamstring stretch Inner thigh stretch Hip flexor stretch 3. Strengthening Walking lunges Russian hamstring Single-toe raises 4. Plyometrics Lateral hops Forward hops Single-legged hops Vertical jumps Scissor jumps 5. Agilities Shuttle run Diagonal run Bounding run
Distance
Repetitions/Time
50 yd 50 yd 50 yd
1 1 1
NA NA NA NA NA
2×30 s 2×30 s 2×30 s 2×30 s 2×30 s
20 yd NA NA
2 passes 30 s 30, bilaterally
2- to 6-in cone 2- to 6-in cone 2- to 6-in cone NA NA
30 s 30 s 30 s 30 s 30 s
40 yd 40 yd 45–50 yd
1 1 1
NA, not applicable.
with 19 in the control group (0.28 injuries/player/1000 exposures) (p = 0.13). ACL injuries were significantly reduced in practice exposures with no ACL injuries in the PEP group compared with seven ACL injuries in the control group (0.13 injuries/player/1000 exposures) (p150 mmHg, consider pharmacologic treatment prior to checking for fecal impaction. If fecal impaction is suspected and the elevated BP is 115 mmHg. Many patients with hypertension are overweight and should therefore be encouraged to follow a program that combines both exercise training and restricted calorie intake.22 Beta-blockers and diuretics alter thermoregulation in hot environments and may provoke hypoglycemia. Patients using these medications should be educated with regard to exercising in the heat, clothing, the role of adequate hydration and methods to prevent hypoglycemia.23,24 Vasodilators, calcium channel blockers and alpha blockers may cause hypotensive episodes on rapid cessation of exercise. A longer cool down period is therefore recommended.
Exercise training in patients with heart failure Heart failure is defined as the condition in which abnormality of myocardial function is responsible for the ventricles’ inability to deliver adequate quantities of blood to the metabolizing tissues at rest or during normal activity. The most common cause of heart failure is loss of cardiac muscle, secondary to ischemia on the basis of coronary artery disease. Viral and other cardiomyopathies are more common in younger patients. Heart failure can also occur in persons with poorly controlled blood pressure or with valvular heart disease. Of the many symptoms experienced by patients with heart failure, dyspnea, fatigue and exercise intolerance are among the most common. The first indication of heart failure is a diminished tolerance to physical exercise. Functional capacity in patients with chronic heart failure is measured in terms of the four-tiered classification of breathlessness, which is subjective and only semi-quantitative. Only recently has exercise testing become more popular for the determination of functional capacity in patients with heart failure. Factors thought to limit exercise tolerance in patients with heart failure are listed in Table 11.6.
The role of exercise rehabilitation in patients with heart failure A number of recent studies have assessed the role of exercise training in the management of patients with heart failure. Studies have varied in intensity, duration and frequency of the training stimulus; however, the majority of studies indicate
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Table 11.6 Factors Thought to Limit Exercise Tolerance in Patients with Heart Failure Cardiovascular factors Left ventricular systolic function altered Reduced cardiac output at rest and during exercise Impaired intrinsic contractility Elevated systemic vascular resistance Increased sympathetic activity Increased activity of the renin–angiotensin system Blunted peripheral arterial vasodilator response Myocardial ischemia (in some individuals) Mitral valve regurgitation (in some individuals) Altered distribution of cardiac output Altered pulmonary hemodynamics Peripheral factors Abnormalities in blood flow Endothelial dysfunction Increased vascular stiffness Thickened capillary basement membranes Increased concentrations of endothelin Skeletal muscle abnormalities Structural skeletal muscle abnormalities Metabolic skeletal muscle abnormalities Abnormal ergoreflex activation From skeletal muscle From diaphragmatic muscle Increased concentrations of tumor necrosing factor alpha Medication effects Physical de-conditioning Aging
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Interval training appears to be an effective form of cardiovascular endurance training. For example, some patients may only be able to manage an initial cycle workload of 15 W for a 20-s interval followed by a 2-min rest period. The exercise stimulus can be progressed by decreasing rest periods, increasing cycling intensity and finally increasing workload. Due to high use of beta-blockers in this patient population, both heart rate and ratings of perceived exertion should be monitored. For high risk patients, telemetry monitoring is recommended. Home-based programs may be suitable for selected stable and well-medicated, low-risk patients with heart failure. Patients should not exercise if they have uncontrolled edema, lung crackles and dyspnea, or new onset arrhythmias. Resistance training in the form of small free weights, elastic bands or circuit weight training can be prescribed in lowrisk patients.
Exercise training for patients with peripheral vascular disease Patients with peripheral vascular disease have a reduced exercise tolerance and walking distance due to calf claudication. Exercise training is an effective first line management for these patients. Indeed, patients with peripheral vascular disease have been able to increase their maximal walking distance by 122% and pain-free walking distance by 179% following exercise training and, in some instances, exercise seems to be more effective than pharmacological agents or angioplasty.32,33
Practical recommendations for exercise training in patients with peripheral vascular disease that most patients demonstrate an improvement in functional capacity, increased duration of exercise and increased peak VO2.25 Only one study to date has noted worsening of ventricular ejection fraction in patients recovering from Q-wave anterior wall infarction randomized to exercise training compared with non-exercising controls.26 Physiological adaptations seen through exercise training include improvements in catecholamine concentrations; enhanced vagal control of heart rate variability; improvement in ventilatory mechanics and diaphragmatic function; decreased perceived dyspnea; improved endothelial function, blood flow and metabolism of skeletal muscles; improvement in myocardial and coronary vessel adaptations; improved stroke volume, cardiac output and peak ventricular filling rate.27–30 To date, large-scale randomized trials evaluating exercise training effects on patient survival rates have not been conducted and the results of such studies are keenly awaited. However, most (but not all) studies evaluating the effects of regular exercise training on quality of life indices in patients with stable heart failure have shown promising results.31
Practical recommendations for exercise training in patients with heart failure ●
Use an individualized approach and be prepared to start at very low workloads after a long warm-up period.
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Interval walking and stair-climbing is the chosen mode of exercise training. Walking at an intensity that causes calf pain of a score of 3 on a 4-point scale should be undertaken with a full recovery between intervals. The initial program may start with 20 min exercise and should progress to over 30 min exercise at 50–70% of peak VO2, most days of the week. Walking and stair-climbing should be supplemented with arm cranking exercise and resistance training, 2–3 times per week. As the patients exercise tolerance improves and greater work rates are achieved, coronary artery disease may be unmasked. Thus patients should be educated as to the symptoms of coronary artery disease. Because cold weather causes peripheral vasoconstriction, the warm-up period should be extended and the exercise session conducted indoors during cold winter months. Smoking cessation programs should be advised in this patient population.
Exercise rehabilitation for patients with cerebrovascular disease Stroke continues to be the third leading cause of death in the US and a major cause of morbidity and mortality in other parts of the globe.34 Patients presenting with stroke frequently have
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atherosclerotic lesions throughout their vascular system and therefore are at increased risk of comorbid cardiovascular disease. Thus, coronary artery disease and ischemic stroke share the same group of risk factors, including hypertension, smoking, abnormal blood lipids, sedentary lifestyle, diabetes and obesity. Modification of lifestyle-related risk factors, including exercise training, plays an important role for secondary prevention of recurrent strokes. Furthermore, improved short-term survival has resulted in a growing number of stroke survivors who have some form of disability or severe de-conditioning which may be improved through carefully directed exercise rehabilitation. Rehabilitation of stroke survivors is difficult as the patient could present with hemiplegia, spasticity, aphasia, disorientation and impaired ability to perform daily functions and thus requires a specialist multidisciplinary team. While a detailed discussion of rehabilitation is beyond the scope of this chapter, the reader with an interest in this area is referred to a more detailed clinical guideline.34 Essentially, the benefits of exercise rehabilitation in stroke survivors include increased aerobic capacity and sensorimotor function, reduction in risk factors for cardiovascular and cerebrovascular disease and improved psychological function.23,35–37 Prior to exercise training, stroke survivors should undertake a medical evaluation and an exercise stress test to determine safety and effective exercise prescription. The exercise test may have to be modified according to the special needs of the patient.
The exercise prescription for patients with cerebrovascular disease The elements of the exercise prescription are similar to exercise prescription in the other forms of cardiovascular disease, with certain individualized modifications for the stroke survivor. Exercise training should include aerobic training, muscle strength and endurance, flexibility and neuromuscular (coordination and balance activities). Aerobic exercise in the form of walking, treadmill, cycling, arm ergometry or arm-leg ergometry should be performed at 40–70% of peak VO2, most days of the week for a minimum of 30 min. Strength training in the form of free weights, or circuit weight training, 1–3 sets of 10–15 repetitions, 2–3 days per week should be encouraged. Stretching and coordination and balance activities should be added during the warm-up or cool down 2–3 days per week.
Practical recommendations for exercise training in patients with cerebrovascular disease ●
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Osteoarthritis particularly of the shoulder, hip and knee is common in stroke survivors; therefore the mode of exercise might have to be modified accordingly. Stroke patients may have pre-existing peripheral vascular disease which may impair the patient’s ability to walk or cycle. Sensation and motor control of limbs may often be impaired, thus careful observation and modification of the exercise environment is necessary to avoid injury.
Risks of exercise training in cardiac patients Exercise training in cardiac patients is a relatively safe endeavor and cardiac events are rare. The average incidence of
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cardiac arrest, non-fatal myocardial infarction and death is approximately 1 for every 117 000, 220 000 and 750 000 patient hours of participation, respectively.38 The low ratio of cardiac arrest to death is thought to be due to resuscitation facilities and medical care on hand at these exercise programs.
EXERCISE REHABILITATION FOR PATIENTS WITH PULMONARY DISEASE Box 11.4: Key Points ●
Exercise training is effective in attenuating the symptoms of dyspnoea and fatigue in patients with COPD.
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Exercise training is effective in improving functional capacity and enhancing quality of life in these patients.
The goals of pulmonary rehabilitation are to reduce symptoms of dyspnea disability and improve functional capacity and quality of life in patients with lung disease.39 While a relatively small number of studies have shown exercise training to be beneficial in chronic asthma, pulmonary fibrosis, cystic fibrosis and bronchiectasis, the vast majority of available data (and indeed rehabilitation participants) are from patients with chronic obstructive pulmonary disease (COPD). COPD is the term applied to a disease that is generally a result of emphysema, chronic bronchitis or a mixture of these two pathophysiological processes. COPD is characterized by gradual, largely irreversible chronic airflow limitation, a chronic cough, overinflated lungs and impaired gaseous exchange. In the US, COPD is reported to be the fourth highest cause of death, similarly in the European Union, it is the third highest cause of mortality. COPD is regarded as a largely irreversible disease. However, treatment of patients suffering from COPD focuses primarily on improvements in, or maintenance of, functional capacity. This is in an attempt to allow continued participation in activities of daily living by these patients.
Functional capacity of patients with COPD Patients with COPD demonstrate marked exercise intolerance compared to healthy individuals, and typically present with exaggerated breathlessness, fatigue, muscle wasting and often malnutrition. The causes of impaired exercise tolerance are listed in Table 11.7. It is of interest to note that COPD affects not only the respiratory system but also has a profound effect on the cardiovascular and musculoskeletal systems and the patient’s psyche.
The effects of exercise training Whereas 20 years ago many physicians generally counseled their patients with COPD to avoid physical exertion, nearly all pulmonary rehabilitation programs today place an important emphasis on exercise training. The importance of a multidisciplinary program comprising not only exercise training but also education, smoking cessation, nutritional counseling, occupational therapy, psychology and social support should be stressed.
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Table 11.7 Postulated Causes of Impaired Exercise Tolerance in Patients with COPD Ventilatory impairments Increased airways resistance Reduced lung compliance Increased work of breathing Ventilatory muscle weakness and fatigue Ventilatory inefficiency Ventilatory failure Abnormalities of gaseous exchange Destruction on the capillary-alveolar membrane Ventilation/perfusion inequality Cardiovascular impairments Cardiovascular de-conditioning Reduced pulmonary vascular conductance Skeletal muscle impairments Peripheral muscle de-conditioning Diaphragmatic muscle abnormalities Skeletal muscle wasting and destruction Psychological alterations Chronic anxiety Depression
patients with COPD, exercise training does not appear to have a significant effect on lung function per se. Programs lasting 4–12 weeks have been shown to be effective and benefits of rehabilitation are seen up to 1 year, irrespective of attendance at a follow-up program.45,46
Practical recommendations for exercise rehabilitation in patients with COPD ●
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Evidence exists that a multidisciplinary individually designed rehabilitation program should improve a patient’s functional capacity and health status, reduce dyspnea, and have some economic advantages.40,41 In a review of exercise training studies, the vast majority showed increased exercise tolerance, reduction in hospital admission frequency, exacerbation rate and bronchodilator usage, after exercise rehabilitation programs both in the form of inpatient and outpatient programs. 41–43 The most dramatic improvements are often seen in the most severely impaired patients. A comprehensive rehabilitation practice guideline has been published by the ACCP/AACVPR.44 The physiological benefits of exercise training for patients with COPD have been well documented and are detailed in Table 11.8. It is of interest to note that many of these adaptations mentioned above which lead to increased functional capacity are in fact not due to pulmonary improvements. In fact, the diseased lung is not ‘trainable’ to the same extent as the peripheral muscles, respiratory muscles and cardiovascular system. Thus in Table 11.8 The Benefits of Exercise Training in Patients with COPD Improved ventilatory efficiency Improved tolerance of dyspnea Cardiovascular reconditioning Improved skeletal muscle strength Improved musculoskeletal flexibility Improved body composition Improved balance and proprioception Improved body image
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Patients with COPD who have significant disease severity should begin with a supervised rehabilitation program. The first step for any patient beginning an exercise program is a careful evaluation to assess cardiac risk and exercise capacity. Many patients also have some cardiac impairment, and an exercise intensity that will not induce arrhythmia, ischemia or hypoxia should be determined. Good tests of functional capacity in this group of patients include the 6-min walk test and the endurance shuttle walk.47,48 Another appropriate form of testing is to use a treadmill or stationary cycle following a protocol that starts at a very low workload and is increased extremely slowly. A pulse oximeter should be used to monitor de-saturation. We find that stationary cycling is an extremely useful mode for exercise training in patients with COPD. Other cardiovascular exercise modalities including treadmill exercise, arm ergometry, walking, or stair-climbing are also acceptable. Patients should aim to exercise at 60% of their VO2 peak or 60% of their maximal walking speed for 20–30 min, for a minimum of 3 days a week. But this goal may not be achievable for the first few months. The patient’s exercise capacity should be your guide and most patients start with 2 min cycling intervals with zero load on the ergometer, followed by 3 min rest. Patients should then progress slowly; even small increments can make a significant difference in the quality of their lives. Progression of exercise can take the form of decreasing rest intervals, increasing duration of exercise or increasing work rate.46,49 Upper and lower body strength training in the form of free or circuit weight programs are beneficial in this group of patients as skeletal muscle dysfunction may be reversed by training.50,51 Many patients can graduate to an independent exercise program after 3 months of structured rehabilitation, but some will require a longer period in the supervised program, and some may always need some supervision. Patients with COPD generally require more monitoring and active encouragement and reassurance than do patients with other chronic disease. Anxiety and discomfort associated with shortness of breath are likely to be a problem, particularly at the initiation of exercise, and in the first few sessions, patients may require a substantial amount of education and encouragement. Psychological and nutritional counseling, as well as special exercises for the diaphragmatic and other respiratory muscles are seen as important aspects of the rehabilitation program for patients with COPD.
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Pursed lip breathing exercises have not shown to be effective in clinical trials, yet individual patients might respond well to this form of training.52 Other modalities of treatment may be necessary for patients with COPD patients. Many patients who have significant COPD might require oxygen supplementation during exercise. This is particularly relevant to patients whose arterial oxygen tension falls to less than 55 mmHg or in those patients where oxyhemoglobin de-saturates to less that 88%. Most patients also require regular treatment with bronchodilators (sympathomimetic agonists), methylxanthines, glucocorticoids, mucolytics and anticholinergic agents. Increases in exercise tolerance and the patient’s functional capacity for everyday tasks can be very slow and, if measured by conventional standards might seem somewhat unimpressive, but the impact of these seemingly small strides makes a big difference in quality of life for patients with COPD. Quality of life may be assessed by the Short Form-36 or the Chronic Respiratory Questionnaire (CRQ).47,53
EXERCISE REHABILITATION IN PATIENTS WITH DIABETES MELLITUS Diabetes is one of the leading causes of death and disability with Type II diabetes accounting for up to 95% of cases.54 While exercise rehabilitation has been shown to have a positive therapeutic effect with Type I and II diabetes mellitus and other specific diabetic conditions, including the metabolic syndrome, this section of the chapter will focus on Type II diabetes.22 Type II diabetes mellitus is a metabolic disease typified by hyperglycemia. It is characterized by an insulin resistance syndrome or relative insulin deficiency, which is usually exacerbated by excess body fat. Patients with diabetes are at risk for developing sequelae of the disease, including either microvascular or macro-vascular pathology.55 These complications may include autonomic and peripheral neuropathy, retinopathy, nephropathy and accelerated atherosclerosis. Medications used in diabetes management not only include glucose-lowering agents, but may also include antihypertensives, lipid-lowering agents and pain medications. The effects of the glucose-lowering agents (oral hypoglycemic agents) on exercise testing and exercise training is important as these agents have the ability to cause hypoglycemia.
Exercise in the prevention and treatment of Type II diabetes mellitus Regular physical activity is effective in the treatment and in some cases primary prevention of diabetes mellitus. The benefits of regular physical activity in patients with Type II diabetes include decreased risk of cardiac disease, reduction in body fat, improved glucose utilization, improved insulin sensitivity, enhanced socialization and stress reduction.
Benefits of exercise training in patients with Type II diabetes mellitus ●
Decreased cardiac risk – Patients have a 2- to 4-fold increase in risk for cardiovascular disease. Contributing to this risk is
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dyslipidemia. Exercise helps to alter favorably the lipid fractions which are: typically low HDL cholesterol, elevated triglycerides and in some cases high LDL cholesterol.14,56 – Blood pressure decreases with exercise training.20–22 High insulin concentrations cause hypertrophy of the media or smooth muscle of the vascular wall, and this hypertrophy is associated with sustained hypertension, common in Type II diabetes.55 – Exercise increases insulin sensitivity (improved glucose tolerance), which may cause circulating insulin concentrations to decrease.56,57 The hypertrophic effects are then lessened, potentially decreasing blood pressure. Reduction of body fat stores – Weight loss favorably alters insulin sensitivity and may allow patients with diabetes to reduce the amount of oral hypoglycemic agents needed. Exercise coupled with moderate caloric intake is considered the most effective way to lose fat and may be most beneficial early in the progression of Type II diabetes when insulin secretion is still adequate.58,59 Improved glucose utilization – Glucose oxidation is enhanced through exercise and endogenous insulin is more effectively utilized in fitter diabetic patients.60 Improvements in glucose tolerance have been shown in the Type II diabetic patients with as little as one week of aerobic training.56 Improved glycogenic control reflected in lower glycosylated hemoglobin or fasting glucose measures, has also been documented after six to 12 weeks of an aerobic exercise program.59,61 A single exercise session has been shown to increase insulin sensitivity for 16 hours or longer.57 Enhanced fitness – Improvement in functional capacity, skeletal muscle hypertrophy and increases in VO2max occur with exercise training.3 Enhanced socialization – Exercise training and organized sports allow diabetic patients to participate in social activity, gain peer acceptance and enhanced self-esteem.57 Stress reduction – Stress can affect diabetes control adversely by increasing counter-regulatory hormones, ketones, and free fatty acids. These findings make stress reduction an important benefit of exercise training and diabetes care.62
Exercise testing and prescription in patients with Type II diabetes mellitus Exercise testing As autonomic neuropathy may be associated with silent ischemia, postural hypotension or a blunted heart rate response to exercise, the primary objective for exercise testing in patients with diabetes is to identify the presence and extent of coronary artery disease, and to determine the appropriate intensity range for aerobic exercise training. Methods of
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exercise testing may require modification of standard protocols or require the use of arm ergometry depending on the patient’s disability.
they enjoy. Thus, working with patients to find activities that are pleasant and effective will encourage compliance.
Exercise prescription
Resistance training
The exercise prescription for patients with diabetes must be individualized according to their medication schedule, presence and severity of diabetic complications, and goals and expected benefits from the exercise training program.
Choosing the appropriate mode of exercise Diabetic patients are usually sedentary and de-conditioned at initial evaluation. Patients should therefore begin exercise by increasing their everyday activity, including using stairs instead of elevators, walking a few extra meters, or doing a few more minutes of housework. Walking is an excellent form of exercise in patients with Type II diabetes due to its low impact nature. Patients should gradually increase their walking distance and then perhaps advance to other forms of aerobic exercise including swimming, running, rowing, or cycling. Exercise training should incorporate all components of a comprehensive program, including aerobic cardiorespiratory training, muscle strength, muscle endurance flexibility and core stability exercises.
Aerobic training It is strongly recommended that patients with Type II diabetes expend a minimum cumulative total of 1000 kcal/wk in aerobic activity.63 A workable goal for many patients is aerobic exercise at 40–70% of VO2max for at least 30 min nearly every day of the week. Exercise sessions should begin with a gentle 5–10 min warm-up and stretching of the muscles to be exercised, and conclude with a 5–10 min cool-down period. Thus, the exercise session may last up to 60 min. Sustained aerobic activities, such as running, cycling, swimming, and aerobic dance, rely on a mix of aerobically processed fuels, but the major sources are fats and carbohydrates (both muscle glycogen and blood glucose fuels). For exercise at higher intensities (70–85% of maximal aerobic capacity or higher), carbohydrates are the body’s fuel of choice. Blood glucose utilization can become quite significant during these activities. As more glycogen is depleted, the risk of hypoglycemia increases. Hypoglycemia can be prevented by ingestion of adequate carbohydrate during exercise and/or modification of the dosage and timing of medication prior to the exercise bout. If weight loss is a primary goal the intensity of aerobic exercise needs to be low–moderate (50% VO2max) and the duration of the aerobic bout should be incrementally increased to approximately 60 min. For prolonged exercise, including marathons, triathlons and long exercise periods, diabetic athletes must reduce their dose of oral hypoglycemic agents as increased carbohydrate intake by itself is not adequate to compensate for the accelerated glucose uptake during exercise When considering types of exercise to prescribe, patients are most likely to continue in programs that involve activities
Box 11.5: Key Points ●
Regular physical exercise is important in the prevention of diabetes.
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Exercise training is important in the management of both Type I and II diabetes mellitus and the metabolic syndrome.
Resistance training is effective in improving skeletal muscle strength and endurance, enhancing flexibility and body composition and decreasing risk factors for cardiovascular disease.6 In both non-diabetic and diabetic subjects, resistance training has resulted in improved glucose tolerance and insulin sensitivity and may have a positive effect on intraabdominal obesity.64–66 Patients with Type II diabetes mellitus should therefore incorporate strength training using light free weights or circuit stations of 8–10 different exercises using the major muscle groups, at least 2 days per week. Each exercise should consist of at lease one set of 10–15 repetitions, with the weight increased when the individual can complete 15 repetitions with ease. Increased resistance, additional sets or combinations of both of these may produce greater benefits and may be appropriate for selected patients. Caution should be used in patients with advanced retinal and cardiovascular complications. For these and older diabetic patients, more repetitions performed at a lower weight may be more suitable.
Flexibility and core stability training Flexibility and core stability training should be incorporated into the overall fitness routine for a minimum of 2–3 days per week to develop and maintain joint range of motion, minimize the potential loss of flexibility which has been hypothesized to result from glycosylation of various joint structures and reduce the chances of developing lower back pain. Stretching for 5–10 min could be done either after the aerobic warm-up or following the completion of an exercise session. This may ease the transition between rest and exercise and help prevent muscle and joint injuries.
Monitoring of exercise in patients with Type II diabetes mellitus Exercise intensity is typically prescribed and monitored using heart rate or a percentage of the maximal oxygen uptake (VO2), which can be initially established during the exercise stress test. However, some patients can develop autonomic neuropathy which can affect the cardiovascular response to exercise and in such patients, exercise intensity can also be measured by rating of perceived exertion. Blood glucose monitoring should be performed before and after physical activity to monitor the effect of the exercise on blood glucose concentration.
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Supplemental carbohydrates are generally not needed in the patients with Type II diabetes; however, if patients are prone to hypoglycemia, they may require additional carbohydrates during and following exercise. A total of 1 h of exercise will require an additional 15 g of carbohydrate either before or after exercise. If exercise is vigorous or of longer duration, an additional 15–30 g of carbohydrate per hour may be required.
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Practical guidelines regarding exercise in the patient with Type II diabetes mellitus ●
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Maintain adequate hydration before, during and after sustained exercise, particularly when exercising in the heat. Autonomic neuropathy may also disrupt thermoregulation in patients with Type II diabetes mellitus. Thus, it is important to avoid exercising in extreme heat and cold. Alcohol is a powerful inhibitor of gluconeogenesis, and the effects on hypoglycemia can persist 20 h after consumption. Patients with Type II diabetes mellitus should be advised not to drink alcohol at night if they plan to exercise the following morning. The pre-participation evaluation is a good time to ensure that patients with Type II diabetes mellitus select appropriate fitting shoes for exercise. Socks also should fit well and be made from material that absorbs moisture to keep the feet dry. When exercising, patients should wear a diabetes identification shoe tag or bracelet in such a way that it is clearly visible. Symptoms of dizziness, weakness, or shortness of breath should alert the physician to the possibility of cardiac disease. Such patients should undertake an exercise stress test and have monitored exercise sessions. Orthostatic hypotension is common in patients with autonomic dysfunction after upright exercise, thus cycling or swimming is more appropriate than running or brisk walking. Diabetic patients with retinopathy should be wary of high intensity activities that precipitate hemorrhage or retinal detachment. This warning applies particularly to activities that cause sudden increases in blood pressure, including weightlifting or sprinting. Non-weight-bearing activities or specially modified footwear should be considered for patients with peripheral neuropathy, so as to reduce trauma to the lower legs and feet. Patients with nephropathy should avoid strenuous activities which cause the systolic blood pressure to be increased above 200 mmHg. A low level program which does not increase the systolic blood pressure 20–30 mmHg above baseline should be prescribed for patients with Type II diabetes mellitus who have advanced retinopathy.
Precautions for exercising patients with Type II diabetes mellitus ●
Measure blood glucose concentrations before, during and after exercise training. Blood glucose monitoring is an essential part of participating in exercise for the patient with Type II diabetes mellitus, particularly in the beginning stages of exercise. This approach has been shown to be effective particularly for diabetic athletes who engage in strenuous
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endurance exercise. According to the American Diabetes Association, patients should avoid exercise if blood glucose concentrations exceed 300 mg/dl (or 250 mg/dl with ketosis), and should ingest a carbohydrate snack before exercise if blood glucose concentrations fall below 100 mg/dl. Hypoglycemic reactions to exercise in patients with Type II diabetes mellitus are rare and mostly limited to those patients on oral sulphonylurea agents and/or insulin and occur mostly following very intense or prolonged exercise. Therefore, in most cases, there is no need for supplementary food intake before or after exercise unless the patient is undertaking extremes of physical activity. To avoid the occurrence of low blood sugar in some Type II diabetes patients the following advice may be beneficial: – Avoid exercise during periods of peak insulin activity. Meal timing is important. Exercise should be scheduled one to two hours after a meal, or exercise should be undertaken when circulating insulin concentrations are lower. Morning exercise usually produces a lower hypoglycemic effect than the same exercise done later in the day. This results from the effects of higher circulating cortisol other glucose-raising hormone concentrations early in the day (i.e. insulin resistance is generally greater in the morning), along with lower circulating concentrations of insulin. Conversely, evening exercise conveys the greatest risk for nocturnal hypoglycemia unless the patient makes changes to food intake or doses of medications. Unplanned prolonged exercise should be preceded by extra carbohydrates, e.g. 20–30 g of carbohydrates (CHO)/30 min of exercise. If exercise is planned, medication dosages may be decreased before and after exercise, according to the exercise intensity duration as well as the personal experience of the patient. During prolonged exercise, easily absorbable carbohydrates (6–8% as opposed to 13–14%) should be consumed, and after exercise, an extra carbohydrate-rich snack may be necessary. It is advisable to educate the diabetic patient to become knowledgeable of the signs and symptoms of hypoglycemia and always exercise with a partner.
THE EDUCATION COMPONENT OF CHRONIC DISEASE REHABILITATION PROGRAM Regardless of the nature of the primary ailment that leads the patient to be referred to the rehabilitation program, it has been shown that patient education remains one of the most important aspects of the program. The components of the educational program presented to our patients are outlined in Table 11.9. The content is non-disease-entity-specific and can be customized for any chronic disease.
CONCLUSIONS Exercise rehabilitation has become an accepted and integral part of the management of patients with chronic disease.
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Table 11.9 Lecture or Note Outlines for Education of Patients with Chronic Disease 1 2 3 4 5 6 7 8 9 10 11 12
Anatomy and physiology of the affected organ system Basic pathology and pathophysiology of the affected organ system Understand the symptoms Common pharmacological and non-pharmacological therapies Benefits of exercise training in prevention and management of the chronic disease Nutritional advice for optimal management of the chronic disease Strategies for anxiety and stress management Coping with setbacks Identifying and challenging belief systems about disease- and healthrelated behavior Goal setting, rewards and relaxation Loving relationships and sexuality Exercise and nutritional options while traveling
While the exercise training component forms the mainstay of chronic disease rehabilitation, programs should have a holistic approach and include nutritional, psychology and lifestyle
counseling. Patient and spouse counseling and education forms an important part of the rehabilitation program. While a comprehensive review of all the chronic diseases where exercise plays an important role in patient management is beyond the scope of this chapter, it is evident that more research is needed in certain areas, for example, the neurological conditions and the immunological/hematological disorders, where small patient numbers have prevented clear patient guidelines from being formulated. Nevertheless, the number of Position Statements and publications in this important area continues to grow rapidly. With the growing evidence that exercise is an effective form of management for a wide range of different pathologies and medical conditions; and that medication dosages may often be reduced in exercising patients, there is an urgent need by the health insurance industry to quantify the cost savings which could be achieved through participation in regular exercise rehabilitation. There is no doubt that this important aspect of Sports Medicine will continue to flourish as more data become available regarding novel mechanisms of action of exercise training and as these findings are applied to a wider number of patients and chronic disease entities.
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CHAPTER
12
Pre-Participation Evaluation Thomas D. Rizzo, Jr
INTRODUCTION
Box 12.1: Key Points
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The pre-participation evaluation is a traditional component of athletic clearance before the beginning of the sports season.
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Standardized aspects of history taking and physical examination identify conditions that may make participation dangerous.
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Involvement of the team physician in the organizational process can build rapport with the athlete and coaching staff and ensure adequate time for rehabilitation or evaluation of any abnormalities.
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Questionable findings in the athlete’s history or physical assessment should be addressed more thoroughly outside the screening process.
At the heart of the pre-participation examination is the goal of making athletic participation safe for the athlete. Athletic participation is desirable, but by its nature, it is physically demanding, stressful to the cardiovascular and musculoskeletal systems and potentially injurious. These risks are amplified in poorly prepared individuals and those with pre-existing, hidden disorders. In young people, their relative health and lack of medical history put them at risk for a severe condition manifesting through the rigors of athletic competition. Such an event can have devastating consequences. There have been well-publicized instances of seemingly healthy athletes dying without warning. Many of these people were participating at an elite level and, presumably, had been evaluated and tested, formally and through the demands of their sport, without a hint of a health defect. Some of their deaths were due to a cardiac disorder, and, even though this is the most common cause of sudden death in the athlete, it is the hardest to detect on screening physical examination. This chapter evaluates the mechanics of the pre-participation evaluation: why it is done, how it is done, what to look for and what to do once you find it.
WHY THE EXAMINATION IS DONE In well-intentioned attempts to improve the health of athletes, pre-participation evaluations have become required, and the ‘cattle call’ of mass screening is a part of the preseason ritual. The American College of Sports Medicine has tried to help this process through position statements and guidelines for participation. The third edition of the pre-participation evaluation was published in 2005 through the joint efforts of the American Academy of Family Physicians, American Academy of Pediatrics, American College of Sports Medicine, American Medical Society for Sports Medicine, American Orthopedic Society for Sports Medicine, and the American Osteopathic Academy of Sports Medicine. It addresses the appropriate aspects of the history and physical examination for athletes of high-school or college age and those with special needs.1 The goals of the pre-participation evaluation are as follows: 1 To gather baseline data for future reference2,3 2 To detect manageable medical conditions that may interfere with sports participation2,3 3 To determine whether there are contraindications to participation2,3 4 To discover predispositions to injury, including previous athletic injuries from inappropriate conditioning programs2,3 5 To assess an athlete’s current fitness level to help prevent injuries from inappropriate conditioning programs2,3 6 To fulfill legal and insurance requirements2,3 7 To provide an opportunity for health education3 8 To establish a doctor–patient relationship with the athlete, identifying the physician and training staff as part of the athletic team 9 To provide an opportunity for training programs to educate residents, student therapists, and medical students about aspects of the physical examination in healthy individuals.
Gather baseline data for future reference One challenge for any rehabilitation team is knowing when an athlete is able to return to play. In a sports-specific evaluation, detailed testing can be done to establish a baseline level of
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objective performance. The training staff thus knows an athlete’s pre-injury condition and will know when the injured athlete is approaching the pre-injury state. Grip strength test, single-leghop test, specific speed tests (e.g. the 40-yard dash) and strength tests (e.g. the bench press) have all been used. Their predictive value in determining sports performance is questionable, but they are reproducible and a functional screen of specific skills. Similar injuries are rarely clustered on the same team. Maintaining data on injuries and sharing this information across teams in a league or on a nationwide basis may identify training errors or dangerous practices and lead to rule changes to make sports safer.
Detect manageable medical conditions that may interfere with sports participation The cyclic nature of sports allows athletes to move from one activity to another during a calendar year. This change allows injured areas time to heal and become less painful. Unfortunately, this process is not the same as rehabilitation. Once an injury is asymptomatic, the athlete needs to regain flexibility and strength before resuming the dynamic components of a particular sport. An injured athlete who does not have rehabilitation may not have symptoms during the off season or while participating in another sport. Re-injury from season to season may actually be incomplete rehabilitation. Sufficient time for rehabilitation dictates that the screening evaluation should occur well in advance of the onset of the sports season. Of course, ideally, injuries are identified and rehabilitation occurs soon after. Changes in schools, uncertainties about participation in the upcoming year and various external factors make the reality less than ideal. The pre-participation evaluation should occur at least 6 weeks before pre-season practices. For some programs, this means that the evaluation should occur at the end of the school year, before the summer break.
Determine whether there are contraindications to participation The key to the pre-participation evaluation is the athlete’s medical history. Abnormal findings on physical examination may be subtle or related to vision, neuromusculoskeletal disorders, or cardiac concerns. Athletes are as likely to give a worrisome history (e.g. presyncope, syncope, exertional palpitations) as have physical abnormalities (e.g. hypertension, new murmur).4 A typical pre-participation evaluation does not include objective testing beyond the physical examination to identify dangerous conditions: dilated cardiomyopathy, hypertrophic cardiomyopathy, neck instability, seizure disorders. Screening for these conditions is prohibitively expensive, and false-positive results add needless expense and anxiety to the process. The nature of athletics, and childhood in general, can serve as a test of an individual’s physiognomy. In an unstructured setting, a child or individual serves as his or her own regulator or monitor of exertion. It is not until there are external forces (coaches, peers or parents) that an individual is stressed to an extreme degree and puts himself or herself at risk. Obtaining an accurate and detailed history from the athlete and his or her
parents can help identify risks and identify individuals in need of more detailed testing.
Discover predispositions to injury, including previous athletic injuries from inappropriate conditioning programs Existing or ‘leftover’ injuries are a logistical problem that can be addressed with proper planning and timing, but not knowing is dangerous to the athlete. The athlete’s medical history is essential (Table 12.1). A family history of sudden death, shortness of breath, and syncope or presyncope (dizziness) should prompt a more thorough evaluation of the cardiac system. Other conditions that are not as dangerous may be problematic in certain sports. Hyperflexibility may seem to be advantageous for some sports (e.g. gymnastics) but may lead to pain and joint problems if the athlete has not developed the muscle to compensate for ligamentous incompetence.
Assess an athlete’s current fitness level to help prevent injuries from inappropriate conditioning programs The typical screening evaluation does little to directly assess cardiovascular fitness. The athlete’s history gives some indication of ability to participate fully. The physical assessment suggests a level of fitness: resting pulse, blood pressure and body weight all may raise concerns about the athlete’s level of fitness, although they are not direct measures of that fitness. Worrisome findings on the history or physical assessment should prompt referral and more in-depth evaluation by the athlete’s primary care physician or a specialist.
Fulfill legal and insurance requirements The frequency of pre-participation evaluations varies from state to state.5 Many states require a physician’s evaluation before the school year in anticipation of physical education class. Sport-specific evaluations may be required to identify sportsspecific conditions or injuries peculiar to a particular activity.
Provide an opportunity for health education In addition to screening for injuries and disqualifying conditions, the physician may have the opportunity to provide some counseling for the athlete. Unfortunately, the pre-participation evaluation has taken the place of the annual physical examination for some children. Athletes and their parents are not always aware that the pre-participation evaluation is a screening examination and not a comprehensive adolescent general medical examination. In some communities, the local primary care physician provides the pre-participation evaluation, an arrangement that can build on the rapport and trust between the physician and patient. Risk-assessment counseling and counseling regarding nutrition and skin care, including protection from sun exposure, can be a set part of the evaluation process or can occur informally during downtime or waiting periods between testing stations.
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Why the examination is done
Table 12.1
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Components of the History Taking in Pre-Participation Evaluations
History
Injury history Performance-enhancing supplements Pulmonary, allergies and asthma
Cardiac and pulmonary
Integument Neurologic
Metabolic Eyes Musculoskeletal
Eating disorders Psychologic Public health Gynecologic (females only)a
Have you had a medical illness or injury since your last check-up or sports physical? Do you have an ongoing or chronic illness? Have you ever been hospitalized overnight? Have you ever had surgery? Do you use any special protective or corrective equipment or devices that are not usually used for your sport or position (e.g. knee brace, special neck roll, foot orthotics, retainer on your teeth, hearing aid)? Are you currently taking any prescription or non-prescription (over-the-counter) medications or pills or using an inhaler? Have you ever taken any supplements or vitamins to help you gain or lose weight or improve your performance? Do you cough, wheeze, or have trouble breathing during or after activity? Do you have asthma? Do you have seasonal allergies that require medical treatment? Do you have any allergies (e.g. to pollen, medicine, food or stinging insects)? Have you ever had a rash or hives develop during or after exercise? Have you ever passed out during or after exercise? Have you ever been dizzy during or after exercise? Have you ever had chest pain during or after exercise? Do you get tired more quickly than your peers do during exercise? Have you ever had racing of your heart or skipped heartbeats? Have you had high blood pressure or high cholesterol? Have you ever been told you have a heart murmur? Has a family member or relative died of heart problems or of sudden death before the age of 50? Have you had a severe viral infection (e.g. myocarditis or mononucleosis) within the last month? Has a physician ever denied or restricted your participation in sports for any heart problems? Do you have any current skin problems (e.g. itching, rashes, acne, warts, fungus, or blisters)? Have you ever had a head injury or concussion? Have you ever been knocked out, become unconscious, or lost your memory? Have you ever had a seizure? Do you have frequent or severe headaches? Have you ever had numbness or tingling in your arms, hands, legs, or feet? Have you ever had a stinger, burner, or pinched nerve? Have you ever become ill from exercising in the heat? Have you had any problems with your eyes or vision? Do you wear glasses, contacts, or protective eyewear? Have you ever had a sprain, strain, or swelling after injury? Have you broken or fractured any bones or dislocated any joints? Have you had any problems with pain or swelling in muscles, tendons, bones, or joints? Do you want to weigh more or less than you do now?a Do you lose weight regularly to meet weight requirements for your sport? Do you feel stressed out? Record the dates of your most recent immunizations (shots) for tetanus, hepatitis B, measles, chickenpox When was your first menstrual period? When was your most recent menstrual period? How much time do you usually have from the start of one period to the start of another? How many periods have you had in the past year? What was the longest time between periods in the last year?
Note: Various screening forms are available. The one endorsed by the major sports medicine groups is shown in Figure 12.1. Alternative questions are listed above. a These questions also help to screen for persons at risk for the female athlete triad of amenorrhea, disordered eating and osteoporosis.
Establish a doctor–patient relationship with the athlete, identifying the physician and training staff as part of the athletic team Other benefits of the pre-participation evaluation include establishing a relationship between the physician and athlete. This interaction is often strained and is related to the athlete’s interaction with the physician in stressful and adversarial
circumstances. If the athlete sees the physician only when an injury occurs and then only to hear bad news, the physician is unlikely to be regarded as a resource. The athletic trainers can be a valuable extension of the physician because they often have a better rapport with the athlete as a result of routine interaction. Subtle changes in condition can be discerned by the training staff and conveyed to the physician for further
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assessment. The pre-participation evaluation allows the team physician to participate with the team during a positive time of the year.
Provide an opportunity for training programs to educate residents, student therapists and medical students about aspects of the physical examination in healthy individuals Another, less-often discussed benefit of the pre-participation evaluation is to the examiners. Rarely do physicians have the opportunity to see a range of healthy individuals in one place. Familiarity with normal examination findings makes any variation all the more obvious. The physician, the athlete, the parents and the school should not expect too much from the evaluation. In essence, it is a screening method to identify athletes at risk for further or potential injury. It will not prevent injuries in healthy, asymptomatic individuals. It may not be the best setting for education and so may be only an opportunity to introduce certain topics.
COMPONENTS OF THE EVALUATION Box 12.2: Key Points There are different ways to complete the pre-participation evaluation, but basic components of the history and the physical examination should be included to identify athletes at risk for injury.
There are two basic approaches to the pre-participation evaluation. The first approach, the single-examiner system, is a focused general medical examination that includes all the components that need to be addressed before participation in the upcoming season. The history needs to consider the intense and risky nature of athletics. The history should identify clues that the individual could be at risk by participating. Single-examiner evaluations may be efficient and are valuable for promoting interaction with the primary care physician. Unfortunately, that format does not compensate for any diagnostic weaknesses of the examiner. A variation of the single-examiner method includes several examiners who do a complete examination on
Table 12.2
a portion of the athletes being screened. This has the same limitations as the typical single-examiner examination, but it may be an efficient option when there are multiple examiners in similar specialties and space does not allow numerous stations.4 The second approach, the station approach, includes multiple examiners at multiple spots in a common area (office suite, gymnasium, locker room). It has the advantage of allowing specialists to focus on their area of expertise. This approach adds efficiency and is a great service to the athlete. The subsequent description of the evaluation is based on the station approach and assumes that the physicians involved are either specialists who may be required to do screening in an area outside their specialty (e.g. a physiatrist listening to a murmur or discerning an arrhythmia) or generalists who are not an athlete’s primary care physician. In these instances, the physician needs to understand what findings are disqualifying and what findings warrant further evaluation. In many instances, the worrisome finding is negative on review by a specialist or a physician who knows the patient. In others, the finding may be normal for a particular patient (e.g. hyperflexibility). It is inappropriate for the screening physician to make the decision to disqualify a player when he or she is not comfortable doing so. It is probably best to refer the athlete for further evaluation by a specialist. This possibility is another reason to schedule the pre-participation evaluation with enough lead time to allow assessment of worrisome findings. Table 12.2 provides one option for the station approach to the pre-participation examination. Ideally, the athlete and his or her parents complete the pre-participation evaluation history and physical examination forms (Figs 12.1, 12.2) before arriving at the assessment site. Non-physician staff can perform the initial assessment and ensure that the paperwork is complete; the heart, lung and visceral examination needs to be done by a physician. The musculoskeletal examination could be done by a skilled physical therapist but the results should be confirmed by a physician. The order of the physical examination stations can vary. However, review of the findings at each of the stations and clearance to play should come from the lead or supervising physician at the last station. In some programs, there may be a preponderance of physicians. In those instances, it is reasonable to have physicians obtain vital signs and clarify the history. They can rotate into the evaluation stations as the athletes progress to other stations. It is important that the
Example of the Station Approach to Pre-Participation Evaluation
Station
Activity
Suggested No. of Staff
1 2 3 4 5 6
Paperwork, height, weight Vision screening Blood pressure HEENT, cardiopulmonary, skin, genitalia/hernia (males) Neuromusculoskeletal Review, disposition/follow-up, dietary, psychosocial counseling
2 1 1 2 physicians 2 physicians 2 physicians
HEENT, head, eyes, ears, nose, throat. (From: Smith and Laskowski,4 with permission.)
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HISTORY FORM
DATE OF EXAM Sex
Name School Grade Address Personal physician In case of emergency, contact Name
Age
Date of Birth
Sports Phone
Relationship
Phone (H)
(W)
Explain “Yes” answers below. Circle questions you don’t know the answers to. Yes No
Yes No 24. Do you cough, wheeze, or have difficulty breathing during or after exercise? 25. Is there anyone in your family who has asthma? 26. Have you ever used an inhaler or taken asthma medicine? 27. Were you born without or are you missing a kidney, an eye, a testicle, or any other organ? 28. Have you had infectious mononucleosis (mono) within the last month? 29. Do you have any rashes, pressure sores or other skin problems? 30. Have you had a herpes skin infection? 31. Have you ever had a head injury or concussion? 32. Have you been hit in the head and been confused or lost your memory? 33. Have you ever had a seizure? 34. Do you have headaches with exercise? 35. Have you ever had numbness, tingling or weakness in your arms or legs after being hit or falling? 36. Have you ever been unable to move your arms or legs after being hit or falling? 37. When exercising in the heat, do you have severe muscle cramps or become ill? 38. Has a doctor told you that you or someone in your family has sickle cell trait or sickle cell disease? 39. Have you had any problems with your eyes or vision? 40. Do you wear glasses or contact lenses? 41. Do you wear protective eyewear, such as goggles or a face shield? 42. Are you happy with your weight? 43. Are you trying to gain or lose weight? 44. Has anyone recommended you change your weight or eating habits? 45. Do you limit or carefully control what you eat? 46. Do you have any concerns that you would like to discuss with a doctor? FEMALES ONLY 47. Have you ever had a menstrual period?
1. Has a doctor ever denied or restricted your participation in sports for any reason? 2. Do you have any ongoing medical condition (like diabetes or asthma)? 3. Are you currently taking any prescription or non-prescription (over-the-counter) medicines or pills? 4. Do you have allergies to medicine, pollens, foods or stinging insects? 5. Have you ever passed out or nearly passed out DURING exercise? 6. Have you ever passed out or nearly passed out AFTER exercise? 7. Have you ever had discomfort, pain or pressure in your chest during exercise? 8. Does your heart race or skip beats during exercise? 9. Has your doctor ever told you that you have (check all that apply): High blood pressure A heart murmur High cholesterol A heart infection 10. Has a doctor ever ordered a test for your heart? (for example, ECG, echocardiogram) 11. Has anyone in your family died for no apparent reason? 12. Does anyone in your family have a heart problem? 13. Has any family member or relative died of heart problems or of sudden death before age 50? 14. Does anyone in your family have Marfan syndrome? 15. Have you ever spent the night in a hospital? 16. Have you ever had surgery? 17. Have you ever had an injury, like a sprain, muscle or ligament tear, or tendonitis, that caused you to miss a practice or game? If yes, circle the affected area below: 18. Have you had any broken or fractured or dislocated joints? If yes, circle below: 19. Have you had a bone or joint injury that required x-rays, MRI, CT, surgery, injections, rehabilitation, physical therapy, a brace, a cast, or crutches? If yes, circle below: Head
Neck
Shoulder
Upper arm
Elbow
Forearm
Hand/ fingers
Chest
Upper back
Lower back
Hip
Thigh
Knee
Calf/ shin
Ankle
Foot/ toes
48. How old were you when you had your first menstrual period? 49. How many periods have you had in the last 12 months? Explain “yes” answers here:
20. Have you ever had a stress fracture? 21. Have you been told that you have or have you had an x-ray for atlantoaxial (neck) instability? 22. Do you regularly use a brace or assistive device? 23. Has a doctor ever told you that you have asthma or allergies?
I hereby state, to the best of my knowledge, my answers to the above questions are complete and correct. Signature of athlete
Signature of parent/guardian
Date
Figure 12.1 History form used for pre-participation evaluation. (With permission from American Academy of Family Physicians, American Academy of Pediatrics, American College of Sports Medicine.1)
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PHYSICAL EXAMINATION FORM Date of Birth
Name Height
Weight
Vision R20/
% Body fat (optional)
L20/
Corrected: Y
N
Pulse Pupils: Equal
BP
/
(
/
,
/
)
Unequal
Follow-up questions on more sensitive issues
Yes No
1. Do you feel stressed out or under a lot of pressure? 2. Do you ever feel so sad or hopeless that you stop doing some of your usual activities for more than a few days? 3. Do you feel safe? 4. Have you ever tried cigarette smoking, even 1 or 2 puffs? Do you currently smoke? 5. During the past 30 days, did you use chewing tobacco, snuff, or dip? 6. During the past 30 days, have you had at least 1 drink of alcohol? 7. Have you ever taken steroid pills or shots without a doctor’s prescription? 8. Have you ever taken any supplements to help you gain or lose weight or improve your performance? 9. Questions from the Youth Risk Behavior Survey (http://www.cdc.gov/Health Youth/yrbs/index.htm) on guns, seatbelts, unprotected sex, domestic violence, drugs, etc. Notes:
NORMAL
ABNORMAL FINDINGS
INITIALS*
MEDICAL Appearance Eyes/ears/nose/throat Hearing Lymph nodes Heart Murmurs Pulses Lungs Abdomen Genitourinary (males only)** Skin MUSCULOSKELETAL Neck Back Shoulder/arm Elbow/forearm Wrist/hand/fingers Hip/thigh Knee Leg/ankle Foot/toes * Multiple-examiner set-up only ** Having a third party present is recommended for genitourinary examination
Notes:
Name of physician (print/type) Address Signature of physician
Date Phone , MD or DO
Figure 12.2 Physical examination form used for pre-participation evaluation. (With permission from American Academy of Family Physicians, American Academy of Pediatrics, American College of Sports Medicine.1)
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physicians testing athletes feel comfortable with their component of the examination. In medical training programs, less experienced physicians may screen athletes for suspicious findings and more experienced physicians or specialists can confirm or clarify a confusing finding. This approach is efficient, improves the knowledge of the less experienced physicians, and may eliminate needless specialty consultations. Preferably, an athlete is examined thoroughly rather than allowed to play while there is uncertainty about the significance of a finding. Ideally, the medical staff of the team or school is involved in the screening process. Their inclusion allows them to establish rapport with the team members and facilitates follow-up.
Specific considerations based on the history Box 12.3: Key Points Components of the history may not preclude athletic participation, but they often prompt further evaluation.
Hypertension Athletes with a history of high blood pressure should be under the care of a physician. If there is no evidence of end-organ damage, they can compete in all sports. If they are older than 18 years and have a systolic blood pressure >159 mmHg or a diastolic blood pressure >99 mmHg, or have end-organ damage, they need to be treated1 and should be held from activity until their blood pressure is controlled. Younger athletes are considered at risk on the basis of their blood pressure related to their sex, height and weight. A systolic blood pressure >130 mmHg or a diastolic blood pressure >90 mmHg needs to be evaluated. If values are close to these, the pressures need to be carefully re-determined and the appropriate tables consulted. Detailed tables can be found at: http://www.nhlbi.nih.gov/ guidelines/hypertension/child_tbl.htm.6 Cardiovascular conditioning may be beneficial but should be prescribed on an individual basis. The athlete on a team is assumed to be able to participate fully and without restriction.
Diabetes mellitus Athletes with diabetes who do not have complications should be allowed to participate in sports that do not constitute a high risk. The American Diabetes Association has guidelines for participation,7 and the athlete should have a program established with his or her treating physician. Sports are considered high risk for athletes with diabetes according to the risk associated with a hypoglycemic episode (to the individual or their competition) or if they are solo endurance activities and so medical support may be problematic (Table 12.3).8
Heat illness The deaths of athletes during exercise in the heat has directed attention toward heat-related illnesses. Obesity, decondition-
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Table 12.3 Sports that Pose a Risk for Athletes with Diabetes Mellitus Risk of Hypoglycemia
Lack of Support
Risk to Competitors
Rock climbing Skydiving Scuba diving
Ultramarathons Cycling Open-water swimming
Motor sports
(Data from American Academy of Family Physicians et al.1 and Draznin.8)
ing, sickle cell trait,9 or febrile illness can put individuals at risk for a heat-related illness.10–12
Kidney abnormalities Athletes with a single functioning kidney should not participate in contact-collision sports (see Table 12.8) until cleared by their urologist or nephrologist due to the consequences of the loss of this kidney.1 Even though the risk of kidney loss is small, some experts believe that kidney abnormalities (e.g. hydronephrosis, multiple cysts) or malposition (e.g. iliac, pelvic) should disqualify athletes from contact-collision sports.13
Specific components of the physical examination Box 12.4: Key Points The purpose of the physical examination is to screen for abnormalities that may predispose to injury and to assess for pre-existing problems.
The physical examination is not the time to redo the history, but the examiner should review the athlete’s forms to determine whether there are any pre-existing injuries or conditions that should be evaluated. In large programs or in a community setting, it may be possible to review the results of previous evaluations or injury records to ensure that components of the history or previous physical conditions have not been omitted. A systematic approach to the examination ensures efficiency and completeness. One approach is provided in Table 12.4 and Figure 12.3.
Height, weight and vital signs
Box 12.5: Key Points Abnormal blood pressure readings necessitate repeated measurements several times during the testing session.
Abnormal blood pressure readings are common in pre-participation evaluations, and mildly increased blood pressures are not disqualifying for most sports.1,14–17 Exercise is therapeutic
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Table 12.4 Components of the Physical Examination in Pre-Participation Evaluations Neuromusculoskeletal examination Instructions to the athlete (Athlete: stands facing the examiner) Look to the left and right Raise arms overhead Put arms behind neck Arms at sides, squat and walk forward 4 steps Stand up. Hop on right foot, hop on left Tandem walk to me Walk on heels Squeeze my hands Shrug your shoulders Don’t let me push down Don’t let me push down Don’t let me push up (May insert visceral examination here) Sit on table (Check biceps, triceps, patella and Achilles reflexes) Turn away Put arms behind back Arms straight ahead, palms together Flex at the waist Walk away on toes Medical examination Instructions to the athlete: Follow my finger with your eyes (Rub fingers near each ear) – Can you hear this? (Tympanic membranes, optional for most, required for swimming) (Heart examination, listen for murmurs that change with inspiration or exertion) (Lung examination) Lie down (Feel for spleen and liver edge) (Genitalia examination, males: descended testicles, presence of a hernia)
Figure 3A Figure 3B Figure 3C Figure 3D Figure 3E Figure 3F Figure 3G (right) Figure 3H Figure 3I Figure 3J Figure 3K
Figure 3L Figure 3M Figure 3N Figure 3G (left)
for adults with hypertension,18 and thus participation should be encouraged for athletes with increased blood pressure. Resistance training should be avoided in athletes with significant essential (unexplained) hypertension (see Table 12.8). Stage 2 hypertension in children is defined as repeated systolic and diastolic pressures that are more than the 99th percentile values based on sex, height and age.1 Detailed tables can be found at: http://www.nhlbi.nih.gov/guidelines/hypertension/child_tbl.htm.6 Table 12.5 lists systolic and diastolic blood pressures at the 99th percentile for boys and girls between the ages of 13 and 17 who are at the 50th percentile for height and the current recommendations for adults. Blood pressure can normally be different in children to that in adolescents, but blood pressures more than 135/90 mmHg
warrant further evaluation. If blood pressure is increased, the athlete should sit quietly for 5 min before it is re-measured. The proper-sized cuff should be used because a small cuff on a large adolescent provides a falsely increased value. If the cuff size is correct and the pressure is still increased, the athlete should lie down for 15 min before the pressure is re-checked. Continued increased pressures require evaluation and treatment before clearance. Practically speaking, if an examiner obtains pressures close to these in a mass screening setting, the first step should be to repeat the test in a quiet part of the testing area. Repeated tests are necessary to diagnose hypertension, but they may not be possible at the evaluation. Athletes should be deferred from participation until evaluated by their primary care physician. Height and weight are used to calculate the body mass index (BMI). Calculations are different for children and adults (defined as persons older than 20 years). In adults, a body BMI of 18.5–24.9 is considered normal, 25 is overweight, and 30 is obese.19 Children and adolescents are younger than 20 years, and they are considered underweight if the BMI is less than the 5th percentile for age and overweight if it is more than the 95th percentile.20 Growth charts of BMI-for-age are age- and sexspecific.20 Athletes who are underweight for their height and age may be at risk for disordered eating. These athletes may need more detailed questioning (Table 12.6).21
Head, eyes, ears, nose and throat This part of the evaluation is considered one of the most straightforward components and is the part in which most of the abnormalities are discovered.4 Visual acuity of 20/40 in one eye is considered adequate vision.1 Athletes whose best visual acuity in one eye is worse than 20/40, even with correction, should be considered ‘one-eyed’.1,22 They would have a significant change in lifestyle if they lost the use of that eye. The risks of eye injury by sport are listed in Table 12.7. Eye protection can help, but the consequences of an eye injury to an athlete with only one functioning eye need to be considered. The build-up of cerumen may compromise hearing, but it may not be possible to correct it and re-assess during a large screening session. The athlete may need to return or see his or her primary care physician. Likewise, nasal polyps or a deviated septum does not affect clearance but should be noted. The athlete may need further treatment at the discretion of his or her primary care physician.1
Cardiovascular
Box 12.6: Key Points Murmurs that increase with Valsalva maneuver or when changing position from sitting to standing need further evaluation.
The cardiovascular examination probably causes the greatest concern for the examining physician. The history provided by the athlete, whether a personal history of fainting, dizziness, loss of consciousness, seizure, or problems associated with physical
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A
B
H
C
D
I
E
J
G
F
K
157
I
M
N
Figure 12.3 Typical testing maneuvers in the screening physical examination. Any abnormalities or asymmetries and any history of injury to a specific joint should be evaluated in more detail. (A) Inspection, athlete standing, facing examiner. (B) Neck rotation to right and left. (C) Arms overhead. (D) Shoulder external rotation and elbow range of motion. (E) ‘Duck’ walk. (F) One-legged hop (both sides should be tested). (G) Walk on heels and toes. (H) Resisted shoulder shrug (trapezius). (I) Resisted shoulder abduction (deltoid). (J) Resisted elbow flexion (biceps, brachialis). (K) Resisted elbow extension (triceps). (L) Inspection, athlete facing away from examiner. (M) Shoulder internal rotation and elbow range of motion. (N) Back flexion, knees straight.
exertion, is as telling as anything that will be discovered on the typical physical examination. More advanced testing has been proposed, but it has not been found to be cost-effective for screening a large number of asymptomatic individuals and may result in a significant number of false-positive results.23 Lawless et al.24 found that portable two-dimensional echocardiography was inexpensive and increased the number of students deferred until further evaluation from 3.9 to 4.95%. It is unclear how many of these subsequently were cleared to participate after further evaluation (e.g. false-positive rate). Cantwell3 suggested screening electrocardiography on entry into high-school sports. Athletes with inappropriately high voltage or marked repolarization variation should have limited echocardiography to rule out hypertrophic cardiomyopathy.
Heart murmurs may be common in adolescents, but those that are loud (3/6 in intensity), any diastolic murmur, and a murmur that increases with Valsalva maneuver or on change in position from sitting to standing are signs of possible hypertrophic cardiomyopathy.3,25 Non-cardiologists should refer such patients to a qualified internist or cardiologist for clearance.
Lungs Both lungs should be evaluated for even air exchange without any wheezing. Athletes with wheezes, rubs, prolonged expiratory phase, or significant cough with forced expiration should be referred for further evaluation.1 The most prevalent pulmonary problem in athletes is exercise-induced bronchoconstriction.1,26
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Table 12.5 Systolic and Diastolic Blood Pressures at 99th Percentile for Boys and Girls at the 50th Percentile for Height
Table 12.6
1 How old were you when you had your first menstrual period? 2 How many periods have you had in the past 12 months? 3 Have you ever gone for more than 2 months without having a menstrual period? 4 How long do your periods last? 5 When was your last menstrual period? 6 Do you take birth control pills or hormones? 7 Have you ever been treated for anemia? 8 What have you eaten in the past 24 h? 9 Are there certain foods you refuse to eat? (e.g. meats, breads) 10 Are you happy with your present weight? 11 If not, what would you like to weigh? 12 Have you ever tried to control your weight with fasting? ____ vomiting? ____ laxatives? ____ diuretics? ____ diet pills? ____ 13 Do you have questions about healthy ways to control weight?
Blood Pressure (mmHg) Boys Age (Years) 13 14 15 16 17 18 or older
Girls
Systolic
Diastolic
Systolic
133 136 138 141 143 160
89 90 91 92 94 100
132 133 134 135 136 160
Questions Regarding Disordered Eating
Diastolic 89 90 91 91 91 100
(Modified from National Heart, Lung, and Blood Institute.6)
(Modified from Johnson MD. Tailoring the pre-participation exam to female athletes. Phys Sports Med 1992; 20:60–72, with permission.)
Symptoms of exercise-induced bronchoconstriction include shortness of breath, wheezing, chest tightness and cough that occurs during or after exercise. These symptoms are more common in athletes participating in cold-weather sports.27 Further testing is necessary. This testing can include spirometry and subsequent pulmonary function tests.1 Participation is rarely restricted because of exercise-induced bronchoconstriction or asthma if proper treatment and monitoring are provided. This part of the examination provides the opportunity to discuss the impact of smoking on athletic participation, particularly if there is an odor of tobacco about the athlete.1 Any history of breathing difficulties during or immediately after
Table 12.7
exercise suggests exercise-induced asthma, and provocative testing may be needed.
Abdomen In adults, we do not expect any organs to be palpable. Palpation of a liver or spleen tip is unexpected and should prompt referral back to the primary care physician. In a young person, particularly with a thin body habitus, this finding may not be unusual. However, masses, tenderness, rigidity, or enlargement of the liver or spleen or an abnormal kidney requires further evaluation.1 Typically, the athlete’s pediatrician can confirm such a finding from prior examinations, or an
Risk of Eye Injury, by Sport Risk
High
Moderate
Low
Safe
Small, fast projectiles Air rifle BB gun Paintball Hard projectiles, ‘sticks’, close contact Baseball, softball Basketball Cricket Fencing Hockey (ice and field) Lacrosse Racquetball Squash Intentional injury Boxing Full-contact martial arts
Badminton Fishing Football Golf Soccer Tennis Volleyball Water polo
Bicycling Diving Non-contact martial arts Skiing (snow and water) Swimming Wrestling
Gymnastics Track and field
(From Vinger PF. A practical guide for sports eye protection. Phys Sports Med 2000; 28:49–69, with permission.)
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athlete’s choice of activities may not pose a greater risk. Patients with chronic hepatomegaly or splenomegaly should have their participation determined individually in consultation with their primary care physician. In women, the lower abdomen can be palpated to determine the presence of a palpable (gravid) uterus.1 Tenderness to palpation is not normal and should prompt a further evaluation, as would a history that suggests a recent infectious process. Because of the risks of injury to affected organs, the athlete should not return to contact or collision sports until the inflammatory process has resolved.28,29 This determination may require serial ultrasound evaluations to accurately assess the size of the spleen and liver.30,31
Genitalia Inguinal hernias are traditionally assessed in men, although their presence does not preclude participation. Asymptomatic hernias should be monitored. Symptomatic hernias may require treatment at some time.1 If the hernia affects participation, that decision may have to come before participation continues. Testicular disorders do not preclude participation.32,33 A solitary testicle requires the use of a protective cup in contact or collision sports (Table 12.8). An undescended testicle should be referred for evaluation given the increased risk of testicular cancer.1 The female genitourinary examination should be done by the primary care physician.1
Skin The skin examination should include attention to acne, evidence of sun damage, rashes, infections, marks of illicit drug use and infestations.1 Suspicious lesions should be referred for further evaluation. Potentially contagious rashes such as herpes simplex, molluscum contagiosum, fungal infections, scabies and louse infestations should be evaluated and treated before the athlete continues contact with other athletes.1,34–36
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Two findings on the musculoskeletal examination bear further discussion. Scoliosis in an adolescent may not have been determined at previous screenings. Scoliosis itself does not prevent athletic participation, but it should be followed to monitor any progression and to take necessary steps to prevent unwanted sequelae of developmental spinal deformities.1 Hyperflexibility and characteristic morphologic features (long fingers, sunken chest) can be found in children with Marfan syndrome. There may be an aortic murmur. Because this condition can have catastrophic consequences, its suspicion should prompt a more thorough evaluation.
Neurologic A performance-based musculoskeletal examination provides a good screening of the neurologic system. Checking the reflexes of the biceps, triceps, patella tendon and heel cord completes that aspect of the assessment of the peripheral nervous system (hearing and vision have already been screened). Asymmetry of strength or reflexes needs further assessment. Hyperreflexia also needs to be explored more fully through the history or detailed questioning about central nervous system injuries.1 Most worrisome neurologic conditions are described in the history. A history of pain in the arm associated with neck motion may be a burner or stinger. These may be benign but may indicate brachial plexus injury or cervical nerve root compression.37 Transient quadriparesis is a controversial phenomenon that needs further evaluation. Evidence of instability or spinal cord injury requires treatment and likely will lead to exclusion from contact-collision sports. Congenital cervical stenosis also may predispose to transient quadripareses, but the disposition is less clear-cut.38–41
EDUCATION Box 12.8: Key Points
Musculoskeletal
Box 12.7: Key Points Previous injuries need to be assessed and rehabilitation completed before clearance for participation.
The key to an efficient neuromusculoskeletal examination is to make it performance-based and to look for asymmetry. Range of motion, strength and performance (e.g. hopping, grip strength) should be equal. Asymmetry should be explained (e.g. previous healed injury with a known deformity) and should be compatible with participation in the chosen activity or it will need more complete evaluation. If the athlete has had an injury since the last evaluation or during the last sports season, he or she should be cleared by the physician who is treating that injury. If the general examination reveals any pain, joint instability, locking, weakness, or atrophy, a more detailed evaluation is indicated or the athlete should be referred to a specialist.1
The pre-participation evaluation is an opportunity to provide needed information to athletes and their parents on various topics.
