Clinical Pediatrics http://cpj.sagepub.com/
Musculoskeletal Injuries: Caused by Weight Training Guidelines for Prevention William L. Risser CLIN PEDIATR 1990 29: 305 DOI: 10.1177/000992289002900602 The online version of this article can be found at: http://cpj.sagepub.com/content/29/6/305
Published by: http://www.sagepublications.com
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Musculoskeletal Injuries Caused
by Weight Training Guidelines for Prevention William L. Risser, MD
Tens of thousands of U.S. children, adolescents, and young adults are using weights either recreationally, to train for sports, or to compete in weight lifting, power lifting, or body building contests. Weight use may cause significant musculoskeletal injury. This review summarizes for the clinician the best available information on injury risks and prevention.
IN
THE UNITED STATES, large numbers of interscholastic athletes use strength training as a conditioning method. Approximately 4,000 adolescents age 14 years and older participate in the competitive sports of weight lifting or power lifting, and more than 8,500 teenagers compete as body builders. Many thousands more lift weights for recreation. Even children now train with weights. Because these activities can cause severe musculoskeletal damage, the clinician needs information on injury risks and
prevention. This review summarizes the best available research the risk of musculoskeletal injury during weight use by children, adolescents, and college students. It also presents brief guidelines on injury prevention, with sources for further reading. on
Definitions and Background Information
Strength training (weight training, resistance training) is the use of several methods, including exercises From the
Department of Pediatrics, University of Texas Medical
School-Houston, Houston,
Texas.
William L. Risser, MD, Professor of Pediatrics, University of Texas Medical School-Houston, 6655 Travis Street, Suite 570, Houston, TX 77030. Received for publication November 1988, revised January 1989, accepted January 1990.
Correspondence to:
with free weights and weight machines, to increase muscle strength, endurance, and/or power.
Weight lifting (Olympic lifting) and pazuer lifting are competitive sports in which athletes attempt to lift a maximal amount of free weight one time. In weight lifting, they perform the clean and jerk and the snatch, and in power lifting, the squat lift, dead lift, and bench press. Body building is a competitive sport in which the participant uses several resistance training methods, including exercises with free weights, to develop muscle size, symmetry, and definition. Free weights are dumbbells and barbells that are not part of a machine. The athlete raises them from the floor or a rack and uses them without external sup-
port.
Major lifts are those the athlete uses in weight lifting and power lifting (see previous definitions) as well
the power clean and the incline and overhead (military) press. All require free weights. In the clean and jerk, athletes in a two-step maneuver lift the barbell from the floor to the chest and then over the head; in the snatch, they accomplish the same movement of the weight in one motion, using a different technique. In the dead lift, they raise the barbell from the floor to a position in front of the thighs by straightening the flexed knees. An athlete performs as
305 Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
the squat lift by holding the barbell behind the head on the shoulders while standing straight, squatting until the thighs are parallel to the floor, and then returning to the starting position. The bench press begins with the athlete lying supine on a bench holding the barbell above the chest with the arms extended ; the weight is lowered to the chest and then raised. The incline press is similar, except that the bench is at about a 30° angle (the head higher than the feet). In the overhead press, the lifter stands and raises the barbell from in front of the chest to over the head by extending the arms. Training programs for body builders and athletes in strength training programs often center around one or more of the major lifts; competitive weight and power lifters use the exercises of their sport. Athletes frequently work with near-maximal amounts of weight, performing relatively few repetitions (e.g., three sets of three to six lifts). As they gain strength, they add weight. They often also perform dumbbell exercises and use leg machines; the latter help develop strength in the thigh muscles via flexion and extension against resistance. Some people do part or even most of their training on machines such as Nautilus or Universal Gym equipment. In these, the weights are connected to the machine, but injuries are still possible. The machines may be too large for small athletes. Athletes training for sports that require endurance rather than power, for example distance running rather than football or basketball, may perform more repetitions using less weight. They frequently use one or more of the major lifts, as do recreational weight lifters. Methods
