Medical aspects of sports: epidemiology of injuries, preparticipation physical examination, and drugs in sports

Clin Sports Med 23 (2004) 255 – 279

Medical aspects of sports: epidemiology of injuries, preparticipation physical examination, and drugs in sports Thomas D. Armsey, Robert G. Hosey Sports medicine as a discipline is a relative newcomer to the medical profession. As the worldwide interest in sports has boomed this past century, it seems natural that a specific niche in the medical world has evolved to provide specialized care for athletes. This branch of the medical community includes a wide range of health care professionals, including orthopaedists, primary care physicians, athletic trainers, physical therapists, and dentists, to name a few. The medical aspects of sports medicine encompass a wide spectrum of topics, including the diagnosis, management, and prevention of illness and injury in an athletic population. As can be imagined, this summarizes a rather expansive list of disease processes, from neurological injuries such as concussions to musculoskeletal injuries to the use of ergogenic aids. This chapter focuses on three rather broad topics that constitute a cornerstone of the practice of sports medicine. Specifically, we examine the epidemiology of sports injuries, the preparticipation physical examination, and the use of drugs in sports.

Epidemiology of sports injuries In the medical literature, epidemiology is the study of the distribution and determinants of disease. [1] In sports medicine, most epidemiological studies regard acute and chronic injuries as ‘‘disease,’’ and the results have broadened our current knowledge in many ways. Specifically, these studies have helped identify causes of injuries, determined the effectiveness of preventative measures, quantified the risks of various sport activities, and identified long-term injury

This article is from: Armsey TD, Hosey RG. Medical aspects of sprots: epidemiology of injuries, preparticipation physical examination, and drugs in sports. In: Fitzgerald RH, Kaufer H, Malkani AL, editors. Orthopaedics. St. Louis: Mosby; 2002; with permission. 0278-5919/04/$ – see front matter D 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.csm.2004.04.007

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trends in sport. [2] With these data, improved management and treatment plans for common injuries can be developed, and proactive measures can be designed to prevent common and catastrophic injuries to this population. The injuries sustained in athletics are widely varied but commonly delineated into two distinct categories: acute traumatic injuries (‘‘macrotrauma’’) and insidious overuse injuries (‘‘microtrauma’’). As one would imagine, the proportion of injuries in each of these categories is dependent mainly on the sport in question. For example, in contact sports, such as football, there is a higher proportion of acute traumatic injuries, whereas in noncontact sports, such as track and field, there is a higher proportion of overuse injuries. Although these types of injuries are inherently different, they both result in debilitation of an athlete’s performance and are therefore considered significant by most epidemiological studies. Injury definition and reporting The current epidemiological data are limited by the lack of a standardized nomenclature among studies. Because the published studies have reported data with different denominators, different definitions of injury, and different selection criteria, each study must be viewed as a separate case report, making it impossible to generalize the results on a broader scale. To remedy this, an attempt is being made to provide all injury data as case rates per 1000 athlete-exposure. An ‘‘athlete-exposure’’ is defined as one athlete’s participation in one practice or game in which there is a possibility of sustaining an athletic injury. The current definition of a ‘‘reportable injury’’ is still under question but should include all of the following to allow valid comparison: (1) the injury occurs in a scheduled practice or game; (2) the injury requires medical attention; and (3) the injury results in restriction or exclusion of the athlete from the remaining practice or competition or the following 1 or more days. [3] Currently, several computer software companies are promoting standardized reporting systems, using this standardized nomenclature, which may provide insight into the causes of injuries that can be confirmed by consistent results from numerous investigators. To date, most studies involving athletic injuries are reported as a cumulative incidence of injury. This is the number of injuries among a specific group of athletes (i.e., ‘‘team’’) followed for a defined period of time (i.e., ‘‘season’’). Although there are inherent problems with these data, the following discussion reports these data unless otherwise noted. Injuries are classified as ‘‘mild’’ if the athlete was out of competition for less than 7 days, or ‘‘significant’’ if the athlete was disabled for 7 days or more. As mentioned previously, good data are not always available, but the most consistent data from well designed studies are reported. Although sports medicine is a relatively new field, epidemiological data have already made an impact. Based on the literature to date, athletics has evolved into a less dangerous activity. This is most evident in football, in which drastic equipment improvements, such as improved helmet strength and face-masks, are now standard in hopes of decreasing brain and facial injuries. Rule changes, including