During the pre-participation evaluation, the examiners may detect poor health practices in the athletes. Furthermore, the typical screening process tends to have a lot of downtime for the athletes. This is an opportunity to provide information in the form of charts, handouts, or other reading material to the athletes, coaches, or accompanying parents or guardians. Some topics to consider include nutrition and ergogenic aids and supplements, proper rest and hydration, cancer awareness from sun exposure and tobacco and general health and safety practices.
Nutrition Updated information on a balanced diet for athletes can be provided during the screening program. It can be perused during waiting periods and brought home and used for reference. Diet information may help female athletes acquire a more appropriate attitude toward calorie intake as it relates to athletic performance.
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Table 12.8
Medical Conditions and Sports Participationa
Condition
May Participate
Atlantoaxial instability (instability of the joint between cervical vertebrae 1 and 2) Explanation: Athlete needs evaluation to assess risk of spinal cord injury during sports participation. Bleeding disorderb Explanation: Athlete needs evaluation. Cardiovascular disease Carditis (inflammation of the heart) Explanation: Carditis may result in sudden death with exertion. Hypertension (high blood pressure) Explanation: Those with significant essential (unexplained) hypertension should avoid weight and powerlifting, body building and strength training. Those with secondary hypertension (hypertension caused by a previously identified disease) or severe essential hypertension need evaluation. The National High Blood Pressure Education Working Group defined significant and severe hypertension.c Congenital heart disease (structural heart defects present at birth) Explanation: Those with mild forms may participate fully; those with moderate or severe forms or who have undergone surgery need evaluation. The 26th Bethesda Conference defined mild, moderate and severe disease for common cardiac lesions.d Dysrhythmia (irregular heart rhythm) Explanation: Those with symptoms (chest pain, syncope, dizziness, shortness of breath, or other symptoms of possible dysrhythmia) or evidence of mitral regurgitation (leaking) on physical examination need evaluation. All others may participate fully. Heart murmur Explanation: If the murmur is innocent (does not indicate heart disease), full participation is permitted. Otherwise, the athlete needs evaluation. Cerebral palsyb Explanation: Athlete needs evaluation. Diabetes mellitus Explanation: All sports can be played with proper attention to diet, blood glucose concentration, hydration and insulin therapy. Blood glucose concentration should be monitored every 30 min during continuous exercise and 15 min after completion of exercise. Diarrhea Explanation: Unless disease is mild, no participation is permitted, because diarrhea may increase the risk of dehydration and heat illness. (See ‘Fever’ below) Eating disorders Anorexia nervosa, bulimia nervosa Explanation: Patients with these disorders need medical and psychiatric assessment before participation. Eyes Functionally one-eyed athlete, loss of an eye, detached retina, previous eye surgery, or serious eye injury Explanation: A functionally one-eyed athlete has a best-corrected visual acuity of less than 20/40 in the eye with worse acuity. These athletes would suffer significant disability if the better eye were seriously injured, as would those with loss of an eye. Some athletes who previously have undergone eye surgery or had a serious eye injury may have an increased risk of injury because of weakened eye tissue. Availability of eye guards approved by the American Society for Testing and Materials and other protective equipment may allow participation in most sports, but this must be judged on an individual basis. Fever Explanation: Fever can increase cardiopulmonary effort, reduce maximum exercise capacity, make heat illness more likely and increase orthostatic hypertension during exercise. Fever may rarely accompany myocarditis or other infections that may make exercise dangerous. Heat illness, history of Explanation: Because of the increased likelihood of recurrence, the athlete needs individual assessment to determine the presence of predisposing conditions and to arrange a prevention strategy. Hepatitis Explanation: Because of the apparent minimal risk to others, all sports may be played that the athlete’s state of health allows. In all athletes, skin lesions should be covered properly, and athletic personnel should use universal precautions when handling blood or body fluids with visible blood. Human immunodeficiency virus (HIV) infection Explanation: Because of the apparent minimal risk to others, all sports may be played as the athlete’s state of health allows. In all athletes, skin lesions should be covered properly, and athletic personnel should use universal precautions when handling blood or body fluids with visible blood.
Qualified yes Qualified yes
No Qualified yes
Qualified yes
Qualified yes
Qualified yes
Qualified yes Yes
Qualified no
Qualified yes
Qualified yes
No
Qualified yes
Yes
Yes
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Table 12.8
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Medical Conditions and Sports Participationa —Cont’d
Condition
May Participate
Kidney, absence of one Explanation: Athlete needs individual assessment for contact, collision and limited-contact sports. Liver, enlarged Explanation: If the liver is acutely enlarged, participation should be avoided because of risk of rupture. If the liver is chronically enlarged, individual assessment is needed before collision, contact, or limited-contact sports are played. Malignant neoplasmb Explanation: Athlete needs individual assessment. Musculoskeletal disorders Explanation: Athlete needs individual assessment. Neurologic disorders History of serious head or spine trauma, severe or repeated concussions, or craniotomy Explanation: Athlete needs individual assessment for collision, contact, or limited-contact sports and also for non-contact sports if deficits in judgment or cognition are present. Research supports a conservative approach to management of concussion Seizure disorder, well-controlled Explanation: Risk of seizure during participation is minimal. Seizure disorder, poorly controlled Explanation: Athlete needs individual assessment for collision, contact, or limited-contact sports. The following non-contact sports should be avoided: archery, riflery, swimming, weight or powerlifting, strength training, or sports involving heights. In these sports, occurrence of a seizure may pose a risk to self or others. Obesity Explanation: Because of the risk of heart illness, obese persons need careful acclimatization and hydration. Organ transplant recipientb Explanation: Athlete needs individual assessment. Ovary, absence of one Explanation: Risk of severe injury to remaining ovary is minimal. Respiratory conditions Pulmonary compromise, including cystic fibrosis Explanation: Athlete needs individual assessment, but generally, all sports may be played if oxygenation remains satisfactory during a graded exercise test. Patients with cystic fibrosis need acclimatization and good hydration to reduce the risk of heat illness. Asthma Explanation: With proper medication and education, only athletes with the most severe asthma will need to modify their participation. Acute upper respiratory infection Explanation: Upper respiratory obstruction may affect pulmonary function. Athlete needs individual assessment for all but mild disease. (See ‘Fever’, earlier) Sickle cell disease Explanation: Athlete needs individual assessment. In general, if status of the illness permits, all but high exertion, collision and contact sports may be played. Overheating, dehydration and chilling must be avoided. Sickle cell trait Explanation: It is unlikely that persons with sickle cell trait have an increased risk of sudden death or other medical problems during athletic participation, except under the most extreme conditions of heat, humidity, and, possibly, increased altitude. These persons, like all athletes, should be carefully conditioned, acclimatized and hydrated to reduce any possible risk. Skin disorders (boils, herpes simplex, impetigo, scabies, molluscum contagiosum) Explanation: While the patient is contagious, participation in gymnastics with mats; martial arts; wrestling; or other collision, contact, or limited-contact sports is not allowed. Spleen, enlarged Explanation: A patient with an acutely enlarged spleen should avoid all sports because of risk of rupture. A patient with a chronically enlarged spleen needs individual assessment before playing collision, contact, or limited-contact sports. Testicle, undescended or absence of one Explanation: Certain sports may require a protective cup.
Qualified yes Qualified yes
Qualified yes Qualified yes
Qualified yes
Yes Qualified yes
Qualified yes Qualified yes Yes
Qualified yes
Yes Qualified yes
Qualified yes
Yes
Qualified yes
Qualified yes
Yes
aThis table is designed for use by medical and non-medical personnel. ‘Needs evaluation’ means that a physician with appropriate knowledge and experience should assess the safety of a given sport for an athlete with the listed medical condition. Unless otherwise noted, this is because of variability in the severity of the disease, the risk of injury for the specific sports, or both. bNot discussed in this chapter. cWhelton PK, He J, Appel LJ, et al. National High Blood Pressure Education Program Coordinating Committee. Primary prevention of hypertension: clinical and public health advisory from the National High Blood Pressure Education Program. JAMA 2002; 288:1882–1888. d26th Bethesda Conference: recommendations for determining eligibility for competition in athletes with cardiovascular abnormalities. January 6–7, 1994. Med Sci Sports Exerc 1994; 26(Suppl):S223–S283; Erratum in Med Sci Sports Exerc 1994; 26(12). (Reproduced with permission from Pediatrics, Vol 107, pp.1205–1209, Copyright © 2001 by the AAP.)
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Ergogenic aids and steroids The mixed messages that adolescents receive regarding their appearance, the importance of sports performance, the misinformation regarding the safety of steroid use and the lack of oversight regarding the use of steroids require that information about these dangerous substances be available to young athletes. The medical community needs to continue to take a strong position against these substances to protect young athletes when they are most susceptible to the promise of an easy route to athletic success.
Rest Adolescents need 8–10 h of sleep each night. Sports participation may provide the impetus to maintain a proper sleep routine, so as to not compromise performance.
Hydration Several clusters of heat-related injuries and deaths highlight the importance of proper fluid intake during training sessions. Proper sodium intake is also important.
Sun exposure Skin cancer due to sun damage is thought to be related to exposure that occurs before the age of 18 years. Therefore, children and adolescents should be counseled about the importance of using sunscreen whenever they are outdoors.
Health practice As previously mentioned, the pre-participation evaluation may be the only opportunity to do health counseling with young athletes. Wearing seat belts while in a car and avoiding drug and alcohol use can be introduced or reiterated to the adolescent athlete during the pre-participation evaluation. Safe sexual practices, including abstinence, also can be addressed. Community standards and school district rules need to be considered in conjunction with this politically charged topic, and the team physician will have to assess his or her role in educating students in this regard.
DISPOSITION Box 12.9: Key Points The majority of athletes are cleared for play without restriction. Any concerns about safer participation should be deferred for further evaluation by a specialist or the primary care physician.
On the basis of the findings on the history and physical screening, the athlete can be cleared to play without restrictions, cleared to play with recommendations for further evaluation or treatment for specific conditions, not cleared for certain sports (e.g. no contact sports) (Tables 12.9, 12.10), or not cleared for any sport.1 Because of possible confusion related to the mixed message of allowing participation but requiring fur-
Table 12.9 Contact
Classification of Sports by Extent of Extent of Contact
Non-Contact
Limited Contact
Contact-Collision
Archery Badminton Body building Canoeing/kayaking (flat water) Curling Dancing Field events Discus Javelin Shot put Golf Orienteering Powerlifting Race walking Riflery Rope jumping Rowing Running Sailing Scuba diving Strength training Swimming Table tennis Tennis Track Weightlifting
Baseball Bicycling Cheerleading Canoeing/kayaking (white water) Fencing Field events High jump Pole vault Floor hockey Gymnastics Handball Horseback riding Racquetball Skating Ice In-line Roller Skiing Cross-country Downhill Water Softball Squash Ultimate Frisbee Volleyball Windsurfing, surfing
Basketball Boxing Diving Field hockey Football Flag Tackle Ice hockey Lacrosse Martial arts Rodeo Rugby Ski jumping Soccer Team handball Water polo Wrestling
ther evaluation, this category should be used for situations in which the condition that needs to be evaluated has little bearing on the athlete’s ability to participate safely. For example, decreased hearing in a football player may not preclude safe participation but should be assessed by the primary care physician. Because of the importance of athletic participation and as a result of epidemiologic research, conditions that were once thought to be disqualifying no longer are labeled as such. For example, the lack of a testicle was once disqualifying. However, the loss of a testicle in sports is infrequent, and contact and collision sports pose the greatest risk for this injury (Tables 12.8–12.10). Murmurs, organomegaly, joint laxity, or conditions that could lead to disqualification should be assessed and clearance withheld until given by a specialist who examines the athlete. The pre-participation evaluation is an opportunity to identify problems that may have a significant impact on the long-term health of an athlete. Some of these findings are summarized in Table 12.11. There are conflicting legal precedents to allowing or refusing an athlete’s participation in organized sports based on perceived risk due to a medical condition. The federal court in Kansas sided with the University of Kansas and its medical staff in prohibiting participation by a football player with a congen-
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Special groups and circumstances
Table 12.10
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Classification of Sports by Dynamic and Static Status
Low Dynamic/ Low Static
Low Dynamic/ High Static
High Dynamic/ Low Static
High Dynamic/ High Static
Bowling Cricket Curling Golf Riflery
Archery Auto racing Diving Equestrian events Field events (jumping, throwing) Gymnastics Karate, judo Motorcycling Rodeo Sailing Ski jumping Water skiing Weightlifting
Badminton Baseball Basketball Field hockey Lacrosse Orienteering Race walking Racquetball Soccer Squash Swimming Table tennis Tennis Volleyball
Boxing Cross-country skiing Cycling Downhill skiing Fencing Football Ice hockey Rowing Rugby Running (sprints) Speed skating Water polo Wrestling
itally narrowed cervical spine and an episode of transient paralysis. In Illinois, the federal court sided with two cardiologists and an athlete with an implanted cardioverter-defibrillator over his school, team physician and two other consultants, a decision that allowed the athlete to play basketball.42 A physician who allows an athlete to play because of the athlete’s desire to play despite medical judgment to the contrary may be liable for malpractice.43 It is inappropriate for the physician to allow clearance if an athlete offers to sign a liability waiver or threatens a lawsuit. The physician needs to make the judgment that he or she believes is medically appropriate. If there is a risk of life-threatening or permanently disabling harm, it is advisable to opt for caution and recommend against participation even though an athlete may legally challenge this recommendation.42
SPECIAL GROUPS AND CIRCUMSTANCES Box 12.10: Key Points Different groups may require specific components in the pre-participation evaluation in order to identify areas of concern.
Weight certification In some states, high-school wrestlers are certified at the beginning of the season as to their minimum wrestling weight for that season. Physicians involved in that process should familiarize themselves with the options available and any allowance for growth during the course of the season. Physicians should know that despite the lack of logic, wrestlers prefer to lose weight to compete at a lower weight class rather than gain weight and compete at a heavier class. Rapid weight loss is unsafe and is typically accomplished through dehydration. Matches, then, become contests between two dehydrated wrestlers. Less weight loss (or better hydration) leads to better performance. At the beginning of the season, the physician can consider the wrestler’s age, competition weight from the previous year, and the time available to lose weight. In a 12-week season, it is inappropriate to allow an athlete to try to lose more than 24 pounds (2 pounds a week). Over time, it is hoped that wrestlers will be closer to their competition weight throughout the year and less likely to try to achieve an unrealistic and unhealthy weight. The American College of Sports Medicine recommends a minimum body fat of 7% in boys 16 years and 5% in those >16. Female wrestlers should have at least 12% body fat.44
Boxing Female athletes There may be objection to addressing issues of female athletes separately. However, attention needs to be called to disordered eating and menstrual irregularities. Eating disorders may occur in 10% of female collegiate athletes.21 An athlete’s concerns about weight may require more detailed questioning. Similarly, a pattern of missed menstrual periods or long durations between periods (i.e. more than 2 months) should prompt closer scrutiny. Osteoporosis is not going to be detected on physical examination, but it may be inferred from a history of stress fractures in conjunction with amenorrhea.21
Despite condemnation of boxing by certain aspects of organized medicine, boxers may need to be cleared by a state commission before being allowed to fight professionally in a state. Again, the physician’s job is to ensure the safety of the participant. Any neurologic abnormality, visual abnormality, or physical finding that would preclude strenuous activity could be fatal. Several professional organizations have come out against boxing as a sport, particularly at the professional level, citing that one way to win is to render the opponent unconscious. Neurologic injury is an undesired occurrence in many sports, but because it is a desired option in boxing, the sport is
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Table 12.11
Findings on History of Physical Examination and Suggested Actionsa
Component of Examination or Specific Consideration
Point of Determination
Heat illness
History
Head, eyes, ears, nose, throat
History
Physical exam
Cardiovascular
Physical exam
Lungs
History Physical exam
Abdomen
Physical exam
Skin
Physical exam
Musculoskeletal
History Physical exam
Neurologic
History
Finding
Action
Possible disposing factors: obesity, history of febrile illness, medications, poor physical condition, sickle cell disease or trait High degree of myopia Surgical aphakia Retinal detachment Eye surgery Eye injury Eye infection Nasal polyps Deviated septum Visual acuity worse than 20/40 with correction, if available High blood pressure 3/6 murmur or greater Diastolic murmur Murmur increases with Valsalva or change from sitting to standing Breathing difficulty during or immediately after exercise Wheezes Rubs Prolonged expiratory phase Significant cough with forced expiration Mass Tenderness Rigidity Enlarged liver Enlarged spleen Suspicious nevi Contagious rash (e.g. herpes) Previous injury
Refer for evaluation
Pain Joint instability Joint locking Weakness Atrophy Excess ankle motion Cavus foot Rigid flatfoot Toe deformities (e.g. bunions, contractures, calluses) Generalized hypermobility of joints Scoliosis Recurrent stingers or burners Multiple or severe concussions Transient quadriparesis Seizures
Withhold clearance until evaluated by ophthalmologist Withhold clearance until evaluated by ophthalmologist Withhold clearance until evaluated by ophthalmologist Withhold clearance until evaluated by ophthalmologist Withhold clearance until evaluated by ophthalmologist Withhold clearance until evaluated by ophthalmologist Clear, F-U with primary care physician Clear, F-U with primary care physician Refer for evaluation and treatment Increased 3 times: withhold clearance until evaluated Withhold clearance until evaluated Withhold clearance until evaluated Withhold clearance until evaluated Provocative testing for exercise-induced asthma Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Withhold clearance until evaluated Withhold clearance until evaluated Withhold clearance until evaluated Withhold clearance until evaluated Withhold clearance until evaluated Refer for evaluation and treatment Withhold clearance until evaluated and treated Clarify status of injury. May need clearance from treating physician Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Refer for evaluation and treatment Withhold clearance until evaluated and treated Withhold clearance until evaluated and treated
Exam, examination; F-U, follow-up. aIn a multistation evaluation in which various specialists are present, the evaluation and recommendations for treatment may occur during the pre-participation evaluation. The intent is not to avoid decisions about participation but to ensure that an appropriate specialist makes a confident decision.
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References
thought by some physicians to be incompatible with their participation in the pre-fight assessment of boxers. These physicians should not participate in the pre-bout certification so as not to interject their anti-boxing bias into the approval (or disapproval) process. Accordingly, pro-boxing physicians need to maintain an objective approach to the process and act in the best interest of the athletes and their risk for injury.
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pation and celebrate the camaraderie of competition rather than emphasize winning and losing. These are still strenuous activities, and athletes may need to be screened to participate. One area of particular concern is atlantoaxial instability in patients with trisomy 21 (Down syndrome) or connective tissue disease.45
Professional and elite athletes Physically challenged athletes The increase in sports participation for the physically challenged is a welcome phenomenon. One desire in sport is to allow fair competition between athletes of similar abilities. In able-bodied athletes, the reason for pre-competition and post-competition assessment (e.g. drug testing, gender testing) is to confirm that there has been no action on the athlete’s part to hide his or her identity or to artificially enhance performance. In the physically challenged population, pre-participation assessments are performed to ensure that athletes compete against others with similar impairments. Physicians are often asked to certify a specific impairment in an athlete.45 Athletes with a physical impairment should participate in the same sort of pre-participation evaluation as those without a known impairment. The answers to many of the screening questions will be positive and thus the process may take longer. Athletes with physical impairments may be susceptible to problems resulting from use of an assistive device (e.g. upper limb injuries due to wheelchair use).45 Regardless, the goal of pre-participation evaluation is to determine safety and risk and not to ascribe value to an individual’s choice of sport or to hypothesize about whether an athlete with an impairment should participate in a particular activity. Presumably, a sport has rules and guidelines for participation. As long as these rules are met, the athlete should be cleared regardless of the examining physician’s opinion on the value of the activity. Physicians who do not agree with a particular activity should not participate in clearing athletes in that activity rather than inject their own bias into the process (see Boxing above).
Special Olympians Another group of athletes engaged in sports are those with cognitive or physical limitations. These events focus on partici-
The professional or elite amateur athlete poses a special problem for the examining physician. While maintaining the best interest of the patient, the examiner is assessing the athlete’s health and fitness to participate in his or her chosen profession. The physician has an important role in determining whether an athlete is hired. In this setting, the physician has two duties: to ensure that the athlete is healthy and physically fit enough to participate fully in the sport and to collect objective data that may be used by team management in making a hiring decision. The physician needs to be objective in dealings with the athletes and coaching staff. Any compromise of integrity or principles of medical judgment will erode the doctor–patient relationship.
SUMMARY The pre-participation evaluation is an opportunity to screen for medical conditions that would make athletic participation dangerous for an athlete. It should be done in a timely fashion so that any worrisome findings can be addressed or injuries rehabilitated. It should be efficient to respect the time of the healthcare professionals and the participants. It is not a substitute for a comprehensive examination done by a primary care physician. It is an opportunity to build rapport between the medical staff and the team and an opportunity for education. As with any screening, it may not yield a diagnosis, but it may lead to more in-depth assessment to ensure safe participation. In sports, there are rarely worthwhile shortcuts to success. The pre-participation evaluation is no different, and the participants should understand that a conservative approach will lead to confidence in safe participation.
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2 3 4 5 6
American Academy of Family Physicians, American Academy of Pediatrics, American College of Sports Medicine, American Medical Society for Sports Medicine, American Orthopaedic Society for Sports Medicine, American Osteopathic Academy of Sports Medicine. Preparticipation physical evaluation. 3rd edn. New York: McGraw-Hill Professional; 2005. Rice SG. Preparticipation physical examinations: giving an athlete the go-ahead to play. Consultant 1994; 34:1129–1144. Cantwell JD. Preparticipation physical evaluation: getting to the heart of the matter. Med Sci Sports Exerc 1998; 30:S341–S344. Smith J, Laskowski ER. The preparticipation physical examination: Mayo Clinic experience with 2,739 examinations. Mayo Clin Proc 1998; 73:419–429. Wingfield K, Matheson GO, Meeuwisse WH. Preparticipation evaluation: an evidencebased review. Clin J Sport Med 2004; 14:109–122. National Heart, Lung, and Blood Institute. Blood pressure tables for children and adolescents. Bethesda, MD: The Institute; 2004 (2005). Online. Available: http://www.nhlbi.nih.gov/guidelines/hypertension/child_tbl.htm
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American Diabetes Association. Diabetes mellitus and exercise. Diabetes Care 2002; 25:S64–S68. Draznin MB. Type 1 diabetes and sports participation: strategies for training and competing safely. Phys Sportsmed 2000; 28:49–56. Martin TW, Weisman IM, Zeballos RJ, Stephenson SR. Exercise and hypoxia increase sickling in venous blood from an exercising limb in individuals with sickle cell trait. Am J Med 1989; 87:48–56. NCAA. 2003–2004 Sports medicine handbook. Online. Available: http://www.ncaa.org/library/sports_sciences/sports_med_handbook/200304/2003-04_sports_med_handbook.pdf Armstrong LE, De Luca JP, Hubbard RW. Time course of recovery and heat acclimation ability of prior exertional heatstroke patients. Med Sci Sports Exerc 1990; 22:36–48. Epstein Y. Heat intolerance: predisposing factor or residual injury? Med Sci Sports Exerc 1990; 22:29–35.
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Sharp DS, Ross JH, Kay R. Attitudes of pediatric urologists regarding sports participation by children with a solitary kidney. J Urol 2002; 168:1811–1814. Goldberg B, Saraniti A, Witman P, Gavin M, Nicholas JA. Pre-participation sports assessment: an objective evaluation. Pediatrics 1980; 66:736–745. Tennant FS Jr, Sorenson K, Day CM. Benefits of preparticipation sports examinations. J Fam Pract 1981; 13:287–288. Lively MW. Preparticipation physical examinations: a collegiate experience. Clin J Sport Med 1999; 9:3–8. DiFiori JP, Haney S. Preparticipation evaluation of collegiate athletes [abstract]. Med Sci Sports Exerc 2004; 36:S102. Pescatello LS, Franklin BA, Fagard R, Farquhar WB, Kelley GA, Ray CA, American College of Sports Medicine. Exercise and hypertension. Med Sci Sports Exerc 2004; 36:533–553. National Heart, Lung, and Blood Institute, National Institute of Diabetes and Digestive and Kidney Diseases. Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults: the evidence report. Bethesda MD: National Heart, Lung, and Blood Institute in cooperation with the National Institute of Diabetes and Digestive and Kidney Diseases; 1998 Report No. 98:4083. Centers for Disease Control and Prevention. BMI – Body mass index: BMI for children and teens. Atlanta: CDCP; 2005. Online. Available: http://www.cdc.gov/nccdphp/dnpa/bmi/bmi-for-age.htm Rumball JS, Lebrun CM. Preparticipation physical examination: selected issues for the female athlete. Clin J Sport Med 2004; 14:153–160. Napier SM, Baker RS, Sanford DG, Easterbrook M. Eye injuries in athletics and recreation. Surv Ophthalmol 1996; 41:229–244. Bonsell S, Grayburn PA. The accuracy of screening echocardiography in detecting hypertrophic cardiomyopathy in the preparticipation athletic physical [abstract]. Med Sci Sports Exerc 2004; 36:S102–S103. Lawless CE, DeJong AC, DeJong JW, Joshi A, Panozzo J, Briner WW. Impact of preparticipation portable two-dimensional echocardiography in screening for cardiovascular disease in school-age athletes. Med Sci Sports Exerc 2003; 35:S316. Andreoli TE, Carpenter CCJ, Griggs RC, Loscalzo J, editors. Cecil essentials of medicine. 6th edn. Philadelphia: Saunders; 2004. Holzer K, Brukner P. Screening of athletes for exercise-induced bronchoconstriction. Clin J Sport Med 2004; 14:134–138. Storms WW. Review of exercise-induced asthma. Med Sci Sports Exerc 2003; 35:1464–1470.
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Maki DG, Reich RM. Infectious mononucleosis in the athlete: diagnosis, complications, and management. Am J Sports Med 1982; 10:162–173. Farley DR, Zietlow SP, Bannon MP, Farnell MB. Spontaneous rupture of the spleen due to infectious mononucleosis. Mayo Clin Proc 1992; 67:846–853. Johnson MA, Cooperberg PL, Boisvert J, Stoller JL, Winrob H. Spontaneous splenic rupture in infectious mononucleosis: sonographic diagnosis and follow-up. AJR Am J Roentgenol 1981; 136:111–114. Dommerby H, Stangerup SE, Stangerup M, Hancke S. Hepatosplenomegaly in infectious mononucleosis, assessed by ultrasonic scanning. J Laryngol Otol 1986; 100:573–579. McAleer IM, Kaplan GW, LoSasso BE. Renal and testis injuries in team sports. J Urol 2002; 168:1805–1807. Committee on Sports Medicine and Fitness. American Academy of Pediatrics: medical conditions affecting sports participation. Pediatrics 2001; 107:1205–1209. Bender TW III. Cutaneous manifestations of disease in athletes. Skin Med 2003; 2:34–40. Brooks C, Kujawska A, Patel D. Cutaneous allergic reactions induced by sporting activities. Sports Med 2003; 33:699–708. Metelitsa A, Barankin B, Lin AN. Diagnosis of sports-related dermatoses. Int J Dermatol 2004; 43:113–119. Nissen SJ, Laskowski ER, Rizzo TD Jr. Burner syndrome: recognition and rehabilitation. Phys Sportsmed 1996; 24:57–64. Torg JS. Cervical spinal stenosis with cord neurapraxia: evaluations and decisions regarding participation in athletics. Curr Sports Med Rep 2002; 1:43–46. Fagan K. Transient quadriplegia and return-to-play criteria. Clin Sportsmed 2004; 23:409–419. Castro FP Jr. Stingers, cervical cord neurapraxia, and stenosis. Clin Sportsmed 2003; 22:483–492. Cantu RC. Cervical spine injuries in the athlete. Semin Neurol 2000; 20:173–178. Mitten MJ. When is disqualification from sports justified? Medical judgment vs patients’ rights. Phys Sportsmed 1996; 24:75–78. Mitten MJ. Team physicians and competitive athletes: allocating legal responsibility for athletic injuries. U Pitt Legal Rev 1993; 55:129–169. Oppliger RA, Case HS, Horswill CA, Landry GL, Shelter AC, American College of Sports Medicine. Weight loss in wrestlers. Med Sci Sports Exerc 1996; 28:ix–xii. Boyajian-O’Neill L, Cardone D, Dexter W, et al. Working Group of the Preparticipation Physical Evaluation. 3rd edn. The preparticipation examination for the athlete with special needs. Phys Sportsmed 2004; 32:13–19, 42.
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CHAPTER
13
Field Evaluation of the Injured Athlete Kai-Ming Chan, Joseph Jeremy Hsi-Tse Chang and Fiona Chui-Yan Wong
INTRODUCTION There has been a great upsurge in participation and public interest in sports in recent years. Consequently, the number of injuries due to sports participation has also been increasing. Tremendous resources have been put into understanding all aspects of medical management of athletic-related injuries and conditions. Although the majority of sports-related injuries are relatively minor, the potential for serious and possibly lifethreatening injuries is constantly present. Therefore, the assessment of an injured athlete on the field is extremely important, since this is the first in a series of steps to provide proper care for an athletic injury, which is essentially the role of a team physician. This chapter provides a brief introduction to the evaluation and fieldside management of acute injuries encountered in sports medicine.
ROLE OF TEAM PHYSICIANS ON FIELD: MEDICAL AND LEGAL CONSIDERATIONS In order to provide the best care to athletes on-field, team physicians should familiarize themselves with the sports they are covering, have the knowledge and skills necessary for assessing the condition of the athlete, and provide early stabilization and first-aid care if necessary. When an athlete is injured, the priority of the team physician is to identify any life-threatening injuries. This can be achieved by the primary survey, with the recommended emergency protocol using the ‘ABCDE’ approach (Airway, Breathing, Circulation, Disability and Exposure), which will be further elaborated later in this chapter. Once the athlete is cleared from life-threatening conditions that require immediate transfer to an emergency medical facility, the team physician can start performing a detailed examination of the athlete as the secondary survey. Upon completion of the secondary survey, the team physician may be required to perform a first-aid procedure to the athlete, or transfer the athlete to a medical center for more definitive care. As team physicians, they should at least comfortably provide certain essential first-aid care, however, they should also recognize their limitations in skills and resources.
The team physicians should transfer the athlete to a medical center for further care or investigations if they find uncertainties or difficulties in providing the most optimal first-aid care. Commonly useful first-aid skills on-field include suturing and wound dressing, application of pressure bandage, splinting and taping, application of ice or heat, massage, stretching and applying protective device and padding. Occasionally, reduction of a dislocated joint may be necessary, given that the physician is familiar with the diagnosis and treatments. After assessment of the athlete’s condition and provision of treatment on-field, the team physicians should decide if the athlete can return to play. They should discuss it with the athlete and the coach regarding the choice of return to play, observe on the sidelines for the athlete’s potential to return to play, or withhold the athlete from continuing the game. To allow an athlete to return to play immediately, the team physician should determine if the athlete can be safe from further injury, efficient in participation and relatively pain-free. One of the ways to test whether the athletes are fit to return to play is to test the athlete functionally, by asking them to perform some sport-specific drills, and look out for any symptoms, pain and efficiency in playing. If athletes experience significant pain upon return to play, the team physician should seriously consider stopping the athletes from playing as the injury may be underestimated. Having said all the necessary responsibilities that team physicians should take on-field, it is mandatory for them to take appropriate measures to avoid unnecessary legal actions. Possessing strict ethics on the safety and well-being of the athletes, team physicians should understand their limitations in knowledge, skills and resources. They should seek advice from other medical professionals whenever necessary to integrate and perfect their treatment. Moreover, it is also an obligation for team physicians to abide by the guiding regulations of the medical professional and the rules of the sport governing organizations. Team physicians must keep confidentiality of the athletes under all circumstances and undoubtedly must not benefit any secondary gain from the commercial body, for example, the mass media at the expense of the athletes’ privacy. The use of illegal performance-enhancing drugs and other banned medications must be absolutely prohibited, unless
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indispensable in an emergency.1 The team physicians should also make sure their own insurance schemes cover the cost of any legal actions that may arise during their duties in the team while in a foreign country. Moreover, the insurance scheme for the athlete should also be checked for details such as the minimum coverage allowed for further medical care, such as special medications or equipment in foreign countries, and the coverage for transfer back to their own countries.
Primary survey
Box 13.1: Key Points
•
In evaluating the severity of injury, team physicians should identify life-threatening conditions which necessitate immediate hospital admission with primary survey.
•
Primary survey with the ‘ABCDE’ approach (Airway, Breathing, Circulation, Disability and Exposure) is commonly adopted in the preliminary assessment. It serves to stabilize the patients’ vitals and triage the patients for subsequent management.
Whether an injury is sports-related or not, any physician or paramedics attending an injured patient should begin with a primary survey by following ‘ABCDE’. This algorithm, as introduced by the American College of Surgeons, provides a uniform examination of an injured patient: the airway and cervical spine; breathing; circulation; disability and exposure. Throughout the primary survey, the athletes should be left in the position in which they are found unless there is immediate danger or there is a serious injury that needs advanced intervention that can not be done in the field (Fig. 13.1).2 The same principle holds true for an unconscious athlete; the ‘ABCDE’ approach is to determine and maintain the vitals and it is the first life-saving step for all injured athletes.
Airway A top priority in management of the injured athlete is to establish an airway and maintain adequate ventilation. Airway compromise can result from occlusion of the air passages with fluid or solid substances, e.g. teeth, foreign bodies. The airway may also be obstructed due to the relaxation of pharyngeal soft tissue in an unconscious patient or soft tissue collapse from severe oral/facial trauma. On the fieldside, a team physician should look for signs of airway obstruction. This could be presented as excessive use of accessory muscles, intercostals retractions, hoarseness, snoring, stridor and nasal alar flaring. Cyanosis is another sign to look out for, and the most common sites to assess are the nail beds and around the lips, where purplish discoloration may be present. The first step to re-establish a patent airway is by manually removing any foreign body that is causing the obstruction. In the unconscious athlete, the attending physician should especially check for tongue relaxation that occludes the airway. If so, a chin lift and jaw thrust maneuver can be performed. The physicians place their index finger under the athlete’s mandible and pull the lower lip down with the thumb, while the middle fingers are placed behind the angle of mandible and displacing the mandible forward. By doing so, the tongue will fall forward and thus relieve the obstruction. Note the neck should be maintained with in-line immobilization at all times while performing the maneuver as this may further damage any unstable cervical spine (Fig. 13.2).2 The survey is simpler in a conscious athlete. One simple test for checking the airway status in conscious athletes is by asking their name. If the athlete can respond clearly in sentence, the airway and breathing are usually secured. For an unconscious patient, the insertion of an oropharyngeal airway can be considered. Adult oropharyngeal airways come in three sizes: 8 cm (size 3), 9 cm (size 4) and 10 cm (size 5). The size of the airway is estimated by measuring the distance between the front of the teeth and angle of the jaw from the side. In most cases, the injured athlete should be able to ventilate with the
Primary survey A = Airway and cervical spine control Make sure the airway is patent B = Breathing Make sure the patient is breathing spontaneously C = Circulation Make sure patient is hemodynamically stable If unstable, address IV replacement and identify sources of blood loss D = Disability Assess for neurological injury; assess for significant musculoskeletal trauma E = Exposure and Environmental Make sure patient is in a safe environment with controlled temperature
Logroll patient if necessary and apply rigid neck collar
Check for abdominal or musculoskeletal trauma as cause of occult blood loss Assess for head injury (pupils and Glasgow coma scale) Assess for fractures, dislocations and neurovascular limb injury Check for heat related illness and cold injury Transfer to spinal board if necessary for transport
Figure 13.1 Primary survey: the ‘ABCDE’ approach. (Reproduced from Luke and Stanish 2001.2)
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indicated by significant trauma to the neck/upper back, head injury, post-traumatic loss of consciousness, post-traumatic shock, neurological deficits consistent with central nervous symptom dysfunction, intoxication or inability to speak.
Breathing
oropharyngeal airway and bag-valve-mask device, however if this fails, a definitive airway, e.g. orotracheal tube, nasotracheal tube, or tracheostomy may be required.
Optimal ventilation requires a patent upper and lower airway, along with the proper functioning thoracic wall, lungs and diaphragm. When assessing for adequate ventilation in an injured athlete, the following sequence can be adopted: ‘look, listen and feel’. Respiratory compromise may present as tachypnea or bradypnea, paradoxical (see-saw movement) of the chest and abdomen indicating failure of normal diaphragmatic function. Check the trachea for any midline deviation, and auscultate each lung field for adequate air entry. If there is a decreased breath sound along with tracheal deviation to the contralateral side, then tension pneumothorax is highly suspected, and a large-bore needle/catheter should be inserted into the pleural cavity immediately through the second intercostal space in the mid-clavicular line anteriorly. Other lifethreatening conditions such as flail chest, open pneumothorax, hemothorax, cardiac tamponade and penetrating wounds warrant immediate hospital care. Athletes with inadequate ventilation can be supplemented with oxygen by a bag-valve-mask device on the fieldside until they are transferred to the nearest institute with oxygen supplement.
Cervical spine control Since injury to the cervical spine may
Circulation
lead to irreversible damage to the spinal cord, initial resuscitation must be conducted under the assumption that cervical spine injury exists until it is disproved radiographically. If unconscious, the player is also presumed to have an unstable fracture until proven otherwise. Hence, the injured athlete should be immobilized by manual in-line cervical control with neck in neutral position (Fig. 13.3).2 A rigid neck collar is
Cardiogenic and hypovolemic shock are the most common problems encountered in sports medicine. Hypovolemic shock can arise among athletes with severe dehydration or when there is a continuous bleeding source; whereas a cardiogenic shock may arise among athletes with pre-existing cardiovascular diseases. Hence, it is important for the team physician to identify these signs. Clinical features of hypovolemic shock
Figure 13.2 Jaw thrust and chin lift maneuver. The index fingers and middle finger lifts the angle of the jaw forward on each side while the thumbs pulls the lower lip and chin down opening the mouth. In-line immobilization of the neck should be maintained. (Reproduced from Luke and Stanish 2001.2)
A
B
Figure 13.3 In-line immobilization techniques of the head and neck from (A) above and (B) below are shown. Hands should stabilize the head on both sides with the 4th and 5th fingers over the occiput. (Reproduced from Luke and Stanish 2001.2)
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include hypotension, tachycardia, pallor, sweaty cold and clammy extremities, delayed capillary refill (>2 s), low jugular venous pressure ( JVP) or confusion. The clinical presentation of cardiogenic shock is similar to hypovolemic shock in its clinical presentation but with high JVP. The cardiovascular system should initially be assessed by feeling for the carotid pulse. If the carotid pulse is not palpable on both sides along with the signs of shock, then cardiac arrest or arrhythmia is suspected. Hence, immediate cardiopulmonary resuscitation should be done. The rhythm can be determined with a portable defibrillation, and rhythm such as ventricular fibrillation or ventricular tachycardia can be converted to a stable rhythm by defibrillation. Time is precious in these conditions as for every minute of delay, there is a 10% decrease in survival.3 In the presence of shock, establishment of peripheral intravenous access with large bore cannula for volume resuscitation should commence as soon as airway and ventilation is secured. The principle for stabilizing an acutely injured athlete with ‘ABC’ should make no difference between conscious and unconscious athletes. Then the athlete should be transferred to the nearest medical center for further management. In the event of trauma, internal bleeding into third spaces such as the chest, abdomen or from fractures of long bones must be considered as a cause of hypovolemia. Therefore, look for any bruising and abdominal distention, and feel for any abdominal tenderness. Also, apply firm consistent pressure for any visible hemorrhage.
Disability After securing ‘ABC’, the next step is to assess the athlete’s level of consciousness. This can be done with the Glasgow coma scale (Table 13.1) by examining the athlete’s speech, eye and motor responses to verbal command or pain.
Table 13.1
Glasgow Coma Scale Score
Eye opening Spontaneous To voice To pain Nil Verbal response Orientated Confused Inappropriate words Incomprehensible sounds Nil Motor responses Obeys commands Localizes pain Withdraw Flexion Extension Nil
4 3 2 1 5 4 3 2 1 6 5 4 3 2 1
Exposure or environment The team physician should check for any imminent danger to the athletes during the assessment. Both the physician and the athlete should be moved to a safer environment if any other dangers are present. It is also necessary to adequately expose the athlete to check for any other sites of injury after the primary survey. In case of suspected heat stroke, any equipment or clothing that prevents the athlete from cooling down must be removed immediately.
Transportation If the athlete is suspected of having vertebral column or spinal cord injury, he should be transported to an emergency department for the serial assessments. When it becomes necessary to move the athlete, the head and trunk must be moved in one unit. In most cases, that means the head and spine are repositioned into a neutral position, so that in-line stabilization can be accomplished with appropriate immobilization devices, although in some instances, it may be better for the head and neck to be immobilized in a position that the athlete is initially found. The appropriateness of repositioning should be assessed on individual basis. The athlete should be placed in a supine position with the spine safeguarded to a suitable backboard. Besides rigid neck collar, other methods of padding like towels or blanket rolls can be used to secure the head to the spine board. It has also been suggested that a cervical vacuum splint is an effective immobilizer in the athlete wearing protective equipment. And the application of spine board should always include straps to secure the pelvis, shoulders, legs and the head. For those who vomit or bleed from the oral cavity, they should be kept prone or placed on their side to prevent aspiration into the airway. However, this can be performed after immobilization and most preferably with suction apparatus being readily available. It should also be noted that the face-mask ought to be removed at the earliest convenience before transportation and regardless of current respiratory status. Due to the difficulty in attaining a definitive exclusion regarding the possibility of spinal injury in an on-field setting, the Inter-Association Task Force recommends that any suspected player should be evaluated in a controlled environment, and that any athlete with significant neck or spine pain, diminished level of consciousness, or significant neurological deficits, be transported to a medical facility with definitive diagnostic and medical resources. Athletes suspected of having a spinal injury should be transported by trained professionals in an ambulance. Transportation in a private vehicle should not be attempted. A transport team may include the team physicians, certified athletic trainers and the emergency medical service personnel. All medical or allied healthcare personnel arriving on the scene must receive a briefing of the situation. The coach, game official and administrative personnel can assist keeping the team-mates and family away from the injured athlete. Emergency equipment should include a spine board with straps, small garden pruners for removing face masks, screwdriver, emergency shears, oxygen supply, rigid cervical collars and suction apparatus, etc.
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Secondary survey Box 13.2: Key Points
• •
After initial resuscitation, a detailed head to toe survey should follow.
•
Neck examination includes looking for any muscular or spinal asymmetry, feeling for any tenderness and muscle spasm, active and passive movement. All unconscious athletes are assumed to have an associated neck injury and should be immobilized until adequate radiological evaluation has been completed.
•
Chest, abdomen and pelvis examination should be followed.
Neurological assessment includes the Glasgow Coma Scale, which covers the eye, verbal and motor responses. A more comprehensive examination with muscle tone, power, coordination, sensation and cranial nerve testing helps localize the lesion and give clues to the pathology.
Once the patient is stabilized with the initial resuscitation, a more detailed head to toe survey is carried out. The back and spine are examined by log-rolling the patients onto their side, looking for any localized tenderness, bruising or stepping. The secondary survey begins with assessment of the head and neck, followed by the chest, abdomen and pelvis, and then finally the rest of the musculoskeletal system, starting from the shoulder and down to the foot and ankle.
Head injury The scope of head injury is immense, and it ranges from minor injuries such as concussion to more serious injuries, such as cerebral contusion or laceration. Hence, if there is a decreased level of consciousness following an impact to the head, an underlying head injury should be assumed. If the athlete has a declining level of consciousness, prolonged confusion, or post-traumatic seizure, then it may suggest a rapidly progressing head injury, and immediate intervention with neurological specialists in a nearby medical center must be done. Before assessing for any neurological deficit, the ears, nose and the scalp should be inspected. Hemotympanum, ecchymosis over the mastoid process (Battle’s signs) and periorbital ecchymosis (raccoon eyes) implicate basal skull fracture. Clear fluid coming out from the ear (otorrhea) or nose (rhinorrhea) indicates cerebrospinal fluid leak from a dural rent. The Glasgow Coma Scale (Table 13.1) is a common system for grading the severity of head injury. The speech and cognitive function can be tested by asking the athlete a simple question such as ‘What is your name?’ ‘What sport were you participating in before the injury’, ‘What is the name of your team?’ During the eye examination, the physician should look for spontaneous eye movement, the size of the pupils, the reactivity of the pupils to light, and symmetry of extra-ocular movements. Any dilation or sluggish light response of one pupil suggests an intracranial injury, while asymmetrical extraocular movements suggest cranial nerve palsy or injury. For motor response in a fully conscious patient, the tone, power and coordination are readily assessed in the standard
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manner. However, in an unconscious patient, the pattern of limb response to painful stimuli provides a useful indication of the conscious level. If a subtle abnormality is suspected, the examination should include cranial nerve testing and muscle strength testing by asking the athletes to close their eyes and hold their arms outstretched, palm upwards for 1 min. Any pronation or downward drift on one side is indicative of brain injury. In addition, a mini mental status exam (MMSE) can be performed for testing the cognitive function. This includes the orientation to time, place and person; comprehension and short-term memory by asking the athlete to remember three words: apple, train, banana, and repeat them after a short while when they are asked after the concentration task which requires them to ‘start at 100, subtract 7 and continue to subtract 7 from the remaining total’.
Neck injury The usual mechanism in neck injury among sportsmen is an impact to the head with an axial load on cervical spine during collision or fall; others include a forceful flexion or extension of the head with or without rotation. All unconscious athletes are assumed to have an associated neck injury and should be immobilized until adequate radiological evaluation has been completed in a medical centre. A thorough neurological examination from head to toe should be performed on any athlete suspected of neck injury. In conscious athletes, they may give a history of neck pain or stiffness, with or without neurological symptoms such as numbness, weakness and paralysis of the limbs. If any of the above symptoms has been present in their history, then the neck should be immobilized. On the fieldside, the stability of the neck should only be tested on an athlete with no complaints of neck pain or neurological symptoms. Otherwise, any tests should be withheld until further radiological evaluation. While examining the neck, the sequence of ‘look, feel and move’ can be adopted. The physician should begin from the back of the neck, look for any muscular or spinal asymmetry, feel for any tenderness and muscle spasm. The alignment of the spine should be noted for any excessive curving of the C-spine. Ask the patient to actively test the flexion (from chin to chest), lateral flexion (ear to shoulder) and rotation (chin just before shoulder). After checking for any structural abnormality, a thorough neurological exam should follow. This includes testing of the cranial nerves II–XII, both motor and sensory functions of the spinal roots. Details of the examination are listed in Table 13.2.4 There are no simple rules to determine return-to-play criteria after sustaining a cervical spine injury. Medical factors are undoubtedly important, although non-medical factors such as age of the athlete, level of competition, psychosocial issues do play a role. Some medical sequelae do represent absolute contraindications to return to contact sports, examples include neck injuries resulting in permanent central nervous system dysfunction, significant peripheral nerve injury, injuries resulting in spinal fusion at C4 level or above.
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Table 13.2
Neurological Exam Maneuversa,4 Test
Cranial nerves II (optic nerve) III, IV, VI (extraocular nerves) V VII VIII IX, X XI XII Sensation/nerve root level tested C5 C6 C7 C8 T4 T8 T10 T12 L4 L5 S1 S3, S4, S5 Motor strength testing (nerve roots involved)b Axillary nerve (C5, C6) Radial nerve (C5, C6) Median nerve (C6, C7, C8) Ulnar nerve (C8, T1) Femoral nerve (L2, L3, L4) Deep peroneal nerve (L4, L5) Tibial nerve (S1, S2) Sciatic nerve (L5, S1, S2) Reflexes Upper extremity Lower extremity Balance Romberg test Coordination Finger–nose testing Tandem gait line
Visual acuity Extraocular movements Sensation to the forehead, cheek, and lower jaw (check both sides) Facial muscles (look for symmetry with raising eyebrows, showing teeth) Hearing Soft palate elevation (open mouth and say ‘Aah’) Trapezius elevation (test shoulder shrug strength) Tongue movement (stick out tongue – look for deviation) Lateral shoulder (deltoid area) Thumb Middle finger (3rd finger) Little finger (5th finger) Nipple line Lower border of the sternum Umbilicus Symphysis pubis Medial aspect of the lower leg Webspace between 1st and 2nd toes Lateral aspect of the foot Perianal area Resisted shoulder abduction (deltoid) Resisted wrist extension (extensor carpi radialis) Resisted elbow extension (triceps) or thumb to little finger (opponens) Resisted abduction or adduction of fingers (interossei) Resisted knee extension (quadriceps) Resisted ankle dorsiflexion (anterior tibialis) Resisted ankle plantarflexion (gastrocnemius, soleus) Resisted knee flexion (hamstrings) Triceps, biceps, brachioradialis Knee, ankle, Babinski (soles of the feet) Have athlete stand with eyes closed, look for loss of balance Have athlete touch own nose, then the examiner’s fingers, repeatedly Heel-to-toe walking in a straight line
a These
are some suggested maneuvers, however, the neurological examination may vary as clinically appropriate. testing is graded on five levels: 5 = normal strength; 4 = active movement against resistance; 3 = active movement against gravity only; 2 = able to move limb with gravity eliminated; 1 = flicker of muscle contraction only; 0 = no contractions.
bMotor
Chest, abdomen and pelvis injury The chest assessment is similar to the primary survey, but it is more in-depth and it is in order to try to pick up any signs that might have been missed previously, e.g. a rib fracture. The abdomen is examined with each abdominal organ palpated carefully. More attention should be paid to the splenic region as a ruptured spleen might be deceptively silent, and signs such
as tender, guarding and rigidity might be vaguely present. However, if there is a local collection of blood, the percussion note will be impaired on the left flank. The perineum is examined with a rectal examination. Signs that should be noted include the anal sphincter tone, the position of the prostate, any presence of blood, especially in cases suspected of internal bleeding or pelvic injury.
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Shoulder injury
Box 13.3: Key Points
•
Proper examination with observation, palpation and range of motion of shoulder region, followed by neurological assessment for associated brachial plexus and peripheral nerve injury is mandatory. Radiological confirmation is also important for making the diagnosis. Resting and immobilizing in an arm sling or splint with ice packing could be provided by team physicians on the sideline.
•
Common shoulder injuries include rotator cuff strains or tears, biceps tendon ruptures and anterior shoulder dislocation. Acute elbow injuries commonly involve posterior elbow dislocation, distal humeral fracture. Hand injuries can be diversified as fracture, dislocation and soft tissue injuries. Fractures include boxer’s fracture, Benett’s fracture, Gamekeeper’s thumb. Ligamental injuries presented as mallet finger and jersey fingers are also common.
Acute injuries of the shoulder frequently encountered on the fieldside include soft tissue injuries, including rotator cuff strains or tears and biceps tendon ruptures; dislocation of joints, like the glenoid-humeral joint, the acromion-clavicular joint and very rarely, the sterno-clavicular joint; and fractures around the shoulder region, including the clavicle, proximal humerus and less commonly the scapula. The team physician should check the bones and joints in a systematic fashion. The sternoclavicular (SC) joint, clavicle, acromioclavicular (AC) joint, acromion process, coracoid process, the greater and the lesser tubercle of the humerus, should be inspected and palpated for deformity, asymmetry, edema, crepitus and tenderness, which are usually obvious in case of fracture or dislocation. For the later scenario, deformity is usually obvious, like squaring of the shoulder or anterior prominence in glenoid-humeral joint dislocation. For soft tissue injuries, most common signs are pain, swelling and local tenderness, while tests for individual muscle injuries on the field are neither specific nor sensitive because of pain. Finally, obtain a general idea of the shoulder function with the active and passive range of movement, and never forget to perform a neurovascular examination at the end of assessment for associated brachial plexus and peripheral nerve injury. Nerves that should warrant special attention include the axillary nerve, musculocutaneous nerve, median, radial and ulnar nerve. The axillary nerve can be tested by asking the athlete to abduct their shoulder, but this will be difficult in a situation where there is a shoulder fracture. The so-called regimental badge area can be tested for sensation (Fig. 13.4).5 The motor supply of the musculocutaneous nerve can be tested by flexion of the elbow. Its sensory supply is along the lateral side of the forearm. The median, radial and ulnar nerve can be quickly assessed with the ‘Stone, paper and scissors’ movement of the hand/fingers. By asking the patients to flex their fingers and forming a firm grip (the ‘stone’ movement), this allow the physician to test the flexors of patients’ hands, which is innervated by the median nerve (Fig. 13.5A). The radial nerve supplies the extensors of the hand, and this can be tested by asking the patients to extend their fingers
Figure 13.4 The circle indicates the regimental badge area; the region where the sensory part of the axillary nerve can be tested. (Reproduced from Gerbino 2001.5)
(forming the ‘paper’) (Fig. 13.5B). Finally, the patient is asked to imitate the ‘scissor movement’ by abducting and adducting the fingers, this allows the testing of the ulna nerve (Fig. 13.5C). Note abduction of the thumb is performed by abductor pollicis brevis which is supplied by the median nerve. In the case of suspected fractures, the injured limb should be supported with sling and applied with ice-packing. The athlete should be removed from play and sent for X-ray confirmation of fracture. In the case of a suspected joint dislocation, the joint should be rested with a sling and the athlete sent for further investigation. However, in the case of glenohumeral joint dislocation, reduction of the joint can be performed by a trained clinician with adequate muscle relaxant and analgesics. If there is a suspected posterior SC separation, an immediate cardiopulmonary assessment and treatment should be done because of its close relationship with the vital organs. The athlete may complain of dyspnea and there may be a plethora of ipsilateral extremity, face and neck as well as diminution of pulses on the affected side. If there are signs of ventilation compromise, an attempt should then be made to reduce the dislocation on the field by applying simple traction to the shoulder in a backward and outward direction with simultaneous outward
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B
C
D
E
F
Figure 13.5 The ‘stone, paper and scissors’ movement of the hand/fingers. (A) The ‘stone’ movement. The patient is asked to flex the fingers and form a grip. The flexors are mainly innervated by the median nerve. (B) The ‘paper’ movement. By asking the patient to extend the fingers and form a ‘paper’, the extensors and the radial nerve are being tested. (C–G) The ‘scissor’ movement. This shows the abduction and adduction movement of the fingers, which imitates a ‘scissor’ movement. This abduction and adduction motion of the fingers is supplied by the ulnar nerve. Continued
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successful, and the athlete should be taken to the hospital immediately for further management.
Forearm and wrist injury
G Figure 13.5 Continued
pressure on the inner end of the clavicle. Any athlete with a soft tissue injury should be rested with ice-packing, immobilized and protected from further injury. A magnetic resonance imaging (MRI) or ultrasound scan can be arranged for the athlete at a later stage.
Elbow injury The elbow is likely to dislocate in a posterior direction when it is hyperextended in either abduction or adduction, causing ruptures of the collateral ligaments and anterior capsule. The athlete may give a history of severe elbow pain following a fall on an outstretched hand with the elbow fully extended. Distal humeral fracture is often seen after a fall or collision to the elbow, and it is relatively easy to diagnose on the fieldside. Usually the injured athlete complains of severe elbow pain together with a decreased range of movement which is then followed by rapid swelling of the elbow joint. Other fractures such as medial epicondyle avulsion fractures and olecranon fracture/epiphysis avulsion may be encountered and may have similar presentation. However, medial epicondyle avulsion fractures usually occur in young athletes following a hard throw. They will complain of sharp pain over the medial side of the elbow. Swelling is mild and localized over the medial epicondyle. The assessment is not complete without a neurovascular examination distal to the injury, as complications from irreversible nerve or blood vessels injury are not uncommon. Since all fractures have similar presentations, the exact site of injury must be confirmed by X-ray. Treatment on the field includes applying splint or sling in the resting position of the elbow. The team physician should place ice over the swollen site, and then assist the athlete to the sideline for further evaluation. In case of close elbow dislocation, close reduction can be done on-field if the team physician is confident in the diagnosis and experienced in performing the maneuver. This can be done by gentle traction along the long axis of the forearm with the wrist and elbow in extension and the extremity slowly moves into flexion. The neurovascular status should be monitored especially if reduction is not
Forearm fractures can result from a fall or direct blow on an outstretched arm, as in a missed wrestling or judo throw. The signs and symptoms of forearm fractures may include local tenderness, swelling, disability and crepitation. Whenever a fracture is suspected, a distal neurovascular examination should be done following the initial assessment. The limb should be splinted from the axilla to the mid-palm, and careful radiological evaluation must be made. The most common wrist injuries include soft tissue strains, followed by fractures with or without dislocation of joints. Common soft tissue strains include collateral ligament sprains, flexor or extensor tendon injuries, and triangular-fibrocartilage complex (TFCC) injuries. Fractures around the wrist joints include the common distal radius fractures, ulnar styloid fractures, the easily missed scaphoid fractures, and less commonly the fracture dislocation of the carpal bones, like perilunate dislocation. The mechanism of injuries is mostly falls onto an outstretched hand or a direct blow, or wrist sprain in racket sports. The appearance may be normal, but usually there is pain, swelling and local tenderness at the injured area, such as at the base of the thumb and tenderness over the anatomical snuffbox for the scaphoid fractures. For any injuries around the wrist, after on-field assessment, unless the team physician diagnoses it as a very minor injury, the wrist and thumb should be splinted, and arranged for further investigations and management.
Hand injury Sports injuries of the hand and finger are quite diversified, and include fractures, dislocation, ligament and tendon injuries. The metacarpal bones are vulnerable to injury after a fall upon the hand or a direct blow with a closed fist or the so-called boxer’s fracture. The usual sites of injury in boxer’s fracture are the distal 4th and 5th metacarpophalangeal bones. While fracture of the base of the 1st metacarpal (Bennett’s fracture) is also not uncommon, with the same mechanism of injury. The finger joints and bones are more prone to injury upon sudden hyperextension or hyperflexion, thus resulted in fractures of the phalanx, dislocations of the metacarpal or inter-phalangeal joint, or tendon ruptures. Gamekeeper’s thumb (ulna collateral ligament sprain) occurs among athletes with a fall onto an outstretched hand with the thumb hyperabducted. Physical examinations usually reveal localized pain, swelling and tenderness over the injured area, with deformity sometimes obvious. Mallet fingers (extensor tendon injuries) and jersey fingers (flexor tendon injuries) are usually presented with the inability to actively extend or flex the finger, respectively and local tenderness and swelling at the region of the distal phalanx. In cases of joint dislocations, it is best to refer to a trained physician for reduction, no matter how minor the injury may seem. It is mandatory for the team physician to perform a neurovascular and motion assessment before any reduction is made. Closed reduction is done by progressive traction along the long axis of the dislocated bone, and then applying
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pressure to the proximal base of the dislocated unit in the direction opposite to the dislocating force. A click may be heard or palpated upon relocation. Whether or not the team physician decides to perform a closed reduction, any suspected dislocations, such as phalangeal fractures, can be managed on the field with a buddy splint, by strapping the injured finger to its neighboring finger. Similarly, mallet finger or jersey finger can be temporarily splinted and referred for further expert care.
Acute back injuries
Box 13.4: Key Points
•
Common back injuries sustained during a game include muscle strains or sprain injuries, acute or chronic disc herniations, facet joints strains and fractures. ‘Move in one piece’ should always be the rule, with the neck supported during any rotation during the assessment. Presence of neurological symptoms and signs including muscle weakness, sensory loss and incontinence point to more serious injuries that require immediate transferal to a medical center.
Common back injuries sustained during a game include muscle strains or sprain injuries, acute or chronic disc herniations, facet joints strains, or less commonly fractures or fracture dislocations of spine (apart from cervical spine), with or without neurological complications. Upon athlete-sustained injury to the back on-field, the team physician should always be aware of possible serious injuries that should not be overlooked initially, as serious consequences can result from initial improper management. Any history of pre-existing back problems will provide the clue to diagnosis, e.g. history of herniated disc. Any complaint of pain or stiffness in the back should be taken seriously, even if the athlete can walk without apparent difficulty. Ask about radicular pain, muscle weakness, numbness, paresthesia and urinary or fecal incontinence. Upon inspection, any bruises of the face, or a superficial abrasion of the forehead, should suggest a hyperextension injury. The limbs should be quickly examined for any evidence of neurological deficits like muscle weakness, sensory loss and asymmetrical reflexes. Bear in mind that examination of the back should be very cautious, as it requires turning of the patient onto one side, which should be done with extreme care. ‘Move in one piece’ should always be the rule, with the neck supported during any rotation. Any bruises or hematoma of the back are sinister features, and the level of the injury, as indicated by local tenderness and regional muscle spasm
Table 13.3
always helps the team physician to better understand the pathology. The presence of neurological symptoms and signs usually represent more serious injuries that may require proper immobilization and immediate transfer to a medical center for further management. Table 13.3 lists a summary of relations of neurological injuries and the corresponding suspicious levels. As most of the cases are muscle strains or sprains, symptomatic treatment on-field followed by proper stretching may allow the athletes to return to play early, given that they are pain free and able to cope with the full demands of the specific sports. However, if there is severe pain persisting after a short period of rest, or when neurological complications arise, the athlete should be withdrawn from the game and further proper investigations and management in a medical center are crucial.
Acute hip, groin and pelvis injury
Box 13.5: Key Points
•
Most lower limb injuries should initially be managed conservatively with the rest, ice, compression and elevation (RICE) principle on the sideline, followed by definite investigation, treatment and rehabilitation.
•
Acute hip injuries include adductor strains in hockey or skating, iliac crest contusions in contact sports, apophyseal avulsions in sprints.
•
In acute knee injuries, pivoting during soccer or skiing are prone to ACL, MCL and meniscus injuries. Direct posterior blow to anterior aspect of proximal tibia in a fixed leg may point to PCL injuries. Giving way of the knee cap from a sprain with a valgus or external rotation force may indicate patella dislocation.
•
The cardinal signs of ACL injuries include hemarthrosis, intensive painful swelling, locking, ‘pop’ sound, dead leg and inability to continue to play.
•
Acute ankle injuries commonly involve inversion sprain with anterior talofibular ligament injuries, ankle fractures and Achilles tendon rupture.
Commonly encountered hip, groin and pelvic injuries on-field include adductor or hamstring strains, iliac crest contusion (hip pointer), or avulsions of apophysis in adolescent athletes, like from the anterior superior iliac spine for the sartorius, anterior inferior iliac spine for the rectus femoris, and the ischial tuberosity for the hamstring. However, the external genitalia
A Summary of the Relations of Neurological Injury and the Corresponding Suspicious Level
Level
Nerve Root
Sensory Loss
Motor Loss
Reflex Loss
L1–L3 L3–L4 L4–L5 L5–S1 S2–S3
L2, L3 L4 L5 S1 S2, S3, S4
Anterior thigh Medial calf Lateral calf, dorsal foot Posterior calf, plantar foot Perianal
Hip flexors Quadriceps, tibialis anterior EDL, EHL Gastrocnemius/soleus Bowel/bladder
None Knee jerks None Ankle jerks Cremasteric
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should never be ignored, as improper early management can lead to serious sequelae. Groin injuries during sports are commonly associated with direct contusion or avulsion fractures. Most of the time the athlete complains of sudden pain in the region involved, and indeed the athlete is usually able to indicate a specific point of pain, which can guide the physician to a diagnosis. Certain sports are particularly prone to certain injuries, e.g. adductor strains are more common in hockey or skating; iliac crest contusions are more common in contact sports such as soccer or rugby; while avulsions of apophysis are more common in running sports such as short distance sprints. Localized swelling, tenderness and muscle spasms around the injured area are quite typical, and usually the athlete is unable to continue the game. Most of these injuries require only conservative definite treatment, with application of the principle of ‘RICE’ in the acute phase on-field. Ice application and compression bandaging can significantly decrease the pain and swelling. Unfortunately, although most of the definitive treatments for these injuries are conservative, the athletes are usually not able to return to play immediately after the injury. The treatment and rehabilitation usually takes at least 4–8 weeks before they can return to play.
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Anterior cruciate ligament rupture
Figure 13.6 Anterior cruciate ligament (ACL) injury. (Reproduced from Rolf and Chan 2001.6)
Acute knee injuries Commonly encountered acute knee injuries included quadriceps strains or contusions, hamstring strains, ligament injuries (mostly medial collateral ligament (MCL) or anterior cruciate ligament (ACL) ruptures), meniscus injuries, osteochondral or chondral fractures, patella dislocation, quadriceps or patella tendon ruptures, or less commonly fractures around the knee. The mechanism of injury always helps the team physician with the diagnosis. Pivoting injuries during soccer or skiing are prone to ACL, MCL and meniscus injuries. Direct posterior blows to the anterior aspect of the proximal tibia in a fixed leg such as in a rugby game endanger posterior cruciate ligament (PCL) injuries. Sudden onset of giving way of the knee cap from a sprain with a valgus or external rotation force points to patella dislocation. Physical examination gives further clues to the diagnosis. Presence of acute hemarthrosis indicates a very high chance of an ACL tear (75% of cases) (Fig. 13.6).6 A positive Lachman test in a swollen knee is commonly illustrated in ACL injury (Fig. 13.7),6 and this test is the most sensitive test in detecting acute ACL injury, compared with other tests (anterior drawer or pivot shift test) (Fig. 13.8).6 Other cardinal signs of acute ACL injury include intensive painful swelling, locking or incomplete extension of the knee, feeling a ‘pop’ sound, a ‘dead’ leg, and finally the inability to continue to play. Local tenderness and pain in valgus stress are manifested in MCL sprain. Local joint line tenderness and pain with compression or rotation are suggestive of meniscal injury. Exquisite tenderness over the medial retinaculum of patella points to patella dislocation. But it is not uncommon that the aforementioned tests for ligamental laxities may not be elicited in the acute stage due to severe pain. Application of the principle of ‘RICE’ is very helpful in the management of acute knee injuries on-field. Since most of these injuries require further investigation and management,
Figure 13.7 The Lachman test. (Reproduced from Rolf and Chan 2001.6)
Figure 13.8 Anterior drawer test. (Reproduced from Rolf and Chan 2001.6)
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the patient should be referred to the medical center for further evaluation and definitive treatment. Apart from minor muscle contusions, players sustaining other knee injuries are advised not to return to play immediately after assessment on-field. This is because the initial signs may not be obvious and are sometimes obscured by pain, so they will be more prone to subsequent injuries if they return to the game immediately, without detailed assessment.
aitf atf
Acute ankle injuries
ptf
Acute ankle injuries mainly revolve around ligament injuries, fractures of the ankles and Achilles tendon sprains or ruptures. Inversion sprain injuries (Figs 13.9, 13.10),7 being common in all athletes, usually result in anterior talofibular ligament injuries, with or without other lateral collateral ligament injuries. Other ligament injuries are not uncommon, like deltoid ligament injuries over the medial side, or anterior tibiofibular syndesmosis disruptions in ‘high ankle sprains’. Local tenderness, swelling and deformities are usually the clues
cf
Figure 13.10 Lateral view of ankle ligaments. The lateral ligamentous complex of the ankle consists of the anterior talofibular (atf), calcaneofibular (cf) and posterior talofibular (ptf) ligaments. Aitf, anterior inferior tibiofibular ligament. (Reproduced from Olmedo and Per Renstrom 2001.7)
Inversion
Figure 13.9 Inversion is the most typical injury mechanism in ankle sprain. (Reproduced from Olmedo and Per Renstrom 2001.7)
to diagnosis, while those instability tests are neither sensitive nor specific early in the acute phase on-field. Where fractures or dislocations cannot be ruled out, the ankle should be protected with temporary splintage, and the application of the principle of ‘RICE’ treatment. Apart from very minor inversion ankle sprains without much pain, the athlete should be directed for further investigations and treatment after first-aid care and protection. Keys for return to play include being pain-free or having very mild pain, the absence of local tenderness or swelling, and the player’s capability to perform sports specific drills.