Literature-Searching
Methods
Computer-based searches on three databases were performed: MEDLINE for the years 1984-1989, Paperchase (1968-1989), and &dquo;The Sport Database,&dquo; (from BRS Colleague; 1949-1989, with thorough coverage since 1984). Additional pertinent articles from the bibliographies of those found by the were selected, and Science Citaused to identify papers citing the above reports and others by the same authors. The 1989 indexes of the following journals were reviewed : Physician and Sportsmedicine, American journal of Sports Medicine, journal of Pediatric Orthopedics, Med-
computer searches tion Index
was
icine and Science in Sport and Exercise, Pediatrics, journal of Pediatrics, American journal of the Diseases of Children, the Yearbook of Sports Medicine, the Journal of the National Strength Training Association, and the Journal of the National Athletic Trainers’ Association. ’Selection of Articles
Articles on musculoskeletal injuries caused by weight training, weight and power lifting, body building, and recreational weight use in subjects aged 6-21 years were included in the search, as were all cohort studies and case series on children, adolescents, and college students, including case reports on adolescents and case series involving mainly adults only if they contained useful information not present in the other articles. Data for 1986 was obtained from the National Electronic Injury Surveillance System (NEISS) of the U.S. Consumer Product Safety Commission. NEISS obtains injury reports from a probability sample of 64 emergency rooms in the U.S. and its territories. From these data, the system makes a projection of the total number of visits for injuries to all emergency rooms in this area. NEISS only reports injuries that are associated with specific consumer products, for example weight training equipment, that it is evaluating for safety. Assessment of Articles
The articles had
demonstrate convincingly the associated sports activities, following: weight caused the injuries; competent professionals determined the type of injury; the data supported any claims that a specific weight training activity caused an injury; and the studies of injury rates ascertained the numbers of injuries reasonably completely, and made accurate determinations of the total numbers of subjects exposed to risk of injury and the mean duration of this exposure. to
use, not
Basis for Guidelines
The brief guidelines for safe weight use by children and adolescents are based on the data in the research reports; position papers of the American Academy of Pediatrics2 and the National Strength
Training Association;3~4 a report on a recent consensus conference on weight training in the prepubescent athlete;’ and one textbook on weight training.’ These sources provide additional information on this topic for the interested reader.
306 Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
TABLE 1.
*
See
text
for
Injuries in
Case
Reports and Series
description. that used self-administered questionobtain data. Faulty recall on the part of the athletes, the majority of whom had not seen a physician, may have affected the validity of the information. Brown and Kimba117 counted all injuries that resulted in one or more days of missed participation; some, therefore, were minor. The mean time lost per injury was 11.5 days. For the more serious ones, this value was nerve injuries (3 injuries), 89.0 days; frac-
investigations
Results
naires
Nature and
Quality
of the Data
Published research was scanty. Case reports or series on adolescent athletes provided much of the information in addition to two cohort studies of adolescent athleteS7 (Risser WL, Risser JMH, Preston D, unpublished data, 19XX) and three of small numbers of children in short-term training programs.8-lo The NEISS data’ apparently described a mixture of recreational weight users, athletes, and children who were injured while playing with weight equipment. Except when noted below, orthopedists evaluated the injuries. The data provided convincing support for the cause-effect relationship between specific exercises and acute injuries. For overuse problems, which are usually gradual in onset, this relationship was sometimes less clear. A variety of types of physicians presumably saw the patients described in the NEISS data, which provided enough information to allow a detailed assessment of kind, severity, and causes of specific injuries in only a small percent of
to
TABLE 2.
Injuries in Cohort Studies
cases.
Kind and
The
Severity
case
of
Injuries
reports and series1-17 dealt with serious
injuries in adolescents (Table 1). They indicated that weight use can cause a variety of significant acute and overuse problems as well as death. The two cohort studies of adolescents, ours (Risser, unpublished data) and Brown and Kimball’s7 gave a more complete picture of the range of possible injuries (Table 2). The design of these investigations was almost identical, they were historical (retrospective) cohort
*
Risser WL,
Risser JMH,
Preston D.