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the banning of ‘‘spear tackling’’ and ‘‘chop blocking’’ have occurred as a means to decrease cervical spine and knee injuries. The current debate is whether artificial turf is a predisposing factor for injuries and if so, this too may be eradicated in the name of medical science. But football is not the only sport that is evolving. Similar efforts are being made in other sports to create a ‘‘safer enviroment.’’ It will be the current and future epidemiological data that will continue to identify high-risk activities and provide the impetus for change. Unfortunately, all physical activity has an inherent risk of injury. According to the 1992 National Institute of Health report, there are approximately 3 million injuries annually in the United States that are directly related to organized sports. Of these, approximately 770,000 require physician visits and up to 90,000 require hospitalization. [4] In 1996, an estimated $1.3 billion was spent for acute management of these athletes. [5] If these injuries were cataloged as diseases, these figures would be unacceptable to the general public and the medical community. But, because of the incredible popularity of athletes and athletics, most individuals blindly accept injuries as a risk of participation. This may not necessarily be the case, and it is imperative that objective data be generated to determine factors that may potentially improve the injury rates in competitive and recreational sporting activities. As previously mentioned, all sports have an inherent risk of injury. But which sport is the most dangerous? Overwhelmingly, football has the highest rate of reportable injuries among all organized sports, with injuries occurring in up to 81% of participants per year. [6,7] Football also has the distinction of leading all sports in the absolute number of catastrophic injuries and fatalities in the United States. Over a 6-year period (1982 –1988), 187 high school athletes and 50 collegiate athletes were catastrophically injured and 73 of these injuries were fatal. [8] Although impressive on paper, these numbers do not adequately reflect the injury rates among different sports, unless reported in a standard unit. In the case of catastrophic injury and fatalities, when calculated as a rate per 100,000 participants per year, football was surpassed by both ice hockey and gymnastics. Furthermore, if the incidence of injury in football were reported as a percentage of the 1.8 million participants in the United States annual injury rates as low as 35.2% have resulted. It is therefore obvious that most of the current epidemiological data suffer from poor generalizability, and any interstudy comparisons must be critically analyzed for valid conclusions. Injury rates and severity Two well-designed studies have reported injury rates that allow broad comparisons among many different sports. In an extensive study by Rice, [3] 18 intercollegiate sports were prospectively studied and the results reported so that comparisons between each sport are valid. According to Rice, female crosscountry running has the highest injury rate per 1000 athlete-exposures (15.9), followed by wrestling (12.8), female soccer (12.6), football (12.2), and female gymnastics (10.2). From these data, it is apparent that several sports have a

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disproportionately higher rate of injuries compared with other sports. Except for some minor differences, these conclusions are consistent with the National Collegiate Athletic Association (NCAA) injury reports. [9] In these reports, spring football was found to have the highest rate of injury per 1000 athlete-exposures (9.8), followed by wrestling (9.6), female gymnastics (9.3), and female soccer (8.6). These two independent studies correlate very well and should prompt further investigations into the reasons that a disproportionate number of athletes are being injured during participation in these sports. As well as describing the number of injuries in sports, epidemiological studies also describe the severity of the injury. Although there are numerous ways to describe the severity of injury in sport, the most common method is reporting severity as a function of time lost from participation. ‘‘Mild’’ is anecdotally used to describe injuries from which it takes less than 7 days for the athlete to return to participation, versus ‘‘severe’’ injuries, from which it takes the athlete more than 7 days to return to sport. When the NCAA analyzed its most current data, [9] it was reported that spring football resulted in the highest percentage of severe injuries. In spring football, 43% of all injuries result in the athletes taking more than 7 days to return to sport. This translates into an injury rate of 4.1 severe injuries per 1000 athlete-exposures. Another means of categorizing injuries as severe is if the injury requires surgical intervention. When reported as such, female gymnastics had the highest percentage of severe injuries, with 8.9% of all surgery-requiring injuries occurring to female gymnasts. Furthermore, female gymnasts have the highest rate of surgery-requiring injuries per 1000 athlete-exposures. The rate is estimated at 0.84 injuries that will require surgery for every 1000 athlete-exposures. This certainly shows that spring football and female gymnastics are high-risk activities that may need to be modified to enhance their safety. The most apparent means to decrease the rates of severe injuries in these sports would be to decrease the number of athleteexposures. Recently, the NCAA has addressed this issue in spring football by decreasing the contact days allowed, and future data will determine whether this modification will significantly decrease the rate of severe injuries occurring in this select population. Injury demographics Characteristic injuries in different sports have been objectively documented by epidemiological studies. Retrospective analysis consistently reports that the knee is the most common site of injury in the sport of football. Of these knee injuries, the medial collateral ligament is the most common structure involved. [10] Few other sports have the amount of data available to make valid conclusions, but certainly trends can be observed. Eighty-four percent of the injuries in soccer involve the lower extremity, with ankle sprains being the most common. [11] In a 12-year prospective study of high school athletes participating in 32 different sports, the knee and ankle were the most common sites of injury in both men and women. [12] When reported as a percentage of all injuries sustained by in-