REFERENCES 1
2
3 4
Stanish WD, Evans NA. The modern-day team physicians: roles, responsibilities, and required qualifications. In: Michell L, Smith A, Bachl N, et al., eds. FIMS team physician manual. Hong Kong: Lippincott Williams and Wilkins; 2001:4–10. Luke A, Stanish WD. Fieldside assessment and triage. In: Michell L, Smith A, Bachl N, et al., eds. FIMS team physician manual. Hong Kong: Lippincott Williams and Wilkins; 2001:136–159. Cummins RO, ed. Defibrillation. Textbook of advanced cardiac life support. Dallas: American Heart Association; 1994. Luke A. Head and neck injuries. In: Michell L, Smith A, Bachl N, et al., eds. FIMS team physician manual. Hong Kong: Lippincott Williams and Wilkins; 2001:241–275.
5 6 7
Gerbino P. Shoulder injuries. In: Michell L, Smith A, Bachl N, et al., eds. FIMS team physician manual. Hong Kong: Lippincott Williams and Wilkins; 2001:278–298. Rolf CG, Chan KM. Knee injuries. In: Michell L, Smith A, Bachl N, et al., eds. FIMS team physician manual. Hong Kong: Lippincott Williams and Wilkins; 2001:366–394. Olmedo ML, Per Renstrom AFH. Foot and ankle injuries. In: Michell L, Smith A, Bachl N, et al., eds. FIMS team physician manual. Hong Kong: Lippincott Williams and Wilkins; 2001:406–427.
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CHAPTER
14
Laboratory Tests and Diagnostic Imaging William Micheo, Eduardo Amy and José Correa
INTRODUCTION Laboratory and diagnostic testing are widely used in the practice of sports medicine. Clinical management guidelines for the sports medicine practitioner are similar to other medical disciplines in which the treating physician should be responsible for the ordering and interpretation of the diagnostic studies necessary for patient management. Initially, the clinician should be guided by a detailed clinical history followed by a complete physical examination that allows the formulation of an orderly differential diagnosis. Once this step is completed, the physician can select the diagnostic and laboratory tests which can provide the most information to corroborate the presumptive clinical diagnosis. In addition, the sports medicine practitioner also needs to consider the cost effectiveness of the diagnostic work-up without sacrificing quality of care for the athlete. In the daily practice of sports medicine, laboratory and diagnostic tests can be used as part of a preventive medicine strategy or to plan appropriate treatment for illness or injury associated to sports or exercise participation. This chapter will address some of the laboratory and diagnostic tests that are crucial in the management of medical and musculoskeletal conditions which are commonly encountered in sports medicine (Table 14.1). Also included in this chapter is an introduction to imaging with the emphasis on magnetic resonance imaging (MRI) as a diagnostic test for sport-associated musculoskeletal injuries, which hopefully will add knowledge about the proper indications and clinical use of this important, but sometimes over utilized study. To discuss each laboratory and diagnostic study in detail is beyond our goals for this chapter, however, we expect readers to have a clinical understanding and practical approach to the use of laboratory and diagnostic studies in the management of common problems confronted daily in sport medicine practices.
PRE-PARTICIPATION EXAM SCREENING TESTING The purpose of the pre-participation physical examination has been identification of conditions that may disqualify an athlete from competition or to fulfill a requirement for medical clearance prior to a competition. In recent years this philosophy has changed to one of using this exam for the prevention of common diseases, orientation of healthy athletes, who would otherwise not see a physician, and identification of high risk behaviors such as drinking and driving, abnormal eating patterns, as well as having unprotected sex.1 Many laboratories and screening test guidelines are based on the individual’s age and disease risk profiles. Some of these, such as the one proposed by the US Preventive Services Task Force, are an effort to develop an evidence-based consensus of recommendations for preventive services. The recommendations include: clinical history, physical examination, immunizations, counseling, laboratories and screening tests for illnesses associated with different ages, levels of activity and sports participation.2 The sport medicine physician should apply these recommendations in pre-participation exams, especially in young individuals, who after 5 years of age are evaluated less frequently by physicians than other patient populations. Laboratory and diagnostic data that can be included in the examination, depending on the patient’s age and health status, include urinalysis, complete blood count, electrolytes, creatinine, liver function tests, cholesterol, thyroid studies and an electrocardiogram.3 However, some clinicians advocate individualizing the exam, and not performing laboratory studies as part of every pre-participation examination because of the low yield of the testing and the possibility of false positive tests in asymptomatic individuals, such as the runner with normal kidneys who presents with hematuria or proteinuria.4
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Table 14.1 Medicine
Basic Diagnostic Studies in Sports
Laboratory Studies
Radiologic Studies
Blood hemogram Blood chemistries Urine analysis Coagulation profile Muscle enzymes Electrocardiogram
Conventional X-rays Computed tomography (CT) Diagnostic ultrasound Technetium bone scan Magnetic resonance imaging (MRI) CT/MRI arthrography
ENVIRONMENTAL PROBLEMS IN ATHLETES Box 14.1: Key Points Heat illness
•
Basic tests
• • •
Initial rectal temperature Clinical assessment, blood pressure and heart rate Emergency room
• •
CBC, serum chemistries (electrolytes BUN/creatinine, phosphate, magnesium, calcium, CPK and liver enzymes), PT and PTT, INR, urinalysis and arterial blood gases Hospitalized athlete
•
Follow-up of above studies, electrocardiogram if there is electrolyte disturbances, fibrin split products if coagulopathy is suspected, brain MRI or CT scan if neurologic deficit appears.
Exertional heat illness/injuries This illness is commonly seen in the summer and particularly in warm and humid climates. Heat illness can be classified in five exertional heat syndromes: heat edema, heat cramps, heat syncope, heat exhaustion and heat stroke.5 In addition, slow runners or participants in long duration events such as ultramarathons may collapse from hyponatremia associated to over-zealous hydration.6 Complications related to severe heat stroke are acute renal failure, disseminated intravascular coagulation, rhabdomyolysis, acute respiratory distress syndrome, acid base disorders and electrolyte disturbances. The prognosis for the patient is better when heat stroke is diagnosed early with appropriate studies and management with cooling measures and fluid and electrolytes replacement is started early. Prognosis is poor if treatment is started after 2 h of the initiation of symptoms.7 The initial evaluation of the athlete with suspected heat illness should include documentation of core temperature with a rectal probe, since tympanic membrane, oral or axillary temperatures do not correlate with core temperature. In addition, complete blood cell count (CBC), serum chemistries (electrolytes, blood urea nitrogen (BUN)/creatinine, phosphate, magnesium, calcium, creatine phosphokinase (CPK) and liver enzymes level), coagulation studies (prothrombin time (PT), partial thromboplastic time (PTT) and INR), urinalysis and arterial blood gases should be obtained.8 The initial abnormal findings may include elevated core temperature, as high as 104˚F in the case of heat stroke, leuko-
cytosis or thrombocytopenia in the CBC, hypokalemia associated with catecholamine effects, hyperventilation and sweat losses, as well as physiologic hyperaldosteronism.9 After a few hours, hyperkalemia is found associated with sustained hyperthermia, hypoxia and hypoperfusion, hypocalcemia and elevated BUN and creatinine secondary to renal dysfunction. Other laboratory abnormalities will include hypophosphatemia due to an increase in glucose phosphorylation seen in alkalosis, hyperuricemia secondary to purine release from injured muscles, and an increase in liver enzymes AST, LDH and total bilirubin commonly seen associated with liver dysfunction. In severe cases of heat illness, a coagulation disorder with evidence of disseminated intravascular coagulation (DIC)/consumption coagulopathy can be seen with elevated fibrin split products, PT, PTT and INR. Muscle damage can be associated with rhabdomyolysis with elevated CPK and myoglobin casts in the urine. Other ancillary diagnostic studies include an electrocardiogram which may show tachycardia, rhythm disturbances (atrial fibrillation, supraventricular tachycardia), conduction defects (right bundle branch block (RBBB), intraventricular conduction defect), prolongation of QT interval most common secondary to hypocalcemia, hypomagnesemia or hypokalemia, or ST changes of myocardial ischemia. Neurological tests may be required in patients with central nervous system involvement associated with heat stroke. Neurological deficits are possibly secondary to metabolic changes, cerebral edema or ischemia. The cerebellum is the most susceptible area to heat illness and cerebellar atrophy can be found after several weeks.9 Brain CT scans or MRI are indicated in patients with persistent neurologic deficit after heat stroke. In exertional hyponatremia, usually the electrolyte tests will reveal sodium levels in the range of 110–130 mmol/l accompanied by symptoms of headache, nausea, dyspnea and muscle cramps. A high level of suspicion is required for this condition that affects particularly the slow runners in long distance events.6
Cold injuries Box 14.2: Key Points
•
Basic tests
• • •
Initial field clinical assessment, blood pressure and heart rate Low reading rectal thermometer Emergency room
• •
Serum electrolytes, arterial blood gases, CPK and electrocardiogram Hospitalized athlete
•
PT, PTT, INR, follow-up of emergency room laboratories.
Hypothermia usually occurs associated with exercise in the cold when the body temperature falls below 95˚F (35˚C). Mild hypothermia is seen when the body core temperature is 35˚C or greater. Shivering, tachycardia, tachypnea and cool extremities are usual associated symptoms. Moderate hypothermia is seen when the body core temperature drops below 34˚C. At this stage, there will be signs of CNS depres-
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sion and the athlete is confused, displays gross incoordination, slurred speech, drowsiness and may become dehydrated. Shivering is diminished or may not be present at all. In severe hypothermia, the body core temperature is less than 32˚C. At this stage, the athlete displays marked cognitive impairment and may be comatose. The body is rigid, cool and there is no shivering. The athlete is hypotensive with bradycardia, and cardiac arrhythmias are commonly seen. Almost all mild hypothermic healthy athletes recover normally. In athletes with moderate to severe hypothermia, rates of recovery are lower with ventricular fibrillation being the most common cause of death.10 A low reading rectal thermometer should be available in the first aid kit to document low temperature during cold weather athletic events.11 If this type of thermometer is not available, the core temperature can be grossly estimated by evaluating if the athlete is shivering, in which case the core temperature is usually >90˚F (32˚C), or if the athlete is obtunded and not shivering usually the core temperature is 0.2 s) and second degree Mobitz I Wenckebach block. Other findings may include increased voltage without left axis, QRS prolongation, or left atrial enlargement. There may also be U waves, early repolarization changes and incomplete right bundle branch block in the EKG. Correct interpretation of these findings is necessary to avoid preventing individuals without cardiac disease from participating in sports.
Coronary artery anomalies The EKG is usually normal, but may show evidence such as Q waves suggesting myocardial infarction. An echocardiogram may show anomalies in the origin of the coronary arteries. The thallium stress test may be abnormal with exercise but conventional stress tests are usually normal. Finally, cardiac catheterization is necessary to definitely identify anomalies of the coronary arteries.8,16
Hypertrophic cardiomyopathy In hypertrophic cardiomyopathy, the EKG is abnormal in 95% of cases. The findings include a marked increase in voltage, prominent Q waves >0.04 s and deep negative T waves in two or more leads. The echocardiogram is the test of choice to diagnose this condition in adults and shows left ventricular wall thickening of more than 15 mm with an unusual distribution (concentric, asymmetrical septal or apical).12
Myocarditis The patient with myocarditis has an EKG that shows diffuse low voltage, ST-T wave changes, heart block and ventricular arrhythmias. Laboratory tests may show a CBC with leukocytosis, eosinophilia, increased ESR and increased cardiac enzymes. Echocardiography will exhibit a dilated left ventricle, global hypokinesia, segmental wall abnormalities and decreased ejection fraction. An endocardial biopsy would help to confirm the diagnosis.19
Aortic stenosis The EKG shows left ventricular hypertrophy and ST-T waves changes of left ventricular strain. An echocardiogram shows left ventricular hypertrophy, narrowing of the aortic valve with estimated gradient across the valve. Exercise testing may be needed to evaluate for evidence of ischemia, arrhythmia, and assess for exercise duration and blood pressure response.8,16
Box 14.4: Key Points Exercise induced bronchospasm tests
• • • •
Peak flow meter before and after exercise Pulmonary function tests before and after exercise 1–3–5–10–15 min Eucapnic voluntary hyperventilation challenge with dry air a Methacholine inhalation challengea a Studies
done only for investigation or as a last resort
EIB is one of the most common conditions in active children, adolescents and young adults. It develops when vigorous physical activity triggers airway narrowing in persons with heightened bronchial reactivity. EIB occurs after near maximum exercise for >5 min. The individual exercising experiences difficulty breathing with shortness of breath, coughing, chest tightness, wheezing and lack of energy. Physicians should have a high index of suspicion for this condition, particularly in children, since signs and symptoms are not a good predictor of EIB in kids with minimal complaints.20,21 A clinical trial with prophylactic medications such as inhaled beta agonists, cromolyn sodium, nedocromil sodium, theophylline, inhaled steroids, or ipratropium bromide can be used for diagnostic purposes. Although this is not a scientific method, it may aid in confirming the diagnosis, however, in patients with chronic asthma this technique may not permit physicians to differentiate this condition from EIB.22 The evaluation of EIB should include some of the following studies. Initial evaluation can start with peak flow measurement before and after exercise. The baseline peak flow should be evaluated at rest, and following sustained vigorous exercise for 6–8 min with heart rate responses of >90% of predicted for age. Pulmonary function tests including forced expiratory volume (FEV), forced expiratory flow (FEF 25–75), peak expiratory flow rate (PEFR) can be measured before and after exercise at 1–3–5–10 to 15 min intervals while running on a treadmill or riding a bicycle ergometer.8,23 Different types of challenge tests can be performed when there is doubt of the diagnosis of EIB. A eucapnic voluntary hyperventilation (EVH) challenge with dry air has been shown to have high sensitivity and high specificity for EIB. However, this test is expensive and generally unavailable. The methacholine inhalation challenge has low sensitivity but high specificity in elite athletes, and is not recommend in the athlete with pure EIB. The osmotic challenge inhalation tests done with hypertonic saline or the inhaled dry powder mannitol challenge have both high sensitivity and specificity for EIB. They may be better alternatives than the EVH test to evaluate EIB.24
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GASTROINTESTINAL PROBLEMS IN ATHLETES Exercise induced diarrhea
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should be ruled out by endoscopic studies. In the case of bleeding associated with exercise, lower gastrointestinal endoscopic studies should be performed within 1–2 days of frank bleeding, since ischemic lesions could resolve after 2 days.
Upper gastrointestinal problems Box 14.5: Key Points Exercise induced diarrhea tests
• • •
Stool samples for culture, ova and parasites, occult blood and leukocytes
•
Some common gastrointestinal conditions are GERD, gastritis, PUD and delayed gastric emptying
•
Upper gastrointestinal endoscopy is recommended if symptoms persist.
CBC, electrolytes, ESR, giardiasis Endoscopic studies.
Diarrhea is seen mostly in intense endurance training and most commonly in running (10–50% of runners). Proposed etiologies include anxiety, increased gastrointestinal motility (exercise increases secretion of gastrin, motilin and other hormones), dietary factors (high fiber, fruits, large doses of caffeine or vitamin C) and changes in the immune system.8,25 Initial laboratory and diagnostic tests are done based on the history, physical examination and stool evaluation (culture, ova and parasites, occult blood and leukocytes). These include tests for giardiasis, complete cell blood count, ESR and electrolytes. Initial treatment may include reduction of exercise intensity, followed by a gradual return to the previous level of training, dietary manipulation or antimotility agents.26 If the diarrhea persists after the initial management endoscopic studies can help to rule out other etiologies such as colitis.
Lower gastrointestinal bleeding Box 14.6: Key Points Lower gastrointestinal bleeding
•
Box 14.7: Key Points
Lower gastrointestinal endoscopy is the study of choice for persistent symptoms.
Mild exercise decreases intestinal perfusion by 40% and strenuous exercises may decrease it by 89%. This intestinal ischemia can cause focal areas of necrosis and ulceration with bleeding.25 Other gastrointestinal pathology that causes bleeding such as colon cancer, hemorrhoids, and inflammatory bowel disease
Table 14.2
These problems include gastrointestinal reflux disease (GERD), peptic ulcer disease (PUD), gastritis and delayed gastric emptying. Upper endoscopy should be considered in patients that exhibit persistent symptoms after treatment trials with H2 blockers, proton pump inhibitors and adequate dietary changes.
NEUROMUSCULAR PROBLEMS IN ATHLETES Headache in athletes The epidemiology of this common disorder is not clear, however it is frequently encountered by the sport medicine physician.27 Most exertional headaches are benign but it is important to exclude secondary headache associated with serious conditions. Athletes should be evaluated for ‘red flags’ that indicate serious disease such as headache onset after the age of 50, sudden onset of headache, increased severity and frequency of headache with activity, new onset symptoms in the immunocompromised patient and headache associated with systemic illness. Other aspects of the history that are important include fever, neck stiffness, focal neurologic deficit, trauma, gait problems, amnesia, alteration of consciousness, early morning nausea, and vomiting (Table 14.2).28 Laboratory studies that should be performed include CBC, ESR, liver function tests and thyroid function tests to rule out metabolic pathology. Other diagnostic studies that may be required include cervical X-rays with flexion/extension views in patients with trauma to rule out cervical fracture and instability, head computer tomography (CT scan) without and with contrast in new onset exertional headache to rule out bleeding,
Classification of Headache
Exertional Headache
Effort Headache
Post Traumatic Headache
Others
Occurs after strenuous activity (lifting weights or sprinting). Located on occipital cervical region. Brief duration.
Occurs after running for several hours. Initiated by aerobic activity and aggravated by dehydration, heat, fatigue, excessive exercise, alcohol, caffeine.
Headache occurring after head trauma.
Cervicogenic, trauma triggered migraine, and headache associated with altitude.
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and magnetic resonance imaging (MRI) in patients with suspected arteriovenous malformation, tumor or posterior fossa lesions. Lumbar puncture can be performed to rule out subarachnoid hemorrhage from ruptured aneurysm since it can detect minor leaks in patients who can later have a rupture even with a negative CT scan.28 In the athlete with migraine, the American Academy of Neurology states that routine brain imaging is not warranted for adults with recurrent headaches that have been identified as migraine with no recent change in pattern, without history of seizures or other focal neurological sign or symptoms.29
play decisions. Also, they may lead the clinician to order further studies including muscle or nerve biopsy.31 The application of molecular genetic techniques has resulted in significant gains in the understanding of the molecular and pathophysiologic bases of many neuromuscular diseases. In addition, molecular genetic studies aid in the diagnostic evaluation of dystrophin-deficient muscular dystrophies or hereditary neuropathies among other neuromuscular diseases that may present in athletes with complaints of weakness.32
Muscle pain Muscle weakness Box 14.9: Key Points Box 14.8: Key Points
• •
Initial laboratories
•
Initial laboratories/studies
•
Serum chemistries electrolytes (calcium, magnesium, glucose), TSH, CPK, ESR, ANA.
Muscle weakness may be a complaint of an athlete presenting for clinical evaluation. A thorough clinical assessment is required to differentiate fatigue, focal weakness, or generalized weakness. Athletes may present with a medical condition associated with exercise or sport which results in weakness, or may have an underlying disease which is exacerbated by activity. The physician evaluating the patient with muscle weakness should try to identify if neurologic, endocrine, inflammatory, rheumatologic, genetic, metabolic, electrolyte-imbalance or drug-related conditions is what causes the individuals symptoms.30 If the cause of muscle weakness in unclear, serum chemistries (electrolytes, calcium, magnesium, glucose) and a thyroid-stimulating hormone assay should be obtained to evaluate for electrolyte disturbances and endocrine myopathies. Next, investigations looking for inflammatory, rheumatologic, or genetic myopathies can be performed. Although nonspecific, the creatine kinase (CK) level usually is normal in the electrolyte and endocrine myopathies with the possible exceptions of thyroid and potassium disorder myopathies. However, the CK level may be highly elevated (10–100 times normal) in the inflammatory myopathies and can be moderately to highly elevated in the muscular dystrophies. In addition to CK, an erythrocyte sedimentation rate (ESR) and an antinuclear antibody (ANA) may help determine if a myopathy associated to rheumatic disease exists. If either the ESR or the ANA is positive, additional studies may be obtained, including rheumatoid factor looking for rheumatoid arthritis, anti-double-stranded DNA or antiphospholipid antibodies to evaluate for systemic lupus erythematosus, or anticentromere antibodies looking for scleroderma.30 Nerve conduction and electromyography studies are a powerful tool for the diagnosis and localization of lesions within the lower motor neuron, neuromuscular junction, peripheral nerve and muscle. In addition, electrodiagnostic studies may help to establish the severity of lesion, prognosis for recovery, and help in making return to
Serum electrolytes, CK, urinalysis, liver function tests, and coagulation studies.
The athlete who presents with muscle pain following activity needs to be evaluated for the possibility of muscle fiber damage. This could range in severity from delayed onset muscle soreness (DOMS) to rhabdomyolysis. Predisposition to muscle damage in the athlete may be related to poor conditioning, dehydration, underlying viral illness or medical condition, as well as intense eccentric exercise. Complications of rhabdomyolysis with severe muscle damage include renal failure, metabolic derangements, DIC and death.33 Initial studies in the athlete with suspected muscle injury associated to pain include serum electrolytes, CPK, urine analysis, liver function tests, and coagulation studies. Muscle injury seen in the individual with DOMS is usually associated to modest elevations of CPK while more severe injury is associated to high CPK, myoglobinuria, abnormal PT, PTT and fibrin split products.
HEMATOLOGIC PROBLEMS IN ATHLETES
Box 14.10: Key Points Anemia
•
Initial laboratories
•
CBC, peripheral smear, ferritin levels, vitamin B12 levels, folate levels
Anemia in athletes Anemia is defined as a reduced number of circulating red blood cells (RBC) or reduced hemoglobin concentration. Hemoglobin or hematocrit levels cannot be used as the unique measure in the evaluation of anemia since both values do not indicate RBC mass. Anemia can be classified instead by RBC morphology (Table 14.3).
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Endurance athletes can present with hemoglobin levels 0.5 g lower and elite athletes 1 g lower than sedentary persons. Increases in plasma volumes of 10–20% lead to dilution of the measured hemoglobin level and has been named ‘sports anemia’ or dilutional pseudoanemia.34 This condition does not seem to be pathologic but an adaptation to endurance training, and usually can revert to normal with training cessation of 3–5 days.35 Although hemoglobin and hematocrit levels are lower, total RBC and RBC mass are increased with a normal morphology index (mean corpuscular volumes), so there is no need to treat this entity.36
athletes after their menstruation starts to establish a baseline, even if the athlete does not present with symptoms or decreased performance.38 Ferritin level is the most commonly used indicator of body iron stores. Low ferritin levels (250 mg/dl urine ketones should be checked and exercise may be permitted if no ketones are present.
GENITOURINARY PROBLEMS IN ATHLETES Hematuria
DIABETIC ATHLETES Box 14.13: Key Points Box 14.12: Key Points Diabetes mellitus
• •
•
Initial laboratories
•
Urinalysis, repeated at 48–72 h post exercise.
Pre-participation evaluation is essential Initial laboratories
•
FBS, HgbA1C, renal function tests, urine microalbumin test, ketones.
Diabetic athletes on insulin or oral hypoglycemic agents are prone to hypoglycemia or hyperglycemia depending on glucose level before starting exercise. Athletes with type I diabetes mellitus (DM) who are insulin dependent are also at risk of developing ketoacidosis. The sport medicine physician must rely on laboratory testing to know which diabetic athlete should be cleared to do training. Physicians should instruct the patient to monitor the blood glucose prior to and after exercising to assess control and the response to specific training of different intensities. Laboratory studies that should be performed in the diabetic athlete include fasting blood sugar, glycosylated hemoglobin (HgbA1C) levels, renal function tests, and urine tests for microalbumin, as well as ketones.43 The diabetic athlete can be cleared to perform strenuous exercise when HgbA1C is within 6–8%. Exercise tests to screen for coronary disease must be done for the diabetic individual >35 years of age who wants to start a program of moderate to vigorous exercises. Renal function needs to be evaluated periodically, adequate hydration and restriction of anti-inflammatory agents (nonsteroidal) in the diabetic training for long periods of time should be encouraged.44 At the time of starting exercise, if the blood sugar is 3 RBC/HPF) and seen in noncontact sports. It usually resolves within 48–72 h but in some cases of prolonged exercise, it may be present up to 7 days. Exercise-induced hematuria can originate from the kidney, bladder, urethra or prostate. Hematuria of renal origin can be caused by either ischemia (non-traumatic) or direct as well as indirect (traumatic) renal injury. Hematuria can also be caused by repetitive trauma to the bladder posterior wall against its base in long distance events.45 Some athletes that present with hematuria may have underlying medical problems such as urinary tract infection, nephrolithiasis, tumor, coagulopathies and rhabdomyolysis. In the individual with persistent painless hematuria, identification of factors associated with malignancy should be addressed (Table 14.5). Table 14.5 Factors Associated with Genitourinary Malignancy Smoking history Occupational exposure to chemicals or dyes History of gross hematuria Age >40 years History of irritative voiding symptoms History of urinary tract infections Analgesic abuse History of pelvic irradiation
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The diagnostic studies include a urinalysis, which may show microhematuria of three or more red blood cells per high power field on microscopic evaluation of urinary sediment from two of three properly collected urine specimens. In the athlete, hematuria persisting after 48–72 h post-exercise should lead to other studies which help to rule out associated diseases. A microscopic urine analysis could be done to assess mean corpuscular volume and red blood cell morphology to search the origin of bleeding. If mean corpuscular volume (MCV) >72 its origin is from a non-glomerular site and if MCV 40 years of age, can be performed to rule out neoplasia. Hematuria is probably not secondary to exercise if it persists after 24–72 h, if there is the presence of gross hematuria, if the athlete is older than 40 years, if it is recurrent, or if it is not associated with intense or prolonged exercise. Distance running athletes have been shown to have post-exercise hematuria at least once, specially after a workout run at 110% of VO2max over short to moderate distances, but in general, cases resolve within 2 h of recovery.48
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Studies have shown that albumin contributes more than other proteins in exercise induced proteinuria, which is probably from glomerular and tubular origin in the kidney, and this change is usually reversible. A urine dipstick method to detect protein is good for screening but does not detect the microalbuminuria seen in diabetics. In the athlete, a dipstick urine and urinalysis should be performed 24–48 h after exercise, if looking for persistent proteinuria associated to renal disease, diabetes mellitus, hypertension or orthostatic proteinuria.50
Renal trauma Renal trauma can occur secondary to a direct blow or from a high speed collision. The patient can present with pain, tenderness, ecchymosis and hematuria. A correlation with the amount of hematuria and the severity of injury is not reliable and the patient can be seen with hypotension from bleeding. Abdominal CT scan with intravenous and oral contrast can evaluate for contusion and localize an injury which can lead to surgery.45
DIAGNOSTIC IMAGING Diagnostic imaging in athletic injuries has taken an increasingly important role in the management of such injuries. The higher level of competitiveness and the urgency to return to competition demands a faster diagnosis in order to make a therapeutic decision. There is also an increasing role for accurate diagnostic tests in the prevention of new injuries, or the exacerbation of existing ones. Although the progress of diagnostic imaging techniques has been impressive, these tests are not a substitute but a complement to a good history, a careful physical exam and an extensive differential diagnosis which continue to be the mainstay of musculoskeletal diagnosis. The most common imaging techniques used in sports medicine are conventional radiography, magnetic resonance imaging, radio nuclide imaging and diagnostic ultrasonography. A brief review of these will be covered in the following section.
Radiography Proteinuria Box 14.15: Key Points
•
Conventional radiography remains the standard in the diagnosis of fractures.
•
High sensitivity in fractures and availability in the case of emergencies.
•
Important in the follow-up of fracture treatment to document healing.
Box 14.14: Key Points
• •
Initial laboratories Urinalysis, urine dipstick at 24–48 h post-exercise.
Increased protein in the urine is present in up to 70% of athletes after exertion. Normal protein excretion is 30–45 mg/day and exertional proteinuria ranges from 100–300 mg/day, which usually occurs within 30 min of exercise and decreases in 24–48 h. It is more commonly seen in strenuous and prolonged exercise but mostly directly related to intensity.49
X-ray diagnosis has been extensively used and is a safe, proven and inexpensive diagnostic test. Plain X-ray can be used in virtually all bone injuries and because of its high sensitivity, as well as relative availability, it remains as the standard in the diagnosis of fractures.51 These include all long bones as well as tarsal and axial skeletal bones.
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In the management of traumatic injury, it is important to order at least two radiographic views of the injured part, perpendicular to each other, and in the child athlete with open growth plates, it may be necessary to compare the films with the uninvolved extremity. In the individual with overuse injury, the use of plain radiographs is less common; however, plain films can still be used to identify anatomical variants, tumors, signs of degenerative joint disease and sub-acute or chronic changes of a stress fracture. In addition, radiographic evaluation is important after treatment of a fracture to ensure proper post-reduction alignment and to document healing. Also, conventional radiographs aid in the diagnosis of certain complications, such as infection, avascular necrosis, or post-traumatic osteoarthritis.
Computed tomography (CT) Box 14.16: Key Points
•
Image slices of variable thickness can be used to depict bone details.
•
Allows identification of intraarticular and stress fractures, which may be missed in conventional radiographs.
•
May be combined with contrast enhancement.
Computerized axial tomography uses X-ray generating tubes and image detectors to produce images in the transverse, sagittal and coronal planes. Image slices can vary in thickness from 1–10 mm and can be used to depict bone detail. Conventional CT consists of a rotating X-ray tube emitting a collimated radiation beam and multiple detectors to measure transmission through a stationary patient. A computer then processes the data to provide a two-dimensional or simulated threedimensional image.52 The use of a CT scan allows the identification of intraarticular fractures, stress fractures and others which may be missed in conventional radiographs. In addition, CT can be used with contrast enhancement, which can be of benefit in particular clinical scenarios, such as the athlete with shoulder instability and a suspected labral lesion.53 The athlete with head or spine trauma may require the use of CT which is an excellent diagnostic modality to evaluate intracerebral bleeding and for vertebral fractures which should be considered for emergency treatment. In the individual with back pain the use of thin cuts across the pars interarticularis may allow for the identification of spondylolysis and performing images across the disc or facet joints may help to diagnose discogenic disease or spinal stenosis.54
Magnetic resonance imaging (MRI) MRI has revolutionized diagnostic imaging of the musculoskeletal system. Non-invasive direct visualization of bone, marrow and supporting soft tissue structures are clearly obtained via this technology. The principles of nuclear magnetic resonance were originally described in 1946 by two independent researchers who
Box 14.17: Key Points
• •
MRI has the ability to display excellent soft tissue contrast.
•
MRI is highly sensitive in the diagnosis of meniscal and anterior cruciate ligament injuries.
Different imaging sequences can be used to study anatomic detail or to diagnose injury.
were awarded the Nobel Prize. These principles were applied to MRI in 1973 for medical use. By 1980, it was widely used for the diagnosis of neurological diseases and since then it has been widely used in the musculoskeletal system. MRI is a tomographic multiplanar technique with the ability to display outstanding soft tissue contrast. It works by detecting the relaxation times of hydrogen atoms. The human body is placed in a strong magnetic field usually 1.5 T (Tesla) provided most commonly by an electromagnet, energized in a super conductor state cooled by liquid helium, and nitrogen to 4˚ above absolute zero. Hydrogen protons in the body will spin and align themselves with the direction of the external magnetic field and reach a state of equilibrium. This is followed by the emission of energy by the machine in the form of radio wave frequencies. This energy is absorbed by the hydrogen protons, which exist in all tissues. Upon discontinuation of the radio waves, the excited protons lose this extra energy through T1 (longitudinal) relaxation and T2 (transverse) relaxation mechanisms. The intensity of the magnetic resonance signal that results is chiefly determined by these two relaxation patterns as well as the proton density. This minute amount of energy released by the resonating hydrogen protons is picked up by coil antennas placed around the extremity. This recorded energy signal is taken through a mathematical process (Fourier) and the computer forms the image. The body is not exposed to ionized radiation but rather to magnetic and radio frequency energy. TR stands for repetition time, the time between successive excitation pulses. The TE stands for echo time, the time that an echo is formed.55 Three basic sequences are used, T1-weighted, T2-weighted and proton density sequences, because tissues in the body emit different intensity signals in T1, T2 and proton density images. For example, fat will look bright in T1-weighted images, and fluid will look dark. However, the opposite is true for T2weighted images. T2 images will show, fluid, soft tissue edema, bone marrow edema and bone contusion as a bright signal (Table 14.6).56 Most acute traumatic injuries will be dramatically revealed in the T2-weighted sequence. Therefore T2 tends to be more of a pathology sequence, while T1 tends to be more of an anatomy sequence. T2 is determined by a long TR >1500 µs and TE >60 µs, while a T1 image is determined by a short TR 2 mm deep with marrow edema on T2 image Segond’s capsular avulsion fracture of the lateral tibial plateau Anterior displacement of the tibia on the femur
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References
resolution and relative lower cost. More importantly, dynamic imaging under sonographic visualization allows the clinician to make diagnoses that cannot be made with other diagnostic imaging studies.72 Sonography is universally tolerated across a broad patient population, including pediatric and pregnant patients and those in whom traditional magnetic resonance imaging is not an option, because of absolute or relative contraindications.73 Ultrasound refers to energy above the perceptible range of frequencies (20 Hz–20 kHz). The frequencies used for diagnostic ultrasound range from 2 to 10 MHz. Ultrasound waves are directed to the tissues and as these bounce back from the tissues their echo is received by sensor and interpreted by a computer and an image is constructed. 52 It is especially useful in the diagnosis of acute tendon ruptures, muscle tears and muscle hematomas, and avulsion fractures. It appears to be safe, sensitive and specific in the hands of a skilled examiner. However, in chronic cases of tendinopathy such as the one affecting the Achilles tendon, only moderate correlation with clinical assessment has been found by some researchers.74
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CONCLUSION Laboratory and diagnostic studies are very important for the clinician treating individuals with exercise or sports related illness or injury. Sports medicine physicians should feel comfortable in ordering specific diagnostic tests for commonly encountered medical conditions and should be able to interpret the results as well as use them to plan an appropriate treatment program. Basic studies that should be available to the sports medicine team include blood hemogram and chemistries, urine analysis, coagulation profiles, muscle enzymes and electrocardiograms. More advanced studies may be required in particular instances of individuals with underlying medical problems and who participate in sports. These include cardiovascular studies such as echocardiography and coronary angiography. Radiologic studies are also part of the basic diagnostic armamentarium that should be available for the sports medicine practitioner. Clinicians who treat athletes should understand the indications and be able to interpret basic as well as advanced imaging studies.
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Kimberley G, Harmon MD. Evaluating and treating exercise-related menstrual irregularities. Phys Sports Med 2002; 30:29–35. Warren MP, Goodman LR. Exercise induced endocrine pathologies. J Endocrinol Invest 2003; 26:873–878. Warren MP, Perlroth NE. The effects of intense exercise on the female reproductive system. J Endocrinol 2001; 170:3–11. Albright A, Franz M, Hornsby G, et al. American College of Sports Medicine position stand: Exercise and type 2 diabetes. Med Sci Sports Exerc 2000; 32:1345–1360. Bhaskarabhatla KV, Birrer R. Physical activity and Type 2 diabetes. Phys Sport Med 2004; 32:13–17. Holmes FC, Hunt JJ, Sevier TL. Renal injury in sport. Curr Sports Med Rep 2003; 2:103–109. Kallmeyer JC, Miller NM. Urinary changes in ultra long distance marathon runners. Nephron 1993; 64:119–121. Jones GR, Newhouse I. Sport-related hematuria: A review. Clin J Sport Med 1997; 7:119–125. Grossfeld GD, Wolf JS, Litwin MS, et al. Asymptomatic microscopic hematuria in adults: Summary of the AUA best practice policy recommendations. Am Fam Phys 2001; 15:6. Gerth J, Ott U, Funfstuck R, et al. The effect of prolonged physical exercise on renal function, electrolytes balance and muscle cell breakdown. Clin Nephrol 2002; 57:425–431. Clerico A, Giammattei C, Cecchini L. Exercise-induced proteinuria in well-trained athletes. Clin Chem 1990; 36:562–564. Tung GA, Brody JM. Contemporary imaging of athletic injuries. Clin Sports Med 1997; 16:393–471. Sanders TG, Fults C. Imaging techniques. Imaging of sports related injuries. In: DeLee JC, Drez D, Miller MD, eds. Orthopaedic sports medicine: principles and practice. Philadelphia: Saunders; 2003:557–596. Lehmann M, Kreitner KF, Kirschner P, et al. Possibilities of computerized arthrotomography in the diagnosis of shoulder instabilities. Unfallchirug 1990; 93:228–231. Hollenberg GM, Beitia AO, Tan RF, et al. Imaging of the spine in sports medicine. Curr Sports Med Rep 2003; 2:33–40. Kaplan PA, Helms CA, Dussault R, et al. Musculoskeletal MRI. Philadelphia: Saunders; 2001. Sanders TG, Miller MD. A systematic approach to magnetic resonance imaging interpretation of sports medicine injuries of the knee. Am J Sports Med 2005; 33:131–148. Miller MD, Osborne JR, Warner JJ, et al. MRI arthroscopy correlative atlas. Philadelphia: Saunders; 1997.
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Gross GW. Imaging techniques. Differences between the immature and mature skeleton. In: DeLee JC, Drez D, Miller MD, eds. Orthopaedic sports medicine: Principles and practice. Philadelphia: Saunders; 2003:597–614. Bruker P, Bennell K. Stress fractures in female athletes: Diagnosis, management and rehabilitation. Sports Med 1997; 24:410–429. Batt ME, Ugalde V, Anderson MW, et al. A prospective controlled study of diagnostic imaging for acute shin splints. Med Sci Sports Exerc 1998; 30:1564–1571. Mandelbaum BR, Finerman GA, Reicher MA, et al. Magnetic resonance imaging as a tool for evaluation of traumatic knee injuries: anatomical and pathoanatomical correlations. Am J Sports Med 1986; 14:361–370. Reicher MA, Hartzman S, Bassett LW, et al. MRI imaging of the knee. Traumatic Disord Radiol 1987; 162:547–551. Carrino JA, Shweitzer ME. Imaging of sports related knee injuries. Radiol Clin North Am 2002; 40:181–202. McCauley TR. MRI evaluation of the postoperative knee. Radiology 2005; 234:53–61. Rosenthall L, Hill RO, Chuang S. Observation on the use of 99m Tc-phosphate imaging in peripheral bone trauma. Radiology 1976; 119:637–641. Martin P. Bone scanning of trauma and benign conditions. In: Freeman LM, Weissman HS, eds. Nuclear medicine annual. New York: Raven Press; 1982:81–118. Gregory PL, Batt ME, Kerslake RW, et al. Single photon emission computerized tomography and reverse gantry computerized tomography findings in patients with back pain investigated for spondylolysis. Clin J Sport Med 2005; 15:79–86. Sterling JC, Edelstein DW, Calvo RD, et al. Stress fractures in the athlete. Diagnosis and management. Sports Med 1992; 14:336–346. Bauer HC, Persson PE, Nilsson OS. Tears of the medical meniscus associated with increased radionuclide activity of the proximal tibia: Report of three cases. Int Orthop 1989; 13:153–155. Mooar P, Gregg J, Jacobstein J. Radionuclide imaging in internal derangement of the knee. Am J Sports Med 1987; 15:132–137. Dye SF, Chew M, McBride JT, et al. Restoration of osseous homeostasis of the knee following meniscal surgery. Ortho Trans 1992; 16:725. Jacobson JA. Ultrasound in sports medicine. Radiol Clin North Am 2002; 40:363–386. Sofka CM. Ultrasound in sports medicine. Semin Musculoskelet Radiol 2004; 8:17–27. Khan KM, Forster BB, Robinson J, et al. Are ultrasound and magnetic resonance imaging of value in assessment of Achilles tendon disorders? A two year prospective study. J Sports Med 2003; 37:149–153.
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15
Prescribing Medications for Pain and Inflammation Julio A. Martinez-Silvestrini
PAIN IN SPORTS Pain is defined as a localized sensation of discomfort, distress or agony, resulting from the stimulation of specialized nerve endings.1 The stimulation of these nerve endings, known as C fibers and A delta fibers, is caused by tissue damage, which releases a variety of mediators such as histamine, peptides, prostaglandins and serotonin. The resulting impulse from the interaction of these chemicals with the pain fibers is transmitted to the dorsal horn of the spinal cord and via the spinothalamic tract to the ventroposterolateral and posterior thalamus.2 The final pain perception depends on the balance between exciting and inhibitory effects, which modulate the pain transmission.3 The inciting factor for musculoskeletal pain in athletes may be a sports-related injury or delayed onset muscle soreness (DOMS). A sports injury arises from acute macrotrauma, chronic repetitive microtrauma or an acute exacerbation of a chronic injury4; the sources of pain may be muscular, vascular, cutaneous, visceral, osseous, ligamentous, neuropathic, or a combination of the above. DOMS is described as muscle tenderness and pain that occur following introduction for the first time to certain types of activities (as eccentric biased muscle contractions) in an athlete’s training. Six hypotheses try to explain the mechanisms of DOMS, including muscular lactic acidosis, muscle spasm, connective tissue injury, muscular micro-injury, inflammation and enzyme efflux theories.5 It is believed that DOMS may affect athletic performance by causing reduction in joint range of motion, shock attenuation and peak torque, as well as by altering the muscle sequencing and recruitment patterns, which may result in increased stress to ligaments and tendons.5 Multiple treatment strategies have been attempted to alleviate the severity and limit the duration of DOMS, including massage, cryotherapy, stretching, ultrasound, electrical stimulation and medications. While most of these measures have been proven ineffective, massage, exercise and medications may have a role treating DOMS, although they only provide temporary relief.5 If not controlled, pain may promote compensatory mechanisms affecting the athlete’s technique, performance, and potentially promote further injury at the same site or other areas of the kinetic chain. Careful history and examination of the possible pain genera-
tors will help the clinician to determine the possible sources of pain. These sources of pain, as well as the general health status of the athlete, are important considerations for the initiation of medications as a part of the treatment plan.
INFLAMMATION Kibler4 categorizes pain as a component of the ‘clinical symptom complex’ of athletic injuries, while inflammation is part of the anatomic alterations observed, or ‘tissue injury complex’. Inflammation is a localized protective response elicited by injury or destruction of tissues, which contributes to the destruction, dilution or sequestration of the injured tissue. An early inflammatory response is the first step of tissue healing, characterized by pain, increased temperature, erythema, swelling and loss of function.1 After an acute injury, a cascade of events, including hematoma formation, inflammatory cell reaction and tissue necrosis will be elicited.6 Increased dilation of arterioles, capillaries and venules will follow, resulting in increased permeability, blood flow, exudation of fluids and plasmatic proteins, as well as hormonal responses and leukocyte (neutrophils, monocytes) and fibroblasts migration.6,7 All these events contribute to the classical signs of inflammation (Table 15.1). Coupled with pain, the inflammatory response limits the use of the injured structure, thereby avoiding the possibility of further injury to the affected tissue. The inflammatory response phase is followed by regeneration of the injured tissue (reparative phase), and scar formation, remodeling and maturation (remodeling phase). Excessive hematoma formation or inflammatory response may interfere with adequate tissue regeneration or scar formation, promoting poor quality healing or a ‘failed healing response’, which is one of the theories for recurrent musculoskeletal injuries, such as tendinopathies.8
SELECTION OF MEDICATIONS Control of pain and inflammation, as well as tissue healing promotion, are the goals of the initial or acute phase of rehabilitation.4 Medications, splinting, modalities, and in some
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Table 15.1
Classical Signs of Inflammation
Latin Term
English Translation
Dolor Calor Rubor Tumor Functio Laesa
Pain Heat Redness Edema Loss of function
cases surgical management, are important treatment components during this phase. But the decision regarding which medication to recommend for an individual patient is not an easy task. The necessity of the drug, its side-effects, and its potential to be banned by a sports governing organization, should be considered prior to the prescription of any agent.9 In most cases, there are no clear guidelines to assist in the selection of the most appropriate agent, but one of the considerations should be compliance. Medication compliance improves dramatically as prescribed dose frequency decreases. Compliance may be as low as 59% of daily dosages on a three times a day regimen, and improves to 83.6% on a once a day regimen.10 More recently, Claxton,11 in his systematic review on associations between doses and compliance recommends simpler, less frequent dosing regimens, which result in better compliance. Low medication compliance has been associated with lack of motivation,12 significant side-effects, complexity and organization of the treatment regimen (including daily multiple doses or multiple agents), cost and low perceived benefits.
Box 15.1: Key Points Factors affecting medication compliance ●
Presence and severity of symptoms
●
Number of medications
●
Side-effects
●
Dosing frequency
●
Length of treatment
●
Motivation for treatment
●
Costs
PAIN LADDER As described by Leadbetter,13 ‘If pain and signs of inflammation are persistent, repeated efforts to turn off the body’s alarm is not a substitute for finding the cause of the fire. Indeed to remove the “fire alarm” of pain from the onset of an injury can clearly place the athlete in great jeopardy with respect to tissue overload and failure’. It is important to control pain and inflammation with either physical or pharmacologic measures, but these interventions are not a substitute for proper medical care and rehabilitation. The World Health Organization
(WHO) designed a three-step ‘ladder’ for pain relief in cancer patients (Fig. 15.1).14 This ‘pain ladder’ has been used more recently with success for non-malignant and musculoskeletalrelated pain,15 as well as in the pediatric population.16 It may be appropriate to use as a tool for initial selection of medications in the athletic population, as well as to guide pharmacotherapeutic regimen changes, if needed. The administration of medications to control pain consists of scheduled, ‘by the clock’ rather than ‘as needed’ or ‘on demand’ doses. The clinician needs to know the pain severity experienced by the patient, prior to selecting which ‘pain ladder’ step to start the treatment plan. Pain is considered to be mild when rated between 1 and 4 on the visual analog scale, moderate when rated 5 or 6 and severe when described as 7 to 10. The first step of the ladder is the use of non-opioid medications, such as non-steroidal anti-inflammatories, acetaminophen or aspirin, for the treatment of patients with pain of mild to moderate intensity. Patients with persistent mild to moderate pain despite the use of first step medications benefit from adding a second step drug, such as codeine, hydrocodone or oxycodone.17 Tramadol has been considered a possible alternative as a second step drug.18 The third step medications, which include morphine, hydromorphone, fentanyl and high doses of oxycodone, are reserved for patients with moderate to severe pain refractory to step 2 medications or that cannot take oral medications, as in patients with acute severe trauma, in which intramuscular or intravenous administration may be more appropriate. This pharmacotherapeutic regimen is considered to be relatively inexpensive and 80–90% effective.17 Adjuvant agents, such as anticonvulsants or antidepressants, are recommended to treat concurrent symptoms that exacerbate pain and may also enhance the effect of the primary steps medication. These adjuvant agents may be used in any of the steps of the ‘pain ladder’ (Fig. 15.1). When implementing the use of this tool, it is important to emphasize that pain perceptions in athletes seem to be decreased, compared to non-exercising subjects. Although
Adjuvant therapy Anticonvulsants Antidepressants Muscle relaxants
Pain scale Step 3: Severe pain Morphine Hydromorphone Fentanyl Oxycodone
10
6 Step 2: Moderate pain Tramadol Codeine Hydrocodone Oxycodone 4 Step 1: Mild pain NSAIDs Acetaminophen Aspirin
1
Figure 15.1 Analgesic pain ladder. (Modified from WHO 1990.14)
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most research studies confirm this observation, the reason for this is unknown. Multiple theories had been postulated for decreased pain perception in athletes, including the presence of high levels of endogenous opiates, such as beta-endorphin and beta-lipotropin, in response to training and acute exercise, stress induced growth hormone, catecholamine and corticosteroid release,19 the presence of a baseline higher pain threshold which increases even more after physical activity,20 motivational factors,21 and enhanced pain tolerance.22 Besides pain perception, other factors that may influence pain management in athletes is their initiative to seek medical care. Staes observed that although 17.8% of adolescents with back pain reduced or stopped their sports activities and 13.1% reported that their pain intensity was high enough to seek medical attention, only 8.5% received medical consultation or treatment.23 Reduction of sports participation or medical interventions were observed in subjects with statistically significant higher pain levels (5.5–6/10) compared with their peers (3–5.5/10).
MEDICATIONS Non-steroidal antiinflammatory drugs The group of drugs known as non-steroidal anti-inflammatories (NSAIDs) is one of the most commonly used classes of medications worldwide. It is estimated that 30 million people take NSAIDs daily,24 and there are 20–24 million NSAIDs prescriptions written in the UK each year.25 NSAIDs are known for their anti-inflammatory, antipyretic and analgesic effects.26 These effects are mediated by inhibition of the cyclooxygenase enzyme (COX), which results in decreased prostaglandin production (Fig. 15.2).27 Prostaglandins promote the initial inflammatory response and sensitize nerves by increasing the nervous membrane permeability to sodium and calcium. The antipyretic
Cell membrane injury
NSAIDs
Corticosteroids
Phospholipids release Phospholipids Cox-1 (GI, kidney, platelets)
Arachidonic acid
Cox-2 (inflammation, pain, other)
Lipoxygenase
Prostaglandins
Leukotrienes
Figure 15.2 Inflammatory cascade and action of NSAIDs and corticosteroids. Cellular membrane injury will promote the release of phospholipids. By influence of phospholipase, phospholipids will convert into arachidonic acid which in turn converts to prostaglandins or leukotrienes mediated by cyclooxygenase or lipoxygenase, respectively.
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effect of NSAIDs is mediated through vasodilation of peripheral vessels, enhancing heat dissipation. Older NSAIDs and salicylates are believed to inhibit both COX-1 and COX-2. COX-1 is a constitutive enzyme which has a role in the regulation of the gastric mucosa, vascular homeostasis, renal function and platelet aggregation.28 COX-2 is an inducible enzyme, also present in brain, kidney and bone in small amounts, but the expression increases during inflammation. In theory, selective inhibition of COX-2 will inhibit the inflammatory effects of prostaglandins, with minimal adverse effects. NSAIDs also have an inherent capacity to inhibit a number of cellular processes. These include disruption of protein to protein interactions, decreased neutrophil endothelial adherence, reduction of superoxide generation, uncoupling of oxidative phosphorylation, inhibition of phospholipase C activity and reduction of glycosaminoglycan synthesis.26 They may also have a role on attenuation of muscle protein synthesis after 24 h of high-intensity eccentric resistance exercise.29 NSAID use for brief periods of time has shown to be beneficial for short-term recovery of muscle function after exerciseinduced muscle injuries.30 There are no guidelines to assist in selecting the most appropriate NSAID. Selection should be based on the athlete’s previous experience and convenience, clinical experience, sideeffects and costs. Knowing the NSAIDs used by the patient in the past, as well as their perceived benefits and adverse effects, may help the clinician in the selection process. Once a patient has failed to respond to one NSAID, some investigators have found that the likelihood of benefiting from another agent in the class is low.31 However, although NSAIDs share the same basic mode of action, there is evidence suggesting that in equipotent doses, individual responses are highly variable.32 These differences may be secondary not only to compliance, but to several functional, biochemical and physiological indicators,33 including enantiomeric forms, protein binding capacity, half-lives, synovial fluid kinetics, metabolism, chronobiology, adverse effect profile and other drug interactions.32 Thus it may be a reasonable therapeutic option34 to substitute one NSAID for another of a different class in patients with refractory pain (Table 15.2). When prescribing NSAIDs, the clinician needs to consider the potential of drug interactions or current over-the-counter NSAID use. Mahler35 observed that 5–10% of endurance athletes use NSAIDs prior to athletic event participation. As some athletes may not perceive over-the-counter drugs as medications, it is important to ask the athlete about current medication or supplement use. Other considerations should include the age of the athlete, as only four NSAIDs have been approved by the United States Food and Drug Administration (FDA) for use in children. These include aspirin, ibuprofen, naproxen and tolmetin. However, recommended doses, efficacy and toxicity for non-FDA approved NSAIDs, are available.34 Also one needs to take in consideration the drug compliance when prescribing a NSAID. To promote better compliance and adherence to the treatment regimen, once- or twice-a-day drugs are recommended (Table 15.3). The use of NSAIDs in patients with chronic tendon injuries or tendinosis may be considered inappropriate by some clinicians, since inflammation has not been observed in pathologic
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Table 15.2 Classes
Non-Steroidal Anti-Inflammatory Drug
Class
Drug
Acetic acids
Diclofenac Etodolac Indomethacin Sulindac Tolmetin Aspirin Diflunisal Salsalate Trisalicylate Celecoxib Etoricoxiba Lumiraxcoxiba Parecoxiba Rofecoxibb Valdecoxibc Meloxicam Piroxicam Phenylbutazone Meclofenamate Mefenamic acid Nabumetone Fenoprofen Flurbiprofen Ibuprofen Ketoprofen Naproxen Oxaprozin
Carboxylic acids
COX-2 inhibitors
Enolic acids
Fenamates Naphthylamines Propionic acids
Daily Maximal Dosage (mg) 150 1200 200 600 2400 6000 1500 3000 3000 400
50 20 30 20 600 400 1000 1500 2400 300 3200 225 1000 1200
aNot available in the US. bRemoved from US market due to increased risks of cardiovascular and cerebrovascular events. cRemoved from US market due to increased risks of cardiovascular and serious skin reactions.
studies.8 Nevertheless, most studies showed improved pain scores at final follow-up in patients with chronic tendon injuries who have used NSAIDs. In an animal study, Virchenko36 observed that NSAIDs may have a detrimental effect during early surgical tendon repairs, if used in the first 5 days after tendon injury. However, if used after 5 days, NSAIDs seems to promote a more efficient healing response,
Table 15.3 Non-Steroidal Anti-Inflammatories: Frequency of Dosage Once a Daya
Twice a Day
Three Times a Day
Celecoxib Ketoprofen Meloxicam Nabumetone Oxaprozin Valdecoxib
Diclofenac Etodolac Fenoprofen Flurbiprofen Naproxenb Sulindac
Ibuprofen Indomethacin Meclofenamate Phenylbutazone Tolmetin Carboxylic acids
aMost
of them may be given twice a day. bAvailable as a once a day preparation.
decreasing the cross-sectional area of the tendon and increasing the maximum stress tolerance capacity. This supports the concept that uncontrolled inflammatory response may interfere with the normal reparative phase of the normal healing response. As long-term prospective studies in patients with tendon injuries are not available, it remains to be determined whether NSAIDs change the natural history of the injury or merely have some analgesic action in these injuries.
Other NSAID subclasses Salicylates Aspirin (acetylsalicylic acid) and other salicylates are usually defined as NSAIDs, as their mechanism of action includes COX inhibition. The biotransformation of aspirin yields salicylate, which has similar anti-inflammatory potency as aspirin, but lacks its inhibitory effect on the COX enzyme. At present there is no common agreement about the anti-inflammatory mechanism of action of salicylates, independent from COX inhibition or expression. The postulated mechanisms include activation of mitogen-activated protein kinases, inhibition of nuclear transcription factors, antioxidant properties, adenosine release and lipoxin formation.37
Peripherally acting NSAIDs Bromfenac and ketorolac tromethamine are peripherally acting NSAIDs indicated for short-term management of moderate to severe pain, requiring analgesia at the opiate level. The use of these drugs is limited to up to 5 days in adults. These drugs may potentially be used in the treatment of acute musculoskeletal injuries although no studies are available for this indication.26
COX-2 inhibitors (Coxibs) COX-2 selective inhibitors were introduced to the market as a possible alternative for patients unable to take conventional NSAIDs secondary to their GI adverse effects. But recently, this class of drugs has come under intense scrutiny owing to reported increased risk of cardiovascular and cerebrovascular events.38,39 The heightened risk of these serious adverse effects may relate to the ability of these drugs to suppress prostaglandin I2.38 Suppression of prostaglandin I2 formation might be expected to elevate blood pressure, accelerate atherogenesis and predispose patients to an exaggerated thrombotic response to the rupture of an atherosclerotic plaque.39 In 2003, Fowles recommended the addition of aspirin for patients with cardiovascular risk who are prescribed a COX-2 selective inhibitor; aspirin’s inhibition of COX-1 leads to decreased platelet aggregation and vasoconstriction.40 Given the current controversy around COX-2 inhibitors, most now advocate the use of nonselective NSAIDs, which are more cost effective. COX-2 inhibitors may be considered in patients with a low risk of cardiovascular or cerebrovascular events.
Adverse effects One of the limitations of the use of NSAIDs is their analgesic ceiling effect. Doses above a certain level produce no additional analgesia but may incur additional toxicity. It is important to
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emphasize that for some NSAIDs, the analgesic ceiling effect is significantly lower than the anti-inflammatory ceiling dosage.27 In athletes with pain and minimal or no inflammation, lower doses of NSAIDs may be used, limiting the potential of adverse effects. The maximal daily doses of the most commonly used NSAIDs are listed in Table 15.2. The NSAIDs cause considerable morbidity and mortality related to gastrointestinal adverse effects, and may contribute to 2600 deaths annually.41 Proton pump inhibitors (PPI), hydrogen receptor (H2) blockers and Misoprostol,42 a prostaglandin E1 analog, has shown to be effective in preventing NSAID induced gastrointestinal ulcerations and dyspepsia. PPI have been useful for gastric ulceration,43 while H2 blockers have been effective in duodenal ulcers.44 The selective COX-2 inhibitors (Table 15.2), inhibit 200–300 times the COX-2 isoform over COX-1. They may have fewer gastrointestinal adverse effects, with a risk of gastrointestinal bleeding lower, but similar to the use of a combination of nonselective NSAIDs and omeprazole.45 This protective effect may be eliminated with the concomitant use of low dose aspirin46 or corticosteroids. Although dyspepsia and other gastrointestinal adverse effects are notoriously attributed to NSAIDs, less than 3% of patients treated with ibuprofen will develop gastrointestinal symptoms.27
Box 15.2: Key Points
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dominant component of the ‘tissue injury complex’. The mechanism of action of APAP is poorly defined, but it is believed to interrupt prostaglandin synthesis within the central nervous system (CNS), with minimal effect in the peripheral tissue, which may explain its analgesic and antipyretic effects, as well as the absence of peripheral antiinflammatory action. The recommended adult dosage is 325–650 mg every four to six hours or up to 1000 mg four times a day. One gram of APAP is considered the analgesic ceiling dosage. In children younger than 12 years old, the recommended dose is 10–15 mg/kg per dose, without exceeding 2.6 g in 24 h. APAP may be delivered orally or rectally with an onset of action of less than 1 h. If needed, APAP may be used in combination with other agents, as NSAIDs or opiates, for a synergistic analgesic action.
Box 15.3: Key Points Acetaminophen ●
Available in combination with other pain medications (opiates, tramadol)
●
Analgesic and antipyretic effects
●
Has analgesic ceiling effect
●
May cause severe hepatic dysfunction in acute or chronic overdosage.
Non-steroidal anti-inflammatories ●
Most commonly used pain analgesic
Adverse effects
●
Have anti-inflammatory, antipyretic and analgesic effects
●
Multiple classes available
●
Have analgesic ceiling effect
●
Hepatic and liver function should be followed closely
●
Most common adverse effect: GI toxicity.
APAP is mainly metabolized by the liver to sulfate and glucuronide metabolites, while approximately 5% is metabolized by the cytochrome P-450 system to N-acetyl-p-benzoquinone, which is conjugated to glutathione, inactivated and excreted by the kidneys.48 Hepatotoxicity may occur with doses of >4 g a day or acute overdosage. In these settings, glutathione conjugation becomes insufficient, resulting in the accumulation of acetylimidoquinone, a metabolite of acetaminophen, which may cause hepatic cell necrosis. The used of ethanol or other medications metabolized by the liver should be limited while using this drug. APAP is also present in combination with other medications and is available without prescription, increasing the potential risk of concomitant use of agents containing acetaminophen and increasing the risk of overdose. Other adverse effects observed include rash, electrolyte disturbances, anemia, blood dyscrasias and nephrotoxicity. Hypersensitivity reactions are rare.
Other adverse effects of NSAIDs include renal toxicity, dehydration, electrolyte disturbances, hepatic injury, skin reactions, elevated cardiovascular and cerebrovascular events risk38,47 and drug-induced aseptic meningitis. They may be relatively contraindicated in patients with platelet dysfunction, bleeding disorders, renal or hepatic insufficiency. Also, this group of medications should be used carefully in patients with allergy to aspirin, while celecoxib and valdecoxib should not be used in patients allergic to sulfa drugs.
Opiates Acetaminophen The medication acetaminophen, also known as N-acetylP-aminophenol (APAP), is indicated for the treatment of mild to moderate pain. Although also an antipyretic drug, APAP does not have anti-inflammatory effects. APAP should be considered as the first line of treatment for athletes allergic to aspirin or NSAIDs, or when inflammation is not a pre-
Since its discovery, morphine has been considered the gold standard for pain control. Currently, multiple opiate derivatives are available (Table 15.4). They are classified as agonists, mixed agonist-antagonists, or partial agonists, based upon their activity at opiate µ- and/or κ-receptors.27 But due to their high potency and risk of physical dependence, potential for abuse and significant side-effects, the use of opiates should be limited to
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Table 15.4 Opiates, Time to Onset and Equivalent Doses Drug Codeine Hydromorphone Levorphanol Meperidine Methadone Morphine sulfate Oxycodone Propoxyphene
Oral Onset (min) 10–30 15–30 30–90 10–45 30–60 15–60 15–30 30–60
Oral: Equivalency between Opiates (µg)a 200 7.5 4 300 20 30 30 200
Table 15.5 Opioids Banned by the World Anti-Doping Agency Buprenorphine Dextromoramide Heroin Fentanyl and derivatives Hydromorphone Methadone Morphine Oxycodone Oxymorphone Pentazocine Pethidine
aOral equivalency between opiates. The doses on this column are equivalent doses between opiates. For example, 200 mg codeine is equivalent to approximately 7.5 mg hydromorphone.
substances, communication with the appropriate anti-doping organization is strongly recommended. athletes with moderate to severe pain levels, and for short periods of time, until the primary treatment of the injury is completed and the pain has diminished. A large number of commercial compounded analgesics are available, combining an opiate (such as hydrocodone, oxycodone or codeine) with acetaminophen or ibuprofen. These preparations are prescribed frequently for the management of acute or chronic pain. For example, hydrocodone combined with acetaminophen is the most common of the compounded analgesics prescribed for acute pain management in the US.27 When prescribing these combination products, the clinician must pay particular attention to the amount of acetaminophen or ibuprofen in these preparations, when used separately, to avoid surpassing the ceiling dosage. The primary objective while using opiates is to achieve an acceptable balance between analgesia and adverse effects. Specifically, in opioid-naive patients, short acting, low potency agents should be started and advanced gradually. It is recommended prescribing stool softeners and antiemetics to minimize adverse effects that may jeopardize compliance. In athletes with a history of severe chronic pain, as in other patients with chronic pain, the optimal maintenance regimen will be focused in long-acting opiates, with short acting agents utilized for breakthrough pain. One of the virtues of opioid use for pain management is the absence of maximal dosage, which permits the dose to be increased until relief is obtained or limiting side-effects develop.27 Relative contraindications for opiate prescriptions include a history of substance abuse or substance abusers in the patient’s household, psychiatric illnesses, non-compliance with treatment regimen and borderline or antisocial personality disorders. Healthy subjects demonstrated decrements in reaction time and task tracking in simple hand–eye coordination.49 These decrements in function may adversely affect athletic performance.
Other considerations The World Anti-doping Agency prohibits the use of multiple narcotics (Table 15.5).50 The use of these substances may result in fines and suspension of the athlete, coach, clinicians and/or team. Prior to use or prescription of these substances, or participation in competition while using these prohibited
Box 15.4: Key Points Opiates ●
Gold standard for pain control
●
Limited use in sports injuries
●
Indicated for moderate to severe pain control
●
Prohibited by the World Anti-doping Agency.
Tramadol Tramadol is a central analgesic with binary action, indicated for moderate to severe pain. This agent acts as a weak opioid µ-receptor agonist, as well as a re-uptake inhibitor of norepinephrine and serotonin. It is considered to be more appropriate than NSAIDs for patients with gastrointestinal or renal disease. The analgesic property of tramadol is greater than that of NSAIDs and weak opiates, such as codeine and dextropropoxyphene. Tramadol is also considered to have fewer sideeffects compared with opiates.51 Tramadol has been used alone and in conjunction with NSAIDs in the management of musculoskeletal pain, including back pain and breakthrough pain.18 The combination of tramadol and NSAIDs is synergistic, producing central analgesia and peripheral prostaglandin synthesis inhibition. A recent report52 concluded that tramadol is an effective treatment for the management of neuropathic pain. It can also be used in combination with acetaminophen, with a more rapid onset of action and greater efficacy than tramadol alone, without an apparent increase in adverse effects.53 Tramadol and acetaminophen compounded tablets are available and provide similar onset of action and pain relief when compared with codeine and acetaminophen combined capsules. Although a compounded combination of acetaminophen and tramadol may be practical and convenient, the increased cost of this preparation compared with single agent tramadol and acetaminophen tablets may be an obstacle for some patients. Dosage recommendations are 50–100 mg every 4– 6 h, without exceeding 400 mg/day. Tramadol is metabolized by the liver, via demethylation, glucuronidation and sulfation;
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however, this is one of the few medications that can be used in patients with hepatic impairment, with a recommended dose of 50 mg every 12 h.