Unpublished data. 307
Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
and dislocations ( 1 ), 113. For others, time lost was muscle strains (60 injuries), 10.1 days; tendonitis (12), 14.6; muscle cramps (10), 3.8; ligament sprains (4), 7.0; and abrasions (4), l.l. Risser used a definition of injury that was more restrictive: disability exceeding 7 days. Of the 27 injuries, three caused disability of more than 21 days. In both studies, the most common type of injury was the muscle strain, and the most common site was the tures
the
(2), 41.7;
mean
lower back. In preadolescent athletes, Rians et al.8 reported one injury, a shoulder strain causing 1 week of disability, among 18 boys aged 8.3 ± 1.2 years (mean ± standard deviation) engaged in a 14-week training program. Sewall and Micheli9 noted no injuries among eight boys and girls age 10-11 years who trained for 9 weeks. Servedio et al. 10 detected no problems during an 8-week program involving six boys aged 11.9 ± 0.5 years. In the NEISS report, injuries caused by weight lifting exercises or equipment resulted in an estimated 43,397 visits to emergency rooms in 1986. This number is approximately 25% of all product-associated injuries. Children age 2-4 years had 2,2711 injuries, children age 5-14 years had 5,943, and adolescents and young adults age 15-24 years had 21,242. NEISS gave few details on the kinds of injury but categorized them by severity. For the three age groups combined, 81 % of injuries were mild (for example sprains, contusions to lower trunk, dislocated arms, arm fractures, and sprained necks); 17% were moderate (crushed fingers, head lacerations, punctured eyes, concussion, neck fractures); and 2% were severe (amputations, anoxia, crushed arms). One boy age 4 years died after falling off a weight training bench and striking his head on the concrete floor.
Incidence of Injury
Only two articles on adolescents, the cohort studies7 (Risser, unpublished data), had information on the number of subjects at risk of injury, permitting the determination of incidence rates. The incidence measure is the cumulative incidence, which is the number of persons in the cohort injured during the follow-up period. It is a measure of the individual’s risk of injury. Twenty-eight of 71 power lifters were injured for a cumulative incidence of 39.4% (95% confidence interval: 32.0%, 46.8%).7 These 28 had 98 injuries, so that several boys had at least two. The
duration of participation in the program was 17.1 months. Twenty-five of 354 junior and senior high school football players were injured (Risser, unpublished data) for a cumulative incidence of injury of 7.1 % (95% confidence interval: 4.3%, 9.5%); two of 25 had a second injury. These athletes had a mean duration of weight training experience of 11.2 months. As mentioned previously, Risser et al. used a more restrictive definition of injury. The three studies8-10 of preadolescent athletes described only a few subjects in short-term programs. The cumulative incidence of injury was low: one injured boy among the 32 participants. mean
Causes of Injury
The
of injury in the case reports and series in presented Table 1. Aggressive use of the major lifts led to significant injuries to the lower back, 12,17 as well as avulsion fractures of the anterior iliac spine (dead lift),17 osteolysis of the clavicle (bench press),&dquo; and meniscus tears (dead lift).17 Overhead lifts 13, 11 caused fractures of the forearm or wrist when the athlete lost control of the barbell and it hyperextended the wrists as it fell backwards behind the lifter’s head. The cohort studies of adolescents also blamed the major lifts for most of the significant injuries. Brady et a1.17 incriminated a machine called the Leaper in severe injuries to the back, pelvis, and neck. To use this device, the athlete places its padded lever arms on his shoulders and leaps upward against resistance. These researchers also found that injuries occurred during use of other machines, in particular the Universal Gym (back injuries and avulsions of the anterior iliac spine during hyperextension exercises) and leg machines (meniscus tears during knee causes
are
flexion)..