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tercollegiate athletes, the knee is injured about 25% of the time, making it the most common site of injury. [13] Halpern et al [14] reported similar results in high school athletes, noting that 25% of all injuries in this population occurred about the knee and ankle, and that these injuries accounted for 33% of all medical costs. Therefore, any modifications that could decrease the number of knee and ankle injuries in high school and collegiate athletics would have a profound impact on the health of millions of athletes. Several confounding variables have been recognized in these studies that need to be addressed. First is the level of play, which may influence the injury incidence and patterns. In a large population of Danish soccer players, it was found that the more experienced athletes suffered fewer injuries than the less experienced athletes, with incidence rates of 11.9 versus 18.9 injuries per 1000 athlete exposures. It was also reported that the elite athletes suffered most injuries during competition, whereas the more novice players sustained most injuries during practice. [15] Age and gender of the athlete may also affect injury incidence. In a 7-year prospective study, it was found that males were most likely to sustain an injury during athletic activity between the ages of 10 to 19, whereas females suffered most injuries between 20 and 29 years of age. [11] It seems that the most likely explanation of these results is that more experienced athletes have superior body control and therefore put themselves at risk for injury less than novice athletes. Anecdotally, boys spend more time playing sports at a younger age than females, and therefore succumb to injury at a higher rate as teenagers simply because of increased exposure. But, because of this increased exposure, the males may gain more proprioceptive skills necessary to prevent injuries as they mature, making the rates decrease as they age. If this theory is true, then as females continue to participate in competitive athletics at earlier ages, their injury rates should begin to mirror those of males. Therefore, it remains to be seen whether gender has any intrinsic effect on injury rates in sporting activities. Conclusion Although this type of data is useful in preparticipation counseling with parents and athletes, the ultimate goal should be to reduce the risk of injury. With the current data, this is quite a difficult task. Therefore, future epidemiological studies must standardize research design, data collection, definitions and terminology, and reporting systems.

Preparticipation physical examination The preparticipation physical examination (PPE) has become an annual undertaking in the sports medicine community. Most sports medicine physicians know all too well the countless hours of preparation, examination, and paper work required to get athletes ‘‘cleared’’ to participate in the upcoming season. At last count there were approximately 6 million high school athletes and over

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300,000 collegiate athletes participating in some form of organized sport. [16,17] Most if not all of these athletes were required to a have a PPE before engaging in athletic activity. At the high school level, 50 out of 51 (District of Columbia included) interscholastic sports governing bodies require athletes to have some form of a medical evaluation before they can participate in high school sports. [18] Many states have also made the PPE a legal requirement for athletes at the high school level. [19] This means millions of athletes each year are required to undergo a PPE. For approximately the past 30 years, the PPE has played a role in the evaluation of prospective athletes. At the outset, this may have entailed only a brief visit to the physician’s office concluded with a cursory examination and the mandatory heart and hernia check. All that has changed. The PPE has evolved in part because of increased legal pressure, greater public awareness and interest in athletic injuries, and the development of sports medicine organizations. The year 1992 saw the development of a standardized PPE, through the combined effort of the American Academy of Family Physicians, American Academy of Pediatrics, American Medical Society for Sports Medicine, and the American Orthopedic Society for Sports Medicine. This monograph was updated in 1996 and provides a template for the preparticipation history and physical examination. [20] Although these documents have been widely accepted and used, a standardized PPE has not been adopted on the national level. Objectives of the preparticipation physical examination As sports medicine physicians, one of our roles is to encourage safe activity for all individuals. Similarly, the major goal of the PPE is to ensure the health and safety of athletes participating in organized sports (to the best of our capabilities). [21,22] To this extent, the PPE examination should accomplish several objectives.








Detection of any underlying condition that would restrict athletic participation. Identification and evaluation of potential problems (including previous injuries) Injury prevention evaluation Fulfillment of legal and insurance requirements Establishing physician rapport with athletes Providing counseling to athletes Establishing a database and record-keeping system

Detection of medical problems such as a heart murmur that increases in intensity with Valsalva maneuver or in the standing position (suggestive of hypertrophic cardiomyopathy) is an example of an underlying condition that would restrict participation. Potential problems that may be elucidated during the

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PPE include pre-existing musculoskeletal injuries that have not been completely rehabilitated, congenital anomalies (alantoaxial instability in Down’s syndrome patients), and an overall low level of fitness that may be seen in obese individuals. Injury prevention includes assessment of the student’s level of maturity. Individuals with delayed growth and physical maturity may be at increased risk of injury participating in collision sports. In addition to assessing the physical health of students, the PPE also satisfies any legal or insurance requirements as mandated by a scholastic institution or the state government. Beyond the practical aspects of the PPE, this time spent with the athlete is important in developing a trusting relationship with the athlete. This in turn may increase the likelihood of the athlete’s discussing an injury or illness with the physician. It may also allow the physician to note changes in behavior in athletes dealing with such struggles as eating disorders or symptoms that can accompany a post-concussive state. Knowing that the PPE may be the only time all year that the athlete sees a physician, some physicians have argued that the PPE is the optimal time to counsel individuals and perform a general health maintenance examination. Topics such as smoking, alcohol and drug use, seat belt use, and violence can be addressed. This may also be an opportune time to teach adolescents self-breast and self-testicular examination. While these efforts should be applauded, the PPE is not meant to take the place of a yearly health maintenance examination performed by the individual’s primary care physician. Another purpose of the PPE is to establish a database and record keeping system. Ideally, each athlete should have a chart maintained in the training room that contains his or her PPE form, consent for emergency treatment, and emergency contact information. These charts could also be used to house injury report forms and subsequent treatment regimens. This system allows tracking of individual injuries and can be maintained throughout the student’s academic career. Injury tracking systems, once established, also provide the framework for possible future research endeavors. Format, timing, and frequency of the preparticipation examination As the PPE has evolved, so has the format and the setting in which the examinations are performed. Traditionally, a single physician would be responsible for conducting individual examinations for a large number of athletes, either on an individual basis or through a mass screening. Mass screenings may encounter several problems. They often take place in the school gymnasium or the locker room, where lack of privacy is an issue. Physician burnout is a strong possibility as well. As an alternative, the concept of the sports medicine team approach using PPE stations has come into favor. [23,24] The team approach includes participation from the athletic training staff, team orthopaedists, and team medical staff, thus allowing the work to be broken up among all the staff. This group effort also fosters a line of communication between the members of the sports medicine team. In a group PPE using a station set-up, the athletes progress through a series of approximately six stations where the full examination