Adverse effects Adverse effects include dizziness, coordination impairment and somnolence. Tramadol should be used carefully in patients using other medications that may cause somnolence. Constipation, nausea, agitation, anxiety, rash, abdominal pain and dry mouth may also be observed. Slow dose escalation (25–50 mg every 6–8 h) may improve the tolerability and decrease the onset of adverse effects. Allergic reactions are rare. This medication may decrease the seizure threshold in patients requiring dosages higher than 400 mg daily or with concomitant use of antidepressant drugs (tricyclic antidepressants or selective serotonin reuptake inhibitors) or amphetamines. Tramadol should be used carefully in athletes with a history of seizure disorder or in those requiring antidepressants.
Box 15.5: Key Points Tramadol ●
Central analgesic with bimodal action
●
May be used in athletes with renal or liver insufficiency
●
May cause somnolence
●
Decreases the seizure threshold.
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have better tolerability and drug interaction profile;56 with these agents, monitoring serum levels is not necessary.
Box 15.6: Key Points Anticonvulsants ●
Multiple drugs available
●
Indicated for neuropathic pain
●
Neuropathic pain use may be an off-label use for certain drugs
●
Newer drugs do not need serologic monitoring.
Carbamazepine Phenytoin and carbamazepine are medications widely and commonly used in the treatment of seizure disorders. In contrast to phenytoin, in which the evidence supporting its use in neuropathic pain is conflicting,54 the efficacy of carbamazepine for pain syndromes is widely known. The medical literature supports the use of carbamazepine in patients with trigeminal neuralgia, diabetic neuropathy, postherpetic neuralgia, central pain and chronic pain.54,57 Dosages used for these pain syndromes range from 300 to 1000 mg/day. Multiple mechanisms of action for analgesia have been postulated including a reduction of sodium and potassium conductance, neuron activity inhibition, upregulation of GABA receptors, reduction of N-methyl-D-aspartate induced depolarization at lower concentrations, potentiation of opioid induced behaviors and antidepressant effects.57
Adverse effects
Anticonvulsants Evidence from neuropathic pain animal models suggests that many pathophysiologic and biochemical changes occur in the peripheral nerve and central nervous system, which have similarities with seizure activity models. This evidence justifies the use of anticonvulsants in the symptomatic management of neuropathic pain, trigeminal neuralgia, diabetic neuropathy, postherpetic neuralgia, HIV neuropathy, central or thalamic pain syndrome and complex regional pain syndrome.54 Anticonvulsants may also be useful as prophylactic agents in athletes with migraine headaches. The mechanisms of action of anticonvulsants include effects on the voltage-gated sodium and calcium channels and inhibition promotion by affecting the gamma-aminobutyric acid (GABA)-A receptors.55 There is no role for anticonvulsant use in musculoskeletal disorders, unless associated neuropathic pain or injury is present. These medications may take several days to weeks to have a beneficial effect. For instance, the use of concomitant fast-acting agents, such as APAP, tramadol or NSAIDs, is recommended. The effectiveness of anticonvulsants correlates with their serum levels. In addition, older agents, such as carbamazepine or phenytoin, have a narrow therapeutic serum level range, thus requiring close monitoring. Rapid dose escalation may increase the serum levels of these drugs, but may result in more adverse effects or toxic levels. Newer anticonvulsants (such as lamotrigine, gabapentin, topiramate and zonisamide) appear to
The most common adverse effects include dizziness, nausea and vomiting, which usually subside 1 week after starting treatment or with dose reductions. Bone marrow suppression occurs rarely, but may be serious. Severe dermatologic reactions may also be observed rarely, requiring discontinuation of therapy. Hepatic and renal toxicity have also been reported. Consequently, complete blood counts, hepatic and renal function tests should be done prior to treatment, followed by repeated tests, including carbamazepine levels, at regular intervals. As the chemical conformation of this drug is similar to tricyclic antidepressants, this drug should be used with caution in patients with adverse reactions to tricyclics.
Gabapentin Gabapentin is approved by the Food and Drug Administration of the United States as an adjunct treatment for seizure disorders, postherpetic neuralgia and bipolar disorders, although popular off label uses with significant literature supporting them include migraine prophylaxis and neuropathic pain. Efficacy in the pediatric population has been suggested, with case series describing the drug utility in athletes with complex regional pain syndrome58 and patients with phantom limb pain.59 Gabapentin was designed as a GABA agonist, but its mechanism of action for pain control is postulated to result from its effect as a ligand at the alpha 2 delta subunits of
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voltage-related calcium channels.60 The dosage range for treatment of neuropathic pain is 900–3600 mg daily, administered in three divided doses. Gabapentin needs to be adjusted in patients with renal impairment, but may be used in patients on hemodialysis. Adverse effects include somnolence, edema, depression, nervousness, nausea and weight gain.
Lamotrigine As a phenyltriazine derivative, lamotrigine blocks voltagegated sodium channels and inhibits glutamate release. This drug has been used in the treatment of trigeminal neuralgia, HIV associated painful neuropathy, central post-stroke pain and a variety of neuropathic pain conditions. In doses from 50 to 400 mg/day, lamotrigine has demonstrated efficacy in relieving pain in patients with some types of neuropathic and central pain,54 but has adverse effects which include dizziness, ataxia, constipation, nausea and somnolence, which can be a limiting factor in the use of this drug.
Tricyclic antidepressants (TCA) TCA are used as the first line of adjuvant therapy for neuropathic pain and may also improve underlying depression and insomnia. The mechanism of action is the reuptake of norepinephrine and serotonin at nerve endings. Amitriptyline has been the most widely used drug of this type, but it has dose limiting sedating and anticholinergic adverse effects. Nortriptyline and desipramine may cause fewer of these adverse effects, facilitating upward titration. Low doses of any of these drugs (10–25 mg) should be administered at night and titrated upward every few days as needed, while monitoring pain relief and adverse effects. Night administration may help to normalize the sleep pattern, due to the sedative properties of this drug class. In healthy young patients, starting with 25 mg daily may facilitate the titration with good tolerability. Usually the dose for clinical response in patients with neuropathic pain is lower than the needed to treat depression. Tricyclic antidepressants should be used with caution in patients with glaucoma, urinary retention or cardiac disease.
Selective serotonin reuptake inhibitors (SSRI)
Topiramate This drug was first licensed in the UK in 1995 for adjunctive treatment of patients with intractable partial seizures. There are preliminary data to support its role as a potential treatment for neuropathic pain, while there are at least three ongoing international placebo-controlled multi-centered trials. The postulated modes of action of topiramate include modulation of voltage-gated sodium and calcium ion channels, potentiation of GABA inhibition, blockage of excitatory glutamate neurotransmission and inhibition of carbonic acid anhydrase. Most of the information about the pharmacology of topiramate is collected from studying hippocampal preparations, but may be useful to understand the molecular behavior of this drug on the peripheral nerves. Studies for the treatment of neuropathic pain in patients with diabetic neuropathy, trigeminal neuralgia, intercostal neuralgia and other neuropathic pain syndromes, including complex regional pain syndrome and other peripheral neuropathies are available. The use of this drug for neuropathic pain management is a not approved by the Food and Drug Administration of the United States.61
Zonisamide Zonisamide is believed to block the sodium and T type calcium channels and to increase GABA release. In a 10-week open label study involving subjects with diabetic neuropathy, peripheral neuropathy, complex regional pain syndrome, postlaminectomy syndrome, and radiculopathies zonisamide recipients showed marginally improved pain scores: Mean Neuropathic Pain and Mean Investigator Global Assessment scores.54
Antidepressants The effects of the antidepressants occur at the level of the nerve synapse. They modulate pain by altering the magnitude of the effects of neurotransmitters at these synapses,62 either by blockage of neurotransmitter uptake, or by blocking certain receptors.
The antidepressants known as SSRI have been used commonly in patients with the classic presentation of pain and dysthymic or depressive disorders. The mechanism of action of the SSRI consist of elevation of serotonin in the neuron synapse, followed by desensitization and down regulation of serotonergic, somatodendritic and presynaptic inhibitory autoreceptors, increasing both synthesis and release of serotonin.62 Nemoto and colleagues63 studied the regional cerebral blood flow and subjective pain and hot sensation during laser evoked pain and heat sensation before and after administration of fluvoxamine for 7 days. They concluded that fluvoxamine reduces activation of multiple brain areas and subjective pain scores in comparison with placebo, with no significant change in the sensory threshold, suggesting a possible mechanism of action for SSRI in pain modulation.
Other agents Muscle relaxants The medications known as muscle relaxants or relaxers have been used frequently for patients with muscular type pain, although their use is somewhat controversial. This group of drugs is very heterogeneous if we take into consideration their mechanisms of action, which range from centrally acting agents to calcium ion release blockage at the sarcoplasmic reticulum level (Table 15.6). The muscle relaxants as a class, seem to be effective in both acute and chronic neck and back pain.5 Although the mechanism of actions of each of these agents is different, no significant differences in outcomes were found between agents when comparing them in the treatment of musculoskeletal disorders. They are used with the goal of reducing muscular tension or stiffness and the resulting pain associated with injury. The muscle relaxants are also believed to control hypertonicity and promote muscle relaxation. These medications may be used safely in combination with NSAIDs and APAP. The most common adverse effects of this drug class include anticholinergic effects, weakness, drowsiness or dizziness, as well as a risk of dependence even after 1 week of use.5
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Table 15.6
Mechanism of Action of Muscle Relaxants
Muscle Relaxant Mechanism of Action Baclofen Carisoprodol Cyclobenzaprine Dantrolene Diazepam Metaxalone Methocarbamol Orphenadrine Tizanidine
Presynaptic inhibition by GABA β-receptor activation Blocks interneural activity at descending reticular formation and spinal cord Central acting agent; reduction of tonic somatic motor activity Blocks release of calcium from sarcoplasmic reticulum Central acting agent; facilitates post synaptic effects of GABA Unknown; possibly CNS depression Central acting agent Unknown Alpha 2 agonist
These medications should be used with caution in patients using other medications that may cause sedation, such as tramadol or opiates, and while operating motor vehicles or participating in activities requiring fast responses, such as combat sports. Muscle relaxers do not have a defined role in the WHO ‘pain ladder’, but may be used as adjuvant therapy, if needed (Fig. 15.1).
Box 15.7: Key Points Muscle relaxants ●
Heterogeneous drug class
●
Multiple modes of action
●
May cause somnolence.
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for more than a decade. Because of their safety, these remedies would have great appeal for the treatment of primary osseous musculoskeletal conditions, such as osteoarthritis, even if they were only modestly effective.65 These supplements are used in an attempt to modulate the glycosaminoglycan and proteoglycan constituents of the articular cartilage. Although more than 500 studies have been done with these supplements, most of them contain design flaws. Trials of glucosamine and chondroitin preparations collectively demonstrate moderate to large treatment effects on symptoms, but detailed methodological analysis suggests that the actual efficacy of these products is likely to be substantially more modest.65 Both supplements appear to be similar in effectiveness and have a minimum onset of action of 2 weeks,66 while the full therapeutic benefit may take longer than 1 month.65 Although the role of glucosamine or chondroitin as analgesics is not completely known, as most studies allowed NSAID rescue doses, the combination of any of these supplements with NSAIDs have been observed to be superior to NSAIDs alone. However, considering the low dose of the rescue medications utilized, it is unlikely that rescue medication use affected the pain relieving effect of these two supplements.66 Regarding the use of combined glucosamine and chondroitin preparations, no studies were found that compared the combination of both supplements versus glucosamine or chondroitin alone. Numerous studies using combination therapy have been reported, with similar results to those that used glucosamine or chondroitin alone. For this reason, the National Institute of Health in the United States has initiated an ongoing, four arms, multi-year study to compare glucosamine and chondroitin in combination with both agents alone and with placebo in the treatment of knee osteoarthritis.
Box 15.8: Key Points Glucosamine and chondroitin
Do muscle relaxants interfere with sports performance? Although in theory, the sedation caused by these agents may negatively affect sports performance, no data was found confirming this hypothesis. Nevertheless, there is a reported case of post-triathlon delirium in an athlete taking muscle relaxers (cyclobenzaprine and benzodiazepines), cocaine, barbiturates and marijuana.64 Muscle relaxer classes should not be combined, unless: (1) the agents are considered necessary for treatment, (2) optimal trials have been attempted unsuccessfully (maximal dosages and adequate frequency, for reasonable time periods, e.g. 2–4 weeks), (3) Patients need to have close medical monitoring, (4) Adverse effect potentiation and drug interactions need to be monitored and avoided. One group of athletes that may benefit from multiple muscle relaxer agents are patients with upper motor neuron syndromes, as spinal cord injury or brain injured athletes.
●
Natural component of cartilage
●
May decrease pain and prevent progression of osteoarthritis
●
Minimal adverse effects.
Glucosamine and chondroitin are considered dietary supplements in the US and their use is regulated by the Dietary Supplement Health Education Act, rather than by the United States Food and Drug Administration Regulation. In Europe, however, they are licensed as pharmaceuticals. Dietary supplements are not required to meet the same standards of purity and labeling as other prescription medications or over-thecounter drugs.67 When recommending any dietary supplement to patients, the clinician should take into account the purity of the ingredients, reputation of the manufacturer and the molecular weight of glucosamine and/or chondroitin supplied.67 No major adverse effects and drug interactions had been observed with these supplements.
Glucosamine and chondroitin Glucosamine and chondroitin are natural compounds found in healthy cartilage, which lately have been used and studied frequently in both human and veterinary medicine. They are extracted from animal products and have been used in Europe
Glucosamine sulfate Glucosamine sulfate is a normal component of glycosaminoglycans in the cartilage matrix and synovial fluid. This salt may have a role in slowing cartilage breakdown. The mechanisms of
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action for glucosamine include maintaining elasticity, strength and resilience of the cartilage, the inhibition of proteolytic enzymes (elastase, hyaluronidase) and promotion of glycosaminoglycan and proteoglycan synthesis. Other mechanisms of action include mRNA transcriptional effects, anti-inflammatory, immunosuppressive and anticatabolic properties.67 Studies have shown the effectiveness of this supplement in decreasing joint space narrowing, and in slowing the degenerative process of the articular cartilage.66 Although no significant drug interactions have been reported, glucosamine containing supplements are believed to alter the glucose regulation and insulin sensitivity. However, Scroggie and colleagues68 concluded that oral glucosamine-chondroitin supplementation does not result in clinically significant alterations in glucose metabolism in patients with type II diabetes mellitus. The dosage recommended for glucosamine sulfate is 1500 mg/day.
Chondroitin sulfate The predominant glycosaminoglycan found in articular cartilage is chondroitin sulfate. It is composed of multiple units of glucuronic acid and galactosamine sulfate. The effectiveness of chondroitin in pain relief compared with placebo has been observed to be statistically significant, while there is no difference between placebo and chondroitin in adverse effects. The mechanism of action is postulated to be water absorption, which increases cartilage thickness, compressibility and load absorption. It may have a role in proteolytic enzymes inhibition. Chondroitin also has anticoagulant effects, which may be one possible mechanism of action. Platelets secrete glycosaminoglycans, including chondroitin, as part of the normal control of coagulation. With aging, the amount of chondroitin secreted diminishes, promoting possible bone microthrombosis. Chondroitin may improve the microcirculation to subchondral bone, synovium and other tissues.67 Although it may have a role in symptom modification, there is no literature supporting the use of chondroitin to slow or prevent joint space narrowing.66 The suggested dosage for this supplement is 880–1200 mg/day. Due to the possible anticoagulant effects, this supplement should be used carefully in patients with blood dyscrasias or using anticoagulant drugs.
Glucocorticoids The adrenal cortex synthesizes and secretes the corticosteroid hormones. These hormones include the mineralocorticoids, androgenic hormones and glucocorticoids. The glucocorticoids have potent anti-inflammatory and immunomodulating effects. At the molecular level, glucocorticoids bind to intracytoplasmic receptors, cross the nuclear membrane and interact with the cell DNA, modulating the production of mRNA. These actions change the rate of protein synthesis and lysosomal stability,69 and induce apoptosis in cells of the hematopoietic system. Amsterdam70 observed that glucocorticoids protect glandular cells and fibroblasts from signals evoked by cytokines, cyclic AMP, tumor suppressors and death genes, suggesting a bimodal, complementary mechanism of action: inducing death of inflammation promoting cells while protecting resident cells of the inflamed tissue by arresting apoptotic signals. The glucocorticoids also decrease vascular permeability, and decrease activity, number, chemotactic attraction and tran-
sit of neutrophils and monocytes. They also block the production of prostaglandins, by blocking the biosynthesis of COX 2,69 and inhibit the production of immunoglobulins, and leukotrienes (Fig. 15.2). Glucocorticoids inhibit phospholipase A2 by induction of the production of macrocortin and lipomodulin.26 There is limited evidence supporting the use of oral corticosteroids for acute injuries, most of it in acute nerve injuries and low back pain.71
Adverse effects Glucocorticoid toxicity is related to both the average dose and cumulative duration of use, although for most toxicities a ‘threshold’ dose or duration has not been established. It is clear that even low dose corticosteroids (≥5 mg/day) for periods of 1 year or more may result in significant adverse effects, including fractures, infections, gastrointestinal ulcers or bleeding, and cataracts.72 The naturally occurring cortisone and hydrocortisone, as well as the synthetic prednisone and prednisolone have both glucocorticoid and mineralocorticoid effects (salt retaining properties). These salt retaining properties promote the development of hypertension, fluid retention, hypokalemia and weight gain (which may be problematic for athletes that compete in weight divisions, such as combat sports or Olympic-style weightlifting). Thus, synthetic compounds, with marked glucocorticoid activity and no salt retaining effects, such as triamcinolone, betamethasone, dexamethasone or methylprednisolone, are preferred. The glucocorticoids may also decrease the systemic immune response if taken orally, limiting the capacity of the athlete to mount an adequate defense mechanism against infections. Other potential adverse effects include skin thinning, changes in corporal hair distribution, acne, cataracts, increased intraocular pressure, dyspepsia, gastrointestinal bleeding, decreased fertility, menstrual abnormalities, osteoporosis and osteonecrosis. Considering the possible systemic effects of oral administration, versus the limited absorption with local administration, local therapy is generally preferred, either topical or injected. Corticosteroids may be used topically, delivered by iontophoresis or phonophoresis. Injections may be recommended in selected cases, for subacute or chronic intra-articular or soft tissue injuries. Each corticosteroid has a specific plasma halflife and potency which should be considered prior to topical administration or injection (Table 15.7). Please refer to Chapter 16 for a discussion of topical corticosteroid use (iontophoresis and phonophoresis) and to Chapter 23 for an extensive discussion of the indications and use of corticosteroid injections.
Other considerations All glucocorticoids are prohibited by the World Anti-doping Agency when administered orally, rectally, intravenously or intramuscularly. Their use requires a therapeutic use exemption approval by the appropriate anti-doping organization. Athletes are particularly susceptible to unintentional antidoping rule violations with multiple substances, including glucocorticoids. A doping violation for glucocorticoid use may result in a reduced sanction provided that the athlete can establish that the use was not intended to enhance sports performance.50
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Table 15.7 Half-Life
Glucocorticoid Equivalency and Plasma
Glucocorticoid
Equivalent Potency (mg)
Half-Life
Cortisone Hydrocortisone Prednisone Prednisolone Triamcinolone Methylprednisolone Dexamethasone Betamethasone
25 20 5 5 4 4 0.75 0.75
30 80–118 60 115–212 >200 78–188 110–210 >300
Box 15.9: Key Points Corticosteroids ●
Dramatic anti-inflammatory effects
●
Limited use by oral route
●
Topical or injectable preparations are recommended for athletic injuries.
203
taneous tissue, while serum concentrations are less than 10% compared with oral administration.76 These drugs produce an improvement in pain scores and range of motion, and a decrease in subjective complaints.26 A quantitative systemic review showed that topical NSAIDs are significantly more effective than placebo for pain relief, independent from the rubbing effect during application.25 In a double blind study, naproxen gel was superior to placebo, with significant improvement of symptoms in 3 days.77 However, the efficacy of topical NSAIDs appears to be of short duration. There is evidence suggesting pain relief and functional improvement for up to 2 weeks, with no apparent benefit after the third or fourth week.77 This route is very promising, as the medication is administered to the site of injury, with minimal systemic absorption and decreased adverse effects. Adverse effects of this class are minimal and limited to mostly topical symptoms, such as itching,77 rash or burning.78 Local reactions are seen in approximately 3.6% of patients, while systemic effects are even rarer (1 month) efficacy and adverse effects of these agents after prolonged use are unknown, as studies for more than 1 month are not available.
TOPICAL AGENTS Topical agents have been used to decrease pain and inflammation. The possible mechanisms of action include decreasing local irritation, local agent absorption,73 blood-borne delivery,74 and the rubbing action during agent application.75 Most of these drugs are available without prescription and advertised for acute and chronic condition management.
Salicylates Salicylic acid derivatives, although frequently defined as NSAIDs, and included in this chapter in this group, do not seem to have the same mechanism of action of this medication group.37 Although the available literature on topical salicylates use is limited by small size, inadequate design and validity, these topical agents have been demonstrated to be significantly superior to placebo in acute and chronic musculoskeletal pain. However, the best assessment of the limited available information suggests that topical salicylates may be efficacious in acute pain and moderately to poorly efficacious in chronic musculoskeletal pain.73 One of the limitations of studies for chronic conditions is that the longest trial lasted only 28 days. Local adverse effects seem to be seen in only 2% of subjects and without significant difference between treatment and placebo groups. Adverse effects associated to prolonged use of these topical agents in unknown.
NSAIDs Topical NSAIDs have been widely used in Europe for decades. Preparations available include felbinac, ibuprofen, indomethacin, ketoprofen, naproxen and piroxicam. Following topical NSAID administration, levels of the drug are found in muscle and subcu-
Capsaicin This topical agent is derived from chili peppers, and is available in preparations of 0.025% and 0.075%. The mechanism of action is depletion, inhibition of synthesis and transport of substance P, decreasing local discomfort. Capsaicin has been used successfully in the management of neuropathic and rheumatologic conditions, but some patients cannot tolerate the drug due to intense itching and burning. One third of patients may experience some local irritation and up to 10% may even stop treatment.79 To avoid these symptoms, broken or irritated skin should be avoided and a four times a day application is important, to achieve maximal substance P depletion. Patients should wear gloves to apply capsaicin, and should avoid touching any mucosal membranes or eyes. Following application, they need to wash their hands with soap and water to avoid local absorption of the drug in other areas.
Lidocaine patch Lidocaine patches of 5% are approved by the FDA for the treatment of post-herpetic neuralgia. The mechanism of action is skin diffusion and binding to sodium channels in the nociceptors and sensory nerve fibers. The amount of lidocaine that penetrates the skin is sufficient to cause analgesia without anesthesia. Only 3% of the lidocaine dose is systemically absorbed. The patch can only be applied on intact skin and a maximum of three patches can be used for 12 h in a 24 h period (12 h on/ 12 h off). There is a one patient, open-label case report that suggests that lidocaine patches may have a role in the treatment of myofascial pain, instead of trigger point injections.80 There are also small uncontrolled reports of lidocaine patch
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use with benefits in painful neuropathies, such as polyneuropathies, meralgia paresthetica and complex regional pain syndrome.81 These uses are off-label and not FDA approved. No randomized controlled studies examining the utility of lidocaine patches in sports-related injuries or musculoskeletal injuries are available.
Adverse effects Local reactions, such as erythema, edema, itching or cold sensation may be experienced after patch application. These reactions are usually mild and transient. The delivery device should be used with caution in patients with severe hepatic disease, those using Class 1 antiarrhythmic drugs (such as tocainide) or during the use of other local anesthetics, as the risk of toxic lidocaine levels in these patients is higher.
CONCLUSIONS Medications for pain and inflammation control may be useful tools for the treatment of acute or chronic injuries. The use of
Box 15.10 Key Points Topical Agents ●
Promising route of administration
●
Limited systemic effects
●
May be effective for short periods of time.
medications is not a replacement for rehabilitation, but may be an important tool for symptom modification during the rehabilitation process. The selection of these agents may be a difficult task. Tools that may help guide drug selection include the past medical history of the athlete, previous or current medication or supplement use, and the medication adverse effects profile. Drugs that may be considered illegal by sports governing organizations should be avoided, if possible. Close monitoring, dose adjustment and the addition or substitution of medications, using tools such as the WHO ‘pain ladder’, is strongly recommended.
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Stephen JM, Ghezzi KT, Bailey K, et al. Post-triathlon delirium. J Emerg Med 1991; 9:265–269. McAlindon TE, LaValley MP, Gulin JP, et al. Glucosamine and chondroitin for treatment of osteoarthritis: a systematic quality assessment and meta-analysis. JAMA 2000; 283:1469–1475. Richy F, Bruyere O, Ethgen O, et al. Structural and symptomatic efficacy of glucosamine and chondroitin in knee osteoarthritis: a comprehensive meta-analysis. Arch Med 2003; 163:1514–1522. Hungerford MW, Valaik D. Chondroprotective agents: glucosamine and chondroitin. Foot Ankle Clin 2003; 8:201–209. Scroggie DA, Albright A, Harris MD. The effect of glucosamine-chondroitin supplementation on glycosylated hemoglobin levels in patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized clinical trial. Arch Int Med 2003; 163:1587–1590. Szczepanki A, Moatter T, Carley W, et al. Induction of cyclooxygenase II in humans synovial microvessel endothelial cells by interleukin-1: Inhibition by glucocorticoids. Arthritis Rheum 1994; 37:495–503. Amsterdam A, Sasson R. The anti-inflammatory action of glucocorticoids is mediated by cell type specific regulation of apoptosis. Mol Cell Endocrinol 2002; 189:1–9. Jonsson E. Back pain, neck pain: An evidence based review. Summary and conclusions. The Swedish Council on Technology Assessment in Health Care; 2000:1–30. Saag KG, Koehnke R, Caldwell JR, et al. Low dose long-term corticosteroid therapy in rheumatoid arthritis: an analysis of serious adverse events. Am J Med 1994; 96:115–123. Mason L, Moore RA, Edwards JE, et al. Systematic review of efficacy of topical rubefacients containing salicylates for the treatment of acute and chronic pain. BMJ 2004; 328:995–997. Cooper C, Kelsey M. Topical NSAIDs in osteoarthritis. 2004; 329:304–305. Vaile JH, Davis P. Topical agents for musculoskeletal conditions. A review of literature. Drugs 1998; 56:783–799. Heynemann CA. Topical nonsteroidal anti-inflammatory drugs for acute soft tissue injuries. Ann Pharmacother 1995; 29:780–782. Thorling J, Linden B, Berg R, Sandahl A. A double-blind comparison of naproxen gel and placebo in the treatment of soft tissue injuries. Curr Med Res Opin 1990; 12:242–248. Lin J, Zhang W, Jones A, Doherty M. Efficacy of topical non-steroidal anti-inflammatory drugs in the treatment of osteoarthritis: meta-analysis of randomised controlled trials. BMJ 2004; 329:324. Mason L, Moore RA, Derry S, Edwards JE, McQuay HJ. Systematic review of topical capsaicin for the treatment of chronic pain. BMJ 2004; 328:991–994. Dalpiaz AS, Dodds TA. Myofascial pain response to topical patch therapy: case report. J Pain Palliative Care 2002; 16:99–104. Galer BS. Topical lidocaine patch relieves a variety of neuropathic pain conditions: An open-label pilot study. Presented at Am Acad Neurology, Seattle, WA, 6–13 May 1995.
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16
Physical Modalities Joel M. Press and Deborah A. Bergfeld
INTRODUCTION This chapter provides a fundamental overview of various physical modalities. It addresses their use as adjuncts in the treatment of sports related injuries and musculoskeletal complaints with an emphasis on current literature pertinent to each individual modality. However, studies regarding the use of physical modalities are often conflicting and a review of such literature leaves the clinician with a sense of ambiguity as to the effectiveness of these treatments. In addition, many studies are performed in patients with arthritis and undifferentiated back pain syndromes. Therefore, the evidence-based use of modalities in clinical sports medicine must be extrapolated from these other patient populations as well. Physical modalities, when used in the appropriate setting, may help minimize time lost due to an injury or facilitate progress in a rehabilitation program, but they are not without some degree of risk. A survey of athletic trainers using physical modalities found a reported complication rate of 26%.1 The most common complications are skin irritation, burns, intolerance to treatment and pain with treatment. That being said, by understanding the basic physiology as well as indications and contraindications for these modalities, a safe and rational prescription can be formulated. It cannot be emphasized enough that it is the duty of every practitioner to recognize that physical modalities should not be used in isolation. They should be part of a comprehensive rehabilitation program with the patient’s eventual goals (i.e. return to sport) and individual response to the overall treatment plan kept in mind.
Box 16.1: Key Points ●
Cryotherapy is most effective in the treatment of acute injuries and postoperatively.
●
It is contraindicated in ischemic areas, cold intolerance and insensate skin.
●
The cold is usually applied for 20–30 min sessions multiple times per day to avoid unwanted complications.
oxygen.4,5 Cold application produces vasoconstriction with vasodilation following reflexively. Cryotherapy, as opposed to therapeutic heat, increases connective tissue stiffness and muscle viscosity, thereby diminishing flexibility. Based on these various effects, cryotherapy is most commonly used during the first 48 h of an acute musculoskeletal injury. Hocutt et al.6 demonstrated that early cryotherapy (started within 36 h of injury) allowed patients with ankle sprains to reach full activity in 13.2 days. This number was in comparison to 30.4 days using cryotherapy initiated at >36 h and 33.3 days using heat therapy. Use beyond the acute phase is justified for continued pain control, muscle re-education, and control of swelling when utilized with compression.7,8 Contraindications for cryotherapy include ischemia, cold intolerance, Raynaud’s phenomenon, cold allergy, inability to communicate and insensate skin. Care must be taken when using cold therapy over nerves due to the potential development of neuropraxia (conduction block). Recommendations to minimize this complication include limiting ice application to less than 30 min and protecting any peripheral nerves in the region.9
CRYOTHERAPY (COLD THERAPY) Cold application produces a variety of physiologic effects. Cold diminishes muscle spindle activity. This may assist in breaking the pain-spasm cycle by decreasing muscle spasticity and muscle guarding.2,3 It also slows nerve conduction velocity, possibly affecting the firing patterns of peripheral sensory pain fibers. It causes decreased local metabolism and minimizes enzymatic activity, decreasing the subsequent demand for
Techniques of application Ice packs, iced compression wraps, slushes, ice massage, ice whirlpool, and vapocoolant sprays are some methods of cold application (Fig. 16.1).10 Regardless of the method used, there is a rapid drop in skin temperature with a delayed effect on muscle. This effect on muscle depends on the amount of overlying subcutaneous tissue with maximum cooling occurring to a
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Figure 16.1 Cold packs.
muscle depth of 1–2 cm.11 MacAuley12 reviewed 45 textbooks and found considerable variation in the recommended duration and frequency of ice. Although there is no definitive recommendation regarding the duration of treatment, cryotherapy is typically used for a period of 20–30 min at a time. In a comparison of various application techniques, a 20 min application of a 454 g packet of frozen peas was more effective than a frozen gel pack in achieving a mean skin temperature adequate to induce localized skin analgesia, to reduce localized nerve conduction velocity and to reduce metabolic enzyme activity to clinically relevant levels.13 As well, care must be taken when using chemical or gel packs due to poor control of temperature and risk of skin irritation should the envelope break and the chemical come in contact with the individual’s skin. Cryostretch and cryokinetics refers to the use of cryotherapy to facilitate joint movement. Decreasing pain and muscle guarding may lead to improved flexibility and muscle function.11,14 An additional method of cryotherapy involves the use of vapocoolant sprays (fluori-methane and ethyl chloride), which provide very effective cutaneous local anesthesia and are commonly used to treat myofascial trigger points. The use of cryotherapy in this context promotes normal muscle resting length by a ‘spray and stretch’ technique rather than by cooling the muscle itself.15 Fluori-methane is less explosive, less flammable and produces less cooling than ethyl chloride.16 Concerns, however, have been raised regarding the destruction of the ozone layer by the use of vapocoolant sprays, some of which are considered chlorofluorocarbons.17,18
The effectiveness of cryotherapy Many studies on the effects of postoperative cryotherapy have been performed. Ohkoshi et al.19 attempted to show a relationship between cryotherapy, intra-articular temperature changes and pain relief in patients having undergone anterior cruciate ligament (ACL) reconstruction. A total of 21 patients undergoing ACL reconstruction were randomized into three groups: cryotherapy at 5˚C, cryotherapy at 10˚C, and no
cryotherapy for the first 48 postoperative hours. A temperature probe was placed intraoperatively in the suprapatellar pouch and the intercondylar notch through arthroscopic portals. Both cryotherapy groups had a triphasic temperature curve. A low temperature phase occurred immediately and lasted approximately 2 h. This was followed by a temperature rising phase, and finally, a thermostatic phase. The control group, however, went immediately to a thermostatic phase. During the low temperature phase, the cryotherapy groups’ suprapatellar pouch temperatures were significantly lower than the intercondylar notch temperatures with both sites being significantly lower than body temperature. Only the suprapatellar pouch temperature remained significantly lower than body temperature during the thermostatic phase. Although the numbers were not large in this interesting study, it helps to link objective intraarticular temperature changes to clinical outcomes. The cryotherapy groups reached 120˚ of knee flexion 4 days sooner than controls. The 10˚C group had significantly lower pain scores and analgesic use as compared with the control group. Similarly, Lessard et al.20 showed decreased pain scores and analgesic use following arthroscopic knee surgery in a randomized, blinded, controlled study of 45 patients using cryotherapy. Levy and Marmar21 reported less swelling, less pain and better range of motion with the use of cryotherapy in patients following total knee arthroplasty. Unlike the previous studies, pain scores were reported in a randomized, controlled study of cryotherapy in 50 postoperative shoulder patients done by Speer et al.22 The cryotherapy group reported decreased pain frequency and intensity, less need to use medication, better sleep, less swelling, and less pain with shoulder movement. On the flip side, in a randomized, controlled study, Konrath et al.23 did not find significant differences in medication usage or range of motion in 100 postoperative anterior cruciate ligament reconstruction patients treated with cryotherapy. Levy et al.24 studied the effect of cryotherapy on temperatures in the glenohumeral joint and the subacromial space following shoulder arthroscopy in 15 patients. They found no significant differences in temperatures as compared to control. The effect of cryotherapy on pain scores was not recorded in either study. Paddon-Jones and Quigley25 and Yackzan et al.26 did not find cryotherapy to be effective in treating delayed onset muscle soreness. In a study of rats, Fu et al.27 found that postendurance training cryotherapy may actually be deleterious by causing histologic myofibril damage.
Contrast baths Contrast baths, which alternate the use of heat and cold, have been described as a form of ‘vascular exercise’ due to alternating dilation and constriction of blood vessels. By alternating cycles of heat and cold, a hyperemic response may by created, thereby improving circulation and assisting in the healing response. More specifically, contrast baths are used to improve range of motion, control swelling and provide pain control. Contraindications include those discussed for therapeutic heat and cold, particularly active bleeding and vascular insufficiency. A protocol commonly used is as follows4,11:
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1 Affected region is submerged in a warm bath of 38–43˚C for 10 min 2 Cold bath of half ice/half water at 13–18˚C for 1 min 3 Warm bath for 4 min 4 Cold bath for 1 min 5 Steps 3 and 4 are then alternated for a total treatment cycle of 20–30 min 6 The sequence ends with cold. Exercising the area may occur during the heating phase with rest during the cooling phase. Frequently in the management of ankle injuries, contrast baths have been used for the treatment of an unchanging effusion, with the alternating cycle of hot and cold being used to create a cycle of alternating vasodilation and vasoconstriction.28 However, Myrer and Safran29 in their study of contrast therapy, found that 20 min of contrast therapy had no effects on the temperature of the gastrocnemius muscle as measured 1 cm below subcutaneous fat with a microprobe.
THERAPEUTIC HEAT MODALITIES Box 16.2: Key Points ●
Heat is indicated in the more subacute to chronic phases of injury and healing.
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Contraindications to the use of heat include: sensory deficits, peripheral vascular disease, bleeding diathesis, malignancy and acute stages of trauma or inflammation.
To best utilize therapeutic heat modalities, an understanding of the physiologic effects of heat is necessary. Heating can create changes, which are both local and distant, with the far-field effects being less pronounced. A consensual response may also be seen whereby heating one part of the body creates an increase in blood flow to other regions. As heat is applied to a body surface, circulatory changes occur. Because of increased metabolic tissue demands with heat, a subsequent increase in blood flow occurs. This leads to the arrival of various leukocytes, improved delivery of oxygen, increased capillary permeability and hyperemia. Diffusion across membranes occurs more effectively and can lead to edema formation, especially with acute injuries.30 Additional physiologic effects of heat include pain control during the later stages of healing. Vasodilation leads to improved tissue blood flow and increased removal of paincausing inflammatory substances such as bradykinins, prostaglandin and histamine substrates. Heat also acts directly on free nerve endings and provides muscle relaxation by decreasing the muscle spindle’s sensitivity to stretch via the gamma system.31 Inhibitory pathways can be activated by the use of heat modalities with subsequent muscle relaxation. Central processes may also provide for sedation and decreased pain awareness. Thus, therapeutic heat assists in altering the pain-muscle guarding (spasm) cycle.32
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Other useful effects of therapeutic heat include improved collagen flexibility (especially when accompanied by prolonged stretching) and a subjective decrease in joint stiffness. Lehmann et al.33 showed that tendon lengthening and decreasing tendon tension occurred most effectively when the tendon was loaded in an elevated temperature bath of 45˚C as compared to that at 25˚C. Furthermore, only when stretch was applied in conjunction with heat, did lengthening occur.34,35 There are some studies, however, that do not support this. In a small study of 24 subjects, Taylor et al.36 showed that application of heat or cold modalities made no significant difference in hamstring length when used in conjunction with a sustained hamstring stretch. Based on the physiologic effects of therapeutic heat, general indications for heat modalities in the athlete include pain, muscle spasm, contracture, bursitis, and tenosynovitis. Contraindications for heat include: sensory deficits, peripheral vascular disease (due to the inability to meet the demands of increased blood flow and metabolism), bleeding diathesis, malignancy, acute stages of trauma and acute inflammation.10 Therapeutic heat, like other modalities, can often provide short-term relief, but there is little evidence to support long lasting effects. Timm37 studied 250 subjects who had persistent low back pain following an L5 laminectomy in a randomized, controlled trial. The subjects were randomized into five groups including control, manipulation, simple home exercise program, supervised exercise program, and physical agents, including hot packs, ultrasound, and transcutaneous electrical nerve stimulation (TENS) (Fig. 16.2). The physical agent group did no better than the control group on the functional Oswestry scale, but was the most costly of all groups (US$1,842 per subject). The exercise groups had the most improvement in the Oswestry disability scores and had fewer recurrences of low back pain The simple home exercise program was the most economical (US$1,392 per subject).
Techniques of application Heat can be transferred to tissue in three ways.
Figure 16.2 Hot packs.
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Conduction Direct heat transfer from one surface to another due to direct contact. This is a form of superficial heat. Examples include hydrocollator packs, paraffin baths, electric heating pads and hot water bottles.
Convection Heat transfer due to the movement of air or water across a body surface. This, too, is a form of superficial heat. Examples include hydrotherapy and fluidotherapy.
Conversion Transfer of heat due to a change in the form of energy. Examples of superficial heat conversion include radiant energy such as that produced by infrared lamps. Deep heating, also known as diathermy, is due to conversion through the use of short waves, electromagnetic microwaves and ultrasound.
Superficial heat modalities The common denominator of superficial heat modalities is direct heat penetration. Penetration is greatest within 0.5 cm from the skin surface, depending on the amount of adipose tissue present.38,39 The more commonly used modes for sports rehabilitation are hydrocollator packs, whirlpool and contrast baths. Other forms of superficial heat include infrared lamps, paraffin baths, fluidotherapy and moist air.
Hydrocollator packs Hydrocollator packs serve to transfer heat via conduction. These packs come in three standard sizes and are heated in stainless steel containers containing water at temperatures between 18 and 32˚C. After appropriate heating, toweling is applied to the packs in order to minimize burning of the skin and to maintain heat insulation. The highest temperatures produced by the hydrocollator packs are at the skin surface. The pack is able to maintain heat for approximately 30 min with treatment sessions lasting 20–30 min. Other heating packs are also available and include hot water bottles, electric heating pads, and chemical packs. The major disadvantage of using these devices is limited temperature control.
Hydrotherapy: exercise in water Hydrotherapy is a term that can describe two distinct entities: warm water immersion and exercise performed in the water. Warm water immersion will be discussed in the next section. A patient exercising in the water can get the therapeutic benefit of exercise while using the buoyancy principles of water to decrease the biomechanical stresses on the musculoskeletal system. The temperature of the water can be modified to individual needs. Patients with acute injuries and pregnant women are typically treated in cooler pools of 28˚C, whereas subacute or chronic injuries are treated in warmer temperatures of 33–34˚C.40 Water exercises can also be used to crosstrain patients who require weight-bearing restrictions, such as those with stress fractures. Buoyancy-assisting devices can be
used to allow patients to run in water (cooler temperatures of 29–30˚C) and maintain cardiovascular fitness.40 Hall et al.41 compared water-based exercise, land-based exercise, seated water immersion, and progressive relaxation in 139 chronic rheumatoid arthritis patients in a randomized trial. At 3 months, the water-based exercise group maintained the most improvement in emotional and psychological scales. In a comparison study of electroacupuncture versus hydrotherapy in the treatment of hip osteoarthritis, Stener-Victorin et al.42 showed that hydrotherapy reduced pain, improved disability rating scores and improved quality of life measurements for 3–6 months post-treatment. Norton et al.43 showed that after anterior cruciate ligament repair, patients had quicker range of motion gains with water-based exercise when compared to conventional land-based therapy. Regardless, the goal of water-based therapy is often to prepare the body for improved function on land. Therefore, for anyone being treated in the water, incorporation of a landbased exercise program is an integral part of a rehabilitation program.
Hydrotherapy: warm water immersion Heating through the use of submersion in water is a form of convection. Whirlpools are used when a small area of the body is to be heated, such as a part of the upper or lower extremity, while Hubbard tanks are used to treat larger surface areas. The Hubbard tank, due to its larger size, also allows for range of motion maneuvers. Since larger body areas are exposed to heat during hydrotherapy, there is an increased risk of elevation in core body temperature. Therefore, water temperature rarely exceeds 40˚C for total body immersion, whereas temperatures as high as 43˚C may be used for partial limb immersion. As larger areas of the body are immersed in the heated water, diminished regulation of core body temperature occurs, as sweating and heat exchange can only occur in the nonimmersed portions.44 As an area with poor circulation is exposed to heat, a greater demand for blood supply is created due to increased metabolic needs. However, this demand for increased circulation may not be adequately met, leading to ischemic results. Therefore, in addition to contraindications for superficial heat, warm water immersion should not be used for pregnant patients and those with cardiovascular disease. The benefits of whirlpool treatment stem from the principle of buoyancy, in which a gravity-eliminated environment assists the patient in upward movement. An additional benefit comes from the resistance to flow, which provides low resistance for muscle strengthening and training. Agitation created by the water flow provides sensory input to the skin, assisting with pain control as well as maintaining appropriate water temperature.
DIATHERMY/DEEP HEATING MODALITIES Diathermy utilizes the principle of conversion to heat deeper tissues. The most commonly used deep heating agents include ultrasound, phonophoresis, shortwave diathermy and microwave diathermy. The general indications and contraindications are
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similar to those already discussed for superficial heat. However, specific clinical uses and precautions will be presented.
Ultrasound Box 16.3: Key Points ●
Ultrasound provides the deepest penetration of all heating modalities since most of the energy conversion takes place at the bone interface.
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A continuous, rather than stationary, application of ultrasound is most often used.
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General indications for the use of ultrasound are similar to those for other therapeutic heat modalities.
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Additional precautions include: using ultrasound over laminectomy sites, fluid filled cavities or in pregnancy (over the uterus).
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Phonophoresis is the use of ultrasound to increase the percutaneous absorption of a drug for the management of pain and inflammation.
Ultrasound is defined as sound waves with frequencies higher than the audible acoustic spectrum (above 20 000 Hz) (Fig. 16.3). It is unique among diathermy modalities in that the production of heat is due to a high-frequency alternating electric current (0.8–1.0 MHz), which is converted via a crystal transducer to acoustic vibrations rather than to electromagnetic energy. Energy transfer occurs due to the piezoelectric effect whereby the crystal undergoes changes in shape when voltage is applied. By altering the crystal’s configuration, vibrations are created which then pass through the tissues being treated. The heating effects depend on the absorption and reflection of ultrasonic energy which, in turn, is based on differences in the acoustic impedance at different tissue interfaces. Selective heating is greatest when acoustic impedance is high, such as at
Figure 16.3 Ultrasound machine.
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the bone-muscle interface. On the other hand, ultrasonic energy is readily conducted through homogeneous structures such as subcutaneous fat or metal implants with minimal thermal effects due to the rapid removal of heat energy. Thus, ultrasound can be safely used in the presence of most metal implants. However, in the presence of methyl methacrylate and high-density polyethylene, which may be used in total joint replacements, a greater amount of ultrasound energy will be absorbed with the potential for overheating.44 Significant heating can occur to depths up to 5 cm below the skin surface, thereby providing therapeutic effects to bone, joint capsule, tendons, ligaments and scar tissue.45 In summary, ultrasound provides for the deepest penetration of all heating modalities since minimal energy is converted to heat in subcutaneous fat or muscle with most of the conversion occurring at the bone interface. In addition to the above noted thermal effects, ultrasound also has non-thermal effects, which do not relate to tissue temperature elevation but rather to molecular vibration. Although heat can increase membrane permeability, diffusion can also occur due to the non-thermal streaming/stirring effect of fluids created by the ultrasonic field. Gaseous cavitation is also a non-thermal ultrasonic event. Gas bubbles are created as a result of acoustic rarefaction and compression causing subsequent enlargement in bubble size and pressure changes within the tissues. As the gas-filled cavity vibrates due to alternating compression and rarefaction, surrounding fluid movement occurs with the potential for cell destruction. Cavitation can be minimized by the application of external pressure and the use of a stroking, rather than a stationary technique, which will be discussed shortly.
Application methods for ultrasound Two primary methods of ultrasound application may be used: continuous and stationary. A coupling medium, such as mineral oil/gel or water for irregular surfaces is utilized to ensure adequate transmission of sound energy.35,46 With the continuous method, the ultrasound head is moved in a stroking fashion over the area being treated. This provides for safer, more uniform heating. The size of the applicator head should be larger than the treatment field with common sizes ranging from 5 square cm to 10 square cm. The stationary method, as the name implies, does not involve the continuous movement of the applicator head. Since a rapid rise in temperature is produced over a localized area with increased risk of burning and gaseous cavitation, this method is less commonly used. When the stationary technique is employed, intensity output is reduced. Dosimetry is measured in W/cm2, which reflects the applicator output divided by the surface area of the applicator. Intensities of 1.0 W/cm2–4.0 W/cm2 are most commonly used for the continuous method. Treatment often begins at 0.5 W/cm2 and the total output gradually increases. When using the stationary head, a safe range would be 0.1 W/cm2–1.0 W/cm2.31 The duration of most treatments is 5–10 min per site based on the size of the treatment area, with 10–12 treatments per series. As with all therapeutic modalities, the patient’s subjective response to heating with ultrasound is the best guide for proper dosing.
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Pulsed application is a method of administering ultrasound waves whereby the energy produced is intermittent. The purpose is to produce the mechanical, non-thermal reactions of ultrasound by allowing for rest periods and subsequent cooling.47 However, evidence is lacking that the non-thermal effects produced by pulsing have any advantage over the similar results produced by the continuous method.31
Ultrasound in musculoskeletal conditions General indications and contraindications for ultrasound are the same as for therapeutic heat. Additional precautions include using ultrasound over laminectomy sites, the heart, brain, cervical ganglia, tumors, acute hemorrhage sites, pacemakers, infection sites and fluid filled cavities such as the eyes.10 Its use is also contraindicated in pregnant women, over the uterus. In general, ultrasound may be effective as a therapeutic modality in subacute and chronic inflammation. There is evidence to suggest that the use of ultrasound during acute inflammation may be detrimental to healing. Leung et al.48 found increased levels of inflammatory mediators (PGE2 and LTB4) when ultrasound was used 2 days post-injury in rats with medial collateral ligament transections. Pain control may occur by both thermal and non-thermal effects. Various studies have shown alteration in nerve conduction velocity after diathermy application, with the changes appearing to be related to energy intensity of the ultrasound field.49–52 The presumption is that by altering the conduction velocity in the peripheral nervous system, analgesic effects may be obtained. Studies have also documented increased levels of cortisol following ultrasound application to peripheral nerves. This release may provide increased anti-inflammatory effects.53 However, Gnatz54 found that ultrasound applied to the backs of two patients with documented lumbar disc herniation caused increased pain in a radicular pattern. Thus, any painrelieving effects secondary to cortisol release may be overcome by the increased edema due to the deep heating effects of ultrasound.
The effectiveness of ultrasound As with many of the physical modalities discussed in this chapter, the literature is unclear and often conflicting in regards to the effectiveness of ultrasound in treating a variety of musculoskeletal conditions. Gam et al.55 studied the effects of ultrasound, massage, and exercise in 58 patients with neck and shoulder myofascial trigger points. The first group received all three treatments. The second group received massage, exercise, and sham ultrasound. And, the third group was a control group receiving no treatment. Both of the treatment groups had significantly improved number of myofascial trigger points compared to the non-treatment control group, but there was no difference between the therapeutic ultrasound and the sham ultrasound groups. van Der Heijden et al.56 studied 180 patients with soft tissue shoulder disorders in a randomized, blinded, controlled trial comparing bipolar interferential electrotherapy to ultrasound as adjuvants to a supervised exercise program. All 180
subjects received exercise therapy: 73 subjects received active treatments, 72 subjects received dummy ultrasound and interferential electrotherapy, and 35 subjects received no adjuvants. At 6 week and 12-month follow-up, there was no apparent benefit seen in the ultrasound and electrotherapy groups versus the exercise program alone. The effect of ultrasound on the treatment of calcific rotator cuff tendonitis has been studied by multiple groups. In a randomized, double-blinded, sham controlled study, Ebenbichler et al.57 studied ultrasound therapy in 54 patients with radiographically confirmed calcific rotator cuff tendonitis. Thirtytwo shoulders were treated with ultrasound and 29 shoulders were treated with sham ultrasound 5 times a week for the first 3 weeks, followed by 3 times a week for the following 3 weeks. At 6 weeks, the treatment group reported greater improvement in pain and quality of life; however, there was no significant difference at 9-month follow-up. Interestingly, 42% of the ultrasound treated shoulders demonstrated resolution of calcium deposits and 23% showed improvement. In contrast, the sham group showed calcium deposit resolution in only 8% and improvement in only 12% of subjects (p = 0.002). Perron and Malouin58 however, did not find improvement with ultrasound and acetic acid iontophoresis above control for their smaller group of 22 patients with calcific shoulder tendonitis. Nykanen59 also found no benefit in using ultrasound over sham ultrasound in 72 in-patients with shoulder pain in a randomized, double-blinded, sham controlled study. In a doubleblinded, sham controlled study of ultrasound use for patients with subacromial bursitis, Downing and Weinstein60 also found no significant benefit from treatment with ultrasound. For a variety of other clinical entities, the evidence is again inconclusive. Binder et al.61 studied the use of ultrasound versus sham ultrasound in the treatment of lateral epicondylosis. A total of 38 patients underwent ultrasound treatments (1 MHz, 1–2 W/cm2) versus 38 patients receiving sham ultrasound for a diagnosis of lateral epicondylosis. There was a significant difference reported between the two groups. Twenty-four subjects in the treatment group versus only 11 in the sham group reported improvement. Other studies evaluating ultrasound as a treatment for lateral epicondylosis do not confirm such satisfactory results.62–66 In addition, a focused review of four placebo controlled trials and the use of ultrasound in ankle sprains by Van der Windt et al.67 does not support the use of ultrasound for acute ankle sprains. In this review, the magnitude of most treatment effects was small and of questionable clinical importance. Regarding muscle pain and injury, Tiidus68 reviewed the literature and found little data to support the use of ultrasound for postexercise muscle damage. However, there is conflicting evidence regarding whether ultrasound may be beneficial for delayed onset muscle soreness.69,70 In addition, Wilkin et al.71 studied the use of ultrasound in rats with a muscle contusion injury and found that ultrasound did not improve or hasten the regeneration of skeletal muscle following such an injury. In a similarly focused human study, Rantanen et al.72 found ultrasound had no significant effect on the overall morphology of muscle regeneration following contusion injuries. There is some evidence to suggest that ultrasound may hasten bone and tendon healing. Ramirez et al.73 performed work with ultrasound and Achilles tendon injuries in neonatal rats.
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They suggest that ultrasound stimulates collagen synthesis in tendon fibroblasts and stimulates cell division during phases of rapid cell growth. Jackson et al.74 also found that ultrasound facilitated the rate of rat Achilles tendon repair by promoting synthesis of collagen which also proved to have a greater breaking strength. Enwemeka75 found similar increased tensile strength in Achilles tendons of rabbits that were treated with ultrasound. In an attempt to determine whether ultrasound dosing impacted these findings, Ng et al.76 found that both high and low dose ultrasound accelerated the healing process of ruptured Achilles tendons in rats. In regards to bone healing, it has been reported that lowintensity pulsed ultrasound (LIPUS) at less than 0.1 W/cm, can reduce fracture healing times by between 30–38% as well as stimulate healing and union in up to 86% of non-united fractures.77 Kristiansen et al.78 studied 61 distal radius fractures in a multicenter, prospective clinical trial comparing low intensity, non-thermal pulsed ultrasound versus a placebo device. The ultrasound group experienced significantly faster radiographic fracture healing (mean of 61 days in treatment group versus 98 days in the placebo group). Brand et al.79 used LIPUS in the treatment of eight patients with radiographically confirmed tibial stress fractures. The authors concluded that daily lowintensity pulsed ultrasound for 4 weeks was effective in improving pain relief and expediting early vigorous return to activity without bracing for posterior-medial stress fractures. This was not the case, however, for one anterior tibial stress fracture that required intramedullary nailing. Multiple authors, through a review of the literature, conclude that there is little evidence to support the efficacy of ultrasound in the treatment of musculoskeletal disorders.68,80–83 Taking the available literature as a whole, there is some evidence to support the use of ultrasound to improve tendon and bone healing. Less convincing evidence suggests a modest benefit of ultrasound in rotator cuff calcific tendonitis and lateral epicondylosis.
synovial and adipose tissue) that ketoprofen phonophoresis achieved higher local tissue concentration of the medication by using continuous or pulsed ultrasound with negligible systemic plasma levels. Clinically, when comparing phonophoresis with iontophoresis of naproxen in treating lateral epicondylitis, there were significant improvements in pain scores and grip strength after treatment, but no significant differences were noted between the two groups.88 Despite the paucity of literature on phonophoresis, there are studies that call into question its effectiveness either alone or in comparison to other treatment modalities. Klaiman et al.89 studied phonophoresis versus ultrasound in 49 patients with various soft tissue injuries in a randomized, double-blinded, uncontrolled trial. Each group underwent treatments 3 times a week for 3 weeks. Both treatment groups had decreased pain levels at the end of 3 weeks, but there was no significant difference between the treatment groups. Kozanoglu et al.90 studied the effects of ibuprofen phonophoresis versus traditional ultrasound in patients with knee osteoarthritis. They found that both modalities were generally well tolerated and effective but that there was no significant difference in improvement rates between the two groups.
Other deep heating modalities Other heat modalities not frequently used today include radiant heat, shortwave diathermy, and microwave diathermy. They will not be covered here, but are mentioned for historical reference.
THERAPEUTIC ELECTRICITY Box 16.4: Key Points ●
Electrical stimulation can be used to promote tissue healing, to stimulate muscle for edema reduction or muscle re-education, to slow muscle atrophy, to improve strength gains and to stimulate nerves for pain reduction.
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Contraindications to the use of therapeutic electricity include: use over cardiac pacemakers, electrical implants, carotid sinus, epiglottis, abdomen, gravid uterus, anesthetic areas, recent scars, areas where metal is embedded.
Phonophoresis Phonophoresis is the use of ultrasound to increase the percutaneous absorption of a drug, usually an anti-inflammatory or anesthetic agents, for the management of pain and inflammation in musculoskeletal/sports-related injuries. There are few randomized, controlled clinical trials documenting the effectiveness of phonophoresis. Initial experiments demonstrated that it is possible to drive cortisol ointment onto pig skin in situ with penetration into underlying muscle using ultrasonic energy at levels within the clinical range.84 Newman et al.85 reported that hypospray injection of cortisol followed by local application of ultrasonic energy showed an improvement in symptoms of shoulder bursitis compared with the use of ultrasound alone. Davick et al.86 demonstrated that ultrasonically treated topical application of tritiated cortisol can lead to significant increases in cortisol penetration beyond the stratum corneum and into the viable epidermis as compared with topical cortisol alone. They concluded that once beyond the stratum corneum, the cortisol may penetrate over time and be absorbed into the deep soft tissue structures. Cagnie et al.87 confirmed by biopsy (of knee
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The use of therapeutic electricity dates back many centuries. One of the earliest accounts of the use of electricity for a musculoskeletal problem occurred in 1747, when a man with rheumatoid arthritis and involvement of the small joint in his hands received marked relief of his pain symptoms through the use of electricity.91 Today, different forms of therapeutic electricity are used in the treatment of musculoskeletal and sports injuries. Electrical currents are used to promote healing of injured tissue, to stimulate muscles, to stimulate sensory nerves in treating pain, or to create an electrical field on the skin surface to drive ions beneficial to the healing process into or
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through the skin. This section will describe different forms of therapeutic electricity, the scientific basis for their use, their indications and contraindications, briefly describe the techniques used in their applications and elaborate on their use in sports medicine. Electrical devices can put out either alternating current (AC or faradic), which is usually found in household appliances, or direct current (DC or galvanic), which is found in a generator or battery. Direct current can be continuous or intermittent, and can have different waveforms, frequencies, duration and amplitudes. Adjustments in any or all of these parameters will have an effect on the quality, type and form of stimulation received by the patient. Details of these parameters can be found in cited texts.47 It is important to note that muscle and nerve responses to electricity vary. Nerve tissue accommodates rapidly to current. Nerve stimulation requires a current which rises rapidly to maximum intensity. High frequencies and short durations are used. Sensory nerves respond to 100–150 cycles/s with a stimulus duration of 100 µs or shorter. Motor nerves respond to short duration (6 weeks duration), Tsukayama et al.207 found electroacupuncture to be more effective at short-term pain relief than TENS after a 2-week trial period. During this study, all patients received ‘conservative orthopedic treatment’ (COT), which included physical therapy, back school and diclofenac. In addition, one group was treated with acupuncture and another group with sham needling. In the whole sample, there was an overall improvement in pain relief of >50% on visual analogue scales (VAS) at the end of the treatment protocol. There was a significant difference between the two treatment groups, however. The acupuncture + COT group had a change of 65% on VAS while sham + COT group reported improvement in pain relief scores of 34%. Carlsson and Sjolund208 studied the long-term effect of acupuncture (both electroacupuncture and manual acupuncture) on chronic low back pain. They found long-term improvement (at 6 months follow-up) in patients that received both forms of acupuncture in comparison with controls. In a randomized trial studying the effects of massage and acupuncture in the treatment of chronic low back pain, Kalauokalani et al.209 found that patient expectations seems to influence clinical outcomes independent of the treatment itself. Patients who expected a greater benefit from massage than from acupuncture were more likely to experience better outcomes with massage than with acupuncture and vice versa. On a greater scale, these expectations likely confound most studies where a specific intervention or treatment is involved and highlights the need to control for the non-specific ‘placebo’ effect. Green et al.210 reviewed the use of acupuncture in treating lateral elbow pain and found that there was inconclusive
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References
evidence in the literature to support or refute the use of acupuncture in treating lateral elbow pain. Two small trials, which could not be combined for meta-analysis, showed shortterm benefits not lasting >24 h. Tsui and Leung211 studied manual acupuncture versus electroacupuncture in a similar population with chronic ‘tennis elbow’. Subjects received either of the two treatments 3 times per week for 2 weeks. After the 2 weeks, there was significantly greater pain relief (as measured by VAS) and pain free hand grip strength in the electroacupuncture group compared with the manual acupuncture group. Kleinhenz et al.212 studied 52 athletes with rotator cuff tendonitis. The treatments included acupuncture with penetration of the skin versus a placebo needling. The acupuncture group showed significant improvement after eight treatment sessions in comparison with the control groups. Koo et al.213 studied an animal model of ankle sprain and the effect of electroacupuncture on this model. Electroacupuncture produced a 40% recovery in stepping force of the sprained foot. This improvement was interpreted as an analgesic effect since this same improvement was noted with systemic administration of 2 mg/kg of morphine. In an interesting study undertaken by Akimoto et al.214 the physiological and psychological effects of acupuncture were studied in elite female soccer players during extended competition. Subjects were divided into a treatment group (those who received acupuncture) and a control group. In the treatment
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group, acupuncture stimulus was applied at four specific points 4 h after each game during a competition period. Measured outcomes included cortisol levels in the saliva, salivary secretory immunoglobulin A (SIgA) levels, subjective ratings of physical well-being and a profile of mood status. They found that exercise induced changes such as decreased SIgA and increased salivary cortisol were inhibited by acupuncture. Subjects also reported improved subjective ratings of muscle tension and fatigue. As with many other modalities highlighted in this chapter, the evidence as to the effectiveness of acupuncture is inconclusive at times. In general, the use of acupuncture can be considered a reasonable adjuvant in the treatment of musculoskeletal pain complaints, especially since it is a treatment that is generally well-tolerated with few adverse side-effects.
CONCLUSION The use of therapeutic modalities is commonplace in the treatment of both acute and chronic musculoskeletal injuries. The rational use of such physical modalities within a comprehensive rehabilitation program requires an understanding of their proposed mechanism of action as well as indications and contraindications for each. Effectiveness of these passive approaches is highly variable. The individual patient and their response to any given individual treatment program is the best guide to their use.
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188 Pujol J, Pascual-Leone A, Dolz C, et al. The effect of repetitive magnetic stimulation on localized musculoskeletal pain. Neuroreport 1998; 9:1745–1748. 189 Gross AR, Aker PD, Goldsmith CH, Peloso P. Physical medicine modalities for mechanical neck disorders. Cochrane Database Syst Rev 2000; 2:CD000961. 190 Bassett A. Therapeutic uses of electric and magnetic fields in orthopedics. In: Carpenter DO, Ayrapetyan S, eds. Geological effects of electric and magnetic fields. San Diego: Academic Press; 1994:13–48. 191 O’Connor M, Bentall R, Monahan J. Emerging electromagnetic medicine. New York: Springer; 1990. 192 Sharrard W. A double-blind trial of pulsed electromagnetic fields for delayed union of tibial fractures. J Bone Jt Surg Br 1990; 72:347–355. 193 Carter R, Aspy CB, Mold J. The effectiveness of magnet therapy for treatment of wrist pain attributed to carpal tunnel syndrome. J Fam Pract 2002; 51:38–40. 194 Collacott EA, Zimmerman JT, White DW, Rindone JP. Bipolar permanent magnets for the treatment of chronic low back pain: a pilot study. JAMA 2000; 283:1322–1325. 195 Washnis G. Discovery of magnetic health: A health care alternative. New York: Health Research Publishers; 1998. 196 Vallbona C, Richards T. Evolution of magnetic therapy from alternative to traditional medicine. Phys Med Rehabil Clin North Am 1999; 10:729–754. 197 Cassidy S, Nielsen D. Cardiovascular response of healthy subjects to calisthenics performed in land versus water. Phys Ther 1992; 72:81–88. 198 Williamson AT, Fletcher PC, Dawson KA. Complementary and alternative medicine. Use in an older population. J Gerontol Nurs 2003; 29:20–28. 199 Weiner DK, Ernst E. Complementary and alternative approaches to the treatment of persistent musculoskeletal pain. Clin J Pain 2004; 20:244–255. 200 Ulett GA, Han S, Han JS. Electroacupuncture: mechanisms and clinical application. Biol Psychiatry 1998; 44:129–138. 201 Han JS. Acupuncture and endorphins. Neurosci Lett 2004; 361:258–261. 202 Zhang W, Luo F, Qi Y, et al. Modulation of pain signal processing by electric acupoint stimulation: an electroencephalogram study. Beijing Xua Xue Bao 2003; 35:236–240. 203 Wu MT, Sheen JM, Chuang KH, et al. Neuronal specificity of acupuncture response: a fMRI study with electroacupuncture. Neuroimage 2002; 16:1028–1037. 204 Cummings M. Percutaneous electrical nerve stimulation – electroacupuncture by another name? A comparative review. Acupunct Med 2001; 91:32–35. 205 Sator-Katzenschlager SM, Szeles JC, Scharbert G, et al. Electrical stimulation of auricular acupuncture points is more effective than conventional manual auricular acupuncture in chronic cervical pain: a pilot study. Anesth Analg 2003; 97(5):1469–1473. 206 Sator-Katzenschlager SM, Scharbert G, Kozek-Langenecker SA, et al. The short- and long-term benefit in chronic low back pain through adjuvant electrical versus manual auricular acupuncture. Anesth Analg 2004; 98:1359–1364. 207 Tsukayama H, Yamashita H, Amagai H, Tanno Y. Randomised controlled trial comparing the effectiveness of electroacupuncture and TENS for low back pain: a preliminary study for a pragmatic trial. Acupunct Med 2002; 20:175–180. 208 Carlsson CP, Sjolund BH. Acupuncture for chronic low back pain: a randomized placebo-controlled study with long-term follow-up. Clin J Pain 2001; 17:296–305. 209 Kalauokalani D, Cherkin DC, Sherman KJ, Koepsell TD, Deyo RA. Lessons from a trial of acupuncture and massage for low back pain: patient expectations and treatment effects. Spine 2001; 26:1418–1424. 210 Green S, Buchbinder R, Barnsley L, et al. Acupuncture for lateral elbow pain. Cochrane Database Syst Rev 2002; 1:CD003527. 211 Tsui P, Leung MC. Comparison of the effectiveness between manual acupuncture and electro-acupuncture on patients with tennis elbow. Acupunct Electro Ther Res 2002; 27:107–117. 212 Kleinhenz J, Streitberger K, Windeler J, et al. Randomised clinical trial comparing the effects of acupuncture and a newly designed placebo needle in rotator cuff tendinitis. Pain 1999; 83:235–241. 213 Koo ST, Park YI, Lim KS, Chung K, Chung JM. Acupuncture analgesia in a new rat model of ankle sprain pain. Pain 2002; 99:423–431. 214 Akimoto T, Nakahori C, Aizawa K, et al. Acupuncture and responses of immunologic and endocrine markers during competition. Med Sci Sports Exerc 2003; 35:1296–1302.