/
The NEISS report* provided limited information about the causes of injury. Children age 2-4 years most often fell over, against, or from equipment or they or an older person dropped weights onto their hands or feet. These accidents also happened frequently among older children and adolescents, as did injuries during actual lifting exercises. Prevention of
Injury
This is a complicated topic that I can introduce only in a brief review. Before starting a weight training program, athletes should probably have a physical examination, although only a few will have prob-
308 Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
lems that contraindicate participation. A coach with appropriate training should then help them plan their activities. These should be appropriate to their level of physical and emotional maturity and to their sport; a distance runner does not need the same kind of approach as a lineman in football. Unfortunately, coaches skilled in guiding young athletes are scarce. No good data indicate at what age athletes may safely train or compete using the major lifts and maximal amounts of weight. The U.S. Weight Lifting and Power Lifting Federations allow participation at age 14. Some experts have recommended an older age, for example 16 yearns. When adolescents reach Tanner stage 5 of their secondary sexual development, they have passed their period of maximal velocity of height growth,18,19 during which the epiphyses may be especially vulnerable to injury.2° The American Academy of Pediatrics has recently suggested2 that this milestone be used to determine the age at which aggressive use of the major lifts may begin. They remain dangerous at any age, as Tables 1 and 2 indicate, and care in their use remains essential. Athletes who are not yet mature enough to use these lifts with maximal amounts of weight can learn proper form at low weight. Athletes must learn proper technique for the exercises they use, and they must be supervised so that they maintain good form consistently. Errors in method, particularly during the major lifts, can cause injuries.11-17 Trained, attentive spotters must assist athletes when they perform a major lift, so that the spotter can catch the barbell if the lifter loses control. Safety equipment is available for some of these exercises, for example the step-down rack for the squat lift. Although the safety rules are important, many children and adolescents lift weights at home without supervision or spotters. Such individuals should avoid using the major lifts, particularly at high loads. Athletes should warm up and cool down before and after training with stretching exercises, calisthenics, and jogging. When they begin lifting, they should start with small amounts of weight and progress to those they will use for their maximal training effort. They will need to move weights from place to place around the training room, and so they must learn how to lift and carry heavy objects. They should wear shoes that will provide good traction. Beginning lifters are particularly likely to exceed their limits and must be cautioned to avoid this. They must learn not to perform exercises with a hyperextended back, and not to hyperventilate or perform a
Valsalva
when lifting. These breathing induce patterns may fainting, with loss of control of the weight and consequent injury. Athletes should exhale when straining. If they have pain when performing an exercise, they must be sure that their form is correct. If pain persists even with proper technique, they should decrease the amount of weight they are using, or stop that particular exercise for several days. Athletes should train a particular muscle group no more than three times a week. Coaches must plan and supervise the training area carefully. The room must be large enough so that the athletes will not be in each other’s way, and it must be well lit and ventilated. The floor must have a padded, nonslippery surface. Loose weights must not be scattered around. The equipment must be of good quality, inspected regularly for defects, and suitable to the size and age of the athletes. For example, standard models of equipment such as the Universal Gym are designed for persons of average adult height, although some machines are now devised for the small athlete. Casual users and children must not have access to the weight room. The researchers who have studied weight training in prepubescent athletes8.9 urge particular attention to safety. They advise against competitive lifting and recommend training with low loads using high numbers of sets and repetitions. They also suggest that weight training be only one part of an activity and fitness program, and that the amount of time devoted to it be limited, for example no more than 20-30 minutes per session, no more than four times per week. Coaches must be competent to train children, maintain a low athlete-to-coach ratio, and ensure that each child is mature enough to follow instructions and preserve an appropriate level of concentration. maneuver
References
Injury Information Clearinghouse. 1986 data summary on injuries caused by weight lifting. Washington, DC: National Electronic Injury Surveillance System, U.S. Consumer Product Safety Commission. American Academy of Pediatrics. Strength training, weight and power lifting, and body building by children and adolescents. Pediatrics (in press). Lincoln, Nebraska National Strength and Conditioning Assoc. Position paper on prepubescent strength training. 1985. Lincoln, Nebraska National Strength and Conditioning Assoc. How to build a strength training and conditioning program in your high school. Cahill BR, ed. Proceedings of the conference on strength
1. National
2.