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Fig. 1. Station format for performing the preparticipation examination. This schematic depicts a blueprint for setting up stations for performing a large volume of preparticipation examinations. The number and type of staffing members at each station will depend on the number of expected athletes to be screened. Physician staff members should be located at stations 4 through 6 with the head team physician at station 6.

is performed in a piece-work fashion. This approach facilitates screening of a large number of people in a relatively efficient manner. (A sample of how the stations may be arranged is shown in Fig. 1). The frequency at which the PPE should be performed has met with varying opinions. One thought is that a full PPE should be performed every 3 to 4 years with interim updating of the athlete’s medical history on a yearly basis. [25] The NCAA has endorsed a similar approach, requiring a PPE only on the athlete’s initial entrance into college and recommending yearly follow-up. [26] At the time of follow-up, a focused examination can be conducted, directed by any problems divulged in the interim history. Many states and universities, however, require an annual physical examination for high school and collegiate athletes. [27] As a general rule of thumb, the PPE should be conducted 4 to 6 weeks before the start of the athletic season. This time lag allows time for follow-up on abnormal findings and rehabilitation of any injuries. [22,28] Preparticipation history and examination A comprehensive medical history is an essential part of the PPE. In fact, most conditions that restrict athletic participation are identified in the history portion of the PPE. [29] The history should divulge previous disease processes, injuries, surgeries, and possible cardiovascular problems. The history portion of PPE should be completed with the help of the athlete’s parents in school-aged individuals to provide the most accurate information. The physician may then review this sheet and investigate any potential problems. The examination focuses on the musculoskeletal and cardiovascular systems and can be further

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directed by any abnormalities uncovered during the history. A standardized history and physical examination form has been developed and gained wide acceptance in the sports medicine community (Figs. 2 and 3.) Although the physical examination is not limited to the musculoskeletal and cardiovascular systems, these certainly are the focal points in asymptomatic individuals with an unremarkable medical history. The musculoskeletal screening examination can generally be accomplished in a short period of time using the 90-second orthopaedic screening examination. [20] This screening examination consists of observing the athlete perform a series of maneuvers and assessing overall musculoskeletal health. Starting at the top, the athlete is asked to 1. Look up, side to side, and down, touch ears to shoulders (cervical spine range of motion). 2. Shrug shoulders against resistance, adduct shoulders to 90 degrees (hold against resistance), followed by internal and external rotation of shoulders at 90 degrees (trapezius and deltoid strength, shoulder range of motion). 3. Flex and extend elbows, pronate and supinate with elbows flexed to 90 degrees with arms at side (elbow and wrist range of motion). 4. Spread fingers apart, make a fist (hand function, any rotational deformities). 5. Contract and relax quadriceps muscles (knee symmetry, patellar function, quadriceps mechanism). 6. Duck-walk away from and toward examiner (hip, knee, and ankle function). 7. Touch toes with legs straight (scoliosis evaluation, hamstring flexibility). 8. Stand on toes, stand on heels (leg and foot strength, calf symmetry). Any abnormalities of motion or maneuvers that elicit pain should prompt further focused examination. This examination serves as a good screening tool when doing mass screening PPEs, but it may not be sufficient for all populations of athletes (e.g., professional athletes). In addition to assessing cardiovascular health, the cardiovascular history and examination is aimed at identifying individuals who may be at increased risk of sudden cardiac death. In the United States, the leading causes of sudden cardiac death in high school and collegiate athletes are hypertrophic cardiomyopathy, coronary artery anomalies, myocarditis, and aortic stenosis. [30] Athletes with a history of exercise-related chest discomfort, syncope or near syncope, unexplained shortness of breath or fatigue, a past history of a heart murmur, or a family history of premature death should raise the suspicion of a potential problem. The American Heart Association’s (AHA) scientific statement on cardiovascular preparticipation screening of competitive athletes recommends Fig. 2. (A,B) Preparticipation medical history. This is the sample form to be used for obtaining the preparticipation medical history. (From Leawood KS. American Academy of Family Physicians, American Academy of Pediatrics, American Medical Society for Sports Medicine, American Orthopaedic Society for Sports Medicine, American Osteopathic Academy of Sports Medicine, 1992, 1996.)