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17
Exercise in the Rehabilitation of the Athlete Sheila A. Dugan
INTRODUCTION Exercise is the mainstay in rehabilitating athletes to return to sport. Restoration of functional strength, flexibility, conditioning and neuromuscular coordination for athletic performance guides the exercise prescription. Deficits in one or more of these areas may have led to the original injury, especially in the setting of overuse injuries, or may result from direct tissue damage at the time of acute injury or from immobilization prescribed to enhance healing. Principles of training, such as specificity and overload, direct the progression of exercise while sports specific activities are incorporated to facilitate motor relearning. Multiplanar functional training is crucial in returning to the field of play where an extensive array of movements beyond unidirectional planes is required. Exercise professionals must recognize that muscles rarely act in isolation and that strength or flexibility deficits or maladaptive movement patterns anywhere along the loaded or unloaded limb and trunk can lead to re-injury.
STAGES OF REHABILITATION The stages of tissue healing and repair must be considered as one plans and executes the rehabilitation exercise program. For instance, the magnitude and direction of tensile load is gauged based on tissue recovery. Wolff ’s law states that changes in form or function of a bone are followed by certain, definitive changes in the bone structure. Hence, it is imperative that bone and other connective tissues be loaded in the appro-
Box 17.1: Key Points Exercise may be progressing too rapidly and the program should be re-evaluated when: ●
Pain increases
●
Swelling increases
●
Joint range of motion declines.
priate direction and with appropriate force to optimize recovery without compromising healing. Additionally, attention to the overall level of cardiovascular fitness and flexibility continues throughout the rehabilitation process. Three stages have been defined to guide the rehabilitation of injured athletes: acute stage, recovery stage and functional stage.1 See Table 17.1 for examples of exercise by type and indication during the three stages.
Acute stage The acute stage of rehabilitation is focused on moderating the inflammatory response and decreasing symptoms.2 Preserving strength and mobility of the injured limb is important but may be forfeited temporarily if immobilization is required. Uninvolved segments of the injured limb should be exercised in conjunction with an overall cardiovascular fitness program. Isometric exercise (in which there is no change in muscle length and no movement of the limb segment) can be utilized to maintain a controlled contraction. Gentle stretching and range of motion exercises are instituted, guided by discomfort. With multidirectional stretching, the practitioner may discover that particular planes are better tolerated than others.
Recovery stage The recovery stage of rehabilitation begins as tissue healing is nearly complete. The focus during the recovery stage of rehabilitation is functional improvement by restoration of joint range of motion, soft tissue flexibility, and strength, then rebuilding endurance and recovering proprioception. It is generally the longest stage. Protected mobility may continue to be necessary but multiplanar re-mobilization drives the flexibility program. A gradated progression in force generation and degrees of freedom is necessary. The athlete must be closely monitored for response to exercise and any resumption of the inflammatory response signifies a need to reduce the level of rehabilitation activities. Any setbacks can delay this stage of rehabilitation. Medications, modalities and therapy techniques are constantly re-evaluated and minimized as active exercise becomes the main feature of this stage of rehabilitation.
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Table 17.1
Exercise by Rehabilitation Stage
Intervention
Example
Indication
Exercise in acute stage
Static strengthening (isometrics) Gentle static stretching Contract relax stretching Closed kinetic chain exercise Open kinetic chain exercise Medicine ball Physioball Balance board Mini trampoline Figure of 8 drills Jump training
Reduce atrophy and weakness Limit loss of range of motion Improve flexibility Improve limb strength and co-contraction Improve strength Prepare for sports specific activity Improve trunk strength Improve balance Increase proprioception Improve agility and foot placement Improve tensile strength of muscle-tendon unit and ligaments Improve force production Regain sports specific neuromuscular control Maintain proximal stability and alignment Prevent future injury
Exercise in recovery stage
Exercise in functional stage
Overhead throwing Progress physioball program
Later in the chapter, specific types of exercises will be reviewed. In general, the exercise prescription must be selected carefully to address impairments. The SAID (Specific Adaptation to Imposed Demand) principle necessitates that the effects of training are velocity, joint angle and site specific.3 The overload principle requires that a muscle must be worked at a level higher than it is accustomed in order to increase strength. The exercise workload can be varied to meet a particular goal. For example, exercising with low resistance and higher numbers of repetition builds endurance. Low repetition, high resistance training builds strength. Trunk or core stabilization exercises are an important part of the rehabilitation process and will be reviewed below. When one considers the kinetic chain and the transmission of forces from the distal extremity to the proximal extremity to the trunk, it is key to maintain or increase proximal stability while training for mobility.
Box 17.2: Key Points The Specific Adaptation to Imposed Demand (SAID) Principle states that training effects of an exercise program are specific to: ●
Speed
●
Joint position
●
Muscles included.
Functional stage The functional stage of rehabilitation commences once range of motion is normal and pain-free and the athlete is tolerating a progressive exercise program. The focus of this stage of rehabilitation includes improved neuromuscular control, sports specific and multiplanar activity and cessation of maladaptive behaviors that could lead to a future injury. The athlete completes this stage when he or she can meet the return to play
criteria. Therapeutic modality and medication use is infrequent related to symptom exacerbations. An exercise program including flexibility, strengthening and proprioception is well established. Progression of sports specific activity is very important to allow successful return to play. The focus on correct technique will prevent future injury. Chapter 20 will focus on returning to training and competition.
APPLIED EXERCISE PHYSIOLOGY Principles of exercise physiology and conditioning have been previously reviewed (see Chapter 2, in the section on general scientific and medical concepts). These principles are directly applied in the rehabilitation exercise program. Appropriate incorporation of specific types of muscle contractions and functional positions guides the execution of the program. The exercise prescription includes intensity, duration, frequency and mode of exercise (Table 17.2) Objective outcomes include strength, power, endurance, flexibility, motor control and functional performance. One cannot discount subjective complaints about pain or instability. This feedback provides valuable input on tissue healing and helps direct progression of training, for example in the setting of stress fractures.4
THE EXERCISE PRESCRIPTION The exercise prescription is based on the particular goals of the athlete. Exercises are selected to meet the desired training effect.
Intensity Intensity of exercise describes the difficulty level of the exercise. The major muscle groups are trained with one or multiple (up to 3) sets of 8–12 repetitions. Once the athlete can perform 12–15 repetitions with ease, the resistance is increased.
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Element
Definition
Common Programs
Type or mode of exercise Frequency
Specific activity the athlete will engage in No. of times per week
Resistance training Cardiovascular training 3–5 times per week (more often in season)
in an athlete with a lower extremity injury, may increase duration. Many sports, such as soccer and basketball, require both short bursts of high intensity anaerobic power in addition to a solid aerobic base. Interval training is one means of providing training for both the anaerobic (work periods) and aerobic systems (relief periods).11 There are many different protocols for interval training.
Duration
For strength training: No. of repetitions per set OR No. of sets per session For endurance training: Total number minutes For strength training: % of repetition maximum
6–10 repetitions per set OR 3 sets per session
Frequency
Table 17.2
Intensity
The Exercise Prescription
For endurance training: No. of repetitions % VO2 OR % maximum heart rate
30–60 min 50–100% of 6–10 repetition max 100% of 15–30 repetition max 40–85% VO2 55–90% maximum heart rate
Frequency of exercise indicates how often the exercise is performed. This can vary depending on if the athlete is in or out of season. Generally, injured and non-injured athletes in season exercise 5–7 days per week. During a given week, game participation substitutes for a training session. In particular sports, athletes may rest on the day after the game. The resistance training component of the rehabilitation program is usually done on an every other day basis to allow for intervals of rest. It will generally take about six weeks for strength improvements.
Mode Resistance or strength training intensity has its roots in the DeLorme method.5 In this schema, a 10-repetition maximum weight was established at the outset of the training program and then weekly. The individual performed 10 repetitions of a weight 50% the 10-repetition maximal weight, followed by 10 repetitions of a weight 75% the 10-repetition maximal weight, and finally 10 repetitions of a weight 100% the 10-repetition maximal weight. The Oxford technique trained in an opposite manner, with the athlete starting at 10 repetitions of a weight 100% the 10-repetition maximal weight, then 75% and finally 50% the 10-repetition maximum.6 Other techniques, utilizing 6- to 10-repetition maximum weight to develop the progressive-resistance training program, have been used over the past several decades.7 Alternatively, intensity can be approached with higher repetition, submaximal resistance sets, which are employed during the acute and recovery stages of rehabilitation.8 This type of resistance training increases endurance. Cardiovascular training intensity is gauged by: percentage of VO2 maximum (40–85%); percentage of calculated maximal heart rate (55–90%); or rating of perceived exertion (14 on the RPE scale).9
Duration Duration of exercise describes the timeframe of the exercise sessions. In general, 30–60 min is the target. Intensity and time of performance of exercise are inversely proportional. Metabolic demand and substrate utilization varies depending on duration of exercise. High intensity exercise is limited by lactic acid build-up; exercise for >1 h performed at low intensity promotes more efficient utilization of free fatty acids.10 The duration of training should mimic the sport participant’s functional needs. In the acute stage, duration may be limited. However, alternative methods, such as upper body ergometry
Mode of exercise includes the type of exercise performed. It should mimic the type of sport the rehabilitating athlete participates in. It can be varied to provide the broadest coverage of muscle groups and to remediate conditioning deficits.
TYPES OF MUSCLE CONTRACTION Box 17.3: Key Points Isometric contractions ●
Hold for 5–10 s
●
Performed at multiple joint angles.
Isometric Isometric (fixed muscle length) contraction is most useful in the acute stage when mobilization of injured tissue may be contraindicated. Isometric contractions can generate significant force and are crucial in many sports. For instance, gymnasts must maintain fixed postures during floor exercise, bars and rings. Isometric co-contraction would be included in the gymnastic exercise prescription throughout all three rehabilitation stages, as this type of contraction is very functional for the athlete. The athlete is typically told to hold the maximal contraction for 5–10 s. The contraction is repeated at multiple joint angles.
Concentric Concentric contraction involves shortening of the muscle with requisite movement of the origin or insertion and limb translation.9 Athletes use concentric contractions to counter a load. They are used to accelerate the distal segment of the limb and
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attached equipment, such as a racquet or ball. With skill training, the ball can be released with kinetic energy at the appropriate time or toward the appropriate target. Initial concentric exercise training can be done using only the resistance of the limb mass against gravity or in a gravity-assisted or gravityeliminated position. Progressive resistance can be advanced using a variety of equipment, including flexible cords, weighted balls, hand weights or resistance training equipment. Body positioning can be manipulated to provide for more functional alignment. In regard to rehabilitating athletes, one must remember that these concentric contractions are not performed in isolation and occur with a host of biomechanical challenges brought about by changes in trunk alignment or surface of play, just to name a few.
Isotonic Isotonic exercise includes contraction against a constant external resistance. The resistance can be manual or mechanical. Isokinetic is the term used to describe contractions that take place at a constant velocity. Isokinetic contractions do not occur in vivo. However, computerized exercise equipment can provide constant resistance or constant velocity. Variable resistance machines have been developed to provide resistance that matches the torque curves produced by particular muscle groups. Isokinetic data has been used to follow post-surgical patients and in research studies but has limited clinical application. Most equipment tests uniplanar movements, limiting its functional applicability.
Box 17.4: Key Points Closed kinetic chain (CKC) exercises ●
Fixed distal limb
Open kinetic chain (OKC) exercises ●
Freely moving distal limb.
Moving beyond therapeutic exercise regimens limited to one muscle, joint or direction, the sport rehabilitation exercise program includes the entire kinetic chain (or linked segments of the limbs and trunk and the muscles that co-contract around them). Open kinetic chain (OKC) exercise is one in which the distal limb segment is not fixed and able to move freely. Closed kinetic chain (CKC) exercise is one in which the distal limb segment is fixed or in contact with a ground reaction force. Different muscle activation patterns are seen between OKC and CKC exercises. Knee extension and flexion CKC exercise with mini-squats co-activates the quadriceps and hamstrings (Fig. 17.1).12 Muscle activation may also be impacted by proximal or distal joint positioning, such as performing the leg press exercise with the hips flexed versus extended (Fig. 17.2). Biomechanical deficits in joints outside of the injured limb can lead to re-injury. In fact, these deficits in the kinetic chain may have led to the current injury. For example, a baseball pitcher transmits forces from the lower limbs via the trunk to augment force production in the upper limb. Therefore,
identifying and treating flexibility and strength deficits in the lower limbs and trunk are an important part of the rehabilitation program of a throwing athlete with an upper limb injury. Motion analysis using videotaping can also be helpful in reinforcing correct movement patterns once biomechanical deficits have been addressed. This should be done prior to return to play when ingrained maladaptive movement patterns are likely to resurface. While kinetic chain consideration has expanded the repertoire of exercise in the rehabilitation of the athlete, functional rehabilitation has moved to another level. Most fundamental is the acknowledgement that sports-related function is dictated by forces of gravity, momentum, and ground reaction in multiple planes of motion.13 Research in the arena of non-contact ACL injuries demonstrates the utility of this multidirectional and functional consideration. Multiplanar control at the knee may be directly impacted by foot position, ligamentous laxity, muscle fatigue after repetitive eccentric contractions or knee joint positioning that inhibits rather than recruits the optimal muscle co-contraction patterns; therefore, all these areas are being studied in conjunction with the increase in non-contact ACL injuries in girls and women compared to boys and men.14 The goals of rehabilitating (and likewise prehabilitating) athletes at risk for ACL injury is to provide exercise training that simulates sports-related activities in order to expand the biomechanical and neurophysiological repertoire of the athlete. This expanded repertoire can then be called into action on the field of play to enhance performance and reduce injury rate. Most crucial to this functional training is expansion of eccentric muscle control. In keeping with the tradition of kinetic chain principles, lower limb performance demands that the joints of the entire lower limb, pelvis and trunk make appropriate adaptations to the forces of gravity, momentum and ground reaction in multiple planes of motion. Eccentric muscle contractions are paramount to regulate limb and body movement. An eccentric muscle contraction generates muscle tension while a muscle is lengthening (muscle origin and insertion are moving away from one another). Eccentric contractions are crucial in slowing or decelerating segments of the body that have acquired kinetic energy, such as the lower limbs in running. Eccentric contractions are associated with delayed onset muscle soreness and microscopic trauma.15 Soft tissue injuries, such as hamstring strains, have been linked to this microscopic damage.16 The microscopic area of damage may progress to a muscle tear with ongoing eccentric contractions. Further research is needed to guide practitioners in prescribing eccentric exercise, especially in the acute stage of rehabilitation. Currently, eccentric training starts at low levels with gradual progression to higher intensity and frequency. Eccentric training is important as it mirrors the physiologic manner in which human muscle performs, in particular the lower limbs. Running has been described as a series of lower limb pronations (during loading) and supinations (during unloading and swing).13 The pronation phase, or first half of stance, involves mostly eccentric contraction to provide for joint control and shock absorption. The supination phase, or second half of stance and early swing, involves mostly concentric contractions. Eccentric training of the lower limbs is employed using various heights and planes of movement from
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A
B
C
A
B
Figure 17.1 Closed kinetic chain (CKC) exercise with a mini-squat. Hamstring and gastrocnemius-soleus contraction is created by flexion moments at the (A) hip, (B) knee and (C) ankle. (From Prentice WE. Rehabilitation techniques in sports medicine. 2nd edn. St Louis, MO: Mosby; 1994:100–101.)
A
B
Figure 17.2 Leg press exercise performed with the hips flexed in standard position (A) and hips extended with modified position (B). The hip extended position provides a more functional pattern of contraction. (From Prentice WE. Rehabilitation techniques in sports medicine. 2nd edn. St Louis, MO: Mosby; 1994:102.)
which the athlete controls loading and unloading (Fig. 17.3). Step up and downs can be done in the frontal, sagittal or transverse plane training both concentric and eccentric lower extremity musculature in a functional way.
Box 17.5: Key Points Plyometric exercises
Plyometric Plyometric training describes rapid eccentric loading followed by an explosive concentric contraction.17 The extent of viscoelastic stretching and joint load varies and must be
●
Rapid eccentric load followed by explosive concentric contraction
●
Moderated by varying height, speed and vigor of contraction
●
Carefully progressed to avoid tissue overload and re-injury.
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Figure 17.4 Upper extremity plyometric exercise with weighted ball. The exercise can be progressed by speed, weight and number of repetitions. (From Paine RM, Johnson RM. Open and closed chain exercises; Non-weight-bearing and weight-bearing exercises. In: DeLee JC, Drez D, Miller MD, eds. DeLee & Drez’s orthopaedic sports medicine: principles and practice, Vol 1. 2nd edn. Philadelphia: Saunders; 2003:347.)
Power and endurance
Figure 17.3 Step up exercises performed in the frontal plane. Variations incorporating diagonal patterns and upper limb reaching can incorporate the sagittal and transverse planes. (From Prentice WE. Rehabilitation techniques in sports medicine. 2nd edn. St Louis, MO: Mosby; 1994:103.)
carefully titrated to avoid re-injury. One can manipulate height from which the athlete drops and speed and vigor of contraction. While plyometric training has been used informally for many decades, it has become a mainstay in rehabilitating athletes and preparing them for return to sports. Lower extremity plyometric exercises can be advanced from tuck jumping to drop jumping (dropping to the ground from a raised height then immediately jumping). Upper extremity plyometric training can be done with press-ups and hand claps or using equipment such as a medicine ball or weighted ball (Fig. 17.4).
Agility drills Agility drills are dynamic exercises that combine plyometric training with coordination, proprioception and neuromuscular control. The shuttle run, for example, is the ultimate kinetic chain activity, requiring coordination of upper and lower body movement, controlling eccentrically the force of gravity and momentum, while challenging aerobic capacity and joint load tolerance. Agility drills are incorporated as part of the sport specific training in the functional stage of rehabilitation.
Power and endurance are also important considerations for the training program. Muscle power is the product of force and velocity and represents the amount of work a muscle can produce per unit of time. Power can be trained with a periodized progressive exercise program, or one that manipulates training variables such as speed, repetitions, and sets over time. Endurance relates to the muscles’ ability to sustain contraction or perform repeated contractions. Endurance training impacts the aerobic pathways, most typically via low load, high repetition exercise. Conditioning with treadmills or elliptical trainers develops muscular and cardiovascular endurance. Workload can be advanced via changing the grade, resistance, speed or duration of workout on the equipment.
CORE STRENGTHENING Exercise to increase trunk stability, or ‘core strengthening’, is included in almost all sports rehabilitation programs. The ‘core’ is defined by the diaphragm superiorly, pelvic floor inferiorly, abdominals anteriorly and lumbar extensors posteriorly.18 While application of core strengthening may be obvious in athletes with low back pain, it is thought to play an integral role in rehabilitating athletes with limb injuries, in particular in the throwing athlete. Co-contraction of the trunk muscles provides active stiffening and reduces spinal loading while connecting the upper and lower limbs via the abdominal fascial system.19 In particular, the posterior layer of the thoracolumbar fascia is crucial in supporting the lumbar and abdominal muscles. The aponeurosis of the latissimus dorsi muscles forms the superficial layer of the posterior thoracolumbar fascia and the transversus abdominus has extensive attachments to the
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Flexibility training
middle and posterior thoracolumbar fascia, thereby connecting the upper and lower limbs.20 The hip girdle musculature plays an integral role in stabilizing the lumbar spine and pelvis, especially in ambulatory activities.21
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cises include the curl-up, side bridge and bird dog (Fig. 17.5).25 Exercise progression includes addition of the physioball or other labile surfaces and upright positioning. Many programs do not include the transverse plane, or rotational movements, so pertinent to athletic function.25
Box 17.6: Key Points FLEXIBILITY TRAINING Muscle groups included in a core strengthening program ●
Transversus abdominus
●
Multifidis
●
Lumbar paraspinals
●
Gluteus maximus and medius
●
Pelvic floor.
Core strengthening programs incorporate specific exercises, some that isolate and others that combine the muscular activation of the core. It is described extensively and is the moniker used to label a wide-variety of exercise programs. The muscles most frequently targeted include the transverses abdominus, multifidus, lumbar paraspinals, gluteus maximus and medius, and the pelvic floor musculature. While theoretically aimed to prevent and treat musculoskeletal injuries in athletes, there have been no randomized controlled studies of core strengthening in sports medicine rehabilitation. Core strengthening has been studied in regards to preventing low back injuries and improving sports performance.22 There may be some inherent risks to at least the spine with some core strengthening programs and further study is warranted. Particular exercises, such as the Roman chair extensor training, are considered unsafe by some researchers.23 Many core strengthening programs have their grounding in dynamic lumbar stabilization exercises.24 The beginning exer-
A
Flexibility is the total achievable excursion of a body part through its potential range of motion.26 Flexibility relates to tissue extensibility to allow for normal motion while laxity describes excessive tissue extensibility to allow for abnormal motion of a joint. Static factors in flexibility include collagen type or inflammation. Dynamic factors include motor control or pain. The goal of flexibility training is adequate flexibility without injury or excessive joint laxity. Joint mobility plays a role in flexibility and must be evaluated by a trained manual therapist. Stretching denotes applying a deforming force along the joint and muscles. Deficits in capsular mobility must be treated at the outset of the flexibility program. Application of an oscillatory or sustained force distally while stabilizing the joint proximally mobilizes the joint. Historically, stretching has focused on end range, single plane force. More recently, functional programs are moving beyond single plane, end range focused stretching programs.13 This is in keeping with the multiplanar muscle, joint and fascial planes. Stretching before sports participation is a routine activity, endorsed by coaches, trainers, and team physicians. Athletes are typically told to warm up to begin to sweat prior to stretching. While stretching is believed to prevent muscle soreness and injury and enhance performance, several reviews of the medical literature have concluded there is insufficient evidence to support these claims.27–29 In many studies, the major
B
C Figure 17.5 Basic exercises for spine stabilization programs include (A) the curl-up, (B) the side bridge and (C) the bird dog. These exercises can be performed with a physioball or other labile surface to increase difficulty. (From Akuthota and Nadler 2004.25)
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predictor of joint injury was previous injury and joint laxity, not necessarily inadequate flexibility.30,31 Stretching is employed in the exercise program of injured athletes after evaluation reveals flexibility deficits. There are many types of stretching exercises used by therapists and trainers and taught to rehabilitating athletes (Table 17.3). Historically, ballistic (bouncing) stretching including rapid, repetitive jerking motions was employed; it has fallen from favor due to concerns of soft tissue injury.32 Passive stretching includes slow sustained external force applied by another individual. Proprioceptive neuromuscular facilitation or PNF may require another individual providing isometric or isotonic resistance followed by passive muscle lengthening.33 PNF relies heavily on the neurophysiological principles of reciprocal inhibition and the stretch reflex in its attempt to impact the muscle spindles and Golgi tendon organs.
Table 17.3
Types of Stretching
Method
Typical Requirements
Passive stretching
Partner for external force Slow sustained stretch Self imposed force Hold for 15–60 s 2 sets for each muscle group Repetitive jerking movement Rapid movements Possibly injurious Partner for external force Immediate application of force after contract isometrically (contract-relax stretching) Self imposed stretch Apparatus for positioning Incorporation of all 3 planes of cardinal movement (frontal, sagittal and transverse)
Static stretching
Ballistic stretching
Proprioceptive neuromuscular facilitation (PNF) Functional stretching
Typical patterns of inflexibility are observed in the sports medicine clinic, reflecting similar patterns in the population at large. The major muscle groups are typically targeted along with the injured limb or area. The stretches for the major muscle groups are generally described with unidirectional, end range focus.34 It is not clear if this type of end range stretching is functional as most athletes do not move at the end range or in one particular plane; rather, they work in midranges with a combination of frontal, sagittal and transverse planes. Several PNF patterns reflect this multiplanar joint movement pattern. There is contradictory research on increased flexibility and performance, with some showing enhancement and others with adverse effects.27 These studies include exercise interventions with the uniplanar, end range stretching described above. It is not clear how to educate and counsel athletes with regard to stretching. Knowledge of the biomechanics of the athletes’ sport will direct one to obligate movement patterns she will engage in. Directing the stretching program to prepare the athlete for these movement patterns is logical. In addition, incorporating multiplanar directionality to the stretch should be useful. For instance, rather than having the athlete stretch the psoas muscle with a sagittal plane, end range stretch, the addition of the frontal and transverse plane is much more in keeping with sports activity required for rebounding in basketball.
CONCLUSION Exercise is the keystone in sports medicine and rehabilitation. It provides a practical means of restoring injured and deconditioned tissue to function, in the case of the athlete, for sport. The exercise building blocks required include strength, cardiovascular fitness, neuromuscular coordination and flexibility. A thorough understanding of the specific sport the athlete competes in allows one to tailor the program to meet the needs of that athlete. The utilization of plyometrics, core strengthening, multiplanar stretching and other novel techniques require further innovative research.
REFERENCES 1 2
3 4 5 6 7 8
9
Kibler WB. A framework for sports medicine. Phys Med Rehabil Clin North Am 1994; 5:1. Herring SA, Kibler WB. A framework for rehabilitation. In: Kibler WB, Herring SA, Press JM, eds. Functional rehabilitation of sports and musculoskeletal injuries. Gaithersburg: Aspen; 1998:1–8. Sale D, MacDougall D. Specificity in strength training: a review for the coach and athlete. Can J Appl Sports Sci 1981; 6:87. Brukner P, Khan K. Clinical sports medicine. Sydney: McGraw-Hill; 1997:404–416. DeLorme T, Watkins A. Technics of progressive resistance exercise. Arch Phys Med Rehabil 1948; 29:263. Vinowieff AN. Heavy resistance exercise: the Oxford technic. Br J Phys Med 1951; 14:129. Knight KL. Knee rehabilitation by the daily adjustable progressive resistance exercise technique. Am J Sports Med 1979; 7:336–337. Childs JD, Irrgang JJ. The language of exercise and rehabilitation. In: DeLee JC, Drez D, Miller MD, eds. DeLee & Drez’s orthopaedic sports medicine: principles and practice, Vol 1. 2nd edn. Philadelphia: Saunders; 2003:319–335. Young JL, Press JM. The physiologic basis of sports rehabilitation. Phys Med Rehabil Clin North Am 1994; 5:9–36.
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McArdle WD, Katch FI, Katch VL. Exercise physiology: energy, nutrition, and human performance. 3rd edn. Philadelphia: Lea & Febiger; 1991. Astrand PO, Rodahl K. Textbook of work physiology. New York: Mc-Graw Hill; 1986. Draganich LF, Jaeger RJ, et al. Coactivation of the hamstrings and quadriceps during extension of the knee. J Bone J Surg Am 1989; 71:1075–1081. Gray G. Course notes, Functional issues. Chicago, IL: 2004. Dugan SA. Sports-related knee injuries in female athletes: what gives? Am J Phys Med Rehabil 2005; 84:122–130. Proske U, Morgan DL. Muscle damage from eccentric exercise: mechanism, mechanical signs, adaptation and clinical application. J Physiol 2001; 537:333–345. Brockett CL, Morgan DL, Proske U. Predicting hamstring injury in elite athletes. Med Sci Sports Exerc 2004; 36:379–387. Sharkey BJ. Training for sport. In: Cantu RC, Michelli LJ, eds. ACSM’s guidelines for the team physician. Philadelphia: Lea & Febiger; 1991:34–47. Richardson C, Jull G, et al. Therapeutic exercise for spinal segmental stabilization in low back pain: scientific basis and clinical approach. Edinburgh: Churchill Livingstone; 1999. Konin JG, Beil N, Werner G. Functional rehabilitation. Facilitating the serape effect to enhance extremity force production. Athl Ther Today 2003; 8:54–56.
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Vleeming A, Pool-Goudzwaard AL, et al. The posterior layer of the thoracolumbar fascia. Its function in load transfer from spine to legs. Spine 1995; 2:753–758. Lyons K, Perry J, et al. Timing and relative intensity of hip extensor and abductor muscle action during level and stair ambulation. An EMG study. Phys Ther 1983; 63:1597–1605. Nadler SF, Malanga GA, et al. Hip muscle imbalance and low back pain in athletes: influence of core strengthening. Med Sci Sports Exerc 2002; 34:9–16. McGill S. Low back disorders: evidence-based prevention and rehabilitation. Champaign: Human Kinetics; 2002. Saal JA, Saal JS. Nonoperative treatment of herniated lumbar intervertebral disc with radiculopathy. An outcome study. Spine 1989; 14:431–437. Akuthota V, Nadler SF. Core strengthening. Arch Phys Med Rehabil 2004; 85:86–92. Saal JS. Flexibility training. In: Kibler WB, Herring SA, Press JM, eds. Functional rehabilitation of sports and musculoskeletal injuries. Gaithersburg: Aspen; 1998:85–97.
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Thacker SB, Gilchrist J, et al. The impact of stretching on sports injury risk: a systematic review of the literature. Med Sci Sports Exerc 2004; 36:371–378. Weldon SM, Hill RH. The efficacy of stretching for prevention of exercise-related injury: a systematic review of the literature. Man Ther 2003; 8:141–150. Herbert RD, Gabriel M. Effects of stretching before and after exercising on muscle soreness and risk of injury: a systematic review. BMJ 2002; 325:468–470. Godshall R. The predictability of athletic injuries: an eight year study. J Sports Med 1975; 3:50–54. Keller C, Noyes F, Buchner R. Sports traumatology series: the medical aspects of soccer injury epidemiology. Am J Sports Med 1987; 15:230–237. DeVries H. Prevention of muscular distress after exercise. Res Q 1961; 32:177–185. Knott M, Voss D. Proprioceptive neuromuscular facilitation patterns and techniques. New York: Harper & Row; 1968:72–73. Anderson B, Burke ER. Scientific, medical, and practical aspects of stretching. Clin Sports Med 1991; 10:63–86.
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CHAPTER
18
Proprioception and Coordination Emin Ergen and Bülent Ulkar
INTRODUCTION From the sports medicine point of view, the coordination of a movement is mainly the internal organization of the optimal control of the motor system and its parts.1 The basis of coordinative capabilities lies in the highest levels of the central nervous system (CNS) and sensory motor subsystems. Thus, the coordination can be regarded as an umbrella term embracing the concept of optimization for intramuscular and intermuscular coordination and cooperation for a given task including internal and external feedback mechanisms. These mechanisms are disrupted in case of an injury and the continuation of information processing is ceased which would lead to performance deteriorations and re-injury. Sometimes the proper management of sport injuries can be complex and challenging for the sports medicine clinician. In order to prevent athletic injuries and program the rehabilitation after a joint lesion, understanding the role of proprioception is essential. Therefore, the terms ‘proprioceptive deficit’, ‘proprioceptive training’, and ‘proprioceptive rehabilitation’ are being used increasingly in sports medicine.2
DEFINITIONS Coordination has been defined as a cooperative interaction between the nervous system and skeletal muscles.1 The optimal development of coordinative capability serves as the basis for successful motor learning in every sport and the eventual performance of movements and sport skills at the highest levels of mastery. This is particularly important for the prevention of injuries in a risky sports situation such as cutting, dribbling, jumping and landing. Coordination therefore encompasses the proprioceptive abilities. With regard to proprioception, many researchers have defined it as the afferent input of joint position sense (i.e. awareness of position or movement), whereas others consider proprioception in a broader sense that includes neuromuscular control. Most contemporary authorities define proprioception as a specialized variation of the sensory modality of touch that includes the sensation of joint movement (kinesthesia) and joint position (joint position sense).3
During any voluntary movements or perturbations occurring during walking, running or jumping, due to rapid responses of lower and to some extent upper extremities, the musculature of these parts play an important role in maintaining the desirable posture. Postural control is dependent on reflex mechanisms that maintain the body’s center of mass over the feet (a static or dynamic balance). Any sudden change of the foot or feet position stimulates a sequence of muscle firing that is dependent upon central generators and programs interacting with peripheral reflexes. Afferent information for necessary fine tuning of movements is provided by proprioceptive, visual, vestibular, and somatosensorial receptors (Fig. 18.1). Somatosensorial receptors are located in muscles, tendons, joints, and other tissues. Classically, three types of somatic senses are described: pain, thermo-receptivity, and mechanoreceptivity. Proprioception relates primarily to the mechanoreceptive sensation which includes tactile and position sense. Proprioception encompasses two aspects of position sense: static and dynamic. Static sense gives conscious orientation of one body part with respect to another. Dynamic sense provides the neuromuscular system feedback about the rate and direction of a movement. Thus, proprioception can be thought of as a complex neuromuscular process that involves both afferent input and efferent signals and allows the body to maintain stability and orientation during both static and dynamic activities.4 There are also two levels of proprioception: conscious (voluntary) and unconscious (reflex initiated). Conscious proprioception enables proper joint function in sports, activities, and occupational tasks. Unconscious proprioception modulates muscle function and initiates reflexive stabilization of joints by way of the muscle receptors.5
PROPRIOCEPTIVE ORGANS – MECHANORECEPTORS Two-way communication between sensory and motor systems is crucial for normal motor control. Visual input is one of the most important aspects in proprioception. Information from the vestibular apparatus about head position in relation to gravity and to head movements is also important. The other
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Afferent proprioceptive organs and receptors
Visual organ
Touch
Vestibular organ
Somatosensorial receptors
Somatic
Joint receptors • Ruffini endings • Pacinian corpuscles • Free nerve endings • Muscle spindles • Golgi tendon organ
Pain
Temperature
Figure 18.1 Afferent proprioceptive organs and receptors.
important body sense is obtained through somatosensorial receptors. The sensory receptors for proprioception that are found in the skin, muscles, and joints as well as in ligaments and tendons all provide input to the CNS regarding tissue deformation.6 Specialized nerve endings and proprioceptive mechanoreceptors (Pacinian corpuscles, Ruffini endings, Golgi tendon organ like endings) have been histologically identified in the knee joint in the capsule,7–9 in the anterior cruciate ligament (ACL),10–12 posterior cruciate ligament (PCL),13 meniscus,14 lateral collateral ligament15 and infrapatellar fat pad.16
Box 18.1: Key Points Proprioceptive mechanoreceptors are present in articular and muscular structures Articular mechanoreceptors ●
Type I: Ruffini endings (SA)
●
Type II: Pacinian corpuscle (QA)
●
Type IV: Unmyelinated free nerve endings
Muscular mechanoreceptors ●
Type III: Golgi-organ tendon (SA)
●
Muscle spindle (SA)
(SA: Slow adapting, QA: Quick adapting).
The role of mechanoreceptors Mechanoreceptors are specialized neurons that transmit mechanical deformation information (e.g. joint rotation due to positional change and motion) into electrical signals.17,18 Stimulation of these receptors results in reflex muscle contraction about the joint as an adaptive control to sudden movements of acceleration or deceleration.9 Each of the above mentioned five mechanoreceptor types responds to different stimuli and transmits specific afferent information that modifies neuromuscular function. All receptors need a stimulus to change their membrane potential caus-
ing an action potential to travel to the CNS. For example, it is speculated that longitudinal tension on a ligament results in compression of the connective tissue that stimulates the mechanoreceptors.19 Mechanoreceptors can also be stimulated by muscle-length change, including the rate of change in tension and length. The mechanical deformation of a receptor stretches the membrane and opens the ion channel. This allows positively charged ions (Na+) into the cell, which creates a net depolarizing effect that generates a nerve receptor potential. Mechanoreceptors detect deformation of the receptor itself or of cells adjacent to the receptor.20 Mechanoreceptors demonstrate different adaptive characteristics related to their response to a stimulus. Quick-adapting (QA) mechanoreceptors (Pacinian corpuscle), decrease their discharge rate to extinction within milliseconds of the onset of a continuous stimulus. Slow-adapting (SA) mechanoreceptors (Ruffini ending and the Golgi tendon organ), remain discharging in response to a continuous stimulus. QA mechanoreceptors are very sensitive to changes in stimulation and are therefore considered to mediate the sensation of joint motion QA mechanoreceptors may be more important in some sports characterized with sudden directional changes like pivoting, shifting, tackling etc. SA mechanoreceptors are maximally stimulated at certain joint angles, and thus a continuum of SA receptors is thought to mediate the sensation of joint position.21,22 Stimulation of these receptors results in reflex muscle contraction about the joint.9,23 When there is no capsuloligamentous strain (or load) on the joint (midrange of position), afferent neurons are not active and they do not play a role in proprioception. Rather, many studies argue that joint afferents (especially Ruffini corpuscle) are limit detectors.24 The muscle spindle receptor is a complex, fusiform, SA receptor located within skeletal muscle. Via afferents and efferents to intrafusal muscle fibers, the muscle spindle receptor can detect muscle tension over a large range of extrafusal muscle length. The monosynaptic stretch reflex involves muscle spindle receptor connecting I-a nerve fibers as well as Golgi tendon organs connecting to I-b fibers. During rapid perturbation such as tripping or falling, monosynaptic reflexes are absent and compensation occurs as a result of transmission along group II and III afferent fibers from secondary muscle spindles. These connect through a polysynaptic reflex system to generate an appropriate response. The contribution of vestibular and visual input to these reflexes is minimal. Gravity and pressure on joints and on the plantar skin surface may be critical to these reflexes.25
CLINICAL IMPORTANCE OF PROPRIOCEPTION In any specific situation there are gravity, inertia and reaction forces creating a specific external load upon musculoskeletal structures. This load is counteracted by the internal forces and the internal forces balance the external. Good proprioception and coordination means that all the components of musculoskeletal fitness are in balance to overcome any overloading on structures and this is important in maintaining dynamic joint stability.26
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Ankle proprioception
Dynamic joint stability can be defined as the ability of appropriately activated muscles to stabilize a joint together with the support of mechanical stabilizers (Fig. 18.2). In essence, dynamic joint stability is the ‘product’ of the proprioceptive system.2 In relation to dynamic (functional) joint stability, cognitive programming also plays a role in the neuromuscular control mechanism which involves the highest level of CNS function (motor cortex, basal ganglia, and the cerebellum). This function refers to voluntary movements that are repeated and stored as central commands. The awareness of body position and movement allows various skills to be performed without continuous reference to consciousness.27 As defined earlier, proprioceptive feedback is crucial in the conscious and unconscious awareness of a joint or limb in motion. Therefore, enhancement of dynamic (functional) joint stability is important both in prevention and rehabilitation of athletic injuries. This requires a constant and appropriate flow of sensory information, integrated with motor output, in a coordinated manner.28 Trauma to tissues may result in partial deafferentation by causing mechanoreceptor damage, which can lead to proprioceptive deficits. Consequently, susceptibility to re-injury may become a possibility because of this decrease in proprioceptive feedback. However, studies have shown at least partial restoration of kinesthesia and joint position sense in surgically reconstructed shoulders and knees after rehabilitation.29,30 The effect of ligamentous trauma resulting in mechanical instability and proprioceptive deficits contributes to functional instability, which could eventually lead to further microtrauma and re-injury. Achieving functional and sport-specific activities following musculoskeletal trauma and rehabilitation can be established significantly if proprioception is addressed and instituted early in the treatment program.
ANKLE PROPRIOCEPTION Functional instability of the ankle is one of the most common residual disabilities after an acute ankle sprain. Ankle joint instability can be defined as either mechanical or functional instability. Mechanical instability refers to objective measurement of ligament laxity, whereas functional instability is defined as the feeling of giving way. Casual factors include a proprioceptive deficit, muscular weakness, and/or absent coordination.31 Ankle instability as a result of partial deafferentation of articular mechanoreceptors with joint injury was first postulat-
Proprioception
Postural control
Functional stability
Muscular properties 1 − Power 2 − Reaction time
Capsuloligamentous properties Mechanical stability
Figure 18.2 Factors effecting functional stability.
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ed by Freeman (1965).32 They observed that a decrease in the ability to maintain a one-legged stance occurred in the sprained ankle versus the contralateral uninjured ankle. Konradsen and Ravn (1990) attributed the cause of functional instability to both mechanical and functional causes in stating that functional instability results from ‘damage to mechanical receptors in the lateral ligaments or muscle/tendon with subsequent partial de-afferentiation of the proprioceptive reflex’.33 Glencross and Thornton (1991) reported deficits in the ability to actively replicate passive ankle and foot positioning while testing the sprained ankle versus the contralateral uninjured ankle.34 Gross (1987) also revealed that an increased probability of re-injury occurs as a result of a decrease in sensory input from joint.35 Konradsen and Ravn (1990) found that chronic ankle instability resulted in a prolonged peroneal reaction time in response to a sudden inversion stress when compared with age matched controls.33 Partial deafferentation resulting in diminished reflex joint stabilization may contribute to these findings. No increases in postural sway were observed by Tropp and Odenrick (1988) when comparing a group of soccer players with previous ankle sprains to a control group of uninjured soccer players.36 However, significant increases in postural sway were observed by Cornwall and Murrell (1991) when comparing patients with acute ankle sprains with uninjured controls as long as 2 years after their injuries.37
Muscle reaction time In terms of lateral foot and ankle perturbations, several authors have evaluated the timing and power of neuromuscular response in the lower leg muscles. A significantly faster reflex time has been found in the peroneal muscles compared with the quadriceps and hamstring.25 Peroneal reaction time has been found significantly shorter in mechanically stable ankles.38 However, all these studies have been conducted on subjects in a standing position with lower extremity muscles at rest. In an action like walking, running or jumping, a considerable preactivation of related muscles prior to touchdown exist.25 Therefore, exercises including perturbations on wobble board may increase ankle stability both for preventive and rehabilitative purposes.
Taping It has been postulated that ankle taping induced prophylaxis is associated with sensory feedback. By uniting the skin of the leg with the plantar surface of the foot, Robbins et al. (1995) suggested that the sensory cues to plantar surface of the foot are increased, thereby allowing a more accurate foot placement and reducing the changes of excessive ligamentous strain.39 Karlsson and Andreasson (1992) concluded that tape may help patients with unstable ankles by facilitating proprioceptive and skin sensory input to the central nervous system.38 Therefore, taping or using lace-up brace may contribute proprioception with sensory stimulation. There are some studies emphasizing that ankle taping rapidly loses its initial level of resistance, nevertheless restraining effect on extreme ankle motion has not been eliminated by prolonged activity as well.40,41
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KNEE PROPRIOCEPTION The presence of neuroreceptors in the human knee joint had been described by Rauber over a hundred years ago, whereas the presence of numerous mechanoreceptors in the human ACL was well documented in the 1980s.42 The afferent innervation of joints is based on peripheral receptors located in articular, muscular, and cutaneous structures. Articular receptors include nociceptive free nerve endings and proprioceptive mechanoreceptors. Mechanoreceptors which have been identified histomorphologically in the ACL, PCL, meniscus, lateral collateral ligament and infrapatellar fat pad are Ruffini endings, Pacinian corpuscles, and Golgi tendon organs.43 Knee joint proprioception which is essential for adequate joint movement and stability, arises from receptors located in muscles, tendons, skin and joint structures. Sensory information from the knee joint receptors affects the activity of the gamma-motor neurons which in turn affect the muscle spindle afferents. The joint receptors are thereby participating in the continuous regulation of muscle stiffness around the joint; thus theoretically, defective proprioception may lead to instability of the joint.44 Proprioception may play a protective role in acute knee injury through reflex muscular splinting. Kennedy et al. (1982) hypothesized that loss of mechanoreceptor feedback from torn knee ligaments contributed to a vicious cycle of loss of reflex muscular splinting, repetitive major and minor injury and progressive laxity.10 The protective reflex arc initiated by mechanoreceptors and muscle spindle receptors occurs much more quickly than the reflex arc initiated by nociceptors (70–100 m/s versus 1 m/s). Thus, proprioception may play a more significant role than pain sensation in preventing injury in the acute setting.45 Mechanoreceptors found in the ACL together with the mechanoreceptors in the PCL and collateral ligaments, is a very important factor in the complicated neural net of proprioception. After an ACL injury, the gait patterns of the ACL-deficient knee are altered, probably due to changes in proprioception. Proprioceptive deficits after ACL rupture can predispose to other injury and may contribute to causing degenerative joint disease by pathological wearing of the cartilage because of the altered gait patterns of a joint with poor sensation.46 In addition to mechanical disruption of articular structures following injury, the loss of proprioception may have a profound effect on neuromuscular control and the activities of daily living. It appears that neurological feedback mechanisms originating in articular and musculotendinous structures provide an important component for the maintenance of functional joint stability.47 Articular deafferentation results following the injury to capsuloligamentous structures. This contributes to alterations in kinesthesia and joint position sense and further degenerative changes in the joint, as the spinal reflexive pathway may be impaired.47 Most clinical studies about knee joint proprioception have dealt with ACL deficient or ACL reconstructed knee joints. There is one unequivocal result of these studies; even when totally different methods of evaluating the proprioceptive
capabilities are applied, patients suffering from an ACL rupture have significantly worse knee joint proprioception than healthy groups.48 Safran et al. (1999) have demonstrated that isolated PCL deficiency in the human knee does result in reduced kinesthesia, as tested by the threshold to detect passive positioning and enhanced reproduction of passive positioning (RPP).43 On the other hand, proprioceptive deficits in studies of patients with ACL disruption reveal greater proprioceptive deficits, both in magnitude and over a greater range of motion, than the findings presented by Safran et al. (1999) for PCL deficiency.43 Disruptions in the afferent pathway which are mediated partly by articular mechanoreceptors may also contribute significantly to an insidious pattern of microtrauma and reinjury.47 Beard et al. (1994) demonstrated the inhibition of reflex arc, which leads to reductions in reflex muscular stabilization resulting from ACL deficiency.49 Partial restoration of kinesthetic awareness on patients who had undergone anterior cruciate ligament reconstruction by a modified MacIntoshJones method has been demonstrated by Barrett (1991).50 This study indicates that proprioception, together with the clinical excellence of the repair and re-establishing the stability, is another important factor in the outcome of anterior cruciate ligament reconstruction. It has been proposed that loss of the proprioceptive feedback after an ACL rupture contributes to the progressive instability and disability that occurs in a high percentage of ACL deficient knee joints.3,46,51 Reconstruction of the ruptured ACL does not always result in the expected successful outcome. Success after ligament reconstruction may depend not only on the tightness or strength of the reconstruction but also on the quality of recovery of proprioception.50,52 Correct stability seems to be the basis for later ligamentization and recovery of proprioception.46
SHOULDER PROPRIOCEPTION Positioning the hand is a necessary motion during activities of daily living in addition to sport-specific patterns. Joint position sensibility not only plays an important role in the maintenance of dynamic shoulder stability but also shows alterations after injury. Ligaments around the shoulder joint are in action during normal kinematics and also provide neurological feedback mediating muscular reflex inhibition. Shoulder articulation is not constrained to a large extent, therefore a coordinated dynamic control of muscles about the joint is necessary for stabilizing the arm during motion. The ligamentous structures function only at extreme positions of rotation to prevent excessive translation or rotation of the humeral head on the glenoid. In the midranges of rotation, the capsuloligamentous structures are relatively lax and joint stability is attained with dynamic action of the rotator cuff and biceps tendons. Contraction of these muscle tendon units generates joint compression and increases the concavity compression fit of the humeral head into the glenoid cavity. In addition, a coordinated, synergistic contraction of the rotator cuff and biceps may protect the ligamentous structures from injury by increasing
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torque resistance against excessive rotation and preventing excessive translations of the humeral head.53 Proprioceptive ability does not show a difference between the dominant and non-dominant shoulder, but in unstable shoulders this has been found to be significantly decreased.3,54 Several studies have demonstrated deficits in shoulder kinesthesia and joint position sense in male non-athletes subjects with unilateral, traumatic, recurrent anterior shoulder instability and proprioceptive deficits have also been observed in the pathologic shoulder as compared with the contralateral normal shoulder.3,55 Reduction in neuromuscular activation of the pectoralis major, subscapularis, and latissimus dorsi muscles was shown to contribute to anterior instability through a decrease in the normal internal rotation force necessary for this motion. Compensatory increases in biceps and supraspinatus muscle activity were also discovered in an attempt to restore anterior stability. This loss in the normal synchronization of neuromuscular firing patterns in the unstable shoulder has been attributed to altered joint kinematics resulting in repetitive microtrauma. Surgical intervention (capsulolabral reconstruction) has been shown to partially restore joint proprioception through the repair of traumatized tissue.3 The authors have commented that the procedure modifies soft tissue dissection and a minimal loss of intact mechanoreceptors and a promotion of re-population were observed. In addition, the use of the capsular shift in these shoulder instability cases, which tightens the capsule, ‘re-tensions’ the soft tissue and most likely facilitates proprioception function. It may be through this procedure of re-tensioning that mechanoreceptor-containing shoulder capsuloligamentous structures send afferent information at a more functional level regarding joint position sensibility. Restoring dynamic neuromuscular control of the unstable or postoperative shoulder is of primary importance for returning to functional activity.
MEASUREMENT OF PROPRIOCEPTION The assessment of neuromuscular control includes the measurement of cortical, spinal reflex, and brainstem pathways. The evaluation of this complex neuromuscular system as different components allows a more detailed explanation of afferent control mechanisms.3 Kinesthesia and joint position sensibility are the two major assessment methods of joint proprioception. Kinesthesia is assessed by measuring threshold to detection of passive motion (TTDPM), while joint position sense is assessed by measuring reproduction of passive positioning (RPP) and reproduction of active positioning (RAP). These tests are performed at slow angular velocities (0.5–2.5˚/s) to selectively stimulate Ruffini or Golgi-type mechanoreceptors, and because the test is performed passively, it is believed to maximally stimulate joint receptors while minimally stimulating muscle receptors.47 Several methods and devices have been described to test proprioceptive status of healthy and injured people. Studies that have investigated the proprioceptive ability of ACLdeficient and reconstructed knees have primarily relied on measurement of TTDPM and reproduction of knee joint angles.45,47,56
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Box 18.2: Key Points Measurement Methods of Proprioception Measurement of kinesthesia and joint position sense ●
Special devices developed for this purpose (PTD)
●
Isokinetic dynamometers
●
Goniometers, inclinometers
●
Motion analysis systems
Measurement of balance and postural control ●
Stabilometers
●
Force plates
Measurement of muscular latency ●
Electromyographic analyses
Non-instrumented methods ●
Limb matching tests
●
Hop tests.
Several researchers utilized proprioception testing devices (PTDs) similar in action and design.51,56–58 These devices have moving arms rotating the limbs through the axis of the joint. A rotational transducer interfaced with a digital microprocessor counter provides the angular displacement values. Pneumatic compression cuffs are placed on each limb distal to the tested joints to reduce cutaneous input. The subjects are blindfolded to eliminate visual cues and headphones with white noise are used to eliminate auditory cues. The subjects are holding an on-off switch to press when they detect the threshold of passive motion or the pre-positioned angle. Some of these devices are designed to perform measurements both on knee and shoulder joints (Figs 18.3, 18.4).51,57–59 Friden et al. (1996, 1997, 1998, 1999) reported several studies conducted with a
Figure 18.3 Threshold to detection of passive motion (TTDPM) and position sense measurement device with shoulder apparatus. (Prosport 1000 HMS, Tümer Engineering Co. Ltd., Ankara, Turkey.)
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Figure 18.4 Threshold to detection of passive motion (TTDPM) and position sense measurement device with knee apparatus. (Prosport 1000 HMS, Tümer Engineering Co. Ltd., Ankara, Turkey.)
PTD which measured the threshold for detecting a passive motion of knee joint in lateral decubitus position.60–63 The abilities of position replication on subjects’ joints are performed by using isokinetic dynamometers as well.57,64–66 Some researchers use modified isokinetic devices to record the changes in positioning.67 Active reproduction of joint position was another way of assessing joint position sense using an electromagnetic tracking device and an isokinetic dynamometer.57,66 Photographic record of the position-matching test with goniometric measurements is useful to investigate the accuracy in position-matching.68 A simple inclinometer may be used for joint position sense (JPS) testing besides range of motion (ROM) measurements.69 In recent years, motion analysis systems have been used to record target joint angles, calculate reproduced angles (e.g. angle velocity reproduction test-AVRT) and to test dynamic sensorimotor abilities of joints.57,70–72 For the determination of the combination of peripheral, vestibular and visual contributions to neuromuscular control; postural sway and balance are evaluated. Functional assessment of the combined peripheral, vestibular and visual contributions to neuromuscular control is best accomplished through the use of balance and postural sway measurements for the lower extremity. The availability of stabilometric methods and instrumentation can provide a relatively accurate index for these measures.73–76 Balance stabilometry provides a specialized mode of assessment for the overall contribution of these various neural afferent signals to maintain upright standing posture. Postural balance and sway measurements are conducted using various types of force platform devices. Postural control is assessed by measuring changes in the center of pressure signal provided by a force plate during tests of limb standing balance.75,77–81 The assessment of the spinal reflex pathway is conducted to determine the latency of muscular activation to involuntary perturbations. Electromyographic (EMG) analysis has been utilized extensively to examine the role of this neuromuscular pathway during movements that place functional loads on the ankle and knee joint.47 The assessment of reflex capabilities is
usually performed using EMG interpretation of firing patterns those muscles crossing the respective joint. The delay between the initiating stimulus and the onset of the peroneal muscle reflex response is defined as the peroneal latency. Electromyographic studies that investigate muscle onset-latency alterations that develop after an ankle sprain have typically used a simulated inversion ankle sprain perturbation in association with surface EMG to record peroneal muscle onset latencies. The electromechanical delay (EMD) was defined as the time interval between the onset of the peroneus longus electromyogram detected by surface electrodes and the onset of the lateral ground reaction force (Fy) measured on a force plate. Mora et al. (2003) investigated ankle instability by measuring the electromechanical delay of the peroneal muscles (foot pronators).82 Non-instrumented, clinically applicable tests to assess neuromuscular and functional deficits, are reliable and valid for both research and clinical purposes.83 Limb matching tasks are examples to evaluate proprioception without utilizing an electromechanical device. Providing different angles joint movements, the patients are asked to reproduce the given angle with the other limb.84 Although various hop tests have been used to measure the lower limb power and functional ability of the athletes, they are assumed to be useful in the evaluation of proprioceptive status of the injured athlete at the end of the rehabilitation periods. These tests are performed either for distance or time to evaluate lower extremity symmetry.85,86
PROPRIOCEPTIVE TRAINING FOR PREVENTION AND REHABILITATION The concept of doing proprioceptive exercises to regain neuromuscular control initially was introduced in rehabilitation programs (see Progression of a Proprioception Exercise Program, Figs 18.5–18.17 and Table 18.1).87 It was considered that because mechanoreceptors are located in ligaments an injury to a ligament would alter afferent input. Training after an injury, would be needed to restore this altered neurologic function. Neuromuscular conditioning techniques have also been advocated for injury prevention. Increased postural and movement accuracy increases the consistency with which activities can be performed safely.26 An intervention program consisting of injury awareness information, specific technical training and a program of proprioceptive training for players with a history of ankle sprains, demonstrated a 47% reduction in the incidence of ankle sprains in the course of single season.88 Studies have also shown that proprioceptive training not only reduces the risk of re-injury, but also the incidence of acute lateral ankle sprain if used prophylactically.88 Proprioceptive or ‘kinesthetic’ awareness is one aspect of rehabilitation obtained through specific exercises. The objectives of proprioceptive rehabilitation are to retrain altered afferent pathways to enhance the sensation of joint movement. Proprioceptively-mediated neuromuscular control of joints comes into action at three distinct levels of motor activation within the CNS.89
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Table 18.1 Progression of a Program Should be Designed to Proceed from Easy to More Difficult Movements as the Pain During the Exercises is Tolerated91
1
2
3
Easy
Difficult
Double leg Standing position (on the floor) Single direction (e.g. rocker board, ankle inversion-eversion boards, ankle flexion-extension boards) Eyes open Free hands Straight leg Fewer repetitions and sets Simple drills (e.g. walking, stepping down and up)
Single leg Moving platforms and different surfaces (e.g. pneumatic or foam pads) Multidirection (e.g. ankle disk, mini trampoline)
Reflexes at the spinal level mediate movement patterns that are received from higher levels of the nervous system. This action provides reflex for joint stabilization during conditions of excessive stress around the articulation and has significant implications for rehabilitation. The second level of motor control, located within the brainstem which receives information from joint mechanoreceptors, vestibular system, and visual input from the eyes to maintain posture and balance of the body. Reactivated neuromuscular actions allowing this pathway to process input from the aforementioned forms of afferent stimuli can be used to enhance brainstem function. The highest level of CNS function (motor cortex, basal ganglia, and cerebellum) obtains cognitive awareness of body position and movement in which motor commands are initiated for voluntary movements. Use of the cortical pathway allows movements that are repeated and stored as central commands to be performed without continuous reference to consciousness. Kinesthetic and proprioception training are such types of activity that can develop this function.
Incorporating the three levels of motor control into activities to address proprioceptive deficiencies should be started in the early phases of rehabilitation program. Encouraging maximum afferent discharge to the respective CNS level should be the target in stimulating joint and muscle receptors. To stimulate reflex joint stabilization, which emanates from the spinal cord, activities must focus on sudden changes in joint positioning that necessitate reflex neuromuscular control. Development of motor function at the brainstem level can be gained by performing balance and postural activities, both with and without visual input. Maximally stimulating the conversion of conscious to unconscious motor programming can be achieved by performing joint positioning activities, especially at joint end ranges. Simple tasks such as balance training and joint repositioning should begin early in the rehabilitation program and should become increasingly more difficult as the patient progresses.27 Some authors believe that adaptations that occur during rehabilitation are mediated by feed-forward processing and are less a function of enhanced afferent pathways.3 This theory suggests that fast movements are controlled by advance information known about the task, while concurrent proprioceptive feedback is relatively less important. Feedback is used
Eyes shut Fixed arms (crossed over the chest) Flexed knee More repetitions and sets Complicated drills (e.g. hops, jumps, perturbations, and plyometrics)
primarily at the cortical level to determine the success or failure of that movement and to a lesser extent at the subcortical level for directing the movement. With repetition, the cerebral cortex can determine the most effective motor pattern for a given task, based on the proprioceptive information of previous attempts. Biofeedback training appears to use the feed-forward learning process.90
PROPRIOCEPTIVE TRAINING FOR THE SHOULDER Proprioception training of the upper extremity has been incorporated into the rehabilitation program to a lesser extent than that of the lower extremity. Because the primary sport-specific activity of the upper extremity is the throwing motion, refined joint positioning and repositioning of the shoulder is vital. Therefore, mechanoreceptor activity plays an important role in both performance and dynamic shoulder stabilization. The following progression of activities is conducted to allow an athlete returning to functional levels91: 1 joint position sense and kinesthesia 2 dynamic joint stabilization 3 reactive neuromuscular control and 4 functionally specific activities. Such a progression allows the rehabilitation program to integrate spinal reflex, cognitive, and brainstem pathways focusing on scapular stabilization, glenohumeral stabilization, humeral motion, and neuromuscular control. Position sensibility activities are designed to restore joint position sense and kinesthesia. These exercises stimulate cognitive level processing through the use of such an exercise as glenohumeral repositioning both with and without visual input and proprioceptive neuromuscular facilitation patterns performed with manual resistance. Dynamic stabilization activities are designed to stimulate muscular coactivation. In the shoulder, such activities include axial loading of the glenohumeral joint promote coactivation of the glenohumeral and scapulothoracic force couples. Ultimately, plyometrics can be used for the integration of both spinal and cognitive levels. Shoulder plyometric exercises stimulate reflexive activity through the facilitation of the myotactic reflex via the release of stored elastic energy. Such activities
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stimulate reflex joint stabilization, which are critical to the overhead athlete. Once joint sensibility and dynamic muscle joint stabilization are restored, functionally specific activities can be accomplished.91
PROPRIOCEPTIVE TRAINING FOR THE KNEE Reconstructing the ACL seems to improve afferent input needed for functional joint stability, and histologic studies have shown a re-population of mechanoreceptors in ACL graft tissue.28 Exercises to enhance motor control therefore are essential after an anterior cruciate ligament reconstruction. In the past several years, there also has been a heightened awareness of the need for preseason sport conditioning to focus on lower extremity balance and conditioning to attempt to diminish the incidence of knee ligament injuries. Neuromuscular training incorporating plyometrics and agility drills and stressing the need for proper technique for pivoting, shifting, and landing, has been advocated to decrease the incidence of ACL injuries. Griffis (quad-cruciate interaction), Henning Sportsmetrics (a three-part prevention consisting of stretching, plyometrics, and strengthening drills), Caraffa (a five-phase progressive skill acquisition program) and Santa Monica by Mandelbaum (a five-part program designed to improve strength, flexibility, injury awareness, plyometrics and agility skills) are some of the program examples successfully implemented in rehabilitation.28
PROPRIOCEPTIVE TRAINING FOR THE ANKLE Freeman (1965), has first recognized the importance of afferent input in neuromuscular coordination and the significant consequences that result when such input is disrupted.32 He has analyzed previously injured patients following a training period and revealed that such exercises can help to achieve less functional instability than patients not trained in this manner. Tropp (1986) found that 10 min daily wobble board training during a 10-week period could improve pronator muscle strength in patients with functional instability.92 Further training has not been found to give any added effect. Wester et al. (1996) have conducted a similar study on 48 patients (24 training and 24 no-training group) with residual functional instability due to Grade II.93 ankle sprain. Comparing with no training group, 12-week training group showed significantly fewer recurrent sprains in a 230 days follow-up period. Eils and Rosenbaum (2001) have studied the effects of a 6-week multistation proprioceptive exercise program.31 Joint position sense, postural sway and muscle reaction times showed significant improvements following this multi-station training program consisting of 12 different exercises (on mat, swinging platform, air squab, eversion-inversion boards, ankle disc, mini trampoline, step, uneven walkway, hanging and swinging platforms, and with exercise bands). The program has been conducted in a way that each exercise was performed for 45 s followed by a 30 s break where subjects move over to the next station.
FOCUS ON THE BACK The lower back is often considered the ‘weak link’ in the kinetic chain. Dynamic lumbar muscle stabilization has become a popular method of proprioceptive training for the low back. This involves coordinated strengthening of the abdominal, back, and trunk muscles in functional movement planes. Dynamic lumbar stabilization exercises are designed to progressively challenge this segment to promote successive adaptation, with an emphasis on balanced load distribution via a neutral pelvis, optimal skeletal alignment, and balanced strength.2
PROPRIOCEPTIVE EXERCISES Although many companies sell fairly complex computerized equipment to help improve proprioceptive input and balance, such training can also be accomplished through various simple drills done on various surfaces with eyes open and eyes shut, progressing from a double to a single limb stance. However, if available, such technologically advanced devices can also be used in proprioceptive training and rehabilitation programs. Exercises should include repetitive, consciously mediated movement sequences performed slowly and deliberately as well as sudden, externally applied perturbations of joint position to initiate reflex, ‘subconscious’ muscle contraction.20 In injury, ‘pain free’ does not necessarily mean ‘completely treated or rehabilitated’ and unless the full proprioceptive ability is restored, rehabilitation has not been accomplished. In addition, correction of a damaged static restraint (e.g. surgical correction of mechanically disrupted tissue) may not be sufficient to maximize the afferent neuromuscular input needed to enhance dynamic joint stability.
Balance training One major category of proprioceptive exercise is balance training. These exercises help to train the proprioceptive system in a mostly static activity. In the lower extremities, activities can include one-legged standing balance exercises, progressive use of wobble board exercises, and tandem exercises in which a postural challenge (e.g. perturbations) can be applied to the individual by the therapist.
Plyometric exercises Plyometric exercises incorporate an eccentric preload (a quick eccentric stretch) followed by a forceful concentric contraction. This exercise technique is thought to enhance reflex joint stabilization and may increase muscle stiffness. It has become increasingly popular as an example of neuromuscular control exercise that integrate spinal and brain stem levels and has been effective addition to upper and lower extremity conditioning and rehabilitation programs.26 As with the ankle and knee, plyometric exercises are added after near-normal strength in all targeted muscles has been achieved. In the shoulder, plyometrics are performed using the balls with
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known weight, thrown or bounced and caught at various angles using stable and unstable rebounding boards or tossed at varying speeds by a physiotherapist.28
exercises also contributes the cerebral cortex to determine the most effective motor pattern for that task and potentially decrease the response time.26
Isokinetic exercises
Sport-specific maneuvers
Isokinetic exercises can be performed to enhance joint position sense using isokinetic devices. The athlete places his/her extremity in a predetermined position and is asked to reproduce this position, initially with the eyes open and then with eyes shut to block visual cues that might aid in neuromuscular control. This exercise can be performed with and without eccentric and/or concentric loads.
The final phase of any functional rehabilitation or conditioning program must include exercises that mimic those the athlete does in daily sport activities. This specificity of training improves feed forward mechanism and reflex and consciously controlled motor functions.28 Sport-specific exercises will serve to ‘hard wire’ the proprioceptive pathways and solidify a neuromuscular engram specific to these activities. Rehabilitation will then be completed as maneuvers specific to the sport and the athlete’s position in the sport can be performed maximally and without pain or loss of function. These skills should be tested in the clinic, laboratory or field before the patient returns to competition. In summary, for constructing programs with the aim of conditioning and rehabilitation, one should incorporate exercises that improve joint motion sense, increase awareness of joint motion, enhance dynamic joint stability, and improve reactive neuromuscular control. Under the light of present literature, an exercise prescription for a proprioceptive training can be seen in Table 18.2. It is generally recommended to continue such a program for at least 6–10 weeks in order to improve proprioceptive abilities, especially during preseason. It should also be remembered that proprioceptive exercises should incorporate with other specific training items such as strength, flexibility, agility etc. during workouts.