3. 4.
5.
training and the prepubescent athlete. Chicago: Orthopedic Society for Sports Medicine, 1988.
American
309
Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
6. Fleck
SJ, Kraemer WJ. Designing resistance training programs. Champaign, IL: Human Kinetics Books, 1987. 7. Brown EW, Kimball RG. Medical history associated with adolescent powerlifting. Pediatrics 1983;72:636-44. 8. Rians CB, Weltman A, Cahill BR, et al. Strength training for prepubescent males: is it safe? Am J Sports Med 1987;15:483-9. 9. Sewall L, Micheli
10.
11.
LJ. Strength training for children. J Pediatr Orthop 1986;6:143-6. Servedio FJ, Bartels RL, Hamlin RL, et al. The effects of weight training, using Olympic style lifts, on various physiologic variables in prepubescent boys (abstract). Med Sci Sports Exerc 1985;17:288. George DH, Stakiw K, Wright CJ. Fatal accident with weightlifting equipment: implications for safety standards. Can
Med Assoc J 1989;140:925-6. 12. Jackson FE, Sazima HJ, Pratt RA II,
ries. J Am College
Health Assoc
et
al.
Weight lifting inju-
1971;19:187-9.
13. Gumbs VL, Segal D, Halligan JB, et al. Bilateral distal radius and ulnar fractures in adolescent weight lifters. AmJ Sports Med 1982;10:375-9. 14. Ryan JR, Salciccioli GG. Fractures of the distal radial epiphysis in adolescent weight lifters. Am J Sports Med 1976;4:26-7. 15. Cahill BR. Osteolysis of the distal part of the clavicle in male athletes. J Bone Joint Surg 1982A;64:1053-8. 16. Kotani PT, Ichikawa N, Wakabayashi W, et al. Studies of spondylolysis found among weight lifters. Br J Sports Med
1971 ;6 :4-7. 17. 18. 19.
20.
Brady TA, Cahill BR, Bodnar LM. Weight training-related injuries in the high school athlete. 1982;10:1-5. Marshall WA, Tanner JM. Variations in the patterns of pubertal change in girls. Arch Dis Child 1969;44:291-303. Marshall WA, Tanner JM. Variations in the pattern of pubertal change in boys. Arch Dis Child 1970;45:13-23. Smith NJ, Stanitski CL. Sports medicine. Philadelphia: WB Saunders Co, 1987:33.
310
Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
Musculoskeletal Injuries: Caused by Weight Training Guidelines for Prevention William L. Risser CLIN PEDIATR 1990 29: 305 DOI: 10.1177/000992289002900602 The online version of this article can be found at: http://cpj.sagepub.com/content/29/6/305
Published by: http://www.sagepublications.com
Additional services and information for Clinical Pediatrics can be found at: Email Alerts: http://cpj.sagepub.com/cgi/alerts Subscriptions: http://cpj.sagepub.com/subscriptions Reprints: http://www.sagepub.com/journalsReprints.nav Permissions: http://www.sagepub.com/journalsPermissions.nav Citations: http://cpj.sagepub.com/content/29/6/305.refs.html
>> Version of Record - Jun 1, 1990 What is This?
Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
Musculoskeletal Injuries Caused
by Weight Training Guidelines for Prevention William L. Risser, MD
Tens of thousands of U.S. children, adolescents, and young adults are using weights either recreationally, to train for sports, or to compete in weight lifting, power lifting, or body building contests. Weight use may cause significant musculoskeletal injury. This review summarizes for the clinician the best available information on injury risks and prevention.