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Fig. 3. Preparticipation physical examination. This is the sample form to be used for recording the physical evaluation part of the preparticipation examination. (From Leawood KS: American Academy of Family Physicians, American Academy of Pediatrics, American Medical Society for Sports Medicine, American Orthopaedic Society for Sports Medicine, American Osteopathic Academy of Sports Medicine, 1992, 1996.)

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that cardiac evaluation include (but not be limited to) (1) precordial auscultation in both the standing and supine position, (2) assessment of the femoral pulses to exclude coarctation of the aorta, (3) brachial blood pressure measured in the seated position, and (4) evaluation for physical signs of Marfan’s syndrome. [31] Detection of a cardiac murmur that is a grade III/VI or louder, a diastolic murmur, or a murmur that increases in intensity with Valsalva maneuver or in the standing position should prompt further evaluation by a cardiologist. Likewise, athletes with blood pressures greater than 135/85 need further follow-up with repeated blood pressure measurements. At this point in time, further cardiovascular screening with either electrocardiogram or echocardiogram is not cost efficient on a large-scale basis. [31,32] The remainder of the physical examination may be used to focus on any complaints noted in the history but also should include examination of the head, ears, eyes, nose, and throat structures, pulmonary examination and abdominal examination including a hernia check. A general assessment of the young athlete’s physical maturity should be noted, and testicular examination performed on collegiate males. Additional testing that may be conducted during the PPE includes measurement of flexibility and percentage of body fat. Although these may provide useful information, they are time and staff intensive. Determination of clearance Determination of clearance status is arguably the most important purpose of the PPE. The physician’s role is to make a decision regarding clearance based on the safety of the athlete and other participants who may come into contact with the athlete. To this extent, several questions must be answered. Does the athlete’s condition put himself or herself, teammates, or competitors at increased risk of injury or illness? Is treatment available for the athlete’s condition that will allow him or her to participate after treatment or once treatment is initiated? Is there protective gear that would allow the athlete to participate safely? Can the athlete participate on a limited basis? Is there an alternative sport that the athlete can participate in safely? Based on the answers to these questions the athlete may be (1) cleared without restriction, (2) cleared after completing further evaluation or rehabilitation for a specific injury or illness, or (3) not cleared for participation (in a particular sport). If the athlete is not cleared, the reasoning leading to that decision should be discussed with the individual, the coaching and training staff, and, for school-aged athletes, the individual’s parents. Often a conference involving all of these parties and the physician allows for the best exchange of information. Disqualifying conditions Certain medical conditions warrant restriction from specific types of sports. However, most of these disqualifying conditions do allow for participation in some form of athletic activity. For example, an athlete with a poorly controlled seizure disorder should not be allowed to participate in contact sports, whereas it

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would be appropriate to allow participation in certain noncontact sports. The American Academy of Pediatrics Committee on Sports Medicine classified individual sports based on the amount of contact and level of strenuousness Tables 1– 3. [33] In addition, a list of potential disqualifying conditions based on these parameters has been generated and may assist team physicians in determining clearance. [20] Athletes with cardiovascular abnormalities present a complex Table 1 Classification of sports by contact Contact or collision

Limited contact

Noncontact

Basketball Boxing* Diving Field hockey Football Tackle Ice hockeyy Lacrosse Martial arts Rodeo Rugby Ski jumping Soccer Team handball Water polo Wrestling

Baseball Bicycling Cheerleading Canoeing or kayaking (white water) Fencing Field events High jump Pole vault Floor hockey Football Flag Gymnastics Handball Horseback riding Racquetball Skating Ice In-line Roller Skiing Cross-country Downhill Water Skateboarding Snowboardingz Softball Squash Ultimate frisbee Volleyball Windsurfing or surfing

Archery Badminton Body building Bowling Canoeing or kayaking (flat water) Crew or rowing Curling Dancingx Ballet Modern Jazz Field events Discus Javelin Shot put Golf Orienteeringk Power lifting Race walking Riflery Rope jumping Running Sailing Scuba diving Swimming Table tennis Tennis Track Weight lifting

* Participation not recommended by the American Academy of Pediatrics. y The American Academy of Pediatrics recommends limiting the amount of body checking allowed for hockey players 15 years and younger to reduce injuries [2]. z Snowboarding has been added since previous statement was published [1]. x Dancing has been further classified into ballet, modern, and jazz since previous statement was published [1]. k A race (contest) in which competitors use a map and compass to find their way through unfamiliar territory. From American Academy of Pediatrics Committee on Sports Medicine. Recommendations for participation in competitive sports. Pediatrics 1988;81:737.

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Table 2 Medical conditions and sports participation* 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 disorder 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 power lifting, 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 [3] defined significant and severe hypertension. 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 [4] defined mild, moderate, and severe disease for common cardiac lesions. 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 [5]. Heart murmur Explanation: If the murmur is innocent (does not indicate heart disease), full participation is permitted. Otherwise, the athlete needs evaluation (see congenital heart disease and mitral valve prolapse) [5]. Cerebral palsy 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 minutes during continuous exercise and 15 minutes 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. Eating disorders Anorexia nervosa Bulimia nervosa Explanation: Patients with these disorders need medical and psychiatric assessment before participation.