Closed and open kinetic chain exercises Closed-kinetic-chain exercises challenge the dynamic and reflexive aspects of proprioception in the legs and feet. During a closed-chain movement at one joint, a predictable movement at other joints is produced, usually involving axial forces. The lower extremities function in a closed-chain manner during sports and daily life activities, so these exercises will facilitate to regain the proper neuromuscular patterns. Leg press, squat, circle running, figure eights, single-leg hops, vertical jumps, lateral bounds, one-legged long jumps, and carioca (crossover walking) are some examples. In the upper extremities, physiotherapist application of graded, multidirectional manual resistance can provide proprioceptive feedback in a closed-chain fashion. Open-chain manual resistance exercises with rhythmic stabilization (rapid change in direction of applied pressure) are also considered proprioceptively useful. In either case, resistance can be modified, depending on pain tolerance, as the patient progresses.
Reaction time The length of reaction time indicates that motor activity cannot be regarded solely in response to environmental stimuli. In order to prevent injuries, a stored set of muscle commands is necessary. This motor programming allows the initiation of activity on exposure to unfolding event. The repetition of such
Table 18.2
Program for Proprioceptive Training
Number of exercises Number of repetitions of exercises Number of sets Duration of total proprioceptive training
2–5 (to be chosen from the figures) 10–15 1–3 5–15 min (shorter for prevention, longer for rehabilitative purposes), preferably training every day (at least 3–5 days a week)
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B
A Figure 18.5 Flat surface single leg exercises (A) hands free, (B) fixed.
A Figure 18.6 Ankle disk/wobble board (A) double leg, (B) single leg.
B
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A
Figure 18.7 Ankle boards, (A) inversion-eversion, (B) plantar flexion-extension.
A
B
C
Figure 18.8 Rocker board (A) double leg, side-to-side, (B) double leg, forward-backward, (C) single leg.
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A
B
Figure 18.9 Exercises on (A) foam, (B) pneumatic pad, (C) perturbated exercise.
Figure 18.10 Mini trampoline exercises.
C
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B
Figure 18.11 Knee bends (A) with and (B) without gym ball.
Figure 18.12 Walk with deep knee bends.
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A Figure 18.13 (A–C) Step up and down.
Figure 18.14 Double leg hops.
B
C
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A Figure 18.15 (A–C) Single leg hops (patterned).
B
C
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A
C
B Figure 18.16 Complex perturbated (with elastic band) lateral jumps. (A) elastic tube resisted forward-backward, (B) elastic tube side to side jumps, (C) same exercise complicated with ball catch and throw.
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B
C
D
F
E Figure 18.17 Upper extremity exercises. (A–B) roller board, (C–D) medicine ball, (E) wobble board, (F) mini trampoline, (G) gym ball.
G
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Hopper DM, Creagh MJ, Formby PA, et al. Functional measurement of knee joint position sense after anterior cruciate ligament reconstruction. Arch Phys Med Rehabil 2003; 84:868–872. Jerosch J, Brinkmann T, Schneppenheim M. The angle velocity reproduction test (AVRT) as sensorimotor function of the glenohumeral complex. Arch Orthop Traumatol Surg 2003; 123:151–157. Barden JM, Balyk R, Raso JV, et al. Dynamic upper limb proprioception in multidirectional shoulder instability. Clin Orthop 2004; 420:181–189. Berg KO, Wood-Dauphinee SL, Williams JI, et al. Measuring balance in the elderly: validation of an instrument. Can J Public Health 1992; 83:S7–S11. Hansen MS, Dieckmann B, Jensen K, et al. The reliability of balance tests performed on the kinesthetic ability trainer (KAT 2000). Knee Surg Sports Traumatol Arthroscopy 2000; 8:180–185. Ageberg E, Roberts D, Holmström E, et al. The effect of short-duration sub-maximal cycling on balance in single-limb stance in patients with anterior cruciate ligament injury: a cross-sectional study. BMC Musculoskeletal Disord 2004; 5:44. Arnold BL, Schmitz RJ. Examination of balance measures produced by the Biodex Stability System. J Athletic Train 1998; 33:323–327. Adlerton AK, Moritz U, Nilssen RM. Force plate and accelerometer measures for evaluating the effect of muscle fatigue on postural control during one-legged stance. Physiother Res Int 2003; 8:187–199. Fuchs S, Tibesku CO, Frisse D, et al. Clinical and functional comparison of uni and bicondylar sledge prostheses. Knee Surg Sports Traumatol Arthroscopy 2004: 24. Online. Available: http://www.springerlink.com. Gosselin G, Rassoulian H, Brown I. Effects of neck extensor muscles fatigue on balance. Clin Biomechanics 2004; 19:473–479. Madeleine P, Prietzel H, Svarrer H, et al. Quantitative posturography in altered sensory conditions: a way to assess balance instability in patients with chronic whiplash injury. Arch Phys Med Rehabil 2004; 85:432–438.
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Kovacs EJ, Birmingham TB, Forwell L, et al. Effect of training on postural control in figure skaters a randomized controlled trial of neuromuscular versus basic off-ice training programs. Clin J Sports Med 2004; 14:215–224. Mora I, Quinteiro-Blondin S, Pe’rot C. Electromechanical assessment of ankle stability. Eur J Appl Physiol 2003; 88:558–564. Gribble PA, Hertel J, Denegar CR, et al. The effects of fatigue and chronic ankle instability on dynamic postural control. J Athletic Train 2004; 39:321–329. Bäthis H, Perlick L, Blum C, et al. Midvastus approach in total knee arthroplasty: a randomized, double-blinded study on early rehabilitation. Knee Surg Sports Traumatol Arthroscopy. Online. Available: http://www.springerlink.com 2005. Noyes FR, Barber SD, Mangine RE. Abnormal lower limb symmetry determined by function hop tests after anterior cruciate ligament rupture. Am J Sports Med 1991; 19:513–518. Risberg MA, Ekeland A. Assessment of functional tests after anterior cruciate ligament surgery. J Orthop Sports Phys Ther 1994; 19:212–217. Unver F. The effects of proprioceptive training on ankles with inversion injuries. Doctoral thesis, Hacettepe University Institute of Health Sciences, Ankara, 2004. Bahr R. Injury prevention. In: Reeser JC, Bahr R, eds. Volleyball; Handbook of sports medicine and science. Madlen: Blackwell Science; 2003:94–106. Guyton AC. Textbook of medical physiology. 6th edn. Philadelphia: Saunders; 1981:122–137, 534–536, 562–564, 588–595, 629. Dunn TG, Gillig SE, Ponsor SE. The learning process in feedback: Is it feed forward or feedback? Biofeedback Self Regul 1986; 11:143–156. Lephart SM, Henry TJ. The physiological basis for open and closed kinetic chain rehabilitation for the upper extremity. J Sport Rehabil 1996; 5:71–87. Tropp H. Pronator muscle weakness in functional instability of the ankle joint. Int J Sports Med 1986; 7:291–294. Wester JU, Jespersen SM, Nielsen KD, et al. Wobble board training after partial sprains of the lateral ligaments of the ankle: a prospective randomized study. J Orthop Sports Phys Ther 1996; 23:332–336.
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Aquatic Rehabilitation Anton Wicker
INTRODUCTION
PRINCIPLES AND PROPERTIES OF WATER
Water is an essential therapeutic medium in rehabilitation programs. The concept of underwater therapy offers many possibilities to develop and specify the rehabilitation of injuries. Several metabolic and kinetic factors can be influenced by utilizing various effective elements of water such as buoyancy, temperature, resistance, hydrostatic pressure and electrolyte content. Patients after injuries, have limited joint motion, pain, edema after surgery, weakness, poor coordination, balance and stamina are all benefit from aquatic rehabilitation concepts. It is the reduced weight of the human body in water that makes it possible to produce motions like walking, jumping and other movement patterns, even though an injured joint cannot be subjected to normal stress. The various kinetic factors affected by the injury and by surgical trauma undergo a phase of repair,1 during which certain reactions are set in motion. These reactions have major effects on the mobility, the loading capacity and the strength of the joints. An additional cumulative effect of the abovementioned factors is that the central regulation of motion is altered. The patient loses confidence and starts to feel afraid. Fear essentially influences the course of motion, in particular the timing of motion.2 The consequences of fear can be immediately observed at a clinical level. The dynamic-motor stereotype of motion, including that of automatized patterns of motion, such as ordinary walking, undergoes marked changes. Reducing stress on the body helps to reduce fear. Fear disturbs the rhythm of motion and rhythm is the primary criterion for the evaluation of motion.3 Additional criteria are flow, precision, stability, force, speed and extent of motion. A summation of these factors causes what is known as the harmony of motion. As an exercise medium, water is very beneficial for those who understand its principles and properties. All aquatic exercise therapy concepts must address two important factors: the body’s physiologic response to being immersed in water and the physical properties of water. By considering these two parts, a special rehabilitation program which is safe and effective can be designed.
The principle of Archimedes states that when a body is fully or partially submerged in a fluid at rest, it experiences an upward thrust equal to the weight of the fluid displaced. Thus, an object with a relative density less than one will float because the weight of the object is less than the weight of the water displaced.4 The heavier the weight of the displaced material, the larger is the buoyancy. The body in the water is more supported by the buoyancy as the water is heavier. An increase of the weight of the water like a water with many minerals leads to an increase of buoyancy. For example, the buoyancy of a human body in the Dead Sea is so big that the body is not able to sink. Water usually used for rehabilitation purposes has a relative density of one. The relative density of an object is the ratio of the weight of an equal volume of water.5 If this value is greater than one, the object will sink; if it is less than one, the object will float. If the value is exactly one, the object will float just below the surface of the water. The specific gravity also indicates the portion of a body’s volume that will be floating underwater. For example, if a floating person’s specific gravity is 0.98, 2% of the body will be above the surface of the water and 98% will be below the surface. The relative density of a body depends on its composition. The specific gravities of fat is 0.8; of bone about 1.8 and of lean muscle about 1.1. Consequently, lean people tend to sink and obese people tend to float. If rehabilitation is done with patients with congenital or traumatic loss of limbs, we have to handle unequal relative densities between the two sides of the body. The side with the higher relative density tends to sink and the other side to float, producing instability in the water. Flotation devices can be used to alter the position of the centre of buoyancy and maintain a vertical position. Buoyancy and relative density are very closely related. Buoyancy can be used in rehabilitation in three ways: assistive, resistive and supportive. This force assists any movement toward the surface of the water and resists any movement down the surface. When buoyancy equals the force of gravity, any horizontal movement is supported (Fig. 19.1).
Buoyancy
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Figure 19.1 Equality of buoyant force and weight of the water displaced by the swimmer (Principle of Archimedes).
With floating devices one can influence the force of gravity and the buoyant force and use these effects in designing the rehabilitation plan (Fig. 19.2). One of the main advantages of underwater therapy is the reduction in weight-bearing forces. Patients exercising in water feel lighter, have a decrease of pain, move more easily, without fear and feel less weight in their joints because of the buoyancy. On land, the center of gravity of a body is just in front of the sacrum. In the water, the center of gravity is located at the level of the lungs.6 Hence, the degree of partial weight bearing varies with pool depth (Fig. 19.3).
Water content The usual buoyancy can be increased by using water with a high content of minerals, such as seawater or special types of natural mineral waters. Salt water is more dense than fresh water and besides influencing buoyancy, the diuretic effect of fluid shifting slightly increases.7 The diuretic response to head-out immersion in hydrated subjects is greater than in dehydrated subjects. The main diuresis-inducing factor during water immersion may be the suppression of antidiuretic hormone.8 The increase of the diuresis induces a fluid shift in the body and in combination with the hydrostatic pressure, edema, caused by the injury or postoperatively decreases. These effects are supported by hydrodynamic-buoyancy processes. The term ‘hydrodynamic buoyancy’ means water in motion in the therapy pool. Water in motion becomes a complex physical substance. When water is moving smoothly inside a pool, with all layers moving at the same speed and parallel, the water is said to be in ‘laminar flow’. Typically, laminar flow rates are slow. When water moves rapidly, even minor oscillations
A
B
C
Figure 19.2 A hand-fixed flotation device can be (A) assistive during shoulder abduction, (B) resistive during shoulder adduction and (C) supportive during horizontal anteversion on the surface of the water.
A
10%
B
25−30%
C
50%
Figure 19.3 Percentage of body weight at various water depths (A) at the neck (C7), (B) the chest (xiphoid process) and (C) the pelvis (anterior superior iliac spine).
create uneven flow and parallel paths are knocked out of alignment. When this happens, another type of pattern occurs called ‘turbulent flow’.9 Within the mass of water, flow patterns arise that run dramatically out of parallel and may even set up paths running in opposite directions. Artificially these ‘turbulent flows’ are built in whirlpools and they cause massage effects and also lead to an increase of buoyancy in its special form, called ‘hydrodynamic-buoyancy’. Aquatic rehabilitation uses these phenomena to reduce pain, muscle soreness and edema.
Resistance The resistance to movement through water is caused by friction between the molecules of the fluid and is known as viscosity. This resistance is usually ignored when the medium is air. In water, however, there are several forces that come into play. Cohesion is the force of attraction between neighboring molecules of the same type of matter. Surface tension is the force of attraction between the surface molecules of a fluid. This is not a factor if the moving body part is completely submerged in water, but it is a significant factor when a limb breaks the surface of the water.10 Viscosity acts as a resistance to movement because molecules of a fluid tend to adhere to the surface of a body moving through it. This force of resistance is known as ‘drag’ and it should be considered during development of an aquatic rehabilitation program. The amount of drag that an object experiences as it moves through water depends on a number of factors. The first factor that must be considered is that the movement can be either streamlined or turbulent. The resistance to turbulent flow is greater than the resistance to streamline flow (Fig. 19.4). The velocity at which the object is moving through the water and frontal area is a very important variable. From the
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occurs in the same direction as moving water will encounter less drag than if it were occurring in stationary water. In addition to increasing the drag forces, reversing the direction of movement adds the work of having to overcome inertia. In order to stop a moving limb, the appropriate muscles must produce the force necessary to decelerate both the mass of the limb and the mass of the water that is moving behind it.
Hydrostatic pressure
Figure 19.4 The movement of a paddle perpendicular to the flow of water produces a turbulence flow.
equation, it can be seen that the drag force is proportional to the square of the velocity. Therefore, if the velocity of a moving limb is doubled, the drag force is multiplied by a factor of four. The fact that frontal area is directly proportional to drag force means that it has a significant effect on the resistance of a given aquatic exercise. So for example, it can be said that doubling the frontal area doubles the drag. With upper limb exercises, the area of the hand can be effectively increased, simply by separating the fingers slightly. This occurs because the ‘boundary layer’ of fluid moving around an object, such as a finger, is greater in water than in air. When the fingers are slightly separated, their boundary layers overlap.11 It is important to understand, however, how small changes in the size, shape and velocity of resistance devices like paddles or fins can affect exercises performed in the water. The fact that an object is buoyant implies that it will assist movement, but its size and shape may produce a drag force that resists movement. The net effect of the device on the limb’s movement must be considered. The combined total of a moving limb’s velocity, the body’s velocity and the water’s velocity also affects the drag force during exercise. If the patient is walking forward and also moving the arm forward, the two velocities must be added together to determine the arm’s velocity relative to the water. Any movement of the water, such as that produced during alternating reciprocal movements, also affects the drag. For example, abduction of the arm causes the water to move in the same direction as the arm. If the arm movement is suddenly reversed, the arm will be moving against the flow of water. The result is a dramatic increase in drag and this increases the resistance of the exercise. Conversely, any movement that
Pascal’s law states that fluid pressure is exerted equally on all surfaces of an immersed body at a given depth. The pressure is directly proportional to both the depth and the density of the fluid. From a baseline of about 15 psi (atmospheric pressure – pounds per square inch) at the surface, fluid pressure of water increases by 0.43 psi per foot of depth.12 This implies that hydrostatic pressure opposes the tendency of blood to pool in the lower portions of the body, which helps to reduce the posttraumatic or postoperative swelling in injured patients. Hydrostatic pressure helps also to stabilize unstable joints. Thus a body immersed to a depth of 48 inches is subjected to a force slightly greater than diastolic pressure. This is the force that aids the resolution of edema but this is also the reason that it is not advisable to put patients with heart diseases or with chronic obstructive pulmonary diseases into a pool at 75% immersion. Such patients may have difficulty breathing because the pressure of the water resists the chest wall expansion. In the worst case scenario, this may be end in death by pulmonary edema.
Specific heat of water One important physical property of water is that of its specific heat. This is defined as the amount of energy required to raise the temperature of 1 g of water by 1˚C. The specific heat of water is several thousand times that of air and heat loss to water is 25 times that to air at a given temperature. The therapeutic utility of water depends greatly on both its ability to retain heat and its ability to transfer heat energy. Exchange of energy in the form of heat occurs in three ways: conduction, convection and radiation. Conduction may be defined as heat transfer through individual molecular collisions occurring over a small distance. Convection transfers heat through the mass movement of large numbers of molecules over a large distance. Liquids and gases in general are poor conductors but good convectors. Radiation transfers heat through the transmission of electromagnetic waves. Water and metals tend to conduct heat well; air and gas-containing materials, like wood, cork, etc. conduct heat poorly. Water is an efficient conductor of heat and transfers heat 25 times faster than air. Heat transfer increases as a function of velocity. Thus, a swimmer loses more heat when swimming rapidly through cold water than a person standing still in the same water. Consequently, both the temperature of the water and the amount of heat produced by the body must be considered when determining a comfortable water temperature in which to exercise. Vigorous exercise performed in warm water (33˚C and more) results in an increase in core temperature and premature fatigue. Vigorous exercise in cold water (20˚C and
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below) leads to a drop in core temperature and an inability to contract muscles. The ideal temperature for aquatic rehabilitation exercises should be kept about 32˚C. In rehabilitation concepts of high level athletes, where vigorous exercises are done, it is suggested that the temperature of the therapeutic pool should be kept about 30˚C.13
devices in flotation equipment are swim bars, the WetVest®, AquaJogger®, kick boards, water tires, webbed gloves, fins and tubes (Fig. 19.5). Weights, like dumbbells, weight belts, ankle and hand weights are often used in the pool for traction or strengthening. These weights must be of a type designed for water exercise. Devices to force coordination and balance, such as wobble boards, trampolines, swing boards and therapydiscs must also be designed for being used in water.
AQUATIC EQUIPMENT Water therapy is becoming more and more popular in the rehabilitative and conditioning environment. Healthcare professionals are becoming interested, educated and skilled in the field of aquatic exercise and rehabilitation. Water’s physical properties alone provide an environment for exercise in which there is little need for elaborate or expensive equipment. With greater understanding of these properties and hydrodynamics, this unique medium offers many possibilities to improve the quality of rehabilitation and helps the patients to return to their normal daily activity and in case of high level athletes to their usual training units, earlier.
Pools Aquatic equipment used for exercise and rehabilitation can range from a custom-designed swimming pool to a wide array of accompanying equipment. The basis for high quality aquatic rehabilitation is an in-ground swimming pool, minimum range 4–5 m, with a depth between 1.2 m and 1.4 m. Where there is no access to a full sized swimming pool, a customized therapy pool is an alternative, but always second choice. For working with groups of patients (n 3–10) a pool minimum 8–10 m is necessary. For offering aqua-jogging and special aquatic exercises, a second pool with a depth of more than 10 m should be used. The author’s standard pool for aquatic rehabilitation is an in-ground swimming pool with a range of 5–6 m and a common depth of 1.3 m. The depth can be changed from 1 m to 1.5 m. The wall of the pool towers 1 m above the floor. When entering the pool one has first to go upstairs on to the top of the pool wall, then downstairs into the water. Wheelchair and other handicapped patients are able to use a lift to enter the water. In one of the pool walls there is an integrated window of double glass in which a video-camera is located. Inside the walls of the pool, 30 cm down the edge is a hand-rail surrounding the pool. Integrated into the pool walls and at the bottom of the pool there are buckles into which ropes and sport cords can be fixed. Also integrated in the bottom of the pool and in every pool wall, are two jets in order that drag forces can be created by moving water. The room in which the pool is located has an air temperature of 26–27˚C. Fixed on the ceiling is one moveable video-screen, so that the patients can observe themselves during exercises. The water temperature in the pool is about 31–32˚C. If specific sports rehabilitation with a high level athlete is required, a temperature of about 30˚C is used.
Access equipment Many manufacturers of aquatic equipment are designing devices to be used in aquatic rehabilitation. The most popular
REHABILITATION Box 19.1: Key Points ●
Begin aquatic rehabilitation as early as possible after the injury.
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Water reduces stress and consequently reduces pain to a great extent.
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Water is an ideal medium for improvement of mobility in the whole body.
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Strengthen and stabilize the body core at a very early stage.
Because of the unique properties of water, aquatic rehabilitation offers advantages over land-based rehabilitation. It is imperative that the clinician applies aquatic principles appropriately when designing a rehabilitation program for an injured patient. Buoyancy decreases weight bearing and joint compressive forces and this allows an early process with closed chain kinetics in usual movement patterns like walking. The patient may also perform sport-specific rehabilitation exercises, mimicking the weight bearing activity. Similar to those of land-based programs, the principles of tissue healing and exercise progression must be considered when an aquatic-based rehabilitation program is designed. Based upon functional limitations, impairments and disabilities
Figure 19.5 Flotation equipment (balls, elastic bands, tubes, ropes, AquaJogger®, chest belts, inline skates, fins, resistive paddles, kickboards, trampoline, swing board).
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identified in the examination, a specific program can be created with the patient’s goals in mind. The stages of healing must be taken into account to prevent delayed healing and further injuries.
Beginning aquatic rehabilitation Aquatic rehabilitation should begin as soon as possible after the injury, because the period of immobilisation of a body or a joint should be kept to a minimum. Immobilization reduces the functional reserve of the musculoskeletal system, resulting in weakness, atrophy and poor endurance.14 After surgery, it is usual to begin therapy as soon as the wound is healed. High level athletes may begin aquatic therapy 1 week after surgery, without concern of infection.15
Reducing fear Owing to mechanical and nociceptive stimulation of sensory nerve endings (Pacini’s, Ruffini’s, Golgi’s organs, free nerve endings and muscle spindles) from the injury as well as from surgical trauma, the activity of motor neurons and the strength of the joint muscles are downregulated, such that these factors adjust to and protect the weakened tissue.16 Disturbances of this magnitude cause the patient to alter his or her movement pattern, for example in an injured lower limb, the gait is altered. In order to relieve the leg of stress, the patient will assume a limp. This so-called ‘stereotyped limp’ may become automatic in the presence of prolonged irritation. Subsequently, ‘learning to forget’ such stereotyped habits will prove difficult and will require a lot of time; a fact that has been known to significantly prolong the time required for complete rehabilitation (i.e. complete fitness). Water reduces stress and consequently reduces pain to a great extent. Moreover, it reduces the inhibitory factors in those sections of the central nervous system that are responsible for the regulation of motor functions. Hence, the development of a ‘stereotyped limp’ can be effectively counteracted by this concept of treatment. Therefore, at the start of the rehabilitation, the patient is trained to move around in the water as he would if there was no injury. The execution of this movement should result in symmetric motions. Since stress is reduced, the muscles and the psyche relax, which helps to reduce fear. Fear disturbs the rhythm of motion. Rhythm is a most important criterion in exercises. The patient also experiences less pain and consequently, a normal gait is achieved early in the water; a fact that counteracts the development of stereotyped patterns of motion. For example, when a patient who has sustained injury of the knee joint and has undergone surgery of the anterior cruciate ligament consistently trains to walk in water during the first 4 weeks following surgery, the following results will be achieved: 1 Fear is reduced and this permits rhythm training and has a favorable effect on the timing of motion. 2 Training of symmetry is easily accepted and there is a less pronounced tendency to develop stereotyped patterns of motion. 3 The water supports the coordination of the trunk, arms and legs, and thus makes it possible to drill the entire chain of motion.
Figure 19.6 Walking in chest high water.
4 Buoyancy of the body in water; the resistance of water permits safe enhancement of kinesthetic perception. 5 The water permits early commencement of proprioceptive training (position, flexion, extension, direction, speed, acceleration and position of body parts in space) and favorably influences the sense of equilibrium. 6 Improvement of the elasticity and the sensitivity of the entire musculature of the trunk and the legs. Aquatic rehabilitation should always be started with walking in water. This is the base of all exercises; the patient learns to move in this new therapy-medium, feels quite relaxed and pain and fear are reduced (Fig. 19.6).
Mobility Mobility may be impaired after an injury or surgery. Mobility can also result from pain of overuse of tendons, ligaments and muscles. A goal of rehabilitation is to restore normal osteokinematics and joint arthrokinematics. Water is an ideal medium for improvement of mobility in the whole body. For example, the upward movement of the glenohumeral joint is assisted by buoyancy and the patient may discover that normal shoulder movement patterns occur earlier in the pool than on land. The athlete can position himself in his sport-specific position, resulting in the restoration of familiar muscle lengthtension relationship in the extremities and the trunk. Buoyant equipment may assist the movement initially and may be discontinued as active and resistive range of motion exercises begin (Fig. 19.7). Water with a temperature of 30–32˚C provides a relaxing environment, which may allow for increased soft tissue extensibility. Stretch techniques are used in two ways: (1) Active stretching done by the athlete himself. The duration of the stretch can vary. To promote tissue elongation and permanent structural changes, a low intensity stretch with long duration (about 30 s) should be tackled. (2) Passive stretching is done by the therapist. The duration is about 30 s. This type of stretching is often combined with manual techniques, like tractions and joint mobilizations. It is important to work in closed chain kinetics, to restore
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Figure 19.7 Assisted elevations of the upper limbs.
the initial movement patterns. PNF (proprioceptive-neuromuscular-facilitation) techniques can also be used to this aim.
Trunk stabilization Trunk stability and postural control are essential for any kind of exercises and sport. For example, basketball players must be able to transfer kinetic energy from the lower limb to the upper limb via their trunk. In all kind of movements, it is necessary and very useful, first to strengthen and stabilize the body core. The stability of the trunk correlates with the stability of the peripheral joints.17
Figure 19.8 High duck position frontal and sagittal.
In all sporting activities, the trunk musculature performs as a dynamic stabilizer. Aquatic rehabilitation offers many possibilities for performing body core stability at a very early stage after the injury. The first step is walking and marching in the pool. Forward walking in the sagittal plane – standing upright, flex one hip and knee – extend the leg and dorsiflex the ankle, landing on the heel – roll forward onto the toes and push off – repeat with the opposite leg and increase velocity of walking – water resistance is increasing – always walk in upright position – trunk muscles and the muscles of the lower limbs are well trained. Marching in the sagittal plane – standing upright – hip and knee are flexed to 90˚ – the leg is brought down and the opposite hip and knee are flexed in a marching action. The second step is jumping in high duck position: Stretched lower limbs with light flexion in knee and hips – similar to floating squats – jumping forward, sideways and backward and sometimes circle around – 180˚ left, then 180˚ right – extend the arms at the side (Fig. 19.8). The third step is arm circling and straight arm pulls: Standing upright – circle both arms forward 90˚ until the surface of the water is reached – then push down and backwards at about 60˚. Step-by-step, the velocity of these exercises should increase (Fig. 19.9). Straight arm pulls – keeping the elbow straight – supinate one hand (palm up) and push the arm in front of the body – at the same time pronate the other hand (palm down) and push the arm behind the body – repeat switching arms. The fourth step is arm supported open chain hip, knee and ankle flexion and extension in backward position: First, sitting in the water – straighten the body in backward position to the surface of the water, supported by the arms and open chain
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Figure 19.11 Aqua jogging.
Functional progression and training of the upper extremity
Figure 19.9 Standing position.
hip, knee and ankle flexion and extension (similar to crawling backwards) is done – stabilized by the trunk The fifth step is arm supported open chain hip, knee and ankle flexion and extension in forward position: First, standing in the water – the body is straightened in the forward position to the surface of the water – supported by the arms and open chain hip, knee and ankle flexion and extension (similar to crawling forwards) is done – stabilized by the trunk (Fig. 19.10). The sixth step is aqua jogging in deep water: Assume a vertical position – alternately flex and extend the hips and knees, performing a walking action – allow the arms to swing diametrical to the legs (Fig. 19.11).
Shoulder-strengthening exercises that are performed on land can also be performed in the pool. For example, glenohumeral abduction/adduction, flexion/extension from 0 to 90˚, outside/inside rotation in shoulder-deep water, horizontal abduction/adduction, elbow flexion and extension can be restored. In addition, diagonal patterns such as those utilized in proprioceptive neuromuscular facilitation may be used. As with stretching activities, resistive exercises can be performed, if indicated, only through a partial range of motion. Another consideration for upper extremity training is that the mechanics are different for some water exercises, compared with their land-based counterparts. For example, in the water, shoulder horizontal abduction and adduction performed at 90˚ abduction are resisted in the transverse plane, but supported in the sagittal plane. That is, the athlete no longer has to hold the arm abducted against gravity while performing the horizontal component of the exercise. Overhead activities can also be very well performed in the pool in the supine position or in the prone position by using a snorkel. Resistive tubing may be used in the pool just as it is on land. It can be incorporated as a part of a total training program that is to be performed in one location. In addition, the water will provide additional resistance to the body core.18 For example, a patient may practice the motion of a tennis serve while standing in shoulder-deep water and using resistive bands. The water is providing core body resistance, while the band resists arm movement. A wide range of activities can be performed in these positions in the pool, but it is necessary that the clinician must be cognizant of these changes in order to appropriately utilize the principles of aquatics.
Functional progression and training of the lower extremity Figure 19.10 Arm supported crawling forwards.
Performing in lower extremity functions can also be done in both, the open and the closed chain kinetics. In water,
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lower extremity strengthening exercises can be performed completely non weight bearing in the open chain. For example, running in deep water with the ‘AquaJogger®’ or the ‘WetVest®’ includes trunk stabilization, hip flexion/extension, abduction/adduction and knee and ankle flexion/extension. These exercises are helping to increase mobility and muscle endurance. Kicking in the prone or supine position with fins is another excellent exercise for increasing muscle endurance of the lower limb. In neck-deep water weight bearing walking can begin; weight bearing can be increased by reducing the depth or by using weight belts during walking exercises and accelerates the velocity. To strengthen the gluteals and the quadriceps in closed chain kinetics, exercises such as squats, lunges and step downs should be incorporated. Resistive boots can increase the resistance as much as 4-fold and exercises using boots are useful in sports requiring explosive power, such as figure skating and gymnastics.19,20 Lower extremity balance and proprioception are important to any athlete and a well-designed rehabilitation program should address all balance impairments. Balance is controlled by sensory input, central processing and neuromuscular responses.21 Proprioception is defined as position sense that orients the body or specific body parts to space or other objects.2 Any self perturbation activity, such as hip flexion/ extension or circumduction in chest-deep water while standing on one leg will challenge balance. Balance devices like the mini-trampoline, wobble boards, swing boards, therapy discs and so on can be used. Additionally the patient may close the eyes, relying more heavily on neuromuscular rather than visual input. When more impact is required for return to daily activities or sport, jumping and hopping drills may be introduced in the pool.
rubber bands. These rubber bands are fixed to the edge of the pool such that the athlete is forced to swim against insurmountable resistance. The patient floats on his back and perform backstrokes, primarily using his arms if suffering a lower limb injury and using his legs if suffering an upper limb injury (Fig. 19.12). The injured extremities are not stressed during the first weeks. Later, once the symptoms have subsided, the athlete may practice kicking injured limbs upwards and downwards. This movement may be performed more intensively, in various rhythms of coordination. Rubber fins may also be used as an additional aid. Depending on the individual performance, the heart rate may vary from 130 to 150 beats/min. One training unit should range from 20 to 40 min and in high level athletes, up to more than 1 h/day. These prolonged training units are entailing continuous cyclic motion of the arms or the legs in water. Its intensity will be determined by the patient’s heart rate. Although this information regarding intensity is rather imprecise, it is adequate for rehabilitation, because the main purpose of the first postoperative weeks is to preserve the athlete’s endurance. As time progresses, especially in high level athletes, a carefully regulated training program, involving measurement of lactate, urea and ammonia levels and the application of tests, such as the Conconi test, is offered. By increasing intensity, the training units can also be performed in the interval method (extensive and intensive interval training).23 In high level athletes, we found that the training unit fitted best with the total daily treatment and rehabilitation program, when it was carried out in the early hours of the evening. The reason is that a lymphatic drainage (special massage technique) of the injured extremity can be performed immediately thereafter, and the resulting vagus impulse and hypotonus of the musculature allow for general relaxation and create favorable conditions for regeneration (Tables 19.1–19.3).
ENDURANCE TRAINING Endurance training and cardiovascular conditioning is a key component of a high quality rehabilitation program. In addition to being suitable for training coordination of motion, water is eminently suitable for training stamina. One focus of an aquatic rehabilitation program is to preserve the athlete’s basic stamina. The movements designed for this purpose can be performed in water for a long period without experiencing pain and without subjecting the injured joint or the injured structures of the body to stress or tensile load. Basic stamina training improves and/or preserves the capacity and the performance of the cardiovascular, respiratory, metabolic and the immune systems. Simultaneously, it supports local adjustment processes in the musculature such as capillarity, and increases the number and size of mitochondria. Moreover, it activates the enzymes involved in aerobic metabolism and increases the intramuscular glycogen store. While carrying out basic stamina training in water, various aids can be used. One such aid is a life jacket provided with
Figure 19.12 Swimming against insurmountable resistance.
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Table 19.1
Sample Training Program for Back Injury
Area of focus
Activity
Trunk stabilization
Walking (forward, backward, sideways) in chest-deep water Pelvic movements (slightly knee bent; moving the hips in sequence forward, backward, right side, left side) Straight arm pulls Side to side steps Duck jumps Ball push downs Marching Deep-water jogging with WetVest® or AquaJogger® Eyes closed hip flexion/extension Eyes closed hip abduction/adduction/circumduction Stand upright on wobble boards, therapy discs, trampoline and swing board One leg stand (up to toes – down to heel – repeating) Standing shoulder horizontal abduction/adduction Standing rows Pendulum exercises of the arms Straight arm pulls Cross country walking with hand-fins Walking with tray Duck jumps Standing buoyancy resisted knee extension/flexion Standing hip adduction, abduction and circumduction Vertical kicking with fins Walking in chest-deep water Rope fixed swimming Deep water walking or running in cross country style
Balance training
Upper extremity training
Lower extremity training
Endurance training
Table 19.2 Injury
Sample Training Program for Shoulder
Area of focus
Activity
Trunk stabilization
Walking in chest-deep water (forward, backward, sideways) Floating squats Duck jumps with rotation Deep water walking with flotation aids Single leg standing on heels (up to toes – back to heels – repeat) Single leg standing like above with eyes closed Stand upright position on unstable devices (e.g. therapy disc) Lunge jumps forward Straddle split jumps Pendulum exercises always symmetric Standing abduction/adduction with gloves Standing flexion/extension of the elbow with gloves Standing kickboard plows (scapular protraction/retraction) Standing wall push-ups Shoulder press down and pull up with flotation devices Cross country walking Walking (forward, backward, sideways) Walking with knee stiff Floating squats Resisted double/single leg jumping all planes Resisted hip flexion/extension, abduction/adduction Walking in hip-deep water Crawling backwards only with the legs (body is fixed by ropes at the WetVest® in supine position) Aqua jogging in deep water
Balance training
Upper extremity training
Lower extremity training
Endurance training
SPORT SPECIFIC AQUATIC REHABILITATION CONCEPT IN HIGH LEVEL ATHLETES Sport specific aquatic rehabilitation in elite skiers after ACL reconstruction Box 19.2: Key Points ●
Trust in the body is synonymous with trust in oneself.
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Athletes can execute motion patterns pertaining to the relevant type of sport.
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Structure of motion is a unit of spatial-temporal and temporaldynamic impulse elements.
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Training consists of motion patterns with full concentration by performing imitative exercises.
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Mimicking skiing motions in the pool by use of videotapes.
Introduction For elite competitive athletes, injury is associated with enormous economic pressures, as well as with public pressure. This
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is particularly true in major competitive events. In such cases, the athlete’s foremost desire is to return to competition or training as soon as possible. The desire is countered by the medical expert, who is forced to place time restraints, depending on the type of injury and the specific problems associated with it. The medical expert’s foremost principle should be not to permit an athlete to re-enter a competition unless he is healthy and able to sustain stress. Injured tissue does not repair faster in competitive athletes than in average human beings. Hence, it has become necessary to improve the quality of rehabilitation by developing and applying rehabilitation techniques specifically designed to treat the injury sustained by the athlete. In spite of the injury, the athlete should be able to train as intensively as possible. The following three aspects should be in harmony: 1 The injured structure of the body should be given specific treatment. 2 Attention should be given to the position of the injured anatomic structure in the chain of motion pertaining to the specific type of sport.
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Table 19.3
Sample Training Program for Knee Injury
Area of focus
Activity
Trunk stabilization
Walking (forward, backward, sideways) Floating jumps in duck position (forward, backward, sideways and with rotation) Arm supported open chain hip, knee and ankle Flexion/extension in floating supine and prone position Single leg standing on heels (up to toes – down to heels – repeat) Single leg standing like above with eyes closed Floating single leg squats (forward, backward, sideways and rotating) Resistive shoulder flexion and extension Pendulum exercises Cross body pull Straight arm pull Combination arm movements Walking (forward, backward, sideways) Marching Resistive knee flexion/extension Proprioceptive training on unstable devices Single leg squats Lunges Single leg heel raises Stork stand Step ups Swimming backwards only with the arms (body is fixed by ropes at the WetVest®) in supine position Walking in deep water with the AquaJogger® in intervals (extensive/intensive intervals)
Balance training
Upper extremity training
Lower extremity training
Endurance training
3 It should be ensured that the athlete’s stamina is not overly impaired, especially in terms of strength, speed and endurance. A training program specifically designed to maintain the athlete’s stamina should be pursued, as far as possible, even while the athlete is affected by the injury. It should be remembered that the athlete is injured, but still in training. In modern rehabilitation centers, an important aspect of treatment is the personality of the injured athlete. This specifically concerns the patient’s ability to learn.24 The treatment should include conscious visualization of the motion pertaining to the specific type of sport. Ski-specific technical motions can be recalled in the present time and made directly available to the patient at the therapeutic pool (by means of modern videotaping techniques). This is one of several aspects of so-called mental training. The major prerequisites for treatment of this type are high motivation, a good mental state of the patient and a clearly specified goal. Notwithstanding his injury, the skier should remain in close contact with his colleagues who are in regular training. Although the incidence of injury to the anterior cruciate ligament has markedly increased among alpine skiers and has become a controversial issue in modern skiing, there are
diverse opinions regarding postoperative rehabilitation measures following injury of this type. All specialists agree that functional treatment should be started as early as possible. However, opinions diverge widely with regard to the type of functional treatment, the steps of treatment, and, last but not least, the temporal sequence of treatment in terms of how much stress is permissible. The goal of treatment after surgical reconstruction of the cruciate ligament may be summarized as follows: ● Swift and painless stress-bearing capacity ● Passive as well as active stability ● Passive and active mobility ● A feeling of confidence with regard to the knee joint. Confidence in the strength of the knee joint is known to be an absolute prerequisite for optimum skiing performance. Once these results are achieved, it may be assumed that the injury has probably healed. From a medical (ethical) point of view, there should be no objection to subjecting the joint to normal stress. The treatment of complex mobility disorders, such as those encountered after knee surgery, necessitates the application of educational and scientific training principles to a much greater extent than has been done so far, especially if the injured person is an elite athlete. A rehabilitation program for a ski racer should be based on the principles of training and motion. The program should include exercises, training instructions and corrective measures specially adapted to the sport and the specific injury. Water is an excellent therapeutic medium for this purpose, because underwater therapy takes the reduced weight bearing capacity of the injured knee into account and yet permits the patient to drill motion patterns that are characteristic for skiing.
Inner training Water may be an entirely new world of experience for the patient. Underwater therapy may be regarded as a step towards so called ‘inner training’. The method of inner training originates from ancient Asian religions. It is based on a practical philosophy whose aim is to arouse and enhance spiritual and creative abilities by meditation and by perfecting the execution of physical exercises.25 An important aspect of inner training is trust in the human body. The human body is an intricate, computer-like organism that regulates itself in a predetermined rhythm. In the final analysis, trust in the body is synonymous with trust in oneself. Accepting a situation for what it is may prove to be a practical way of approaching it and may be of great psychological help. The patient who goads himself to make maximum use of the rehabilitation will not achieve maximum benefit from the program. Rather, the patient who consistently pursues the program but also realizes that the injury is an integral aspect of his being will be happy and will rapidly achieve success. Awareness of this fact will help the athlete to accept the injury and will make it easier for him to develop a positive attitude towards it. So-called inner training is a valuable adjunct to conventional training and treatment, because it takes not only external aspects, but also the athlete’s subjective world of experience into account.
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Inner training enhances the ability to relax, to regenerate and reduces the subjective stress associated with training and treatment.
Ski-specific imitative training In the treatment of sports injury, a lot of attention has been given to the injured part of the body. The fact that every aspect of the body is an integral part of a kinematic chain that is indispensable for the execution of any sport or, for that matter, any motion, is not given enough attention. If it were possible for the athlete to execute the complete sequence of a complex motion even with a knee joint that is, in fact, not capable of sustaining normal stress levels, it would mean less loss of coordination during the rehabilitation period. The neurologist Jackson26 came to the conclusion that the brain does not know anything about the existence of muscles. Rather, the brain is only aware of motion patterns. Hence, the major goal of rehabilitation should be purposeful application of water in a manner that would enable the athlete to execute motion patterns pertaining to his daily life as well as specific motions associated with his kind of sport. The buoyancy of the human body in water makes it possible to perform natural motions which are executed in threedimensional fashion, in a spiral pattern and via several joints, in spite of the fact that the knee joint is too weak to sustain ordinary stress levels (Fig. 19.13).27 As far as the execution of movements is concerned, the same neuromuscular principles that apply to motion outside water apply to motion inside water. However, the stress level is highly reduced because water relaxes both the body and the psyche. While the athlete drills skiing movements in water, he is surrounded by a sum of spatial and temporal motion-related stimuli. In our rehabilitation program, many of these stimuli are specifically related to the sport. Drilling this type of motion makes the athlete aware of his potential abilities, which, owing to the injury, are temporarily passive. Functionally significant patterns of motion can be drilled in this environment (Fig. 19.14). The term spatial summation here refers to the sum of stimuli that may be released by various factors such as extension, physical contact and resistance. Thus, performing specific skiing movements in water permits early commencement of a training program designed on the basis of motion techniques that are specifically adapted to the injury. Moreover, the program is designed such that it favorably influences neuromuscular patterns of motion.
Figure 19.13 Proprioceptive training by increased ordinary stress levels.
The structure of a motion may be defined as a unit of spatialtemporal as well as temporal-dynamic impulse elements In other words, the structure of the program of a motion is the rhythm of the motion and the rhythm of the program of motion, which may also be interpreted as the personality or the character of a motion.28 For execution of imitative exercises whose purpose is optimum rehabilitation, it is not the activity of a specific muscle that is of prime importance but the structural program of a motion. This structure should be preserved. The structure of the program is determined by and is the expression of the interaction of various impulses.
Timing Successful motor execution of motions related to any type of sport consists of the following: Application of the right measure of strength, a high degree of coordination and exact timing The motion of elite skiers is characterized by certain uniformity in terms of specific accentuated muscular contraction. The rehabilitation program, proposed here, is designed such that this uniformity is preserved to a great extent. This is achieved by a high level of task-oriented and target-oriented coordination while mimicking specific skiing motions (Fig. 19.15).
Figure 19.14 Transferring weight by a swinging motion similar to skiing.
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3 A basic guideline for learning motion is that initially the motion should be precisely acquired in the phase of learning. After it has been learned, it may be performed swiftly. This principle could be applied in a converse manner for rehabilitation. In this context, it may be interpreted as follows: Motion patterns that cannot be performed swiftly and under full stress (because of injury) can be repeated slowly and precisely by maintaining a rhythm that may be modified to suit the specific conditions, and can be conserved by being performed in water). Several skiing techniques can be drilled in water at various degrees of skill, in a highly realistic fashion, without subjecting the knee to high levels of stress. The movements related to a specific kind of sport are stored in the athlete’s motor memory. These programs of motion can be recalled at various degrees of proficiency, with the help of interpretation and decoding systems, and the programs can be used for specific training. These systems of interpretation and decoding may be presented in verbal (words, sentences) and/or visual (videos, diagrams, pictures, demonstrations) form.
The use of imagination in water
Figure 19.15 Mimicking parallel swinging.
The inter-relationship between the following aspects is of decisive importance: 1 Time interval (beginning of the impulse) 2 Duration (length of the impulse) and 3 Muscular intensity (extent of intensity of the impulse). These temporal and dynamic aspects determine the structure of the program. Owing to these factors, the program acquires form-related elements and spatial implications. Moreover these factors determine the quality of an observable motion pattern. The quality of coordination of the three factors mentioned above (the beginning, duration and extent of the impulse) within the structure of a motion is known as the impulse timing of a motion.29 The unity of temporal-spatial and temporal-dynamic impulse elements may also be summarized as ‘the rhythm of motion’. A characteristic aspect of rhythm is that it retains its individual structure and nature even it is performed at a different (fluctuating) speed, i.e. at a speed that denotes a deviation from the norm. A thorough understanding of these aspects is highly significant for preserving consolidated motion programs during rehabilitation. These aspects may be summarized as follows: 1 The essence of a motion pattern is expressed by its rhythm, i.e. by its temporal and dynamic determinants. 2 If the preservation of a program is defined as the preservation of motion and technique, it may be argued that the preservation of motion and technique is, in fact, synonymous with the preservation of rhythm (because the essence of motion is rhythm).
An athlete’s imagination permanently influences his performance, both consciously and unconsciously. If the athlete’s idea of a situation matches with the challenge the situation actually poses, the idea will help him to preserve the stored structure of a motion in his motor memory. The more precisely the steps of motion are processed in the athlete’s imagination, the more effectively can the proposed rehabilitation plan (whose major goals are minimum loss of the skiing feeling and maximum preservation of the skiing technique) be realized. Owing to the fact that elite athletes undergo several years of intensive training, they are highly proficient in their kind of sport. Hence, during rehabilitation, they are much superior to persons who do not practice sports and even to those who pursue sports in terms of a hobby. We apply athlete’s imagination in consciously regular, controlled and targeted manner. The athlete is made to train motion patterns with full concentration by performing imitative exercises, the basic pattern of which is similar to that of the skiing techniques performed on snow. This specific imitative training for skiers may be regarded as a special type of training. Specific aspects of so-called mental training are combined with certain technical elements of so-called ‘regular training on the skiing piste’. The chain of motion, although executed under less pressure, is carried out in the correct rhythm, and what is more in three-dimensional fashion. With regard to mental training, this training program offers the following possibilities: 1 Subvocal training a The athlete is trained to repeat the training sequences in the form of a monologue. 2 Concealed perception training b This involves looking at a film on the execution of a motion (that the athlete is accustomed to perform) through the ‘mental eye’. To put it more simply, one
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imagines one’s movement with the help of video recordings. In our setting, the athlete takes on the role of an observer, i.e. he looks at himself from an exterior point of view. 3 Ideomotor training c In contrast to concealed perception training, ideomotor training is an interior process. From an interior perspective, the athlete vividly recalls the motion and re-experiences it in the present. He imagines himself performing the motion and tries to experience the mental processes that usually take place when he performs the motion (for instance, he may recall a cut swinging motion in the under-surface of his foot). Various techniques of regular training are transferred to water and mimicked in this setting. The following motions can be drilled well in chest-high water without putting too much stress on the injured knee joint: ● Parallel swinging motion ● Transferring weight by a swinging motion ● Canting techniques ● Sliding motions. In order to train motion in an even more realistic fashion, the athlete is asked to wear inline skates (mimicking the feeling of the canting process in skiing) while performing some of the underwater training techniques in the therapeutic pool (Fig. 19.16). These above-mentioned aspects of training are combined such that they form a harmonious unit, whose application in rehabilitation has proved to be of great value for ace skiers. There are two reasons why this aquatic training program succeeds. First, athletes are familiar with mental training and second, water is a convenient medium and does not pose any major problems for drilling ski-specific motion patterns. It is interesting to note how swiftly top competitive athletes adapt to motion conditions that are initially unusual for them. When the athlete drills skiing techniques in chest-high water in a pool with a flat ground, it is obvious that external factors, such as speed, the inclination of the slope, the texture of snow and centrifugal forces do not exist. Hence, the steering phase of a swinging motion cannot be mimicked at all. Balancing and turning skills can be drilled to an extent that certain aspects of the kinematic chain of skiing may be reproduced on a neuromuscular level. Consequently, these skills are not jeopardized as much as they would be if the athlete did not train at all. Once the knee joint is trained such that it is capable of sustaining more stress, and once the athlete feels fit to advance from skill drills to full participation (training on actual skis), he will be able to start at a higher level than he would have done without this training. Thus, the program shortens the total time needed for rehabilitation, i.e. from the time of the injury or surgery until complete fitness for participating in a competition.
Use of videotapes to train motion in the pool Sport-motor-video-training is defined as video-based learning of motor skills in the context of sports training.30 It is a process
Figure 19.16 Inline skates in water.
regulated by information and its aim is to achieve maximum approximation of a realistically performed motion to a pregiven, kinematically defined ideal technique.31 Sport-motor video training is based on the fact that one of the basic prerequisites for the acquisition of specific motor skills32 is the creation of an internal representation of a motion, which, in this context, is based on the characteristic kinetic conditions of perception and execution of motion in video training.33 The creation and preservation of this representation of motion are based on the processing of information. The information obtained by video documentation has two aspects: 1 The ideal technique is presented and is intended to communicate what exactly should be done (video instruction). 2 The presentation informs the observer about what he has actually done (video feedback). We do not use video training to learn sport-motor-skills. Rather, we use it as a means to transfer actual skiing conditions to this specially designed rehabilitation training. In the pool, we try to create an environment that is similar to the environment on the skiing slope. A major goal of video training is the conservation of training and motion patterns during rehabilitation. A further goal is to ensure that the injured athlete is in close contact with the remaining team members who are in training or are participating in the competition. Evidently, when the athlete is able to mentally participate in the regular training program of his team, his motivation is significantly enhanced. These factors increase the efficiency of the training and rehabilitation.
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One of the essential principles of modern rehabilitation ‘injured but still in training’ is expressed in this program in an excellent manner. Almost all elite athletes have been filmed in action at some time or other. Video tapes of excellent quality are available from regular training as well as from television broadcasts of major competitions. These films can be intensively used for the program. In any kind of training, but particularly in rehabilitation training, there should be a great deal of emphasis on attention. During video training, the tasks should be demonstrated and reproduced accurately. And this is possible only if the athlete applies full concentration. Mentally, the rehabilitation training program should be carried out as if the techniques were being performed during regular training on snow. In other words, the athlete should carry out the training program with total concentration and with his entire attention directed towards the motion patterns and the training conditions. While using video-taped documentation, the following three types of video recordings can be used in the training setting (Fig. 19.17): 1 Video recordings of the training runs, performed by the athlete himself: The athlete can analyze his own runs and train these motions in the therapeutic swimming pool by mimicking the skiing motions in a slower rhythm, without subjecting the injured knee joint to high stress. This will make it possible for him to consciously examine his own technique. He may discover technical errors that may have become automatic and can discuss these with his trainer and he could learn to conceal or rectify these errors by mentally rehearsing the correct pattern of motion. 2 Video-taped recordings of training with one’s own team or with opposing teams: In spite of being in rehabilitation, the injured athlete will be able to participate actively in the regular training program of his team by watching these video films. Provided all members of the team cooperate, it will be quite easy to make the most recent training videotapes available to the athlete. This, in turn, will enable him to be in close contact with this team. This will also enhance his
Possibilities of video training
motivation and will help him to better accept the treatment and the training program. Moreover, it will favorably influence the outcome of the therapeutic measures. 3 Video-taped recordings of alpine ski slopes: Video-taped recordings could also provide the athlete with valuable information about alpine ski slopes and racing pistes. The athlete would be able to carefully observe the downhill run of well-known slopes, such as the ‘Hahnenkamm’ (‘cockscomb’) slope in Kitzbühel in the Austrian Alps. While mimicking skiing motions in the pool, the skier could mentally run the downhill slope such that his motor memory is trained and the information is stored. When the athlete is capable of sustaining full stress, he will have the racing piste well stored in his motor memory and will be able to adjust better and more swiftly to the competition.
Training (mimicking) ski-specific motion in deep water It has been proven that the AquaJogger® is very useful for mimicking ski-specific motions in deep water. This accessory ensures buoyancy and enables the athlete to move freely, with a slight forward inclination of 10˚ when he is in neck-high water. The skier has to stabilize his body by using the muscles of his trunk. In this position and using the AquaJogger®, he will be able to mimic all the ski-specific exercises that he practiced in chest-high water, with the additional advantage of having no contact with the ground. The same applies to video training. The only difference is that in video training there is absolutely no ground contact, a fact that further reduces stress on the injured joint. However, the neuromuscular aspects of motion can be practiced several times and the rhythm of ski-specific imitative exercises can be preserved. This is highly valuable when the athlete transfers the skills acquired during rehabilitation to the actual training environment in the piste.
CONCLUSION It has been shown that applying various possibilities of modern underwater therapy and combining these techniques with a rehabilitation concept specifically designed to suit the type of injury and the injured athlete improves the quality of rehabilitation and helps the skier to return early to competitive training after surgery of the anterior cruciate ligament.
SUMMARY OF AQUATIC REHABILITATION Principles of aquatics Buoyancy Figure 19.17 Video training.
The submerged body loses weight equal to the weight of the water displaced (Principle of Archimedes) – thus resulting in less stress and pressure on the body.
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Hydrostatic pressure Hydrostatic pressure is proportional to depth and equal in all directions. It increases the venous return to the heart and also assists resolution of edema related to musculoskeletal injuries.
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ous system.34 These effects are both immediate and delayed, and allow water to be used with therapeutic efficacy in a great variety of rehabilitative problems.
Viscosity
Therapeutic medium
Viscosity acts as a resistance to movement of a body. This resistance is proportional to the effort exerted and allows the aquatic environment to be used as an effective strengthening medium.
Water is an essential therapeutic medium in rehabilitation programs. The concept of underwater therapy offers many possibilities to develop and specify the rehabilitation of injuries, especially of sports-injuries. As an exercise medium, water is very beneficial for those who understand its principles and properties. All aquatic exercise therapy concepts must address two important factors: the body’s physiologic response to being immersed in water and the physical properties of water. By considering these two parts, a special rehabilitation program, which is safe and effective, must be designed and then the outcome will be optimized.
Temperature The aquatic environment allows regulation of the temperature during exercise and can have a significant effect on heart rate response and on the mobility of the tendons and muscles.
Biologic and physiologic effects Aquatic immersion has profound biologic effects on the circulatory, the pulmonary, renal, the musculoskeletal and the nerv-
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Thein-Nissenbaum JM. Aquatic rehabilitation. In: Andrews JR, Harrelson GL, Wilk KE, eds. Physical rehabilitation of the injured athlete. 3rd edn. Philadelphia, PA: Saunders; 2004:295–313. Frey LA, Smith GL. Underwater forces produced by the Hydro-Tone bell. J Orthop Sports Phys Ther 1996; 23:267. Visnic MA. Aquatic physical therapy comes of age. Aqua Phys Ther Rep 1994; 1:6. Wegener L, Kisner C, Nichols D. Static and dynamic balance responses in persons with knee osteoarthritis. J Orthop Sports Phys Ther 1997; 25:13–18. Anderson MA, Foreman TL. Return to competition: Functional rehabilitation. In: Zachazewski JE, Magee DJ, Quillen WS, eds. Athletic injuries and rehabilitation. 1st edn. Philadelphia, PA: Saunders; 229. Harre D. Trainingslehre. Einführung in die theorie und methodik des sportlichen trainings. Berlin: Sportverlag; 1983. Pöhlmann R. Motorisches Lernen, 3. Auflage. Berlin: Sportverlag. Willimczik K, Roth K. Bewegungslehre. Grundlagen – methoden – analysen: Berlin: Rowohlt-Verlag; 1991:2. Jackson JH. Willkürbewegungen und linkshemisphärisches Bewusstsein. In: Birbaumer N, Schmidt FR, eds. Biologische psychologie. Berlin: Springer Verlag; 1996:3. Knott M, Voss D. Komplexbewegungen im sport. Stuttgart: Gustav Fischer Verlag; 1970. Hotz A. Praxis der trainings und Bewegungslehre. 1. Auflage. Frankfurt am Main: Sauerländer Verlag; 1991:57–76. Roth K. Die Impuls – timing – hypothese. In: Röthig P, Grössing ST, eds. Wiesbaden: Bewegungslehre; 1990:9–54. Olivier N, Blischke K, Daugs R, Müller H. Visuelle selektion beim sportmotorischen videotraining. Psychol Sport 1994; 4:140–141. Daugs R, Blischke K, Marschall F, Müller H. Videotechnologien für den spitzensport. Leistungssport 1990; 20:12–17. Müller H, Olivier N, Blischke K, Daugs R. Visuelle selektion beim sportmotorischen videotraining. Psychol Sport 1994; 4:1. Prinz W. Wahrnehmung. In: Spada H Huber, ed. Berne: Allgemeine Psychologie; 1992. Wilder PR, Cole AJ, Becker BE. Aquatic strategies for athletic rehabilitation. In: Kibler BW, Herring StA, Press JM, Lee PA, eds. Functional rehabilitation of sports and musculoskeletal injuries. Gaithersburg, Maryland: Aspen; 1998.
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CHAPTER
20
Functional Restoration: Return to Training and Competition W. Ben Kibler and Christopher J. Standaert
INTRODUCTION Box 20.1: Key Points
•
Optimal athletic function results from the coordinated interaction of anatomic, physiologic and biomechanical factors that generate forces and actions.
•
The athlete presents to the sports medicine clinician because of dysfunction.
Athletes desire optimal athletic function. This requires three inter-related components: anatomy, physiology and mechanics. Optimal athletic function is the result of physiological motor activations creating specific biomechanical motions and positions using intact anatomical structures to generate forces and actions. The athlete presents to the sports medicine clinician because of dysfunction. This alteration in or deviation from normal function in the sport may be due to pain, injury, or decreased performance. Dysfunction may involve pathoanatomy, pathophysiology, or pathomechanics. The goal of function-based rehabilitation programs is the return of the athlete to optimum athletic function. To accomplish this goal, the athlete should be treated so that they can return to function in a specific sport or activity. Sport-specific function occurs when the activations, motions and resultant forces are specific and efficient for the needs of that sport. We use the ‘critical point’ framework (Fig. 20.1) to understand sport specificity. Every sport has metabolic, physiological and biomechanical demands inherent in the way the sport is played, at whatever level of skill or intensity. Every athlete brings a specific musculoskeletal base to interact with the demands. Performance in the sport and risk of injury are the results of the interaction. The initial phase of the functional restoration program should include the assessment of the inherent demands of the sport and a complete evaluation of the musculoskeletal alterations that are associated with the presenting dysfunction. After this assessment, rehabilitation should be instituted in organized protocols or structures that are designed to protect healing tissues while maximizing functional capacity. The rehabilitation protocols
should merge into pre-habilitation, a phase which is preparatory for return to play. Finally, return-to-play decisions should be based on the achievement of optimal anatomy, physiology and mechanics in preparation for the sport-specific demands. This chapter will discuss sport-specific demands, musculoskeletal base assessment, rehabilitation protocols, prehabilitation, and return-to-play criteria.
SPORT-SPECIFIC DEMANDS Box 20.2: Key Points
•
Each sport has its own specific set of inherent demands, and these demands may change with the level of skill, intensity, or frequency with which the sport is played, or with the position played or event performed in a given sport.
•
An evaluation system that profiles the physiological requirements and the biomechanical kinetic chains necessary to play the sport can allow good discrimination between sports.
There are many similarities in the demands sporting activities in general place on athletes. Most sports require some level of energy expenditure to generate the forces necessary to move the body, ball, or other object toward a certain goal. Most require some stability of one part of the body to achieve some movement of another part. Most require some degree of flexibility of some body parts and some degree of aerobic fitness. However, each sport has its own specific set of inherent demands, and these demands may change with the level of skill, intensity, or frequency with which the sport is played, or with the position played or event performed in a given sport. The specificity of the physiological variables required for sports performance is reflected in the specificity with which the body adapts to training and physiologic demands. Numerous examples of this are documented in the medical literature. Although there are clearly limitations to the value of isokinetic training, studies performed using isokinetic dynamometry at different velocities generally show velocity-specific improvements in performance.1 Immobilization of a limb has
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Inherent sport-specific demands
sports and generates enough information about the specific sport to plan an adequate prehabilitation program that will be sufficiently specific for the sport.
Sports performance Critical point
Box 20.3: Key Points
Individual musculoskeletal base
Injury risk
Figure 20.1 The ‘critical point’ framework showing the relationship between sports demands and the musculoskeletal base in determining performance and injury risk.
been shown to result in a decrease in the area of the motor cortex associated with the activation of the specific muscles affected, a process which reversed with subsequent movement of the limb.2 Overall, there are a variety of means by which the body responds to training, including neural adaptations, cardiovascular changes, direct changes in muscle volume and structure, and alterations in the viscoelastic properties of soft tissues.3,4 These factors are all affected by injury and disuse and can all potentially be addressed by specific methods of training. Training is clearly associated with a host of specific physiologic changes that may both directly impact the efficiency, speed, control, or force with which a certain complex motion is performed and have more broad effects on general physical performance. In designing a rehabilitation program for an injured athlete, therefore, it is important to understand the actual physiological effects of training maneuvers and to be able to coordinate the use of a variety of techniques in an appropriate manner to optimize functional outcome for the performance of a given task. In order to accomplish this, therapists and doctors need to know the parameters involved in a sport in order to prehabilitate the athlete properly for that sport. Many different systems may be set up to profile sports and their demands. They may be based on anatomical requirements (range of motion required, strength required), metabolic requirements (aerobic or anaerobic activity) or amount of contact (collision, frequent contact, or minimal contact). We use an evaluation system that profiles the physiological requirements and the biomechanical kinetic chains necessary to play the sport.5 This method allows good discrimination between
Table 20.1
Basketball Tennis Golf Soccer Swimming Running Sprinting Bicycling Volleyball
•
The kinetic chain is a coordinated sequencing of activation, mobilization, and stabilization of body segments to produce an athletic activity.
•
Athletic performance is dependent upon appropriate functioning of the individual components of the kinetic chain and appropriate coordination of the individual segments.
•
Dysfunction of a particular segment in the chain can result in either altered performance or injury to a more distal segment.
The five physiological parameters we use are flexibility, strength, power (force × distance per unit of time), anaerobic capacity and aerobic endurance. We grade each sport from 1 to 3 based on the parameter’s importance in the sport: 1 The parameter is important for general body fitness (e.g. aerobic endurance in golf) 2 The parameter is important in performance or injury risk reduction (e.g. flexibility in tennis or basketball) 3 The parameter is essential for maximum performance (e.g. aerobic endurance in running, strength in weightlifting). Each sport will then have a profile that can be used to help an athlete meet the demands of that sport. Table 20.1 lists some sports and their resulting profiles. Similarly, each sport can be characterized by the kinetic chains necessary to perform the sport. The kinetic chain is a coordinated sequencing of activation, mobilization and stabilization of body segments to produce an athletic activity.6 Body segments have been described according to the Hanavan model as major bone and the joints on each end (Fig. 20.2). Kinetic chain activities have been grouped into open and closed chains.7 Characteristics of open chains generally include free movement of the terminal segment, large terminal segment velocities and relatively many degrees of freedom in the proximal segments. Characteristics of closed chains generally include fixed or minimal movement of the terminal segment,
Individual Sport Profile Flexibility
Strength
Power
Anaerobic
Aerobic
2 3 3 2 2 2 3 2 2
2 2 2 2 2 1 2 2 2
3 3 3 3 3 2 3 3 3
3 3 1 3 3 1 3 3 3
3 2 1 3 3 3 1 3 1
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Musculoskeletal assessment
1
6
2
7
3 8
9
10
11
4
5
12
14
13
15
Figure 20.2 The Hanavan model of body segments. (Redrawn with permission from Hanavan EP. Mathematical model of the human body. AMRL-TR 1964; 18:1–149.)
low terminal segment velocities, minimal degrees of freedom and coupling of movements of the segments. Many kinetic chains exhibit both closed and open chain activity.
substantial angular velocities seen at the shoulder during throwing; the force is largely generated by the more proximal segments of the lower extremities and trunk.6,8,9 The substantial forces that are transferred to, and subsequently reabsorbed by, the distal segments at the shoulder and arm during throwing leave these segments vulnerable to injury.10 Rehabilitation of the injured athlete must address the performance and kinematics of the entire kinetic chain. General descriptions of kinetic chains have been demonstrated for many sports and activities. The kinetic chains represent general patterns that appear to be reproducible for a specific activity with some variation between individuals doing the activity.11,12 Table 20.2 lists some of the most common sports and their predominant kinetic chain patterns. When the physiological and biomechanical requirements of the sport or activity are categorized, exercises and progressions of load and intensity can be employed to prepare the body for the sport. A runner will need back and leg flexibility exercises, progressive aerobic training with longer duration of training bouts, and eccentric strength training of the legs to absorb the closed chain loads in the stance phase. An ice hockey player will need anaerobic training for short bursts of activity and power training in both the arms and legs. A baseball pitcher will need appropriate arm and back flexibility, lower body strength, power training to develop force, and eccentric training for the arm to control deceleration loads.
MUSCULOSKELETAL ASSESSMENT Box 20.5: Key Points
•
Evaluation of injured athletes using the kinetic chain approach should take into account the broad scope of causative and contributing factors that may exist in addition to the clinical symptoms
•
These factors include deficits in joint flexibility, relative muscle weakness or lack of endurance, sub-optimal mechanics, and any other biomechanical deficits that may be present
•
The frequent association of distant tissue alterations with clinical symptoms can lead to a ‘victims and culprits’ approach to evaluation and treatment of sports medicine injuries, especially overload or chronic injuries, where the ‘victim’ is the site of clinical symptoms, and the ‘culprits’ are the distant alterations.
Box 20.4: Key Points
•
Kinetic chain activities can generally be characterized as either open or closed chain.
•
Open chain activities include free movement of the terminal segment, large terminal segment velocities, and relatively many degrees of freedom in the proximal segments.
•
Closed chain activities include fixed or minimal movement of the terminal segment, low terminal segment velocities, minimal degrees of freedom and coupling of movements of the segments.
•
Closed chain activities may be particularly helpful in the rehabilitation of an injured athlete.
•
Many functional kinetic chains exhibit both closed and open chain activity.
Athletic performance is dependent upon appropriate functioning of the individual components of the kinetic chain and appropriate coordination of the individual segments. Dysfunction of a particular segment in the chain can result in either altered performance or injury to a more distal segment. For example, the muscles of the shoulder girdle are not capable of generating the
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Table 20.2
Sport Kinetic Chains
Ground → Leg → Hip/trunk → Opposite leg → Ground Ground → Leg → Hip/trunk/opposite leg → Shoulder → Arm Serving Ground → Legs → Trunk → Shoulder → Arm Golf Ground → Legs → Trunk → Shoulder/arm → Wrist Kicking Ground → Plant leg → Trunk/opposite hip → Kick leg → Ball Swimming Water → Hand/wrist → Arm/shoulder → Trunk/legs → Arm → Water Shooting ball Ground → Legs → Arm/wrist → Ball Running Throwing
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Any system of evaluating injuries using the kinetic chain approach should take into account the broad scope of causative and contributing factors that may exist in addition to the clinical symptoms. These include deficits in joint flexibility, relative muscle weakness or lack of endurance, sub-optimal mechanics, and any other biomechanical deficits that may be present. The frequent association of distant tissue alterations with clinical symptoms can lead to a ‘victims and culprits’ approach to evaluation and treatment of sports medicine injuries, especially overload or chronic injuries.13 This approach allows a broad-based perspective on the pathophysiology underlying these injuries and an extensive clinical evaluation of all the physiological and biomechanical alterations that may be associated with the injury. The ‘victim’ is the site of clinical symptoms, and the ‘culprits’ are the distant alterations. For example, patellar tendinopathy may be associated with hip inflexibility or hip abductor weakness, and ‘tennis elbow’ (lateral elbow tendinosis) may be associated with posterior deltoid weakness. Our evaluation is based on a framework in which most of the factors related to an injury or dysfunction are categorized into five main areas, called complexes.14 These complexes interact with each other in the causation of micro-traumatic injuries, can be present as a result of macro-traumatic injuries, and are detectable on a clinical level. These complexes are composed of the following: • Clinical symptom complex: that group of overt symptoms and signs that clinically characterize the injury • Tissue injury complex: that group of anatomic structures that have overt pathological change • Tissue overload complex: that group of structures that have non-symptomatic but clinically detectable changes • Functional biomechanical deficit complex: alterations in biomechanics due to injury or overload • Subclinical adaptations: substitute actions that the athlete uses to compensate for altered mechanics to maintain performance. These complexes interact in a negative feedback vicious cycle to cause or maintain a soft tissue injury (Fig. 20.3).14 In microtrauma cases, an athlete may ‘cycle’ as a ‘susceptible’ athlete for some time before overt clinical symptoms appear. Most
EXAMPLES OF KINETIC CHAIN-BASED EVALUATION AND TREATMENT This section gives examples of the assessment of specific conditions utilizing the approach described above. Evaluation and treatment in this manner may result in a more thorough clinical evaluation and, subsequently, a more efficacious rehabilitation program. Each condition is covered more extensively in other sections of the book.
Plantar fasciitis
Tissue overload Absolute
acute injuries exhibit relatively fewer tissue overloads and biomechanical deficits, but some of these may occur as a result of treatment, such as loss of endurance, lower extremity strength, and ankle range of motion following immobilization after Achilles tendon surgery. In this model, clinical symptoms are a relatively small part of the entire pathophysiologic picture. These obviously require treatment, but it is also important to emphasize restoration of function encompassing all of the physiological and biomechanical alterations, rather than only resolution of symptoms. The medical history should include questions about previous injury, either local to or distant from the present injury. Examples include inquiring about previous ankle injury (present ankle injury or knee injury), previous hip injury (present knee pain, low back pain, or shoulder injury), previous back pain (present knee pain, low back pain, or shoulder injury), and previous shoulder injury (present shoulder injury or elbow injury). Also, one should ask questions about the exact nature of any treatment and rehabilitation of previous injury as both prior injury and inadequate rehabilitation of a prior injury have been suggested as risk factors for further injury.15,16 The physical exam should include not only standard peripheral joint and neurologic examinations but also some functional screening tests for distant parts of the kinetic chain to highlight deficits. Good screening tests include standing posture evaluation from front and back, the ‘one-leg stability series’ of one-leg stance and one-leg squat, sit and reach for lumbar flexibility, repetitive arm elevation/depression for scapular stability, and glenohumeral rotation off a stabilized scapula.7,17,18 Further evaluation can take place if the screening exam shows alterations.
Relative
Tissue injury
Subclinical adaptations
Clinical symptoms
Functional biomechanical deficits
Surgery injury
Figure 20.3 The negative feedback vicious cycle.
Plantar fasciitis is exacerbated by loss of dynamic protraction control of the foot and ankle. Several kinetic chain alterations may be present. Factors evident in the complexes include the following: • Clinical symptoms: point tenderness over plantar fascial insertion into calcaneus, stiffness in the morning or upon standing after sitting • Tissue injuries: plantar fascia, short flexors • Possible tissues overloaded: gastrocnemius/soleus complex, Achilles tendon, gluteal muscles • Functional biomechanical deficits: look for decreased active ankle dorsiflexion, decreased foot pronation/supination
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•
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ball behind the body, or trying to swing the racquet using the wrist extensors.
control or positive Trendelenburg sign with one-leg stance, or both; decreased strength in toe-off Subclinical adaptations: look for shorter stride on affected leg, look for leg external rotation with stance.
REHABILITATION AND PREHABILITATION Chronic hamstring muscle strain Chronic hamstring strain results from repeated episodes of reinjury. Each re-injury creates more deficits and adaptations. • Clinical symptoms: point tenderness and pain localized along the course of the muscle, possibly a defect (tear) or a palpable knot (scar), pain when running, stiff at rest • Tissue injury: hamstring at muscle–tendon junction • Possible tissues overloaded: adductors, hip extensors • Functional biomechanical deficits: look for excessive hip flexion and knee flexion in stance or running, a positive Trendelenburg sign on one-leg stability testing • Subclinical adaptations: shortened stride on injured leg, no pivoting on injured leg
Rotator cuff tendonitis Rotator cuff injury has obvious local causative factors (poor intrinsic blood supply, subacromial abrasion, direct or indirect trauma), but also may be associated with many kinetic chain alterations. • Clinical symptoms: pain over anterior or lateral acromion; (+) impingement testing; pain and weakness with horizontal abduction, forward flexion, external rotation; pain at night • Tissue injury: rotator cuff tendon, partial or complete • Possible tissues overloaded: shoulder capsule, scapular stabilizing muscles • Functional biomechanical deficits: look for glenohumeral internal rotation deficit, scapular dyskinesis with lower trapezius weakness, upper trapezius hyperactivation and acromial depression • Subclinical adaptations: look for shoulder shrug with arm elevation, thoracic kyphosis, dropping the arm below shoulder elevation in throwing or serving.
Lateral elbow tendonitis Lateral elbow tendonitis (misnamed lateral epicondylitis, more properly named lateral elbow tendinosis) is common in older athletes and is commonly associated with mechanical kinetic chain deficits. • Clinical symptoms: point tender pain over lateral epicondyle and extensor carpi radialis brevis; pain with grip; pain with one-hand backhand tennis stroke • Tissue injury: extensor carpi radialis brevis, occasionally extensor carpi radialis longus or joint capsule • Possible tissues overloaded: biceps, shoulder external rotators, lateral epicondyle • Functional biomechanical deficits: look for scapular dyskinesis, alterations in scapular position and motion that affect scapular roles in activity, deficits in strength of shoulder external rotation • Subclinical adaptations: look for alterations in hitting mechanics, including leading with the elbow, hitting the
Box 20.6: Key Points
•
Our rehabilitation approach includes three phases:
• • • •
Acute Recovery Functional. Different levels of exercises may be used in the early (acute) phase, the intermediate (recovery) phase and the late (functional) phase of rehabilitation.
•
The functional phase marks a transition between rehabilitation and prehabilitation, which can be defined as conditioning strategies in the formerly injured athlete to prepare him or her for the stresses and demands inherent in the sport, and which must be faced in return to sport.
•
The functional progressions in a rehabilitation program should simulate the actual activities required in the sport.
Rehabilitation protocols are structured around frameworks of progressions of exercises, loads, and applied and generated forces as the athlete improves his or her ability to generate and control sport-specific forces. Our rehabilitation approach includes three phases: acute, recovery and functional (Fig. 20.4).14 The patient progresses through each phase in a ‘flow’ dependent upon reaching certain criteria of injury healing and achievement of control of certain physiological and biomechanical functions. The acute phase is a broad, relatively non-specific phase with goals of: 1 protection or healing of injured tissues 2 improvement of general flexibility and strength 3 improvement in function of the distant links in the kinetic chains involved in the sport or activity.
Functional sport-specific fitness
Recovery general sport fitness Acute injury healing
Power Strength Endurance Flexibility
Flexibility Strength Kinetic chain Injury Modalities
Power Endurance Surgery Bracing
Figure 20.4 Phases of the rehabilitation process. The start of rehabilitation includes all causes of injury, but the end focuses on return to function.
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The recovery phase is a relatively long phase with goals of: 1 preparation for maximum physical activity 2 improvement in kinetic chain linkage sequencing 3 normalization of any distant kinetic chain dysfunction such as inflexibility or strength imbalance 4 setting up the strength and power base for sport-specific progressions. The functional phase is a focused phase, with the goals of: 1 obtaining sport-specific flexibility and strength 2 optimization of sport-specific physiological activations and biomechanical motions 3 sport-specific functional progressions. Our experience has led us to favor closed-chain rehabilitation protocols for most of our patients. Closed-chain rehabilitation protocols have beneficial characteristics that are associated with functional physiology and biomechanics. Closed kinetic chain exercises, in general, may simulate functional tasks more effectively, provide more appropriate proprioceptive feedback, and protect joint surfaces through co-contraction and more ‘physiologic’ loading of joint structures when compared to open chain exercise.19 They may be utilized early in the rehabilitation sequence to protect the injured area and to prepare the entire kinetic chain for function. Different levels of exercises may be used in the early (acute or healing) phase, the intermediate (recovery) phase, and the late (functional) phase of rehabilitation, depending on the degree of tissue healing, the possible positions of the extremity, and the amount of load and the range of motion that are allowed.20,21
Knee and leg rehabilitation Closed-chain rehabilitation techniques have been utilized to accelerate and improve functional restoration after ACL injury and reconstruction.22–24 These techniques create weight-bearing forces across the joint that increase local agonist–antagonist muscle co-activation, decrease joint shear, minimize joint displacement and ACL strain, and reproduce proprioceptive stimuli. In addition, they activate the kinetic chains of weightbearing, running, and jumping. This reproduces the normal biomechanics of the entire leg, allowing hip-muscle activation to increase quadriceps and hamstring force output by transferring muscle work to these biarticular muscles and by creating a hip moment that is a major contributor to the knee moment.25,26 Hip-muscle activation and work output create load-absorbing capacity that can compensate for a low load-absorbing capacity in the knee so that the entire leg functions at an acceptable level early in rehabilitation.26 Closed-chain exercises also reproduce the physiologic length-dependent patterns for hip- and knee-joint stability, as well as force-dependent patterns of coordination of hip, knee, and ankle joint motion. The effect that closed-chain exercises have on the entire kinetic chain is more functionally important than the effect on the knee joint alone. Closed-chain techniques are also useful in rehabilitation of the patient with patello-femoral pain, largely due to the same factors of joint position control, larger improvements in the strength of the entire kinetic chain, and alteration of the magnitude and position of applied forces. Increased total leg stiff-
ness, with resultant knee joint control, is achieved by activating the hip muscles concurrently with the knee muscles.25,27 Closed-chain exercises have been shown to produce greater improvements in quadriceps strength and leg performance than open-chain exercises.28 When compared with open-chain exercises, closed chain exercises of the quadriceps muscles have also been shown to result in more simultaneous activation of the different components of the quadriceps with more effective motor-unit synchronization.19,29 Closed-chain exercises produce lower patello-femoral joint stresses in the functionally and symptomatically important arc of motion from extension to 45˚ of flexion than do open-chain exercises.30
Shoulder rehabilitation On superficial analysis, it would appear that closed-chain rehabilitation would have little application for the shoulder and arm. The hand is moving in an open-chain fashion in throwing and serving, and the arm assumes a weight-bearing position only in gymnastics and blocking in football. However, shoulder position, motion and force transfer fit the physiologic and biomechanical requirements of closed-chain activities. In throwing and serving, the scapula and shoulder display intersegmental coordination, with coupled movements that are predictable on the basis of arm position.31,32 The shoulder acts as a stable funnel, transferring and regulating forces in the kinetic chain from the legs to the hand.6,33 The shoulder muscles are activated in mainly co-contraction length-dependent patterns to stabilize the joint.25,32–34 Proprioception plays a major role in controlling and activating muscle patterns.35 In swimming, weightlifting, and playing on the offensive or defensive line in football, the hand meets considerable resistance but still moves, creating mobile end-external load conditions at the distal end of the extremity. Closed-chain exercises should, therefore, be utilized in shoulder and scapula rehabilitation for functional return to most athletic activities from all types of shoulder injuries. Rehabilitation protocols for tendonitis, postoperative instability and postoperative labral injuries are basically the same in the acute phase and in the early functional phase.20,36 Postoperative rotator cuff protocols should vary with the integrity of the repair, but can also benefit from the proximal activation and low shear characteristics associated with closed-chain activities. Just as in knee and leg rehabilitation, closed-chain exercises may be used in the early stages of rehabilitation, and emphasis should be placed on involving all of the joints of the kinetic chain.
Functional progression The functional progressions in a rehabilitation program should simulate the actual activities required in the sport. Return-toplay criteria are based on successful completion of the functional phase goals. The functional phase marks a transition between rehabilitation and prehabilitation, which can be defined as conditioning strategies in the formerly injured athlete to prepare him or her for the stresses and demands inherent in the sport, and which must be faced in return to sport.37 Prehabilitation focuses on sport-specific musculoskeletal areas that have been shown to be weak or susceptible to injury, or have actually been injured, in a specific sport.38
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Specific examples: prehabilitation protocols
Functional musculoskeletal prehabilitation exercises can be strenuous as they replicate the motions, positions, forces, intensities and muscle activations inherent in the sport. The athlete’s body should have enough general athletic fitness to allow these vigorous activities without undue injury risk. The anatomical lesion should be healed. The physiological muscle activations, flexibility and endurance capabilities should be capable of withstanding the strength and power exercises. The physician and therapist should monitor and test for these parameters as rehabilitation progresses and as the athlete goes into the prehabilitation protocols. For throwing athletes, the general criteria should include hip and trunk control over the planted leg, trunk rotational flexibility and strength, control of scapular elevation and protraction, functional glenohumeral internal rotation, and rotator cuff co-contraction strength.39 For running athletes, general criteria should include appropriate gastrocnemius, quadriceps and hamstring flexibility, hip and trunk control over the planted leg, trunk extensor strength and aerobic capacity. As noted previously, athletes frequently have areas of inflexibility and weakness in other parts of the kinetic chain that may contribute to the injury or to decreased performance, and these issues should be addressed in the prehabilitation exercises. The frequency of these distant alterations may be as high as 50–85% in association with injury.18,40–43 A thorough evaluation of the entire kinetic chain involved in sports performance should result in the identification of these functional and biomechanical alterations.
At this stage of healing and rehabilitation, physical therapy modalities (heat, ice, ultrasound, stimulation) are usually not indicated. Very little tissue alteration is expected at this stage of healing that would be modified by these modalities. Some heat may be used to help in increasing tissue pliability before the exercise bout, and cold may occasionally be used if there is some swelling postexercise (Table 20.3)
Table 20.3 Tennis/Baseball Prehabilitation Program Weeks 1–2 Flexibility (daily, after activity): Cross body stretch, scapula stabilized Internal rotation, scapula stabilized Triceps stretch Racquet stretch Strength (3–5 × week): Shoulder external rotators/scapula retraction with tubing Rows with dumbbells/tubing, elbows down Reverse flies with dumbbells/tubing Plyometric/agility (3–5 × week): 5-dot drill (Fig. 20.5) Hexagon drill (Fig. 20.6) Line drill (Fig. 20.7) Footwork ladder, bounding
SPECIFIC EXAMPLES: PREHABILITATION PROTOCOLS The prehabilitation protocols should be based on progressions of flexibility, strength exercises, increasing loads and durations and progress from closed-chain to open-chain configurations. This is illustrated by specific protocols for: (1) tennis/baseball, for overhead activities; (2) running, for long distances and for a long duration; and (3) soccer, for high-intensity power running and jumping.
Tennis/baseball Prehabilitation plan The athlete should begin a shoulder flexibility and strengthening program focusing on increasing the internal rotation range of motion and external rotation strength. Flexibility exercises are performed after the throwing activity is complete for the day. Due to the high tensile loads developed in the shoulder external rotators and due to the inflexibility of the athlete in this area, a flexibility program is warranted. For strengthening, the goals of the training program are to increase the strength of the scapular stabilizers and shoulder external rotators, while maintaining explosiveness in those muscles. Plyometric/agility drills are incorporated into the prehabilitation program as they may reduce the risk of injuries related to these ballistic movements. In addition to the prehabilitation program, it is assumed the athlete participates in a general resistance training program two or three times per week.
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Footwork ladder, quick feet Footwork sprints (carioca, shuffle, back pedal, cross-over step, skip, high knee, etc.) Weeks 3–4 Flexibility (daily, after activity): Cross body stretch, scapula stabilized Internal rotation, scapula stabilized Triceps stretch Racquet stretch Strength (3–5 × week): Shoulder external rotation/scapula retraction with tubing Rows with dumbbells/tubing, elbows down Shoulder internal rotators with tubing Medicine ball forehand Medicine ball backhand Medicine ball serve Plyometric/agility: 5-dot drill Hexagon drill Line drill Footwork ladder, bounding Footwork ladder, quick feet
3 × 30 s 3 × 30 s 3 × 30 s 3 × 30 s 3 × 25 reps (moderate speed) 3 × 15 reps 3 × 15 reps 2 × 20 foot contacts 3 × 15 s, double leg 2 × 20 double leg foot contacts 2 × 20 single leg foot contacts 2 × 20 double leg foot contacts 2 × 20 single leg foot contacts 4 × 20 low-intensity foot contacts 5–8 × 9 meters
2 × 30 s 2 × 30 s 2 × 30 s 2 × 30 s 4 × 25 reps (high speed) 4 × 25 reps (high speed) 4 × 25 reps (high speed) 2 × 25 reps 2 × 25 reps 2 × 25 reps 2 × 20 foot contacts 4 × 10 s, single and double leg 2 × 20 double leg foot contacts 2 × 20 single leg foot contacts 2 × 20 double leg foot contacts 2 × 20 single leg foot contacts 3 × 20 low-intensity foot contacts Continued
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Table 20.3 Tennis/Baseball Prehabilitation Program— Cont’d Footwork sprints (carioca, shuffle, back pedal, cross-over step, skip, high knee, etc.) Weeks 5–6 Flexibility (daily, after activity): Internal rotation, scapula stabilized Racquet stretch Strength (2–4 × week): Shoulder external rotation/scapula retraction with tubing Shoulder internal rotation with tubing Plyometrics/agility: 5-dot drill Hexagon drill Line drill Footwork ladder, bounding Footwork ladder, quick feet Footwork sprints (carioca, shuffle, back pedal, cross-over step, skip, high knee, etc.)
5-dot drill 4
5 3
1
10–15 × 4.5 meters
2 × 30 s 2 × 30 s
6
2
5
3
2 × 25 reps (high speed) 4
2 × 25 reps (high speed) 2 × 20 foot contacts 5 × 10 s, single and double leg 2 × 20 double leg foot contacts 2 × 20 single leg foot contacts 2 × 20 double leg foot contacts 2 × 20 single leg foot contacts 3 × 20 low-intensity foot contacts 10 × 4.5 meters
1–2
2 Right leg 2
3 Left leg 1
4 Both feet 1
3
3
3
3
5
5
4
5
4
5
4
3
3
3
1
2
2
1
1
Figure 20.6 The hexagon drill. Do in the sequence shown and repeat three times.
1m 2
0.5m
Do each sequence with 5 repetitions Figure 20.5 The 5-dot drill. Each sequence should be done in the order listed and completed five times. (Redrawn with permission from Kibler WB, Chandler TJ. Functional rehabilitation and return to training and competition. In: Frontera WR, ed. Rehabilitation of sports injuries: Scientific basis. Oxford: Blackwell Science; 2003:288–300.)
Figure 20.7 The line drill. Jump back and forth across a line, which could be a tennis court sideline, baseball foul line, soccer touch line, etc. Land on both feet (double leg) or one foot (single leg).
Soccer Prehabilitation plan Soccer requires aerobic endurance, anaerobic capacity and power. It is common that injuries may recur if prehabilitation is not complete, because of the varied and large loads inherent in the demands (Table 20.5)
Running Prehabilitation plan It is suggested that the athlete should start prehabilitation on a more forgiving surface for training purposes whenever possible, such as grass or a rubber track. The main goal of the prehabilitation program is to allow the athlete to progress at 10–25% increases in work load, which are usually safe progressions. Strengthening the ankle while trying to improve ankle range of motion is warranted. Flexibility of the hamstrings and gastrocnemius is stressed. Low-intensity plyometric and eccentric activities may help prepare the athlete to withstand the repetitive loads of running, as well as improve explosiveness for the kick at the end of the race (Table 20.4).
CRITERIA FOR RETURN TO SPORTS Box 20.6: Key Points
•
The injured athlete must be anatomically healed and must complete all of the rehabilitation stages to be considered for return to sport.
•
All injured athletes must complete sport-specific functional progressions of activities, demonstrating that they have the physiology and biomechanics necessary to withstand the inherent demands of the sport, before returning to sports competition.
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Criteria for return to spor ts
Table 20.4
Running Prehabilitation Program
Weeks 1–4: The athlete is running 1.6–4.8 km, 3–4 days per week Flexibility (daily, after activity): Lying hamstring stretch 3 × 30 s Standing quadriceps stretch 3 × 30 s Leg twists for iliotibial band 3 × 30 s Wall calf stretch 3 × 30 s Trunk sit and reach 3 × 30 s Strength (4–5 × week): Squats (light resistance) 3 × 20 reps Lunges with light dumbbells 3 × 20 reps Weighted heel raise 3 × 20 reps Plyometrics/agility (3 × week, non-running days on grass): 5-dot drill 3 × 30 foot contacts Line drill 3 × 30 double leg foot contacts Weeks 5–8: The athlete is running 4.8–8 km on Monday and Wednesday and 8 km on Friday and Saturday Flexibility (daily, after activity): Lying hamstring stretch 3 × 30 s Standing quadriceps stretch 3 × 30 s Leg twists 3 × 30 s Wall calf stretch 3 × 30 s Trunk sit and reach 3 × 30 s
Table 20.5
281
Strength (2–3 × week): Squats (light resistance) Lunges with light dumbbells Weighted heel raise Plyometrics/agility (non-running days on grass): 5-dot drill Line drill Bounding drill Weeks 9–10: The athlete is running 8–16 km on Monday and Wednesday and 16–24 on Saturday Flexibility (daily, after activity): Lying hamstring stretch Standing quadriceps stretch Wall calf stretch Strength (2 × week): Squats (light resistance) Lunges with light dumbbells Weighted heel raise Plyometrics/agility (non-running days on grass): Fartlek progressions: alternating low-intensity and high-intensity running bouts
3 × 10 reps 3 × 10 reps 3 × 10 reps
2 × 20 foot contacts 2 × 20 single leg foot contacts 2 × 10–15 foot contacts
2 × 30 s 2 × 30 s 2 × 30 s 2 × 10 reps 2 × 10 reps 2 × 10 reps
20 meter jog → 10 meter run → 10 meter sprint
Soccer Prehabilitation Program
Weeks 1–3 Flexibility (daily, after activity): Lying hamstring stretch 2 × 30 s Standing quadriceps stretch 2 × 30 s Leg twists 2 × 30 s Wall calf stretch 2 × 30 s Trunk sit and reach 2 × 30 s Strength (3 × week, body weight as resistance): Squats 2 × 20 reps Forward lunges 2 × 20 reps Side step/cross step lunges 2 × 20 reps Heel raise 2 × 20 reps Plyometrics/agility (3 × week): 5-dot drill 2 × 20 foot contacts Line drill 2 × 20 double leg foot contacts Footwork ladder, bounding 2 × 20 double leg foot contacts Footwork ladder, quick feet 3 × 30 low-intensity foot contacts Weeks 4–6 Flexibility (daily, after activity): Lying hamstring stretch 2 × 30 s Standing quadriceps stretch 2 × 30 s Wall calf stretch 2 × 30 s Standing knee to chest 2 × 30 s Strength (medicine ball or dumbbells as resistance): Squats 3 × 15 reps Forward lunges 3 × 15 reps Side step/cross step lunges 3 × 15 reps Heel raises 3 × 15 reps
Plyometrics/agility (3 × week): 5-dot drill Line drill Footwork ladder, bounding
2 × 30 foot contacts 2 × 20 double leg foot contacts 2 × 20 single leg foot contacts 2 × 20 double leg foot contacts 2 × 20 single leg foot contacts 4 × 30 low-intensity foot contacts 5–8 × 18 meters
Footwork ladder, quick feet Footwork springs (carioca, shuffle, back pedal, cross-over step, skip, high knee, etc.) Weeks 7–10 Flexibility (daily, after activity): Lying hamstring stretch 2 × 30 s Standing quadriceps stretch 2 × 30 s Wall calf stretch 2 × 30 s Standing knee to chest 2 × 30 s Strength (3 × week, medicine ball or dumbbells as resistance): Squats 2 × 10 reps Forward lunges 2 × 10 reps Side step/cross step lunges 2 × 10 reps Heel raises 2 × 10 reps Plyometrics/agility (3 × week): 5-dot drill 2 × 20 foot contacts Line drill 2 × 20 double leg foot contacts 2 × 20 single leg foot contacts
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The injured athlete must be anatomically healed and must complete all of the rehabilitation stages to be considered for return to sport. Understanding the inherent demands of the sport allows for an objective set of criteria for return. Throwers must have sport-specific functional range of motion of arm joints, stable scapula, trunk/core stability and plyometric power development in the leg, no matter where their original injury occurred. Runners must have leg flexibility, trunk/core stability and aerobic endurance, no matter where their original injury occurred.39 All injured athletes must then complete sport-specific functional progressions of throwing, running, jumping, kicking or swimming. These exercises demonstrate that the athlete has the physiology and biomechanics necessary to withstand the inherent demands of the sport. Some authors have advocated return to sport based on quantitative criteria such as quadriceps/hamstring ratios in run-
Soccer field run 5 6 9
4
1 2 3 4 5 6 7 8 9
Sprint Jump and head a ball Run around cones Run backwards Pick up soccer ball Dribble around cones Three running jumps Plyometric jumps over lines Sprint
8 7
3
1 2 Start
Table 20.6 Mound
Interval Throwing Program Starting off the
Stage 1: Fastball only Step 1: Interval throwing 15 Throws off mound 50% Step 2: Interval throwing 30 Throws off mound 50% Step 3: Interval throwing 45 Throws off mound 50% Step 4: Interval throwing 60 Throws off mound 50% Step 5: Interval throwing 30 Throws off mound 75% Step 6: 30 Throws off mound 75% 45 Throws off mound 50% Step 7: 45 Throws off mound 75% 15 Throws off mound 50% Step 8: 60 Throws off mound 75% Stage 2: Fastball only Step 9: 45 Throws off mound 75% 15 Throws in batting practice Step 10: 45 Throws off mound 75% 30 Throws in batting practice Step 11: 45 Throws off mound 75% 45 Throws in batting practice Stage 3 Step 12: 30 Throws off mound 75% 15 Throws off mound 50% 45–60 Throws in batting practice Step 13: 30 Throws off mound 75% 30 Breaking balls 75% 30 Throws in batting practice Step 14: 30 Throws off mound 75% 60–90 Throws in batting practice 25% Step 15: Simulated game: Progressing by 15 throws per workout
Figure 20.8 Return to soccer functional program. The drill encompasses all of the soccer-specific demands. (Redrawn with permission from Kibler WB, Chandler TJ. Functional rehabilitation and return to training and competition. In: Frontera WR, ed. Rehabilitation of sports injuries: Scientific basis. Oxford: Blackwell Science; 2003:288–300.)
Use interval throwing to 120 ft phase as warm-up
All throwing off the mound should be done in the presence of your pitching coach to stress proper throwing mechanics
Use speed gun to aid in effort control
Warm-up Breaking balls Fastball only
Breaking balls
ners or internal rotation/external rotation ratios in throwers. These ratios are usually based on isokinetic data, which have not been conclusively shown to be associated with true muscle capability.1 These ratios can be helpful in determining weaknesses, but do not represent total capabilities, and should not be used as sole determinants of return to play. It is more important to know if the athlete can do all of the functions required in play, rather than if the athlete can generate torque at one joint. It may appear that the criteria for return to sport are rigid or easily determined. Actually, the criteria should be employed with some leeway, based on the athlete and the situation. The athlete should not be allowed to ‘play yourself into shape’, with no guidelines or input. This allows deleterious kinetic chain substitutions and increases the chances of reinjury.44 The athlete also should not be ‘rushed’ through the prehabilitation protocol, because the sport-specific exercises do impose significant demands, once again increasing the chances of re-injury. Experience has taught us the value of gradual return to play, with emphasis on steady progression of exercises, strict attention to the preparedness of the musculoskeletal base for new exercises, involvement of the kinetic chain, and resolution of both the local and distant alterations that may exist in association with the injury.14,41 Return to play is completed by sport-specific functional progression of doing the specific activity. Table 20.6 illustrates a sport-specific throwing progression, while Figure 20.8 illustrates a sport-specific soccer progression.45,46
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Cronin JB, McNair PJ, Marshall RN. Is velocity-specific strength training important in improving functional performance? J Sports Med Phys Fitness 2002; 42:267–273. Liepert J, Tegenthoff M, Malin JP. Changes of cortical motor area size during immobilization. Electroencephalogr Clin Neurophysiol 1995; 97:382–386. Grimby G, Thomee R. Strength and endurance. In: Frontera WR, ed. Rehabilitation of sports injuries: Scientific basis. Oxford: Blackwell Science; 2003:258–273. Schwellnus M. Flexibility and joint range of motion. In: Frontera WR, ed. Rehabilitation of sports injuries: Scientific basis. Oxford: Blackwell Science; 2003:232–257. Kibler WB. The sports preparticipation exam. Champaign, IL: Human Kinetics; 1990. Putnam CA. Sequential motions of body segments in striking and throwing skills: Descriptions and explanations. J Biomech 1993; 26:125–135. Kibler WB, Livingston BP. Closed chain rehabilitation for the upper and lower extremity. J Am Acad Orthop Surg 2001; 9:412–421. MacWilliams BA, Choi T, Perezous MK, Chao EY, McFarland EG. Characteristics of ground reaction forces in baseball pitching. Am J Sports Med 1998; 26:66–71. Press JM, Young JL. The role of the spine in the throwing athlete. SpineLine 2000; September/October:21–23. Fleisig GS, Barrentine SW, Escamilla RF, Andrews JR. Biomechanics of overhand throwing with implications for injuries. Sports Med 1996; 21:421–437. Hirashima M, Kadota H, Sakurai S, Kudo K, Ohtsuki T. Sequential muscle activity and its functional role in the upper extremity and trunk during overarm throwing. J Sports Sci 2002; 20:301–310. Marshall RN, Elliott BC. Long axis rotation: The missing link in proximal to distal segmental sequencing. J Sports Sci 2000; 18:247–254. MacIntyre JG, Lloyd-Smith DR. Overuse running injuries. Sports injuries, principles of prevention and care. London: Blackwell Scientific; 1993. Kibler WB, Chandler TJ, Pace BK. Principles of rehabilitation after chronic tendon injuries. Clin J Sports Med 1992; 11:661–673. Emery CA. Risk factors for injury in child and adolescent sport: A systematic review of the literature. Clin J Sports Med 2003; 13:256–268. Standaert CJ, Herring SA, Cole AJ, Stratton SA. The lumbar spine and sports. In: Cole AJ, Herring SA, eds. The low back pain handbook. Philadelphia: Hanley & Belfus; 2003:385–404. Kibler WB, McMullen J. Scapular dyskinesis and its relation to shoulder pain. J Am Acad Orthop Surg 2003; 11:142–152. Burkhart SS, Morgan CD, Kibler WB. Shoulder injuries in overhead athletes: The ‘dead arm’ revisited. Clin Sports Med 2000; 19:125–159. Stensdotter A, Hodges PW, Mellor R, Sundelin G, Hager-Ross C. Quadriceps activation in closed and in open kinetic chain exercises. Med Sci Sports Exerc 2003; 35:2043–2047. Kibler WB, Livingston B, Bruce R. Current concepts in shoulder rehabilitation. Adv Oper Orthop 1995; 3:249–300. Nichols TR. A biomechanical perspective on spinal mechanisms of coordinated muscular action: An architecture principle. Acta Anat (Basel) 1994; 151:1–13. Shelbourne KD, Nitz P. Accelerated rehabilitation after anterior cruciate ligament reconstruction. Am J Sports Med 1990; 18:292–299. Bynum EB, Barrack RL, Alexander AH. Open versus closed chain kinetic exercises after anterior cruciate ligament reconstruction: A prospective randomized study. Am J Sports Med 1995; 23:401–406.
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Beynnon BD, Johnson RJ. Anterior cruciate ligament injury rehabilitation in athletes: Biomechanical considerations. Sports Med 1996; 22:54–64. Umberger BR. Mechanics of the vertical jump and two-joint muscles: Implications for training. Strength Cond 1998; 10:70–74. DeVita P, Hortobagyi T, Barrier J. Gait biomechanics are not normal after anterior cruciate ligament reconstruction and accelerated rehabilitation. Med Sci Sports Exerc 1998; 30:1481–1488. Thomeé R, Augustsson J, Karlsson J. Patellofemoral pain syndrome: A review of current issues. Sports Med 1999; 28:245–262. Augustsson J, Esko A, Thomeé R, Svantesson U. Weight training of the thigh muscles using closed vs. open kinetic chain exercises: A comparison of performance enhancement. J Orthop Sports Phys Ther 1998; 27:3–8. Mellor R, Hodges PW. Motor unit synchronization of the vasti muscles in closed and open chain tasks. Arch Phys Med Rehabil 2005; 86:716–721. Steinkamp LA, Dillingham MF, Markel MD, Hill JA, Kaufman KR. Biomechanical considerations in patellofemoral joint rehabilitation. Am J Sports Med 1993; 21:438–444. Zattara M, Bouisset S. Posturo-kinetic organization during the early phase of voluntary upper limb movement. I. Normal subjects. J Neurol Neurosurg Psychiatry 1988; 51:956–965. Happee R, Helm FCT Van der. The control of shoulder muscles during goal-directed movements: An inverse dynamic analysis. J Biomech 1995; 28:1179–1191. Kibler WB. Biomechanical analysis of the shoulder during tennis activities. Clin Sports Med 1995; 14:79–85. Kibler WB. The role of the scapula in athletic shoulder function. Am J Sports Med 1998; 26:325–337. Lephart SM, Pincivero DM, Giraldo JL, Fu FH. The role of proprioception in the management and rehabilitation of athletic injuries. Am J Sports Med 1997; 25:130–137. Lephart SM, Henry TJ. The physiological basis for open and closed kinetic chain rehabilitation for the upper extremity. J Sports Rehab 1996; 5:71–87. Kibler WB, Chandler TJ. Sports specific conditioning. Am J Sports Med 1994; 22:424–432. Chandler TJ. Exercise training for tennis. Clin Sports Med 1995; 14:33–46. Kibler WB, McMullen J, Uhl TL. Shoulder rehabilitation strategies, guidelines, and practice. Oper Tech Sports Med 2000; 8:258–267. Ekstrand J, Gilquist J. The frequency of muscle tightness and injuries in soccer players. Am J Sports Med 1982; 10:75–78. Kibler WB, Goldberg C, Chandler TJ. Functional biomechanical deficits in running athletes with plantar fasciitis. Am J Sports Med 1991; 19:66–71. Knapik JJ, Bauman CL, Jones BH, et al. Preseason strength and flexibility imbalances associated with athletic injuries in female college athletes. Am J Sports Med 1991; 19:76–81. Warner JJP, Micheli L, Arslenian LE, et al. Scapulothoracic motion in normal shoulders and shoulders with glenohumeral instability and impingement syndrome. Clin Orthop Relat Res 1992; 285:199–210. Devlin L. Recurrent hamstring symptoms in rugby. Sports Med 2000; 29:279–287. Andrews JR, Wilk KE. Throwing progressions for return to baseball. Birmingham, Alabama: American Sports Medicine Institute; 1996. Kibler WB, Naessens GC. Soccer pre-participation physical exam. In: Garrett WE, Kirkendall DT, Contigulia SR, eds. The US soccer sports medicine book. Chicago, IL: US Soccer Federation; 1996:147–167.
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21
Common Injections in the Injured Athlete Ted A. Lennard
INTRODUCTION Today’s athlete has come to expect aggressive treatment for complex as well as self-limiting injuries. This expectation is driven, in part, by the desire to maintain their competitive edge, team pressures, and, in the case of the professional athlete, financial renumeration. As a result, numerous strategies and techniques have been developed to effectively treat the athlete injured with soft tissue disorders, intrinsic joint dysfunction and spinal injuries. The treatments include minimally invasive surgery, exercise programs, manual medicine techniques, medications and injections. This chapter will focus on injections and is divided into two basic sections,1 basic principles of injections in the athletic population and2 specific injection techniques for disorders arising from the soft tissue, joints and spine. Details of common injection procedures will be covered for joint and soft tissue injuries. An overview of spine injections will be discussed, but details of these advanced procedures will be left to other texts.3–5
BASIC PRINCIPLES OF INJECTIONS IN THE ATHLETIC POPULATION Injections are commonly performed to reduce, eliminate, or diagnose a painful stimulus originating from the soft tissue, joint, nerve, or spinal disc. These procedures should be utilized within the framework of broader goals of recovery and rarely in isolation to cure or repair a disorder. For example, the tennis player with lateral epicondylitis should undergo careful scrutiny of their technique, i.e. grip position, racket weight, string tension, handle diameter, etc., all known biomechanical factors in the development of lateral epicondylitis.6,7 This analysis should be implemented simultaneously with a supervised therapy program that emphasizes modalities, stretching and progressive exercises. Only when progress stagnates should an injection be considered.8 The response to the injection should be noted for confirmation of the working diagnosis. Any interval improvement can be used to advance their therapeutic exercise program.
Box 21.1: Key Point ●
Injections should be utilized within the framework of broader goals of recovery and rarely in isolation to cure or repair a disorder.
Prior to an injection, a thorough medical history is required. One should inquire about drug allergies, current medications and medical conditions. The use of injections in patients on blood thinners such as coumadin, aspirin, or other anti-platelet drugs should be approached with caution, but are not contraindicated in superficial injections, but should be avoided in deep injections such as spinal blocks.9 Injections are contraindicated in patients who have local infections or an immunosuppressed condition. Diabetics should be cautioned about a transient elevation of their blood glucose when corticosteroids are used. Adequate skin prep with Betadine or Hibiclens is usually recommended and reduces the chance of local infections.10,11 Common sense precautions should be adhered to regarding numbers of injections and placement of injections. One should avoid intratendinous needle placement,12 advancing into the periosteum of local bone, or injecting into vascular or neural structures.
Medications Most injections consist of a mixture of anesthetics and corticosteroids. The specific concentrations and types of these drugs injected varies among practitioners’ preferences and is dependent on their intended use. For example, a single subacromial injection for a clear diagnosis of subacute bursitis may consist of a short acting corticosteroid, i.e. triamcinolone, and a short acting anesthetic, i.e. 1% lidocaine. By comparison, the athlete with a complex shoulder and neck injury with diffuse shoulder and neck pain, may benefit from a single diagnostic subacromial anesthetic injection, i.e. 2% lidocaine, without corticosteroid. The response to the injection would be closely monitored to help differentiate the possible pain generators within the neck and shoulder complex. Other injectables such as normal saline or sterile water can be used when one needs to expand the volume injected without risking possible side-effects such as
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anesthetic toxicity. In cases when proliferation therapy is considered, dextrose, glycerin, phenol or sodium morrhuate may be used.13
Table 21.2
Comparison of Common Anesthetics16,18,19 Onset Duration Equal (min) (min)a concentration
Esters Procaine (Novocaine) Tetracaine Chloroprocaine Amides Lidocaine Bupivacaine Mepivacaine Etidocaine
Corticosteroids Corticosteroids produced by the adrenal cortex can be classified as androgenic or estrogenic, salt-retaining (mineralocorticoids) and anti-inflammatory (glucocorticoids). The glucocorticoid class is commonly used in injections for the treatment of inflammatory disorders. The primary glucocorticoid produced in humans is cortisol (hydrocortisone). Cortisol and other synthetic glucocorticoids possess varying degrees of anti-inflammatory and salt-retaining properties. It is these properties that dictate which glucocorticoid should be injected (Table 21.1).14–17
Toxicityb
5
30–60
2
6
6–12 15
30–60 175
2 0.25
7 1
0.5–1 5 3–5 5
100 120–240 100 120–240
1 0.25 1 0.25
5 2 4 3
aVaries
with method of administration. ranks among the anesthetics listed (1, most toxic; 7, least toxic). (Adapted from Lennard 1995.16)
bApproximate
Box 21.2: Key Point ●
Corticosteroids commonly cause subcutaneous fat atrophy. Flush the needle with anesthetic or sterile water during withdrawal.
Anesthetics Most physicians are familiar with common anesthetics, such as lidocaine or Marcaine®. The pain within a joint, tendon, or nerve can be reduced or eliminated when these drugs are used to provide temporary anesthesia. This change in their condition assists the physician in the ultimate diagnosis. There are two common classes of anesthetics: esters and amides. Table 21.2 outlines the differences and compares individual anesthetic drugs.16,18,19
cial tissue (Fig. 21.1). These points can be found in other tissue such as periosteum, joint capsules, ligaments and tendons. Characteristically, trigger points refer pain to distant locations also known as reference pain zones.20–22 Autonomic phenomenon and changes in proprioception may often accompany this referred pain. Tender points, like trigger points, have areas within the taut bands of skeletal muscle that cause pain. These spots, however, do not refer pain or cause other symptoms such as
SOFT TISSUE INJECTIONS Myofascial trigger point injections Myofascial trigger points (Tp) are localized tender spots within taut bands of skeletal muscle located within the muscle or fas-
Table 21.1
Figure 21.1 Trigger point within a taut band of muscle fibers.
Comparison of Commonly Used Glucocorticoid Steroids14–17
Agent
Hydrocortisone (cortisol) Cortisone Prednisone Prednisolone Methylprednisolone (Medrol, Depo-Medrol) Triamcinolone (Aristocort, Kenalog) Betamethasone Dexamethasone (Decadron) aRelative to hydrocortisone (Adapted from Lennard 1995.16)
AntiInflammatory Potencya 1 0.8 4–5 4–5 5 5 25–35 25–30
Salt Retention Property 2+ 2+ 1+ 1+ 0 0 0 0
Plasma Half-Life (min) 90 30 60 200 180 300 100–300 100–300
Equivalent Oral Dose (mg) 20 25 5 5 4 4 0.6 0.75
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proprioceptive abnormalities or autonomic dysfunction, but rather cause isolated and well localized areas of discomfort within muscle. The anatomic components of trigger points are not entirely understood. Travell and Simons propose that muscle strain leads to isolated fiber overload, which leads to muscle fiber damage. This event results in elevated calcium levels, which, in combination with adenosine triphosphate, cause sustained isolated fiber contraction, increased metabolism, and local base constriction. Nearby muscle fibers shorten independently and result in taut fibers.21
Myofascial trigger point injection techniques Various needle sizes, techniques and injected medication have been well discussed in the literature.2,20,21,23–27 The most important factor in myofascial trigger point injections appears to be the mechanical disruption of abnormal tissue, rather than the actual solution injected. The primary purpose of the injection is to disrupt the sensitized abnormal tissue mechanically by the repeated probing of a needle. The injection of solution such as an anesthetic tends to increase the mechanical disruption during the procedure. Typically, a needle ranging from 25–27-gauge in diameter is required to facilitate this mechanical disruption (Fig. 21.2). Once the examiner has identified a trigger point within a taut band of muscle tissue, a needle is introduced through the skin, fatty tissue and fascia directly into the muscle. The needle is directed toward the fibrotic tissue previously noted on manual examination. The needle is redirected along the taut band and within the myofascial trigger point itself. The solution injected into each area requires a volume of 1–3 cc. The resistance is reduced when one has penetrated through the taut band of a myofascial trigger point as well as at the edges superior to the band and trigger point. A trigger point injection could theoretically be performed in any specific muscle or muscle group that is found to have trigger points as described above. The example below demonstrates the technique in the trapezius muscle.
Trapezius muscle trigger point injection Athletes who present with diffuse neck and shoulder pain may be candidates for Tp injections. Localized areas of tenderness within taut bands of the trapezius muscle that when palpated
287
Box 21.3: Key Point ●
The most important factor in myofascial trigger point injections is the mechanical disruption of abnormal tissue rather than the actual solution injected.
radiate pain in well-defined areas may confirm one’s suspicion of the diagnosis of Tp. The physician should be keenly aware of the differential diagnosis of neck and shoulder pain in the athlete including primary pathology within the shoulder joint or cervical spine. The patient is placed in a relaxed prone position and the trapezius muscle is palpated. Many practitioners use some type of lubricant such as soap or gels to improve their tactile abilities. Once a trigger point is located, the skin is cleaned with alcohol, and a 25–27 -gauge needle is inserted into the trigger point. Using a repetitious insertion and withdrawal of the needle through the trigger point, but not out of the muscle, the Tp is mechanically disrupted. Small amounts of anesthetics (1–3 cc of 0.5% or 1% lidocaine) can be injected during this mechanical disruption as one option for treatment. As long as one’s needle stays within the trapezius muscle, few complications are likely to occur. However, caution should be exercised if the needle tip is allowed to advance too deeply and possible complications may arise depending on the segment of muscle that is being injected. For example, if the thoracic portion of the trapezius muscle is the target site, the deep structures including the intercostal space and underlying thorax should be noted. However, if the upper cervical portion of the trapezius muscle is being injected, cervical spinal structures including the nerve roots and vertebral artery should be remembered.
Bursa injections The bursa is a fluid filled sac located between tendons and/or bony prominences that act to reduce friction. These synovial lined sacs secrete fluid that when injured by overuse or trauma can swell and be a source of pain in the athlete. Often other structures, i.e. tendons, ligaments, etc., are injured and act as a co-existing source of pain. Most bursa are located adjacent to joints and can be easily and safely injected. Below is a list of the more commonly injected bursa.
Box 21.4: Key Point ●
An injection into the bursa may help differentiate various pain syndromes.
Trochanteric bursa injection
Figure 21.2 Trigger point injection. The needle tip is shown in the trigger point.
Inflammation of this bursa is located in the proximal lateral femur over the greater trochanter adjacent to the attachment of the gluteus maximus muscle and under the iliotibial band from the tensor fascia. Characteristic findings of trochanteric bursitis include pain at the proximal lateral thigh on manual palpation typically directly over the greater trochanter. At
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Coracoid Humeral head
Greater trochanteric bursa Figure 21.3 Trochanteric bursa injection. The needle tip is placed inside the bursa.
times, it radiates along the lateral thigh to the knee. Injection into the trochanteric bursa is common. The examiner should palpate the superior and posterior surface of the greater trochanter directed adjacent to these landmarks (Fig. 21.3). Typically, a 22–27-gauge needle will be utilized injecting volumes ranging between 5 and 8cc of anesthetic and corticosteroid mixture. Some have proposed the use of fluoroscopy for this injection to confirm proper needle placement.28 If the needle trajectory is placed superiorly, an intraarticular injection may occur. One should also be cautious as the needle tip advances past the bone of the greater trochanter.
Figure 21.4 Subacromial bursa injection. The needle is inserted through the deltoid muscle and adjacent to the acromion.
suspicion should remain high for other etiologies that mimic pes anserine bursitis such as meniscal and ganglion cysts and other benign or malignant soft tissue tumors.30 On clinical examination, a focal area of tenderness can be palpated at the insertion site of the above noted muscle groups. Injection utilizing a 25–27-gauge needle and 2–5cc of corticosteroid and anesthetic at the point of maximum tenderness within the bursa is identified by palpation and the needle advanced to the bursa (Fig. 21.5). The physician should be aware of the superficial nature of this injection and the injection may penetrate the articular space of the knee joint.
Subacromial bursa injection The subacromial bursa is located on the superior aspect of the humerus and appears as a ‘cap’ in this region. The bursa’s medial extension is seen under the acromion, coracoacromial ligament, and coracoid process and further extends inferiorly under the proximal bicipital tendon and bicipital groove. An injection into this bursa may reduce or eliminate shoulder pain, and can allow the physician to better differentiate bursitis, rotator cuff tears or tendonitis. A 25 or 27-gauge 1.5–2in needle is inserted after a Betadine prep. The insertion point is usually anterolateral or posterior under the acromion (Fig. 21.4). The accuracy rates of these approaches are not significantly different.29 Inferior traction on the arm can increase the acromiohumeral space and make the injection easier. The needle is advanced approximately 1.5–2in and a 4–8cc volume containing an anesthetic and corticosteroid solution injected. If the needle tip is advanced too far medially or inferiorly, an intraarticular injection may occur. If the needle tip is too superficial or directed superiorly, a subcutaneous fat or muscular injection will occur.
Tendon injections Bicipital tendonitis Bicipital tendonitis of the shoulder is characterized by proximal anterior arm pain and is made worse with resisted
Patella
Tibia
Femur
Pes anserine bursa injection The pes anserine bursa is located on the proximal medial tibia at the insertion site of the sartorius, gracilis and semitendinosus muscles. Deep to this bursa lies the medial collateral ligament of the knee and the medial joint space. Clinical
Pes anserine bursa Figure 21.5 Pes anserine bursa injection.
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Figure 21.6 Bicipital tendon injection. The needle is placed parallel to the tendon.
shoulder flexion. Focal tenderness can be palpated along the tendon proper between the greater and lesser tuberosities along the proximal humerus. An injection adjacent to the biceps tendon can be performed by palpating the greater tuberosity of the proximal humerus and by locating and injecting the needle just inferior to the point of directing the needle cephalad in a parallel fashion to the tendon itself (Fig. 21.6). One should be careful not to penetrate the tendon with the needle tip. A 25–27-gauge needle can be used with an anesthetic and steroid mixture between 2 and 5cc of volume. It is important to recognize the greater tuberosity of the humerus and the easily palpable long head of the biceps brachii muscle when using the anterior approach. The border of the deltoid muscle can be sometimes mistaken for the bicep’s tendon, especially in overweight or large patients. Superficially, the cephalic vein can be found adjacent to the deltopectoral groove, although usually this vein is medial to the entry point of the injection. If the needle trajectory is too far laterally, conceivably the axillary nerve could be encountered.
Box 21.5: Key Point ●
The border of the deltoid muscle can be mistaken for the bicep’s tendon, especially in large patients.
De Quervain’s tenosynovitis Tendonitis involving the abductor pollicis longus or the extensor pollicis brevis tendons is generally known as stenosing tenosynovitis or de Quervain’s tenosynovitis. Clinically, the patient has focal tenderness over these tendons at the dorsoradial aspect of the wrist and pain is reproduced with a provocative maneuver known as Finkelstein’s test (thumb abduction in flexion with the wrist deviated to the ulnar side). Prior to injection, the abductor pollicis long and extensor pollicis brevis tendons are palpated. Utilizing a small needle ranging from 25–27-gauge in diameter,
Figure 21.7 De Quervain’s injection. The needle is placed parallel to the extensor pollicis tendons within the tendon sheath.
the physician inserts the needle adjacent to the tendon proper into the tendon sheath and advanced parallel to the tendon (Fig. 21.7). One should avoid direct penetration into the tendon with the needle tip. A volume of 2–5cc of injectate utilizing a corticosteroid and an anesthetic mixture is normally used. If the trajectory of the needle deviates into the anatomic snuffbox, potentially the radial artery could be penetrated. The physician should also be aware of the location of the superficial radial sensory nerve that crosses the extensor pollicis tendon in the distal forearm.
Box 21.6 Key Point ●
Avoid injections directly into the tendon.
Lateral epicondylitis Lateral epicondylitis, often referred to as ‘tennis elbow’, is often treated with local corticosteroid injection. The hallmark of this diagnosis is well localized tenderness directly over the lateral epicondyle of the distal humerus. Reproduction of pain in this region is often noted with resistance to wrist extension and gripping activities. Typically a 25–27-gauge diameter needle is directed at the point of maximum tenderness in the region of the lateral epicondyle. The needle traverses the skin, subcutaneous fat, and into the substance of the common extensor tendon from the extensor compartment of the forearm. Then the needle tip strikes the lateral edge of the bony end of the lateral epicondyle (Fig. 21.8). Small volumes of injectate ranging from 2–5 cc is typically required. The injection is typically quick and simple if the practitioner is well versed in the regional anatomy. If the needle were to stray medially to the inferior portion of the cephalic vein at its
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Clavicle Acromion
Figure 21.8 Lateral epicondylitis injection. The needle is injected at the site of maximal tenderness at the lateral epicondyle and extensor mass.
juncture with the median cubital vein or the lateral antebrachial cutaneous nerve may be encountered. If the needle strays deep in the medial direction, one could potentially encounter the radial nerve. Post-injection, subcutaneous atrophy could occur in this region and cause cosmetic deformity if the physician who injects fails to flush the corticosteroid from the needle prior to withdrawing through the subcutaneous fat.
Medial epicondylitis Medial epicondylitis, commonly referred as golfer’s elbow, can be diagnosed in patients who present with isolated tenderness over the medial epicondyle of the distal humerus. This condition can be found in athletic sports that require prolonged or resisted wrist flexion with supination, such as golf. Patients may also experience pain in the proximal forearm or distal arm. This condition is amenable to injection using a similar technique to that described for the lateral epicondylitis. Using aseptic technique, the point of maximum tenderness is located and a 25 or 27 gauge needle injected and advanced to this point usually along the medial epicondyle. A total of 2–5cc of a corticosteroid/anesthetic mixture can be injected. The physician should be aware of the proximity of the medial epicondyle to the ulnar nerve in the cubital tunnel during the injection.
Box 21.7 Key Point ●
Be aware of the proximity of the ulnar nerve to the medial epicondyle during the injection.
Humerus
Figure 21.9 Glenohumeral joint injection. This diagram demonstrates the anterior and lateral approach.
coracoid process, and advanced inferiorly into the glenohumeral joint (Fig. 21.9). The needle trajectory is through the deltoid muscle. When the physician advances the needle medial to the AC joint, he or she should avoid the coracoacromial ligament. The acromial branches of the thoracoacromial artery usually lie anterior and just inferior to the coracoid process with no other significant vascular structures nearby. The musculocutaneous and axillary nerves are the largest nerves in the region; each are inferior to the coracoid process and are rarely at risk with the superior approach. When a physician uses the anterior approach to the glenohumeral joint, he or she should insert the needle 1–2cm lateral to the lateral tip of the coracoid process. Needle insertion is advanced laterally and then inferior to the coracoid process passing through the coracobrachialis and subscapularis muscles until the needle tip is advanced through the glenohumeral ligaments. One should be aware of the axillary sheath containing the axillary artery and vein in the region, this sheath maintains its greatest distance from the coracoid process with the patient’s arm adducted to their side.
Box 21.8 Key Point ●
JOINT INJECTIONS
The axillary sheath can be avoided during the anterior approach if the patient’s arm is placed in adduction.
Glenohumeral joint The glenohumeral joint can be injected from a superior, anterior, or posterior approach.1,31 All three injection approaches are relatively safe, though of the three, the anterior approach is closer to larger neurovascular structures. Regardless of the approach used, each joint is injected with strict aseptic technique, with Betadine prep and a total volume of 5–10cc of anesthetic and corticosteroid mixture. The superior approach32 can be performed when the needle is inserted just anterior to the acromioclavicular (AC) joint, lateral to the
The thoracoacromial artery branches anteriorly off the axillary artery just above the coracoid process. The smaller acromial branch from the thoracoacromial artery travels laterally, superficial to the upper border of the glenohumeral joint. The needle tip should be kept lateral and inferior to the coracoid process to avoid this portion of the arterial branch. Furthermore, the brachial plexus travels adjacent to the axillary sheath at the level of the glenohumeral joint. This is commonly found approximately 5–6 cm medial and caudal to the
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Clavicle Acromion Clavicle
Spine of scapula
Acromion
Scapula
Humerus
Humerus
Figure 21.11 Acromioclavicular (AC) joint injection.
Figure 21.10 Glenohumeral joint injection. This diagram demonstrates the posterior approach.
Hip joint coracoid process. The musculocutaneous nerve exits the lateral cord at the level of the coracoid process closest to the anterior glenohumeral joint. The posterior approach to the glenohumeral joint requires that the needle be placed approximately 3cm below the posterior lateral angle of the acromion. The needle should be advanced anteromedially toward the coracoid process (Fig. 21.10). One should be aware of the suprascapular nerve and artery, which lie close to the injection site or typically medial to this injection approach.
Box 21.9 Key Point ●
The suprascapular nerve and artery lie close to the entry point of the posterior injection approach.
Acromioclavicular joint The acromioclavicular joint is located along the superior medial aspect of the shoulder complex. This joint is comprised of the distal portion of the clavicle and the acromion and is a small superficial, easily palpable joint. This joint is commonly injured when athletes fall directly on the shoulder, which often results in separations. The joint is injected with the patient either in the supine or sitting position. The examiner palpates along the distal portion of the clavicle until the end of clavicle can be palpated and the adjacent acromion noted. Following Betadine prep, a small gauge (25 or 27-gauge) needle is quickly and easily inserted into the joint from a superior approach (Fig. 21.11). Small volumes are usually injected of an anesthetic and/or corticosteroid mixture between 2 and 5cc. One can inject this joint successfully by tapping the tip of the needle along the distal portion of the clavicle with a sudden ‘give way’ with gentle advancing pressure on the needle tip. If one keeps the needle tip at the edge of the distal clavicle and acromion, very little room for complication can occur.
The hip joint can be injected from either an anterior or lateral approach. The anterior approach poses more potential for injury because of significant neurovascular structures injury.33 Gatter recommends inserting the needle at the intersection of a vertical line extending from the anterior superior iliac spine (ASIS) with a horizontal line even with the trochanter. He notes that the femoral artery is usually about two fingerbreadths medial to this point. The needle is directed posteromedially toward the umbilicus, angled at 60˚ from the frontal plane. Others have recommended inserting the needle 2–3cm lateral to the femoral artery pulse and 2–3cm inferior to the ASIS and directing the needle 60˚ from the frontal plane.34,35 The femoral sheath is located just below the inguinal ligament and contains, from lateral to medial, the femoral artery, vein and lymph vessels. These vessels should pose minimal risk during hip injection if the femoral pulse is palpable as a landmark. The only arteries and veins in close vicinity of the needle path are the superficial and deep circumflex iliac arteries and veins branching laterally from the femoral artery heading superiorly and laterally. Typically, these vessels are represented by small branches at a level 2cm inferior to the ASIS. The femoral nerve is located just lateral to the femoral sheath. The main trunk of this large nerve usually is safe if the needle is inserted 2–3cm lateral to the adjacent femoral artery. Two primary cutaneous nerves travel superficial to the anterior hip joint. The lateral femoral cutaneous nerve (LFCN) of the thigh typically passes about 2–3cm medial to the ASIS beneath the inguinal ligament and continues on an inferior slightly lateral course. Also at this point, the LFCN is usually divided into three or four branches. A needle placed into the hip joint at this level passes within 2–4mm of the medial branches. A small femoral branch of the genitofemoral nerve lies superficially and directly above the anterior hip joint and can pass directly through the field of the injection. For the lateral approach, the needle is inserted just anterior or posterior to the greater trochanter and advanced in a medial and slightly cephalad direction.35,36 The needle passes through
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Femur
Patella
Figure 21.12 Hip joint injection. Lateral approach is demonstrated.
the iliotibial band and usually through the gluteus medius muscle before entering the thick iliofemoral ligament just superficially to the joint capsule (Fig. 21.12). The lateral approach to the hip joint places no significant vascular structures at risk. The superior gluteal nerve travels in a posterior/anterior direction across the deep surface of the gluteus medius and is located an average of 4.4 cm superior to a probe directed into the lateral hip joint described above.37
Box 21.10 Key Point ●
The lateral approach to the hip joint places no significant vascular structures at risk.
Knee joint The knee joint is the most commonly injected joint in the body. The approaches commonly used are the lateral or medial approach (Fig. 21.13). In both cases, the patient is placed in a supine position with a pillow or plinth placed under the knee joint with the knee in a flexed position. Betadine prep is utilized prior to the injection and typically 10–15 cc of volume is injected with a combination of corticosteroid and anesthetic.38 The lateral approach to the knee is quick and easy. This approach has been reported as being less reliable with low volumes because smaller volumes result in an intraarticular delivery less than half the time with a high incidence of soft tissue infiltration.39 The knee is in slight flexion, approximately 10˚, the patella is manually displaced laterally to enlarge the distance between the femur and the patella in this lateral position. Local anesthetic is usually applied and the needle is injected midway between the upper pole of the patella and the midbody of the patella lateral and inferior to the patella. The needle is advanced in an inferior medial trajectory. If aspiration is desired, the needle is advanced and one aspirates with the syringe. Furthermore, if aspiration is desired a large bore needle is placed such as an 18- or 20-gauge. The medial approach is also felt to be quick and simple. The practitioner places slight lateral pressure on the patella subsequently increasing the space between the patella and the femur medially. The needle is injected at the level of the midportion of the patella just medial to the patella between the
Fibula
Tibia
Figure 21.13 Knee joint injection. The medial and lateral approach is shown.
medial border of the patella and the femur. After the injection, an anesthetic is given to the skin. As described above, if aspiration is desired, a larger bore 18–20-gauge needle is advanced while aspirating with a syringe.
Ankle joint The ankle can be injected at the medial tibiotalar, lateral tibiotalar (talofibular), or the subtalar articulation (Fig. 21.14).35,36 The tibiotalar joint is injected from an anterior medial or anterior lateral approach, depending on the origin of pain and injury. The anterior medial approach involves needle insertion either just medial to the tibialis anterior tendon35 or between the tibialis anterior (TA) and extensor hallucis longus (EHL) tendons.36 The anterior tibial artery is typically located just lateral to the EHL tendon and then travels distally into the foot as the dorsalis pedis artery. Near the level of the tibiotalar joint, the medial
Fibula
Tibia Talus
Calcaneus
Figure 21.14 Ankle joint injection. Medial, lateral, and posterior sites for injection are demonstrated.
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malleolar artery branches medially from the anterior tibial artery through the interval between the EHL and TA tendons. The great saphenous vein lies between the TA tendon and the medial malleolus, usually along the anterior edge of the anterior malleolus, and in some patients may make the approach just lateral to the TA tendon preferable. The deep peroneal nerve lies beside the anterior tibial artery and is often medial to the artery just lateral to the EHL tendon. The saphenous nerve is located immediately anterior and lateral to the saphenous vein and is best avoided by needle insertion just medial to the TA tendon. The anterolateral approach to the tibiotalar joint involves needle entry just medial to the distal fibula and lateral to the digitorum extensor tendons.36 The lateral anterior malleolar artery typically runs along the anterior medial aspect of the fibula at this level. The cutaneous branch of the superficial peroneal nerves traverse the anterior lateral ankle. At the level of the tibiotalar joint, the larger sensory branch of the superficial peroneal nerves is the medial dorsal cutaneus nerve, which lies about midway between the medial and lateral malleoli. The smaller branch, named the lateral dorsal cutaneus nerve, lies one third of the distance from the lateral to the medial malleolus and is more at risk from the anterolateral approach.40 The subtalar articulation accessible to injection is the posterior talocalcanean joint or facet, whereas the anterior medial calcanean facets are relatively inaccessible to injection. The posterior subtalar joint is injected by inserting the needle midway between the anterior tip of the lateral malleolus and the Achilles tendon and progressing in the medial direction.35,36 Immediately posterior to the lateral malleolus is a common tendon sheath containing the peroneus brevis and longus tendons, with the peroneus longus tendon most posterior and nearest the injection site. Deeper at the injection site lies the calcaneal fibular ligament connected at the posterior tip to the lateral malleolus to the calcaneus. The vascular structures in this region include the small branches of the lateral calcanean artery, a continuation of the peroneal artery. The small saphenous vein and its branches are usually slightly lateral to the injection site described above and located just posterior to the lateral malleolus. The small lateral calcaneal branch of the sural nerve lie adjacent and usually medial to the small saphenous venous network and may traverse the injection site.
SPINE INJECTIONS Spinal injections are an important part of the treatment algorithm in the evaluation and management of spinal disorders in the athlete. When these injections are used in a judicious manner, they can eliminate a painful stimulus or confirm a working diagnosis. As noted above with other forms of injections, the athlete should be involved in an active rehabilitation program when the consideration of an injection is given.41–46
Box 21.11 Key Point ●
Spinal injections are an important part in the treatment algorithm in the management of the athlete with spinal pain.
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Preparation for a spinal injection Specialized training is required to become proficient in spinal injections. The physician who performs these injections should be confident in radiographic, surface and spinal anatomy, well versed in the treatment of spinal disorders, educated on proper patient selection and be able to recognize and treat any complications that may arise from the procedure. A procedure room should be properly staffed with experienced assistants and have equipment available for patient monitoring and resuscitation. The spinal injection suite should also contain high quality fluoroscopy. The use of fluoroscopy allows the physician to accurately place the needle tip into the desired target location which can then be confirmed with contrast dye.
Box 21.12 Key Point ●
The use of fluoroscopy is essential in proper needle placement.