Qualified yes

Qualified yes

No Qualified yes

Qualified yes

Qualified yes

Qualified yes

Qualified yes Yes

Qualified no

Qualified yes

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Table 2 (continued ) Condition

May participate

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 [6,7]. 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 [8]. Human immunodeficiency virus infection 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 [8]. 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 neoplasm Explanation: Athlete needs individual assessment. Musculoskeletal disorders Explanation: Athlete needs individual assessment.

Qualified yes

No

Qualified yes

Yes

Yes

Qualified yes

Qualified yes

Qualified yes Qualified yes

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Table 2 (continued ) Condition

May participate

Neurologic disorders History of serious head or spine trauma, severe or repeated concussions, or crainotomy [9,10]. Explanation: Athlete needs individual assessment for collision, contact, or limited-contact sports and also for noncontact sports if deficits in judgment or cognition are present. Research supports a conservative approach to management of conclusion [9,10]. 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 noncontact sports should be avoided: archery, riflery, swimming, weight or power lifting, 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 heat illness, obese persons need careful acclimatization and hydration. Organ transplant recipient Explanation: Athlete needs individual assessment. Ovary, absence of one Explanation: Risk of severe injury to the 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. 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 [11]. These persons, like all athletes, should be carefully conditioned, acclimatized, and hydrated to reduce any possible risk.

Qualified yes

Yes Qualified yes

Qualified yes

Qualified yes Yes

Qualified yes

Yes

Qualified yes

Qualified yes

Yes

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Table 2 (continued ) Condition

May participate

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

Yes

* This table is designed for use by medical and nonmedical 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 of the severity of the disease, the risk of injury for the specific sports listed in Table 1, or both. From Academy of Pediatrics Committee on Sports Medicine. Recommendations for participation in competitive sports. Pediatrics 1988;88:737.

Table 3 Classification of sports by strenuousness High to moderate intensity High to moderate dynamic and static demands

High to moderate dynamic and low static demands

High to moderate static and low dynamic demands

Boxing* Crew or rowing Cross-country skiing Cycling Downhill skiing Fencing Football Ice hockey Rugby Running (sprint) Speed skating Water polo Wrestling

Badminton Baseball Basketball Field hockey Lacrosse Orienteering Race walking Racquetball Soccer Squash Swimming Table tennis Tennis Volleyball

Archery Auto racing Diving Horseback riding (jumping) Field events (throwing) Gymnastics Karate or judo Motorcycling Rodeo Sailing Ski jumping Water skiing Weight lifting

Low intensity (Low dynamic and low static demands) Bowling Cricket Curling Golf Riflery * Participation not recommended by the American Academy of Pediatrics.

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situation regarding medical clearance. In 1994, a multidisciplinary task force developed guidelines that were based on the most up-to-date scientific data as well as years of anecdotal experience. [34] Although these guidelines are helpful in determining eligibility, each athlete’s case should be considered individually. This year, many athletes will be cleared to play sports with conditions that were once considered disqualifying. For example, an athlete with Marfan’s disease may be cleared to participate in highly strenuous sports by an experienced team physician who is comfortable that the athlete understands the risks involved and agrees to serial cardiac, opthomalogical, and musculoskeletal evaluations. Furthermore, in these types of situations it is a good idea to obtain written consent or a legal waiver to be signed by the athlete and parent (if the athlete is a minor). The legal counsel for any academic institution may provide useful information regarding legal issues related to athletic participation or disqualification. The PPE is an opportune time to address the issue of supplement or drug use in the athlete. Education regarding the potential side effects or legal ramifications may also be discussed. Use of prescription and over-the-counter medications should also be reviewed, as many of these medications appear on the ‘‘banned’’ list and require a physician’s note for approved usage. A more detailed account of commonly used performance-enhancing drugs is covered in the next section.

Drugs in sports In 1968, formal drug testing was adopted for the Summer and Winter Olympics in an attempt to maintain the integrity of sports by enforcing compliance with the ‘‘banned-substance list.’’ Banned substances are ergogenic in nature and used with the sole intention of increasing in an artificial and unfair manner the athlete’s performance in competition. Since the commencement of testing by the International Olympic Committee (IOC), numerous elite athletes have been sanctioned for ‘‘doping’’ and subjected to the predetermined penalties. In 1986, after the highly publicized cocaine-related death of a collegiate student-athlete, the NCAA adopted drug testing. Currently, every major sports governing body has adopted a plan to combat drug use among its athletes. But, owing to the lack of uniformity in banned substances across sports, it is essential for every team physician to prescribe and council athletes according to each governing body’s specified regulations. Banned substances Generally, banned substances fall into several categories: stimulants, narcotics, anabolic steroids, beta-blockers, diuretics, and growth hormones. Certain restrictions are in place for other medications, including alcohol, local anesthetics, corticosteroids, and beta-agonists. For a complete listing of the NCAA and United States Olympic Committee (USOC) banned and restricted drug list, refer to the Athletic Drug Reference ’99. [35]