Patient selection As noted earlier in this chapter, injections should be performed within the framework of broader rehabilitation goals. A sport specific exercise program should be incorporated within the treatment algorithm and every opportunity to improve without injections should be encouraged. When an injection is contemplated, X-rays and imaging studies should be performed to eliminate the possibility of the unexpected fracture, infection, or tumor. Advanced imaging studies such as MRI, can be used, along with the physical examination, to determine what specific type and location the injection should be performed. For example, the middle-aged softball player who reports a twisting injury and presents with unilateral right sided lumbar pain that extends into the buttock and proximal posterior thigh appears to have injured his right sided lumbar facet joints. On physical examination the patient’s pain is reproduced with manual palpation along the right-sided lumbar paraspinals and the pain is aggravated with extension and twisting maneuvers. In addition, the neurological exam remains normal. This clinical presentation suggests the lumbar facet joints as the primary pain generator. In this case, lumbar facet injections would be the procedure of choice. If however, MRI reveals a L5–S1 herniated disc, a lumbar epidural steroid injection may be indicated. Combined injections may become necessary if the earlier selected location is unsuccessful.47,48 The spine can be divided into three sections: anterior (intervertebral disc and vertebral body), neuroaxial (neural structures and epidural space) and posterior (zygapophyseal (z or facet) joints). Injections into the epidural space are typically used to treat disorders within the anterior or neuroaxial compartments, while injections directed into the spinal facet joints are used to treat disorders of the posterior compartment.
Epidural injections Injections into the epidural space can be performed from a midline, paramedian, transforaminal, or caudal approach. The specific approach to the epidural space is usually dependent on the underlying spinal pathology or the physician’s preference.
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Midline epidural approach A midline epidural approach is normally used for primary discogenic pain. This technique has been used for decades for spine pain and continues to be in common use. This procedure is performed with the patient in the prone position. The spinous processes of the vertebral body of the vertebrae above and below the affected disc level is marked on the skin under fluoroscopy. In addition, the inferior border of the lamina of the most cephalad vertebrae and the superior border of the lamina of the most caudad vertebrae are also marked on the skin. The skin is scrubbed with Betadine and 3–5cc of 1% lidocaine are used to anesthetize the skin, subcutaneous tissue, and interspinous ligaments. Once proper anesthesia is obtained, an 18-gauge Tuohy needle is advanced through the interspinous ligament using the loss of resistance technique (Fig. 21.15). A small skin puncture can be made with an 18-gauge needle for the anticipated entry point for the Tuohy needle. Once the 18gauge Tuohy needle has penetrated the ligamentum flavum the epidural space will be entered. It is helpful to check lateral views under fluoroscopy to monitor depth of penetration especially in larger patients. One should be cautious to avoid aggressive advancement of the needle to avoid penetration of the dural sac. Contrast is injected under fluoroscopy to confirm proper epidural spread and to avoid vascular uptake. A test dose of lidocaine with epinephrine may also be given and the patient monitored for changes in heart rate and blood pressure. Once confirmation is definitively determined, a solution of corticosteroid and anesthetic can be injected.
L2
L3
Figure 21.15 Midline epidural injection. The needle tip is located in the interspinous ligament and adjacent to the ligamentum flavum.
an 18-gauge Tuohy needle, the needle entry point is lateral to midline outside the interspinous ligaments through the paraspinal muscles. The Tuohy needle is advanced to the upper edge of the lamina in the most inferior marked vertebrae. The tip of the Tuohy needle is felt to tap the lamina and slowly ‘walked off ’ in a cephalad direction until entering the ligamentum flavum (Fig. 21.16). Once again, the needle is slowly advanced into the epidural space and when one senses loss of resistance the epidural space has been entered. Aggressive advancement of the needle tip may risk dural puncture. Proper needle localization can be identified with contrast. Corticosteroid and anesthetic solution can then be injected.
Paramedian epidural approach Similar to the midline approach, the paramedian approach utilizes loss of resistance technique. Landmarks are identified as noted above including the spinous processes and lamina that border the discs that are the purported pain generator. Utilizing
Transforaminal epidural approaches Perhaps the most difficult of the epidural approaches is that of the transforaminal injection. This requires proper needle trajectory and depth of needle placement under fluoroscopic
Figure 21.16 Paramedian epidural injection. This AP radiograph (A) demonstrates a typical contrast dye pattern following a paramedian lumbar epidural injection. The needle tip is located in the epidural space. (B) Lateral X-ray demonstrating contrast in the epidural space. (With permission from Woodward, J, Herring, S, Windsor, RE. Epidural procedures in spine pain management. In: Pain procedures in clinical practice. Lennard T, ed. Philadelphia: Hanley & Belfus; 2000 and courtesy of Paul H Dreyfuss, MD.)
A
B
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guidance. The foramen to be injected based on the probability of specific radicular symptoms is correlated with imaging studies. In the case of lumbar foraminal injections, the superior and inferior transverse process above and below the foramen and the lateral portion of the lamina are identified and marked on the skin. In the lower lumbosacral level, the upper margins of the sacrum are identified. For example, when one is to perform a L5 transforaminal epidural injection, the L5 transverse process, upper border of the sacrum, and the lateral lamina of the L5 vertebrae are identified and marked on the skin. The area is scrubbed with Betadine and the patient is dressed in the routine sterile fashion. A total of 3–5cc of 1% lidocaine can be used to anesthetize the skin and subcutaneous tissue, fascia, and paraspinal muscles. Once proper anesthesia is obtained, a 22-gauge spinal needle (some physicians prefer other needle sizes) is inserted inferior to the L5 transverse process and slowly advanced in a superior medial trajectory just inferior to the pedicle. It may take several adjustments of the needle tip under fluoroscopy prior to proper needle placement. Contrast is injected, and with proper needle placement, can be seen to flow under the pedicle and into the epidural space (Fig. 21.17). Once needle placement is confirmed, a solution of 3–5cc of a corticosteroid and anesthetic mixture can be injected. This same technique can be utilized at other spinal levels despite changes in the regional anatomy. In the case of an S1 transforaminal injection, the S1 foramen is the target site.
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has less risk of dural puncture since the dural sac typically terminates at the second sacral segment.
Box 21.13 Key Point ●
Caudal epidurals are limited to patients with lower lumbo-sacral pain.
The use of caudal epidural steroid injections is limited to those patients with lower lumbosacral disc disease. This approach
Landmarks for a caudal injection include the sacral hiatus and sacral cornu. These structures can be palpated with the patient in the prone position. Large individuals will require extra tactile pressure in this region to localize these landmarks. It helps if the patient internally rotates both hips to aid in the relaxation of the buttock muscles. Once located a sterile prep is performed and the skin is anesthetized with 1% lidocaine. A 22-gauge, 3.5 in spinal needle can then be inserted into the sacral hiatus. The initial needle entry point is positioned at a 30˚ angle to the sacrum and once the needle tip penetrates the hiatus, the needle is lowered and advanced parallel to the sacrum. The tip of the needle can be advanced about 2cm, when the epidural space is commonly encountered. Contrast dye is injected to confirm needle placement which creates a typical ‘Christmas tree’ pattern that outlines the lower sacral nerve roots (Fig. 21.18). Contrast is also used to avoid injection into vascular structures. A corticosteroid and lidocaine solution is then injected in volumes ranging from 10–20cc. Some physicians prefer the use of sterile water rather than large volumes of anesthetic. During the injection, patients may feel pressure in their sacrum
Figure 21.17 Transforaminal epidural injection. This AP radiograph demonstrates contrast dye adjacent to the L5 nerve root. The thin radiopaque structure that crosses the midline is tubing attached to the needle. (With permission from Woodward J, Herring S, Windsor RE. Epidural procedures in spine pain management. In: Pain procedures in clinical practice. Lennard T, ed. Philadelphia: Hanley & Belfus; 2000.)
Figure 21.18 Caudal epidural injection. This AP radiograph demonstrates a typical ‘Christmas tree’ pattern of contrast dye. Note the needle tip in the mid-lower portion of the radiograph. (With permission from Woodward J, Herring S, Windsor RE. Epidural procedures in spine pain management. In: Pain procedures in clinical practice. Lennard T, ed. Philadelphia: Hanley & Belfus; 2000.)
Caudal epidural approach
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and buttocks region and at times tingling into the lower extremities.
Facet joint injections Facet joint injections can be performed in the cervical, thoracic or lumbar regions and are considered the gold standard in diagnostic evaluation for posterior element pain.49 The facet joint nerve (medial branch of the posterior ramus) can be temporarily anesthetized (medial branch block or MBB) or solution can be placed within the joint (intraarticular or IA). The diagnostic MBB is often performed as a prelude to a medial branch rhizotomy. These techniques are well described in the literature.3–5 The intraarticular approach can be performed for diagnostic and therapeutic reasons.
Box 21.14 Key Point ●
Facet injections are the gold standard for the diagnosis of posterior element pain.
Intraarticular lumbar facet joint injection Intraarticular facet injections are commonly performed throughout the spinal axis. Variation in regional anatomy within the cervical, thoracic, or lumbar spine requires minor adjustments in technique and awareness of potential complications. IA facet injections require fluoroscopy to visualize each joint prior to injection. In general, these procedures are technically easy to perform in comparison to epidural injections, but can be time consuming, especially when multiple joints are to be injected. In the lumbar spine, these joints are best visualized with the patient in a prone-oblique position. Using fluoroscopy, the target joints are identified and marked on the skin. At times, the position of either the patient or C-arm fluoro unit must be adjusted to locate the joint. If the L5–S1 joint is targeted, an oblique approach may be difficult due to the height of the iliac crest and therefore a direct posterior approach may be required. The patient is scrubbed with Betadine and dressed in the routine sterile fashion and 3–5cc of 1% lidocaine are used to anesthetize the skin, subcutaneous tissue, fascia, and muscle overlying the injection target. Using a 22- or 25-gauge 3.5in spinal needle and fluoroscopic guidance, the needle is slowly advanced to the joint. The needle tip can be felt to tap the adjacent articulating process as a sudden ‘give way’ is felt as the joint is penetrated. This can be confirmed under fluoroscopy and with the injection of contrast dye (Fig. 21.19). The contrast can be aspirated and 0.5–2cc of corticosteroid-anesthetic solution injected.
Figure 21.19 Intraarticular facet injection. This oblique radiograph demonstrates contrast dye in the L5–S1 facet joint. The superior and inferior capsular recesses are demonstrated. (With permission from Dreyfuss P, Kaplan M, Dreyer S. Zygapophyseal joint injection techniques in the spinal axis. In: Pain procedures in clinical practice. Lennard T, ed. Philadelphia: Hanley & Belfus; 2000.)
with 3–5 cc of 1% lidocaine. Once proper anesthesia is obtained, a 22- or 25-gauge 3.5in spinal needle can be slowly inserted into the lower portion of the joint. Slight changes in the needle trajectory are often required under fluoroscopy. As the needle advances, the tip usually taps the joint margin and can be felt to ‘walk off ’ into the joint. This can be visualized under fluoroscopy which makes this technique quite simple (Fig. 21.20). Contrast can reconfirm needle placement within the joint. A solution of corticosteroid and anesthetic can then be injected.
Sacroiliac joint injection Intraarticular sacroiliac (SI) joint injections are technically easy to perform with fluoroscopic guidance. The patient is placed in the prone position and under fluoroscopy, the lower third of the sacroiliac joint is identified and marked on the skin. The patient is scrubbed with Betadine and dressed in a routine sterile fashion. The skin and subcutaneous tissue are anesthetized
Figure 21.20 Sacroiliac joint injection. This diagram depicts the needle entry point into the lower portion of the sacroiliac joint. (Redrawn with permission from Fortin J, Sehgal N. Sacroiliac joint injection and arthrography with imaging correlation. In: Pain procedures in clinical practice. Lennard T, ed. Philadelphia: Hanley & Belfus; 2000.)
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References
Box 21.15 Key Point ●
The entry point for a sacroiliac joint injection is in the lower third of the joint.
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the sports medicine physician to become experienced with soft tissue and joint injections as described in this chapter. A solid understanding of the benefits and pitfalls of spinal injections is also helpful when determining which athletes need procedures. Injections clearly expand one’s treatment options and ultimately improve outcomes.
CONCLUSIONS The athlete in pain can be treated successfully with injections when used within a broader scope of rehabilitation. It behoves
REFERENCES 1 2 3 4 5 6 7 8 9
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Arroll B, Goodyear-Smith F. Corticosteroid injections for painful shoulder: a metaanalysis. Br J Gen Pr 2005; 55:224. Baldry P. Management of myofascial trigger point pain. Acupunct Med 2000; 20:2–10. Fenton DS, Czervionke LF. Image-guided spine intervention. Philadelphia: Saunders; 2002. Lennard TA. Pain procedures in clinical practice. Philadelphia: Hanley & Belfus; 2000. Renfrew DL. Atlas of spine injections. Philadelphia: Saunders; 2003. Boyer MI, Hastings H. Lateral tennis elbow: ‘Is there any science out there?’ J Shoulder Elbow Surg 1999; 8:481–491. Whaley AL, Baker CL. Lateral epicondylitis. Clin Sports Med 2004; 23:677–691. Newcomer KL, Laskowski ER, Idank DM, McLean TJ, Egan KS. Corticosteroid injection in early treatment of lateral epicondylitis. Clin J Sport Med 2001; 11:214. Thumboo J, O’Duffy JD. A prospective study of the safety of joint and soft tissue aspirations and injections in patients taking warfarin sodium. Arthritis Rheum 1998; 41:736. Unglaub F, Guehring T, Fuchs PC, et al. Necrotizing fasciitis following therapeutic injection in a shoulder joint. Orthopaedics 2005; 34:250. Hofmeister E, Engelhardt S. Necrotizing fasciitis as complication of injection into greater trochanteric bursa. Am J Orthop 2001; 30:426. Hugate R, Pennypacker J, Saunders M, et al. The effects of intratendinous and retrocalcaneal intrabursal injections of corticosteroid on the biomechanical properties of rabbit Achilles tendons. J Bone Jt Surg Am 2004; 86:794–801. Dagenais S, Haldeman S, Wooley JR. Intraligamentous injection of sclerosing solutions (prolotherapy) for spinal pain: a critical review of the literature. Spine J 2005; 5:310–328. Celeste C, Ionescu M, Robin Poole A, et al. Repeated intraarticular injections of triamcinolone acetonide alter cartilage matrix metabolism measured by biomarkers in synovial fluid. J Orthop Res 2005; 23:602. Cole BJ, Schumacher HR Jr. Injectable corticosteroids in modern practice. J Am Acad Orthop Surg 2005; 13:37–46. Lennard TA. Fundamentals of procedural care. In: Lennard TA, ed. Physiatric procedures in clinical practice. Philadelphia: Hanley & Belfus; 1995:5–6. Olin BR. Adrenal cortical steroids. In: Olin BR, ed. Drug facts and comparisons. St Louis: Facts & Comparisons; 1993:465–466. Covino BG. Clinical pharmacology of local anesthetic agents. In: Cousins MJ, Bridenbaugh PO, eds. Neural blockade in clinical anesthesia and management of pain. 2nd edn. Philadelphia: Lippincott; 1988:111–144. Olin BR. Local anesthetics. In: Olin BR, ed. Drug facts and comparisons. St Louis: Facts & Comparisons; 1993:2654–2665. Fisher AA. Trigger point injection. In: Lennard TA, ed. Physiatric procedures in clinical practice. Philadelphia: Handley and Belfus; 1995:28–35. Travell JG, Simons DJ. Myofascial pain and dysfunction: The Trigger Point Manual. Baltimore: Williams & Wilkins; 1983. Wheeler AH. Myofascial pain disorders: theory to therapy. Drugs 2004; 64:45–62. Garvey TA, Marx MR, Wiesel SW. Perspective randomized double blind evaluation of trigger point injection therapy for back pain. Spine 1989; 14:962–964. Ingber RS. Shoulder impingement in tennis/racquetball players treated with subscapularis myofascial treatments. Arch Phys Med Rehabil 2000; 81:679–682. Iwama H, Akama Y. The superiority of water-diluted 0.25% to near 1% lidocaine for trigger-point injections in myofascial pain syndrome: a prospective, randomized, doubleblinded trial. Anesth Analg 2000; 91:408.
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Iwama H, Ohmori S, Kaneko T, Watanabe K. Water-diluted local anesthetic for triggerpoint injection in chronic myofascial pain syndrome: evaluation of types of local anesthetic and concentrations in water. Reg Anesth Pain Med 2001; 26:333–336. Hong CZ, Hsueh TC. Difference in pain relief after trigger point injections in myofascial pain patients with and without fibromyalgia. Arch Phys Med Rehabil 1996; 77:1161. Cohen SP, Narvaez JC, Lebovits AH, et al. Corticosteroid injections for trochanteric bursitis: is fluoroscopy necessary? A pilot study. Br J Anaesth 2005; 94:100. Matthews PV, Glusman RE. Accuracy of subacromial injection: anterolateral versus posterior approach. J Shoulder Elbow Surg 2005; 14:145–148. Koh WL, Kwek JW, Quek ST, Peh WC. Clinics in diagnostic imaging. Pes anserine bursitis. Singapore Med J 2002; 43:485–491. Buchbinder R, Green S, Youd JM. Corticosteroid injections for shoulder pain. Cochrane Database Syst Rev 2003; 1:CD004016. Micheo WF, Rodriguez RA, Amy E. Joint and soft tissue injections of the upper extremity. Phys Med Rehab Clin North Am 1995; 6:823–840. Gatter RA. Arthrocentesis technique and intrasynovial therapy. In: McCarty DJ, ed. Arthritis and allied conditions, a text book of rheumatology. Philadelphia: Lea and Fibiger; 1989:646–656. Resnick D. Arthrography, tenography, bursography. In: Resnick D, Niwayma G, eds. Diagnosis of bone and joint disorders. Philadelphia: Saunders; 1988:302–440. Millard RS, Dillingham MF. Peripheral joint injections: lower extremity. Phys Med Rehab Clin North Am 1995; 6:841–849. Obermiller JP, Locks MD. Peripheral joint injections. In: Lennard TA, ed. Physiatric procedures in clinical practice. Philadelphia: Handley and Belfus; 1995:14–27. Byrd JW, Pappas JN, Pedley MJ. Hip arthroscopy: An anatomic study of portal placement in relationship to the extraarticular structures. Arthroscopy 1995; 11:418–423. Bellamy N, Campbell J, Robinson V, et al. Intraarticular corticosteroid for treatment of osteoarthritis of the knee. Cochrane Database Syst Rev 2005; 2:CD005328. Wind WM Jr, Smolinski RJ. Reliability of common knee injection sites with low-volume injections. J Arthroplasty 2004; 19:858–861. Blaire JM, Botte MJ. Surgical anatomy of the superficial peroneal nerve of the ankle and foot. Clin Orthop Relat Res 1994; 305:229–238. Tong HC, Williams JC, Haig AJ, et al. Predicting outcomes of transforaminal epidural injections for sciatica. Spine J 2004; 4:605–606. Weinstein SM, Herring SA. Lumbar epidural steroid injections. Spine J 2003; 3:37–44. Vad VB, Bhal AL, Lutz Ge, et al. Transforaminal epidural steroid injections in lumbosacral radiculopathy: a prospective randomized study. Spine 2002; 27:11–6. Papagelopoulos PJ, Petrou HG, Triantafyllidis PG, et al. Treatment of lumbosacral radicular pain with epidural steroid injections. Orthopedics 2001; 24:145. Lutz GE, Vad VB, Wisneski RJ. Fluoroscopic transforaminal lumbar epidural steroids: an outcome study. Arch Phys Med Rehabil 1998; 79:1362. Botwin KP, Gruber RD, Bouchlas CG, et al. Fluoroscopically guided lumbar transforaminal epidural steroid injections in degenerative lumbar stenosis: an outcome study. Am J Phys Med Rehabil 2002; 81:898–905. Butterman GR. Lumbar disc herniation regression after successful epidural steroid injection. J Spinal Discord Tech 2002; 15:469–476. Michel JL, Lemaire S, Bourbon H, et al. Fluoroscopy guided L5-S1 transforaminal injection as a treatment for S1 radiculopathy. J Radiol 2004; 85:1937–1941. Bogduk N. International Spinal Injection Society guidelines for the performance of spinal injection procedures. Part I: Zygapophysial joint blocks. Clin J Pain 1997; 13:285–302.
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22
Orthotic Devices for Injury Prevention and Rehabilitation Karl B. Fields and Katherine M. Walker
INTRODUCTION Shoe inserts are one type of orthotic device designed to correct skeletal abnormalities, provide cushioning, correct gait abnormalities, stimulate sensory feedback and decrease injury rates.1–5 Over the past five decades orthotic devices have become part of the treatment of multiple diagnoses including plantar fasciitis, Achilles tendonitis, patello-femoral disorders, metatarsalgia and ‘shin splints’.1,6–8 In addition, orthotic devices often are prescribed for individuals with specific skeletal abnormalities including leg length inequality, cavus feet, Morton’s foot and pes planus. The typical gait problems modified by orthotic use include excessive pronation, excessive supination and forefoot varus.
Box 22.1: Key Points Orthotic devices Orthotic devices are shoe inserts designed to: ●
correct skeletal abnormalities
●
provide cushioning
●
correct gait abnormalities
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stimulate sensory feedback
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decrease injury rates.
Physicians utilize many different types of orthotic devices including ‘off the shelf ’ brands and custom made inserts molded from the patient’s foot. Numerous techniques and materials exist for the manufacture of custom orthoses. Currently, no randomized controlled trials demonstrate an unequivocal benefit of orthotic devices. Blinding patients to the use of orthotic devices poses logical difficulties. Some studies seek to compare ‘off the shelf ’ versus custom-made products or products using different materials. However, the literature remains of limited value since even these studies cannot control for the marked differences in the types of devices used. Nonetheless, a number
of studies show a high degree of patient satisfaction with the devices.6–8 The authors reviewed 100 patients with 1–3 years of usage and found that 90% continued wearing prescribed custom-made full-length orthotic devices. Of these, 50% found complete relief from the diagnosed condition; 25% significant improvement; 15% felt more comfortable in them even though the original problem had not responded; and 10% found they were not helpful. These response rates are similar to those reported by others. Traditionally, orthotic devices were thought to work by changing skeletal alignment, however, recent research questions this theory. Some studies show patient improvement with orthotic devices despite minimal change in the biomechanical problems suspected of causing the injury. Kannus described the classical theory of prescribing orthotics: ‘In treatment of athletes’ overuse injuries it should be kept in mind that custom-made, expensive orthotics should not be prescribed for overuse symptoms without obvious malalignment, for asymptomatic athletes with a malalignment, or for symptoms in which a causal relationship between the biomechanical abnormality and symptoms is difficult to see.’9
To illustrate the point made by Kannus, an individual with pes planus would not necessarily need orthotic devices unless the history and physical exam suggests that the flat feet contribute to a physical symptom that could be improved by mechanical correction. This was a departure from earlier clinical thinking that suggested that anatomical changes alone, such as pes planus, were sufficient to predict injury. During the Second World War, the US military considered the diagnosis of pes planus a sufficient risk marker to merit disqualification from active duty. Studies by Ifeld and others discovered that more than 15% of the military population had asymptomatic flat feet.10,11 In addition, during the 1930s, military physicians like Ifeld and Bingham began to note higher rates of foot and lower extremity injury in soldiers with cavus feet versus flat feet.11,12 More recent studies indicate limited risks for pes planus but substantial increased injury rates for pes cavus. Cowan found a relative risk of 6.1 for lower extremity injury in individuals having a navicular soft tissue arch height >3.15 cm (highest 20% of individuals.) Other authors found an association of cavus feet with recurrent stress fractures and with patello-femoral syndrome.10,13 While pes planus may not be
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enough of an anatomical problem to merit treatment for all affected individuals with orthotics, perhaps the same will not hold true with pes cavus. Additional research is needed to define the magnitude and type of static anatomical and dynamic biomechanical problems that may pose a risk for injury. Since orthotic devices also seem to work well in individuals without obvious anatomical or biomechanical problems, newer theories have emerged to help explain the beneficial effect of the devices.2–3 Nigg’s research2 shows differences in muscular work when individuals wear orthotic devices. Changing the sequence of muscle firing or reducing the workload of individual muscle groups has the potential of changing injury risk through modulating both the impact and the pattern of stress throughout the lower extremity. In addition, coupling anatomical changes with gait analysis to see if the anatomy affects the function may be more beneficial than relying on static examination. Individuals make significant form compensations for anatomical variations that may effectively reduce the risk that the anatomical change would imply. Gait analysis demonstrates whether a given abnormality translates to a specific breakdown of form that would affect injury risk.
PHYSICAL EXAMINATION Box 22.2: Key Points Physical examination Inspection ●
calluses
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Morton’s foot (longer 2nd metatarsal)
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cavus foot
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leg length inequalities
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forefoot varus and valgus
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first metatarsal insufficiency
Gait analysis ●
symmetry of motion
●
pronation or supination
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foot strike and orientation
●
body position
●
limb swing patterns.
Physical examination of the foot should begin with inspection. A normal foot bears approximately 50% of weight at the heel, 35% at the first metatarsophalangeal (MTP) joint and 15% at the 5th MTP joint. Typically, skin calluses should not occur under other metatarsal heads, as they are a part of the transverse arch. Skin callous patterns provide clues as to where the patient’s foot has broken down and to the location of excessive plantar surface pressure. A Morton’s foot (2nd metatarsal longer than 1st metatarsal) is particularly noteworthy because of its long-term association with injuries such as metatarsalgia and Morton’s neuroma. Two distinct patterns often get labeled as Morton’s foot. The first
actually results from a first metatarsal significantly shorter than the second metatarsal. This pattern more correctly described as first metatarsal insufficiency affects the ability of the great toe and first metatarsal to act as a counter to prevent excessive pronation in the toe-off phase of the gait cycle. This has the potential to lead to stresses that cause hallux valgus (bunion) formation or midfoot and longitudinal arch breakdown. Oftentimes, the first metatarsal-cuneiform joint is hypermobile as well. A second pattern, the classic Morton’s foot, consists of long thin metatarsals in which the second metatarsal is longer than a normal length first metatarsal. This foot type is at risk for Morton’s callous (thick callousing under second metatarsal head), metatarsalgia, stress fracture and Morton’s neuroma. The thin first metatarsal recruits the second metatarsal for more effective function during the toe-off phase of gait (Figs 22.1, 22.2). A second foot type that has a strong association with injury is the cavus foot deformity. A cavus foot can be measured using a bony arch index, a ratio of the navicular height to foot length measured from the heel to the first metatarsal phalangeal joint.10 A high ratio indicates a cavus foot. Another measure of cavus change is the distance from the floor to the soft tissue arch height of the navicular. The examiner palpates the surface anatomy of the navicular prominence and measures at this level. Arch height in this location greater than 3 cm suggest cavus deformity (Fig. 22.3). In cavus feet, the relative weight bearing shifts forward to the forefoot. Since form follows function, the examiner typically sees a broad forefoot and a narrow heel. More narrow heels may also point to extreme restriction of dorsiflexion of the foot and a shortened Achilles tendon as the heel rarely strikes the ground in these ‘toe runners’. Excessive transverse width at the forefoot identifies strong impact to this region and increases the likelihood of specific forefoot injuries such as hallux rigidus, bunionettes (5th MTP varus subluxation) and sesamoid stress fractures. While clinical studies have not established standard anthropomorphic measures for the foot, the author’s clinical experience suggests that ratios of forefoot width (measured at the 1st and 5th MTPs) to heel width at the mid-portion of the calcaneus typically average 1.6 to 1 or less. Width ratios >1.8:1 have strong association with forefoot breakdown in our clinics. Leg length inequalities are usually evaluated by measuring the distance between the anterior superior iliac spine and the
Figure 22.1 Morton’s toe.
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Figure 22.2 Metatarsal insufficiency. (It is the authors’ experience that individuals with first metatarsal insufficiency often have a ratio of the length of the 2nd metatarsal to the 1st metatarsal of 1.6:1 or greater).
toe being elevated. Measurements can be done standing or in the non-weight bearing position. For the supine patient, the examiner places the calcaneus in the sub-talar neutral position and the angle between the 1st and 5th metatarsals is measured. For extreme forefoot varus, when the patient lies prone with knees flexed at 90˚ the examiner cannot return the foot to a neutral position. Gait analysis is needed to assess pronated or supinated foot strike. However, the examiner can estimate static degrees of pronation/supination by observing patients standing and then flexing their knees to 45 degrees while their feet are flat on the ground. The pronated foot causes the medial malleoli to move inward and downward during knee flexion, whereas little change occurs in a supinated foot. On observation, an excessively pronated foot will show malalignment of the midfoot making it more prominent than the medial malleolus. Pronation beginning at the rear foot also shows calcaneal valgus on inspection from the rear (Figs 22.4, 22.5). Walking and running gait either demonstrates an exaggeration of the static observation or will show that the athlete can compensate for the static anatomy with form changes. This gives the examiner a better idea of the dynamic function of the feet. Asymmetry of foot strike (‘toeing-in or toeing-out’), unequal knee lift, upper body lean, a limp or an unbalanced arm swing are findings that merit analysis to understand why the gait pattern is altered. Comparison of the gait analysis to the wear pattern of the athlete’s shoes often helps confirm impression of form change and excessive pressure patterns at foot strike.
Figure 22.3 X-ray extreme cavus foot.
medial malleolus. The examiner measures the individual lying and sitting. An apparent leg length difference that reverses from lying to sitting may indicate a pelvic rotation or fixed sacroiliac joint. When questions arise, a standing evaluation allows the examiner to compare relative heights of the iliac crests; length from the umbilicus to each medial malleolus and other confirmatory maneuvers to evaluate leg length inequality. Another examination method is to place blocks of wood with different widths underneath the suspected shorter leg. Once the width of the block exceeds the leg length inequality, the patient starts to feel the lift. When problematic, differences >5 mm should be measured via standing AP radiograph that include the lower extremities and pelvis. Forefoot varus and forefoot valgus can be measured standing by placing the patient in a subtalar neutral position. If the great toe is elevated off the ground, the forefoot is in some degree of varus. Forefoot valgus is indicated by the 5th
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Figure 22.4 Calcaneal valgus.
Figure 22.5 Pronated foot with pes planus.
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Evaluation of the remainder of the lower extremity and foot and ankle flexibility are also important in the examination. Full range of motion at each joint allows the individual to have a balanced gait pattern. For example, when individuals return to running after piriformis syndrome or any injury to the external rotators of the hip, a decrease in internal rotation triggered by some contracture of the hip rotators often occurs. The corresponding gait observation may be external rotation (‘toeing-out’) of the foot on the affected side. Similarly, an iliopsoas strain may leave residual weakness and contracture of the hip flexors. The corresponding gait change likely would be uneven lift of the knees. Knee examination looks for genu varum/valgum as this correlates with changes in foot strike or gait and dictates changes in the preparation of the orthotic.
TYPES OF ORTHOTIC DEVICES/FABRICATION
Box 22.3: Key Points General types of orthotic shoe inserts Three primary types ●
Rigid: typically used in industrial settings and for post surgery correction
●
Semi-rigid: most commonly used by athletes
●
Soft: most commonly used for neurological injury (i.e. diabetic patients).
There are three main types of orthotic devices: rigid, semirigid and soft. Rigid orthotic devices are made of acrylic plastics and thermoplastic polymers which makes them more durable and supportive. While some athletes prefer these, they find most usage in industrial settings and for individuals who need correction post surgery. Soft orthotic devices are commonly composed of polyethylene foams and provide cushion, flexibility and the most padding. Soft orthotic devices are beneficial for those patients with neurological injury that decreases the normal sensation of the feet. Diabetics frequently use these in combination with high volume shoes. They also help athletes recovering from stress fractures, surgery and other injuries in which the need for the orthotic is felt to be temporary and not permanent. For example, runners with plantar fasciitis who seem to have developed the injury from overtraining as opposed to other possible causes may use these until symptoms resolve. Semi-rigid orthotic devices are the type used most commonly by athletes and are sometimes marketed under the term ‘athletic orthotics’. These inserts have cushioned upper surfaces made of leather, urethanes, ethyl vinyl acetate polymers, high-density rubber compounds and similar materials. Their interior has a thermolabile plastic that becomes moldable when heated and gives enough support to maintain the correction applied for the athlete. Styrofoam, plastic and cork bases
stabilize the base and provide protection of the upper materials from impact and wear and tear. The combination of padding and support provide both theoretical benefits that orthotic devices accomplish: impact protection and biomechanical correction.1 Once the material is selected, there are various mechanisms for custom molding the orthotic. Plaster-cast molds sent to an orthotic fabrication laboratory have been the most common method employed in past years. These have lost popularity to newer processes such as standing impressions of the feet with a crushable foam box or a similar technique using wax impressions. Newer technology includes CAD/CAM (ComputerAided Design/Computer-Aided Manufacture) in which a digitalized foot pressure pattern drives the formation of the orthotic.1,14 The authors use a system where patients stand in a semi weight bearing position on heated orthotic blanks. The base employs cushions with memory foam so that once the individual is correctly positioned the orthotic molds into the desired shape. Regardless of the fabrication method, the patients’ feet are placed in the subtalar neutral position. This position aligns the foot, ankle and lower extremity and is believed to be the most efficient for running and walking. Removing anatomical rotations and malalignments puts less stress on the surrounding ligaments, tendons and muscles.1,8 Subtalar position is found by placing one’s thumb and forefinger on the talus, while pronating and supinating the foot. If the foot is hyperpronated, the talus will be more prominent on the medial side and with supination, the talus will be felt more on the lateral side. The subtalar neutral position is when the talus is felt equally on both sides. Corresponding physical findings include a vertical Achilles tendon and a level tibiotalar articulation. Since the subtalar joint is not palpable, these techniques at best approximate true subtalar neutral position but have been correlated by X-ray imaging. With the plaster casting technique, the foot is held in the subtalar neutral position and the cast is formed. Once it has hardened, a positive mold can be made from the negative mold and the orthotic constructed from this positive mold.8 Positive molds can also be generated from foam or wax impression boxes. The CAD/CAM method cuts down on the storage space of the plaster casts or box molds and uses a digitized computer image of the foot to manufacture the orthotic.1,14 With the weight bearing method, using crushable foam pillows, the orthotic blank is heated in a convection oven and then placed under the patients’ feet. An orthotic stand allows positioning of the patient in semi weight bearing at 10–15˚ of knee flexion and 5–10˚ of ankle dorsiflexion. (This simulates late stance phase, before push-off, when maximum muscle stresses occur and when patients typically increase their pronation.) The patient is then placed in the subtalar neutral position and arch support can be molded. It takes approximately 4 min for the orthotic to mold and harden. Once the orthotic is molded, a base is applied to level the insole platform for impact, increase cushioning and prevent movement within the shoe. The base is glued onto the bottom of the orthotic and a grinder is used to help with custom fitting. Other adjustments to the orthotic such as adding a metatarsal pad to help those with metatarsalgia or adding a medial post for hyperpronators will be described in the following section (Figs 22.6–22.8).
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Figure 22.8 Grinding the orthotic. Figure 22.6 Orthotic materials.
a cutout under the involved metatarsal. Heel spurs can be treated with heel spur cutouts. A forefoot medial wedge is commonly added in the case of forefoot varus. In hyperpronation, some advocate a medial extension and accommodation of the first ray to allow for a kinetic wedge.15 Also, a higher heel cup may prevent excessive motion of the rearfoot.
Box 22.4: Key Points Special adjustments to orthotic devices
Figure 22.7 Orthotic stand in subtalar neutral position.
SPECIAL CONSIDERATIONS AND ORTHOTIC ACCOMMODATION Orthotic devices can be modified to treat various types of foot abnormalities. For example, in patients with a Morton’s foot, a first ray extension post (cushioned material) added to the bottom of the orthotic allows the first metatarsal to bear more weight. This theoretically lessens the burden on the other metatarsals and reduces the risk of transverse arch breakdown.1 In patients with metatarsalgia, a metatarsal pad can be added that takes pressure off the metatarsal heads. If a leg length discrepancy is detected, a lift can be added to the base of the orthotic. Metatarsal stress fractures can be managed by making
●
first ray extension posts
●
metatarsal padding and cutouts
●
medial or lateral wedges
●
heel cup
●
heel lift.
Achilles and posterior tibialis tendinosis are examples of specific conditions in which adjustments to the orthotic help treat an acute condition. The posterior tibialis is a major inverter/plantar flexor of the foot and is a key muscle for the toe-off phase of gait. Valgus stance and excessive pronation place increase stress on the posterior tibialis. Since injury and inflammation of this tendon dramatically alters function of the foot, special support may be needed to help the athlete return to normal gait. Supporting the medial aspect of the orthotic with additional longitudinal arch support lessens pronation and the stress this tendon undergoes during toe-off. This may be an essential type of splinting to help athletes recover from this condition. In addition, those athletes with anatomical or functional excess pronation may need the orthotic correction on a permanent basis.1 Modification of the orthotic for Achilles tendinosis includes incorporating a heel lift or additional cushion which theoretically decrease the stress on the Achilles tendon during
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eccentric contraction.1,16 Achilles tendon injury risk increases for individuals with a rigid, high-arched cavus foot so this seems a logical intervention. Other anatomical changes such as the foot with a plantar flexed first metatarsal and forefoot valgus may respond to application of lateral wedging and padded support of the first metatarsal head. Lateral foot instability such as that found in a runner with recurrent pain over the lateral aspect of the foot and suspected peroneal-cuboid syndrome warrants treatment with a lateral extension post.15
DO ORTHOTIC DEVICES DECREASE INJURY RATES? Few prospective randomized controlled trials address the benefit of orthotic devices in injury prevention. A recent Cochrane review of interventions for preventing and treating stress fractures and stress reactions of bone of the lower limbs in young adults included a few studies of orthotic use in military recruits.17 A study done by Schwellnus et al. showed that neoprene insoles were associated with a decrease in overuse injuries suffered by military recruits.18 Smith et al. compared two different types of insoles: Spenco (a closed cellular neoprene polymer) and Poron (cellular polyurethane). The greatest number of injuries occurred in the control group (no insoles), followed by the individuals using Poron insoles and then the group using Spenco insoles. Most of the injuries prevented were less severe than stress fractures and included plantar fasciitis, metatarsalgia, callus, and blister formation.19 Not all studies show benefits of orthotic inserts. A study done by Gardner et al. showed no significant differences in stress reactions among 3025 marine recruits using an elastic polymer insole versus the standard mesh insoles during a 12week intensive training program.20 Similarly, Andrish et al. prospectively followed first-year midshipmen on five different shin splint prophylactic protocols. One of these groups incorporated a heel pad for running activities and this type of intervention did not decrease the incidence of shin splints.21 Thus, studies looking at any of the types of shoe inserts showed mixed results. Research design demonstrates limitations that lessen the clinical conclusions one can draw from studies of orthotic inserts. The studies cited above involved asymptomatic individuals and were used as primary prevention. Most clinicians prescribe orthotic devices for situations in which they feel the athlete has a biomechanical or symptomatic structural abnormality. Thus high satisfaction rates by users and reports of good clinical outcomes are comparing symptomatic and asymptomatic individuals and would be expected to show differences. In addition, studies use a wide range of materials and devices most of which were not customized for the individual users as would typically be done in an office setting. No specific method has arisen which blinds users to orthotic inserts, thus making double blinded trials impractical. A study by Simkin et al. addressed the relationship between specific foot structure abnormalities, foot orthotics and stress fracture patterns. Tibial and femoral stress fractures were more common in those with high arched feet, while metatarsal stress fractures were more common in those with low arches.
Orthotic devices did decrease the rate of femoral stress fractures with cavus feet and metatarsal stress fractures with flat feet. While the rate of injury was decreased, the mechanism by which it occurred remained unclear.22 There are a number of non-randomized observational studies that examine the benefit of orthotic devices by patient questionnaires. Gross et al. received 347 questionnaire responses from long distance runners and found that >75% of the patients reported either complete resolution or great relief of their symptoms. The most common diagnoses for orthotic devices in this population were excessive pronation, leg length discrepancy, patello-femoral disorders, plantar fasciitis, Achilles tendonitis and shin splints. Over 90% of the patients continued to wear their orthotic devices even after their symptoms had resolved indicating a high level of patient satisfaction.6 Donatelli et al. also reported a high level of patient satisfaction in non-athletes with the use of custom-made orthotic devices. Some 96% of patients reported pain relief with the orthotic devices and 94% were still wearing their orthotic at the time of follow-up (3 months to 2 years). A total of 76% were able to return to their previous level of activity and 52% would not leave home without their orthotic devices.23 Eggold et al. surveyed 146 runners who were prescribed orthotic devices for knee pain, plantar fasciitis/heel spurs, arch pain, Achilles tendonitis, and shin splints. Approximately 75% of respondents obtained at least 80% pain relief or better.7 D’Ambrosia prescribed orthotic devices for 200 runners at Louisiana State University Runners’ Clinic, with posterior tibial syndrome being the most common diagnosis. Some 70% of the men and 83% of the women improved. A cavus foot deformity was less common (13 out of 200 runners), however orthotic devices only improved 25% of these patients. This data may be misleading in that a three-quarter length orthotic was used, which would not be ideal for the cavus foot deformity.8 Fauno et al. published one primary prevention study that showed potential benefit. They evaluated the incidence of soreness in the lower extremities and back in soccer referees with the use of shock absorbing heel inserts. A total of 91 asymptomatic referees were randomly assigned to either a control group or to receive shock-absorbing inserts during a 4-day period of refereeing 4–5 games per day. Those referees who wore the shock absorbing insoles reported less soreness in the back, calves and Achilles tendons.24 Considering the studies done to date, the effect of orthotic devices for primary prevention is uncertain. Stronger evidence does show that the use of orthotic devices has resulted in a high degree of patient satisfaction, continued use and symptom resolution. Weaker data suggests use of orthotics for specific foot types and injuries.
HOW DO ORTHOTIC DEVICES WORK? One of the proposed mechanisms through which orthotic devices work is by better alignment of the skeleton for a more efficient gait and decreased impact forces. Nigg et al. challenged this hypothesis by citing a number of studies that show that orthotic devices have not resulted in predictable changes in biomechanics. He studied four different types of shoe inserts (full medial, full lateral, half medial and half lateral compared to
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References
neutral insert) in 15 subjects to study whether kinematics, center of pressure, and leg joint movements could be predictably altered. For the most part, the subjects’ responses to the various orthotic devices were not consistent and occasionally counterintuitive to what the researchers expected. For example, the full lateral insert resulted in a shift of the center of pressure laterally and not medially as was expected.5 Williams et al. recently studied inverted orthoses (a more aggressive type of orthotic in which there is more lateral tilt) to evaluate whether they changed biomechanics. While there was no change in rearfoot eversion, there was a decrease in measures of peak rearfoot inversion and a change in biomechanics at the knee.25 Since the orthotic may increase the load on lateral structures of the knee, this type of intervention merits caution until data indicates whether the risk of knee injuries is affected. A recent study examined the effect of orthotic devices on postural sway in asymptomatic soccer players. The results revealed that the addition of an orthotic to a soccer shoe did not affect postural sway.26 Others have shown that orthotic devices are helpful in improving balance in those with a history of an ankle injury.27,28 Nigg has proposed a new theory on the function of orthotic devices. The skeleton has a preferred movement for a task. If an orthotic intervention can support that movement, then muscle activity is reduced. A reduction in muscle work would theoretically be perceived as more comfortable and result in a delayed onset of fatigue. Therefore, if muscle activity is minimized, performance should improve. Nigg has shown some evidence with a small sample size that subjects running in comfortable shoes used less of their max VO2 than those wearing a shoe that was uncomfortable. Another study showed that orthotic comfort is related to a series of kinematic, kinetic and electrodiagnostic variables.3 This study found some objective correlation of comfort with various biomechanical variables. Certainly, more studies are required to confirm this hypothesis.
305
CONCLUSION
Box 22.5: Key Points ●
Good response rates in non-randomized clinical trials.
●
No prospective randomized clinical trials demonstrate benefits.
●
Favorable review by Cochrane for prevention and treatment of stress fractures in lower limbs (moderate strength evidence).
●
No strong evidence for primary prevention in asymptomatic individuals.
Orthotic devices have become a standard part of the treatment approach for running athletes. High levels of patient satisfaction, symptom relief and continued usage drive the prescribing patterns of sports medicine physicians. Nevertheless, the scientific support for their use remains at best limited. The fabrication of orthotic devices is an art, thus those with more experience will construct or prescribe devices that would be expected to have better results. The wide variety of methods, materials and practice experience of the various physicians, orthotists, athletic trainers, and physical therapists utilizing orthotic inserts makes comparison of clinical results complex. Even the basic mechanisms through which orthotic devices work warrant additional scientific scrutiny. A completely new understanding of the beneficial effects of orthotic devices; whether they can be used for primary or secondary prevention; their role in the treatment of specific injuries; and identification of patients most likely to benefit from their prescription; holds the promise of improving their utilization in the care of athletes.
REFERENCES 1 2 3 4
5
6 7 8 9 10 11 12 13
Goodman A. Foot orthoses in sports medicine. South Med J 2004; 97:867–870. Nigg BM, Nurse MA, Stefanyshyn DJ. Shoe inserts and orthotics for sport and physical activities. Med Sci Sports Exerc 1999; 31:421–428. Nigg BM. The role of impact forces and foot pronation: A new paradigm. Clin J Sports Med 2001; 11:2–9. Mundermann A, Nigg BM, Humble RN. Stefanyshyn. Orthotic comfort is related to kinematics, kinetics, and EMG in recreational runners. Med Sci Sports Exerc 2003; 35:1710–1719. Nigg BM, Stergiou P, Cole G.S, Mundermann A, Humble N. Effect of shoe inserts on kinematics, center of pressure, and leg joint moments during running. Med Sci Sports Exerc 2003; 35:314–319. Gross ML, Davlin LB, Evanski PM. Effectiveness of orthotic shoe inserts in the longdistance runner. Am J Sports Med 1991; 19:409–412. Eggold JF. Orthotics in the prevention of runners’ overuse injuries. Physician Sports Med 1981; 9:125–128. D’Ambrosia RD. Orthotic devices in running injuries. Clin Sports Med 1985; 4:611–618. Kannus VPA. Evaluation of abnormal biomechanics of the foot and ankle in athletes. Br J Sp Med 1992; 26:83–89. Fields KB. Flatfeet become respectable. Arch Fam Med 1993; 2:723–724. Ilfeld FW. Pes planus military significance and treatment with simple arch support. JAMA 1944; 124:281–283. Bingham R. Painful feet. JAMA 1944; 124:283–286. Cowan DN, Jones BH, Robinson JR. Foot morphologic characteristics and risk of exercise-related injury. Arch Fam Med 1993; 2:773–777.
14 15 16 17
18 19 20 21 22 23 24 25
Staats TB, Kriechbaum MP. Computer aided design and computer aided manufacturing of foot orthoses. J Prosthet Orthotics 1989; 1:182–186. Subotnick SI. Foot orthotics. In: O’Connor FG, Wilder RP, eds. Textbook of running medicine. New York: McGraw-Hill; 2001:595–603. McLauchlan GJ, Handoll HHG. Interventions for treating acute and chronic Achilles tendonitis. Issue 4. The Cochrane Library; 2004. Gillespie WJ, Grant I. Interventions for preventing and treating stress fractures and stress reactions of bone of the lower limbs in young adults. Issue 4. The Cochrane Library; 2004. Schwellnus MP, Jordan G, Noakes TD. Prevention of common overuse injuries by the use of shock absorbing insoles. Am J Sports Med 1990; 18:636–641. Smith W, Walter J, Bailey M. Effects of insoles in coast guard basic training footwear. J Am Podiatr Med Assoc 1985; 75:644–647. Gardner LI, Dziados JE, Jones BH, et al. Prevention of lower extremity stress fractures: a controlled trial of shock absorbing insole. Am J Public Health 1988; 78:1563–1567. Andrish JT, Bergfeld JA, Walheim J. A prospective study on the management of shin splints. J Bone Jt Surg 1974; 56:1697–1700. Simkin A, Leichter I, Giladi M, Stein M, Milgrom C. Combined effect of foot arch structure and an orthotic device on stress fractures. Foot Ankle 1989; 10:25–29. Donatelli R, Hurlbert C, Conaway D, St. Pierre R. Biomechanical foot orthotics: A retrospective study. J Ortho Sports Phys Ther 1988; 10:205–212. Fauno P, Kalund S, Andreasen I, Jergensen U. Soreness in lower extremities and back is reduced by use of shock absorbing heel inserts. Int J Sports Med 1993; 14:288–290. Williams DS, Davis IM, Baitch SP. Effect of inverted orthoses on lower-extremity mechanics in runners. Med Sci Sports Exerc 2003; 35:2060–2068.
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Percy ML, Menz HB. Effects of prefabricated foot orthoses and soft insoles on postural stability in professional soccer players. J Am Podiatr Med Assoc 2001; 91:194–202. Orteza LC, Vogelbach WD, Denegar CR. The effects of molded and unmolded orthotics on balance and pain while jogging following inversion ankle sprain. J Athl Train 1992; 27:80.
28
Guskiewicz K, Perrin D. Effect of orthotics on postural sway following inversion ankle sprain. J Orthop Sports Phys Ther 1996; 23:326.
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23
Complementary and Alternative Medicine and the Athlete Joseph F. Audette and Allison Bailey
INTRODUCTION In recent years, the popularity of complementary and alternative medicine (CAM) has been increasing. A 1993 survey found that 33% of adult Americans had used some sort of CAM therapy in the previous year.1 In 1998, the percentage had increased to 42%.2 It has been estimated that Americans made 629 million visits to CAM providers in 1997, exceeding the total number of visits to primary care physicians. The same survey estimated that US$27 billion was spent on CAM that year, comparable to the out-of-pocket expenditures for all physician services in the US in 1997.2 The most common diagnoses for which patients sought CAM in these surveys were back pain, headache, depression and anxiety. The most comprehensive information on CAM use was gathered by the National Center for Health Statistics (NCHS) as part of the National Health Interview Survey (Fig. 23.1). 3 As part of this study, tens of thousands of Americans were interviewed about their experiences with health and illness. The 2002 version, which was completed by 31 044 adults, included detailed questions on CAM. This survey found that 36% of adult Americans had used some form of CAM, excluding megavitamins and prayer for health reasons, in the last 12 months. People who were more likely to use CAM included women greater than men, those with higher educational levels, those who had been hospitalized in the last year, and former smokers more than current or never smokers. One difficulty in surveys of CAM use is that the definition of CAM may vary. The National Center for Complementary and Alternative Medicine (NCCAM) has defined CAM as diverse healthcare systems, practices and products that are not currently considered to be part of conventional medical training and practice.4 While scientific evidence has begun to accumulate regarding some CAM therapies for certain diagnoses, important questions regarding most of these approaches remain unanswered. The list of treatments that
are considered to be CAM will continue to shift as certain CAM therapies are shown to be effective and are accepted into mainstream practice. Despite the strong interest in CAM therapies among the general population, the numbers of athletes who make use of CAM are not known. There have been no large-scale observational studies of CAM use by athletes published in the medical literature. The few small surveys available have focused on specific CAM modalities, such as nutritional supplementation and chiropractic care, rather than on more general information relating to CAM use. There are many reasons, however, why athletes may be interested in CAM therapies. Athletes may be willing to try new and unproven treatments as they seek new methods by which to gain a competitive advantage over their opponents. They are frequently vulnerable to injury as they challenge themselves to perform at high levels for long periods of time, and when an injury has occurred, they will often try any means to hasten their recovery and return to their sport promptly. The conditions for which athletes may seek CAM are numerous. These include hastening recovery from fatigue and muscle soreness after intense athletic competitions and training sessions, treatment of acute injuries, and help with recovery from chronic, overuse or over-training injuries. CAM strategies may also be used generally for overall enhancement of athletic performance. For the purposes of this chapter, some of the major CAM therapies that may be used by athletes will be reviewed briefly. The scope of this chapter does not permit an in-depth review of each of these therapies. In many cases, CAM treatments may overlap with areas no longer considered ‘alternative’. For example, sports nutritionists are now recognized as vital members of the treatment team involved in the care of elite athletes. The importance of proper nutrition to athletic performance is well accepted. However, many athletes use nutritional supplements that are not well proven with the intention of improving sports performance. The use of nutritional supplements in sport has been covered in depth in Chapter 3 of this text.
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Men
Women
Percentage
100 80 60
69.4 54.0
53.0 36.4
40
16.7 21.0
20
8.6
14.4
0 All CAM
Prayer
Natural products
Relaxation exercises
Figure 23.1 Percentage of adults aged ≥18 who used complementary and alternative medicine (CAM) for health reasons during the preceding 12 months, by gender in the US in 2002. (Modified from the National Center for Health Statistics.)
BODY-ORIENTED/MANUAL THERAPIES Box 23.1: Key Points ●
There are a number of different types of massage practices from classical methods such as Swedish massage to methods based on acupuncture theory such as shiatsu.
●
Massage has not proven effective for the treatment of delayed onset muscle soreness.
●
There is evidence in the literature that massage is safe, and may be a cost effective treatment for low back pain and other soft tissue injuries, however, better studies are needed within the athletic population.
Massage Massage is the manipulation of body tissues using rhythmically applied strokes with varying amounts of pressure and stretching. The classical or Swedish system of massage uses strokes such as effleurage, pétrissage, friction and tapotement. Effleurage is the deep or superficial stroking of the skin, which produces various therapeutic effects depending on the amount of pressure applied. Pétrissage, the lifting and kneading of the skin, stretches and separates the underlying muscle fibers and is thought to be helpful in breaking up underlying scar tissue. Friction, or deep tissue massage, involves the application of deep transverse or circular friction to a small area of tissue with the thumbs or fingertips in order to stimulate an inflammatory response and increase healing. Tapotement, also known as percussion, involves tapping or pounding of the skin to promote relaxation and desensitize nerve endings.5 There are many additional forms of massage therapy. Some of the more popular include myofascial release, a technique used to relieve hyperirritable foci within taut bands of skeletal muscle, known as myofascial trigger points; acupressure, which is based on Chinese acupuncture theory and involves the application of circular friction to acupuncture points; and shiatsu, a Japanese technique that also employs acupuncture principles.5 The purported positive effects of massage include increased blood flow in muscles, increased lymph flow, a relaxing effect on the central nervous system and loosening and prevention of
adherent scar tissue. Massage has also been used to increase flexibility and coordination; increase pain threshold; decrease neuromuscular excitability; stimulate circulation, thus improving energy transport to the muscle; restore joint range of motion; and to relieve post-exercise muscle soreness by removing lactic acid from tissues. Like many complementary therapies, the evidence regarding many of these purported effects of massage is lacking. The limitations of studying such a technique are numerous and include the wide variation in technique, experience of the practitioner, and frequency, timing, and duration of treatment used in the available studies, making comparison between studies difficult. Massage has been utilized for its therapeutic effects in the context of athletics since early civilization.6 The use of sports massage has remained popular, despite the above mentioned research difficulties. The treatment of delayed onset muscle soreness (DOMS) is among the most common uses of massage by athletes. Studies examining the effect of massage on DOMS have shown varying results. The proposed benefit of massage in the treatment of DOMS is felt to be due to increased blood flow to the injured area. However, studies examining the effect of massage on blood flow have been equivocal. Some researchers reported an increase in local blood flow during massage.7 Conversely, a study by Tiidus showed no difference in arterial or venous blood flow during effleurage of the quadriceps.8 However, reductions in serum CK levels have been noted in study participants who were massaged for 15 min or 30 min, both 2 h following exercise.9 Despite these encouraging results, other studies have found no differences in soreness levels or force deficits between the massaged or control limb with an 8-min massage following high intensity exercise.10 If some of the effects of massage can be explained by central mechanisms, the use of the contralateral limb as control in these studies could explain the negative findings. Massage is often used prior to sporting activities to enhance performance, although scientific evidence has not supported this use. No significant changes in VO2max, cardiac output, heart rate, blood pressure, or lactic acid levels were noted in studies of pre-exercise massage in 10 healthy men.11 Another study examined the effects of massage versus warm-up and stretching on joint range of motion. Warm-up and stretching significantly increased range-of-motion at all joints examined. Massage and warm-up, both separately and in combination, increased ankle range of motion only. It was concluded that warm-up and stretching were more effective than massage at increasing flexibility.6 Massage may also be used as part of a rehabilitation treatment plan after an injury has occurred. Athletic activities often require the repetitive use of one group of muscles more than others, which may result in strength imbalances and compensatory strain patterns in other areas of the body. Massage is often used to treat this kind of soft tissue dysfunction. Although it has not been studied specifically in athletes, some evidence has accumulated for the use of massage to treat non-specific low back pain. A randomized control trial comparing therapeutic massage, acupuncture and self-care education for persistent low back pain showed that massage was superior to self-care in terms of symptoms and disability reduction and superior to acupuncture in terms of disability reduction at 10 weeks. At 1 year, massage was no better than self-care but better than
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acupuncture. The massage group used the least medications and had the lowest cost of subsequent care.12 In a review of massage for low back pain, three randomized clinical trials were identified that reported effectiveness of massage for treating chronic or subacute low back pain.13 In clinical practice, the type, frequency and duration of massage will vary according to the goals of treatment. Massage given for the general purpose of relaxation or stimulation can be given as often as needed with durations ranging from several minutes to an hour. When performed for edema reduction, daily massage lasting 5–10 min is generally recommended. Likewise, friction massage should be performed on a daily basis for approximately 5 min. Caution should be used whenever massage is performed early after an injury, as it may potentiate the inflammatory response. Absolute contraindications to massage include deep venous thrombosis, malignancy, atherosclerotic plaque, unhealed fractures, and infection. Relative contraindications include anticoagulation, acute soft tissue injury and skin grafts.14
Acupuncture Box 23.2: Key Points ●
There is strong pathophysiological evidence in the literature that acupuncture can modulate pain, reduce inflammation, and promote tissue healing via central neuromodulatory and hormonal mechanisms.
●
The clinical evidence suggests that acupuncture is safe and may be helpful for the treatment of tendonitis of the elbow and shoulder, osteoarthritis of the knee, and hasten recovery from shoulder surgery. These studies need to be repeated in the athletic population.
Gallbladder
Governing vessel
Pericardium
309
Acupuncture is part of a complex system of health care, known as traditional Chinese medicine that has been practiced throughout Asia for at least 2000 years (Fig. 23.2). Interest in acupuncture in this country has been growing since the opening of China in the 1970s. Today, acupuncture is practiced to a great extent in this country by both physician and non-physician practitioners. A National Institutes of Health (NIH) consensus development panel that convened in 1997 found good evidence to support the use of acupuncture for postoperative and chemotherapy related nausea and vomiting, nausea of pregnancy, and postoperative dental pain.15 The panel also found evidence to support the use of acupuncture as an adjuvant treatment for addiction, stroke rehabilitation, headache, dysmenorrhea, lateral epicondylitis, fibromyalgia, low back pain, carpal tunnel syndrome and asthma. The use of acupuncture by athletes to treat acute injuries is very common in Asia and Eastern Europe and is increasingly becoming an option in many Western nations. International exposure came at the Winter Olympics in Japan in 1998 when an acupuncturist in Nagano offered treatments to Olympic athletes and officials, emphasizing that it is a drug-free way to treat injuries. The public was stunned by the near miraculous recovery of the Austrian, Hermann Maier in response to acupuncture. Maier won the gold medal in the giant slalom and super G, 3 days following a dramatic fall that occurred during the downhill competition. Maier attributed his quick recovery from shoulder and knee injuries sustained in that fall to his treatments with acupuncture. Over the last 30 years, a great deal of scientific evidence has accumulated to substantiate that acupuncture stimulation (AP) and electroacupuncture stimulation (EA) have physiological effects that strongly influence the neurohumoral systems that modulate pain. The evidence for the release of endogenous opioids with AP and EA goes back to the seminal work of
Urinary bladder
Heart
Stomach
Lung
13
11
9
7
5
3
1
14
12
10
8
6
4
2
Conception vessel
Liver
Figure 23.2 Acupuncture meridians.
Triple warmers
Kidney
Small intestine
Spleen
Large intestine
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Pomeranz in animals and Mayer in humans in the early 1970s.16,17 We now know that acupuncture causes the release of endorphins and enkephalins in the CNS and that these neuropeptides play a significant role in its analgesic efficacy. There is growing evidence that the descending inhibitory control system also plays a role in acupuncture analgesia. This involves the activation of serotonergic neurons in the midbrain that in turn act to inhibit the transmission of nociceptive information at the level of the dorsal horn (Fig. 23.3). Release of 5-hydroxytryptamine (5-HTP) in the raphe nucleus of the midbrain has been shown with both EA and AP, and acupuncture analgesia is attenuated with the injection of a serotonin antagonist such as parachlorophenylalanine.18 Acupuncture has been shown in animal models to strongly influence the pituitary-hypothalamic system as well. The arcuate nucleus of the ventromedial hypothalamus contains the β-endorphin-producing cells and lesions of this nucleus abolish acupuncture analgesia in rats. 18 The hypothalamus secretes β-endorphin into the bloodstream, consistent with the elevated blood levels of endorphin found with both AP and EA. Concurrent with the release of β-endorphin is the secretion of adrenocorticotrophic hormone (ACTH) with acupuncture, which in turn stimulates adrenal secretion of cortisol causing a general anti-inflammatory effect.19 Given that peripheral opioid receptors have been found to be present on C-fibers in inflammatory conditions,20 the elevation of systemic beta-endorphin with acupuncture may exert both an analgesic and an anti-inflammatory effect in sports injuries. Recent studies indicate that acupuncture also influences the release of immune modulating cytokines from the hypothalamus such as interleukin 1B and 6 during experimental models of fever.21 The rise of blood β-endorphin with acupuncture also influences peripheral cytokine production in the spleen by
PAG
B
Substantia C D
Dorsal horn
Raphe
A
Figure 23.3 Schematic of pain transmission and modulation in CNS: (A) Nociceptive input into the dorsal horn. (B) Ascending pain pathway via the spinothalamic tract with synapse in the peri aqueductal grey area (PAG) in mesencephalon. (C) Descending, excitatory pathway to raphe magnus in rostral medulla. (D) Serotonergic descending pain modulating tract has inhibitory action on Dorsal horn.
causing increases in interferon-gamma and reduction of natural killer cell activity.22 These early data suggest that acupuncture has physiological effects that go far beyond the release of endorphins in the CNS, and has important immune-modulating effects that may prove to be important in the recovery from injury. The use of acupuncture for acute injuries has not been studied extensively in athletes. However, a study of rotator cuff tendonitis in subjects with sports-related injuries found that true acupuncture needling was significantly superior when looking at both its analgesic effects as well as strength, range of motion and functional scores when compared with a placebo needling group. Treatment consisted of using a combination of points in the hands and feet, based on Chinese acupuncture principles, together with meridian-based local points around the shoulder based on tenderness. Subjects received two 22-min treatments/week for 4 weeks and had follow-up assessments at the end of the treatment period and again at 4 months.23 Another study has shown that acupuncture hastens recovery from arthroscopic acromioplasty performed for impingement syndrome. Subjects in this study were randomized to treatment with either real or sham acupuncture beginning 3–8 days following arthroscopic acromioplasty. Subjects in the real acupuncture group had significantly lower pain intensity scales, less analgesic use, and improved range of motion for abduction than the sham acupuncture group at all follow-up visits through the four month follow-up period.24 There is also strong evidence to suggest that acupuncture is effective in short-term relief of lateral epicondyle pain. Haker and Lundeberg randomized 86 patients to receive either real or sham acupuncture treatments for lateral epicondylitis. Patients underwent 10 treatment sessions. At initial follow-up, the real acupuncture group had significantly less pain complaints than the sham group. However, these differences did not remain significant at either 3-month or 1-year follow-up.25 In a separate study, 48 patients with lateral epicondylitis were also randomized to real versus sham acupuncture treatments. A single 20 min treatment was given using only one point near the fibular head (gallbladder 34) on the leg ipsilateral to the elbow pain. The treatment group had significantly greater acute pain relief following this treatment.26 Acupuncture has also shown some efficacy in the treatment of knee osteoarthritis (OA). The risk for knee OA is elevated in athletes with histories of knee injuries, such as those commonly incurred in American football and soccer. One of the most thorough systematic reviews of acupuncture examined its efficacy in knee OA. A major strength of this review was that it rated seven different clinical trials on how closely they conformed to guidelines put forth by acupuncture experts. These guidelines included (1) an average of 10 treatment sessions for a chronic condition, (2) stimulation of at least eight points per session, (3) elicitation of the De Qi sensation, and (4) use of a combination of high and low frequency stimulation, when used, to avoid accommodation to the impulse.27 The meta-analysis found four of the seven studies to have a positive effect on pain and three of the seven studies were neutral.28 None of these studies followed all four treatment guidelines. However, the most important of these
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Chiropractic care is utilized by a high percentage of athletes both in professional sports such as American football and baseball and in the international Olympic arena.
●
Safety is generally good, although high velocity manipulation especially in the cervical region can cause serious neurological complications; anywhere from 1 in 100 000 to 1 in 1 million cases.
●
The current clinical literature has focused on the use of chiropractic care for spine-related pain and suggests that it may provide shortterm benefit for subacute low back pain.
●
More evidence is needed to assess efficacy in athletic populations.
Chiropractic medicine is a drug-free, non-surgical branch of healthcare that considers humans as integrated beings and gives special attention to structural, spinal, musculoskeletal, neurological, vascular, nutritional, emotional and environmental relationships (Fig. 23.4). The practice and procedures of chiropractic medicine are based on academic and clinical train-
al
●
mic
Box 23.3: Key Points
HUMAN BEING
he
Chiropractic
311
-c Bio
guidelines is felt to be treatment duration for a chronic condition, such as knee OA. The three studies that administered the minimum of 10 treatments all had positive results. Supporting the importance of treatment length, a recent large NIH supported randomized controlled trial assessed the effect of acupuncture as an adjuvant treatment for knee OA. This trial compared 24 acupuncture sessions over 26 weeks with sham acupuncture or arthritis education in 570 patients with osteoarthritis of the knee. Acupuncture led to greater improvements in function but not pain after 8 weeks and in both pain and function after 26 weeks. No adverse effects were associated with acupuncture.29 Of all the pain related conditions, back pain is the most frequently studied using acupuncture as an intervention. In a meta-analysis of randomized controlled trials of acupuncture for low back pain, it was concluded that acupuncture is superior to the various control treatments, but insufficient evidence was available to state whether it was better than placebo needling methods.27 In conclusion, acupuncture appears to be a safe and potentially effective method of treating the pain and inflammation of sports-related injuries. There is sufficient evidence to suggest a physiological mechanism of action that involves neurohumoral processes that have both a central and peripheral effect. Clearly, better designed and more specific studies are needed to assess the clinical efficacy of acupuncture in various sports injuries. In addition, there is much interest in the effects that acupunctu