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Nutritional supplements Recently, athletes have attempted to gain a competitive edge through over-thecounter ‘‘natural’’ preparations, known as nutritional supplements. As defined, nutritional supplements are any foodstuff or dietary procedure that either improves or is thought to improve ones’ health (dietary aids) or physical performance (ergogenic aids). Because of this nebulous definition, nutritional supplements fall outside of the Food and Drug Administration’s umbrella of jurisdiction and are therefore largely unregulated. Because of the lack of federal regulation, the manufacturers of these compounds may advertise unsubstantiated claims as to their effectiveness. In the United States, more than 12 billion dollars was spent on supplements in 1997 and an estimated 15 billion dollars in 1999. [36] Because of the obvious popularity of these substances and the potential effects on one’s health, it is essential for allopathic physicians to be knowledgeable in this arena. Therefore, to counsel potential consumers, physicians must be adequately educated to the risks and benefits of these nutritional supplements. It is important to remember that competitive athletes must scrutinize all overthe-counter supplements for any substances that may be banned by their governing bodies. Since the USOC (1983) and the NCAA (1986) began random drug testing, many athletes have claimed that an over-the-counter supplement caused them to test ‘‘positive’’ for banned substances. This may well be the truth, since various preparations do contain chemicals that are prohibited by the USOC and the NCAA. Creatine Creatine (methylguanide-acetic acid) is an amino acid identified in 1835 by Chevreul. It is naturally synthesized in the human liver, pancreas, and kidneys and is available from a normal diet in meats and fish. [37] In 1993, creatine monohydrate was introduced to the American public as a ‘‘safe’’ nutritional supplement that provides enormous strength gains when taken in conjunction with resistive exercise. Theoretically, there are two major physiological benefits of creatine supplementation. The first benefit is the fact that increased creatine intake enhances the bioavailability of phosphocreatine in skeletal muscle cells. This, in turn, allows faster resynthesis of adenosine triphosphate from adenosine diphosphate and results in quicker recovery from brief, high-intensity exercise. [38 –40] The second theoretical benefit of creatine supplementation is its ability to delay fatigue. Phosphocreatine, as well as acting as an energy source for working muscle, also buffers the intracellular hydrogen ions that occur during exercise. It is thought that these hydrogen ions contribute to fatigue. Therefore, elevated intracellular phosphocreatine levels should enhance performance by delaying muscle fatigue and prolonging time to exhaustion. Numerous laboratory and field studies have demonstrated significant performance enhancement in athletic males, in both brief, high-intensity work output and total time to exhaustion, with creatine supplementation of 20 to 30 g per day.

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[41 – 43] Currently, no clinical studies have reported a direct improvement in athletic performance due to creatine supplementation, but in strength athletes, this supplement must be seriously considered as a potential ergogenic aid. Some of the ambiguity of scientific data concerning creatine supplementation may be due to large variation in intracellular creatine concentrations among athletes. Many athletes naturally exhibit concentrations above the mean because of higher rates of endogenous synthesis or elevated intake of creatine in food sources. Further supplementation by these athletes may result in no significant improvements in strength or stamina. On the other hand, athletes with lower than average intracellular creatine levels (e.g., females and vegetarians), may demonstrate significant improvements if creatine is added to their normal diets. Although creatine monohydrate is considered a nutritional supplement with potential ergogenic effects, some investigators are concerned about its side-effect profile. The potential hazards of this supplement include severe muscle cramping and possible kidney damage when used in a dehydrated state. In 1997, creatine supplementation was blamed for the deaths of two NCAA wrestlers, but autopsy results proved that severe dehydration, not supplemental creatine, was instrumental in their deaths. Currently, there are no data regarding the use of creatine in adolescents and no studies to evaluate the effects of long-term creatine supplementation. Therefore, according to the current scientific data, creatine monohydrate may be a safe and effective ergogenic aid when taken in recommended amounts for short durations in healthy individuals. Dehydroepiandrosterone Dehydroepiandrosterone (DHEA) is touted as a ‘‘fountain of youth’’ supplement by marketers and consumed by millions of Americans because of the reported anti-obesity, anti-aging, and anti-cancer effects. In 1985, DHEA was taken off the market by the Food and Drug Administration (FDA) because of a potential association with liver damage. But with the passage of the federal ‘‘Dietary Supplement Health and Education Act’’ in 1994, the supplement industry was able to reclassify this substance as a ‘‘nutritional supplement,’’ and DHEA was released to the public as an over-the-counter preparation. Since its introduction, the popularity of this supplement has continued to grow in the United States, and with the recent admission of use by prominent athletes, this growth is certain to increase. DHEA was first identified in 1934 as an androgen produced in the adrenal glands. It is a precursor to the endogenous production of both androgens and estrogens. As an androgenic precursor, DHEA is thought to increase the production of testosterone and provide an anabolic steroid effect. Popularity for supplementation of DHEA stems from the observation that concentrations of this endogenous hormone steadily decline after approximately 20 years of age, [44] propagating the theory that DHEA may play a role in the aging process. Currently, well-designed published studies regarding the efficacy of DHEA have been scarce. Investigators have determined that DHEA supplementation in doses of 50 to 100 mg/day will significantly increase androgenic steroid plasma levels as well as subjective improvements in physical and psychological well-being. [45,46]

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Currently, there is no literature to show the effect of DHEA on body composition, fat distribution, strength, or athletic performance. It is also unknown what effect, if any, DHEA would have on a young, healthy individual, since all research participants have been mature adults ( > 40 years old) with chronic illness. Although few adverse effects of DHEA supplementation have been reported, there is the potential for serious irreversible morphogenic changes. [47] These include virilization in women, hirsutism, voice deepening, and alopecia. Once again, long-term effects are unknown, but theoretically, DHEA has the potential to increase the risk of uterine and prostate cancer because of the prolonged elevation of estrogens and testosterone. DHEA may also have a feminizing effect with prolonged use by competing with testosterone for receptor binding sites. Although unreported, there are concerns that prolonged use may lead to insulin resistance, decreased levels of high density lipoprotien cholesterol, and potentially liver cancer. DHEA is a banned substance according to the NCAA and the USOC, falling under the heading of an androgenic-anabolic agent. Therefore, the use of this supplement may lead to disqualification from competitive athletics. Given the sparsity of information, DHEA supplementation must be viewed with caution and skepticism. The use of this agent should be discouraged until scientific studies determine whether it is safe and effective. Androstenedione Androstenendione, which is chemically related to DHEA, has recently overwhelmed the nutritional supplement market. As a precursor to endogenous testosterone, this supplement is thought to enhance testosterone levels and therefore provide significant gains in fat-free muscle mass. To date, little research has been completed on this supplement. One prospective study showed no improvement in strength or fat-free muscle mass with androstenedione supplementation in dosages of 100 and 300 mg per day over an 8-week period, but this study had multiple design flaws and therefore may not have achieved valid results. [48] The most current data show that oral androstenedione administration at dosages of 300 mg/day will significantly increase serum testosterone and estradiol levels. [49] This increase in serum sex hormones is short-lived and nomalizes within 24 hours. Therefore, to observe androgenic benefits, a much more frequent dosing schedule may be necessary. Side effects similar to those of DHEA should be expected (e.g., virilization, hirsuitism, uterine and prostate cancer, gynecomastia, and liver damage) and no data on long-term use have been published. Androstenedione use is prohibited by the NCAA and the USOC, and if detected will potentially lead to disqualification. Therefore, the use of this agent for unsubstantiated gains in strength must be cautioned until further research can be completed. Beta-hydroxy-beta-methylbutyrate Beta-hydroxy-beta-methylbutyrate (HMB) is one of the most recent additions to the ‘‘nutritional supplement’’ armamentarium. HMB is a metabolite of the essential

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amino acid leucine and is produced in small amounts endogenously. It is found in the normal diet in catfish, citrus fruits, and breast milk. HMB was introduced as an ergogenic aid by investigators at Iowa State University, who believe that it may participate in the regulation of protein metabolism. Promoters hypothesize that HMB regulates the enzymes responsible for protein breakdown, and with supplementation muscle mass may increase by slowing muscle degradation. Currently, researchers have concluded that HMB supplementation may increase muscle mass and strength in livestock and humans. The literature regarding this supplement is sparse, but several randomized, placebo-controlled studies have produced promising results. [50] These studies have yet to be duplicated by anyone besides the original investigators, who hold the patent on the supplement; therefore, the results have met with much scientific scrutiny. Although supplementation with HMB may produce significant increases in muscle mass and strength, it is too early to recommend this agent because of the limited knowledge available regarding its safety profile and mechanism of action. Conclusion Most nutritional supplements sold in the United States are considered safe by consumers, if taken in appropriate doses and in a pure formulation. But, owing to the lack of quality control in the supplement industry, it is difficult to determine the levels of active ingredients in each tablet or capsule. In a recent consumer report, it was found that there was significant brand-to-brand as well as dose-todose variation among the concentrations of supposed active ingredients. [51] Therefore, consumers may be over- or under-estimating the doses of these preparations, even when taken according to labeled instructions. From January 1993 to October 1998, the Food and Drug Administration received 2621 reports of serious problems, including 101 deaths, linked to supplements. Furthermore, contaminants have been found in supplement preparations. The most remarkable case resulted in 32 deaths from eosinophilia-myalgia syndrome that were directly linked to the use of the popular nutritional supplement L-tryptophan. [52] The contaminant responsible was formed during the process of purifying L-tryptophan. Also of note are the numerous reports of hepatotoxicity associated with ‘‘health food’’ products (jin bu huan, germander, chaparral, senna, mistletoe, skullcap, comfrey, and crotolaria). [53 –55] This is an important reminder that ‘‘natural’’ or ‘‘herbal’’ on a product label does not ensure safety. With these substantial risks and the paucity of scientifically proven benefits, it would seem that nutritional supplementation is unnecessary and potentially dangerous.

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