IN
THE UNITED STATES, large numbers of interscholastic athletes use strength training as a conditioning method. Approximately 4,000 adolescents age 14 years and older participate in the competitive sports of weight lifting or power lifting, and more than 8,500 teenagers compete as body builders. Many thousands more lift weights for recreation. Even children now train with weights. Because these activities can cause severe musculoskeletal damage, the clinician needs information on injury risks and
prevention. This review summarizes the best available research the risk of musculoskeletal injury during weight use by children, adolescents, and college students. It also presents brief guidelines on injury prevention, with sources for further reading. on
Definitions and Background Information
Strength training (weight training, resistance training) is the use of several methods, including exercises From the
Department of Pediatrics, University of Texas Medical
School-Houston, Houston,
Texas.
William L. Risser, MD, Professor of Pediatrics, University of Texas Medical School-Houston, 6655 Travis Street, Suite 570, Houston, TX 77030. Received for publication November 1988, revised January 1989, accepted January 1990.
Correspondence to:
with free weights and weight machines, to increase muscle strength, endurance, and/or power.
Weight lifting (Olympic lifting) and pazuer lifting are competitive sports in which athletes attempt to lift a maximal amount of free weight one time. In weight lifting, they perform the clean and jerk and the snatch, and in power lifting, the squat lift, dead lift, and bench press. Body building is a competitive sport in which the participant uses several resistance training methods, including exercises with free weights, to develop muscle size, symmetry, and definition. Free weights are dumbbells and barbells that are not part of a machine. The athlete raises them from the floor or a rack and uses them without external sup-
port.
Major lifts are those the athlete uses in weight lifting and power lifting (see previous definitions) as well
the power clean and the incline and overhead (military) press. All require free weights. In the clean and jerk, athletes in a two-step maneuver lift the barbell from the floor to the chest and then over the head; in the snatch, they accomplish the same movement of the weight in one motion, using a different technique. In the dead lift, they raise the barbell from the floor to a position in front of the thighs by straightening the flexed knees. An athlete performs as
305 Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
the squat lift by holding the barbell behind the head on the shoulders while standing straight, squatting until the thighs are parallel to the floor, and then returning to the starting position. The bench press begins with the athlete lying supine on a bench holding the barbell above the chest with the arms extended ; the weight is lowered to the chest and then raised. The incline press is similar, except that the bench is at about a 30° angle (the head higher than the feet). In the overhead press, the lifter stands and raises the barbell from in front of the chest to over the head by extending the arms. Training programs for body builders and athletes in strength training programs often center around one or more of the major lifts; competitive weight and power lifters use the exercises of their sport. Athletes frequently work with near-maximal amounts of weight, performing relatively few repetitions (e.g., three sets of three to six lifts). As they gain strength, they add weight. They often also perform dumbbell exercises and use leg machines; the latter help develop strength in the thigh muscles via flexion and extension against resistance. Some people do part or even most of their training on machines such as Nautilus or Universal Gym equipment. In these, the weights are connected to the machine, but injuries are still possible. The machines may be too large for small athletes. Athletes training for sports that require endurance rather than power, for example distance running rather than football or basketball, may perform more repetitions using less weight. They frequently use one or more of the major lifts, as do recreational weight lifters. Methods
Literature-Searching
Methods
Computer-based searches on three databases were performed: MEDLINE for the years 1984-1989, Paperchase (1968-1989), and &dquo;The Sport Database,&dquo; (from BRS Colleague; 1949-1989, with thorough coverage since 1984). Additional pertinent articles from the bibliographies of those found by the were selected, and Science Citaused to identify papers citing the above reports and others by the same authors. The 1989 indexes of the following journals were reviewed : Physician and Sportsmedicine, American journal of Sports Medicine, journal of Pediatric Orthopedics, Med-
computer searches tion Index
was
icine and Science in Sport and Exercise, Pediatrics, journal of Pediatrics, American journal of the Diseases of Children, the Yearbook of Sports Medicine, the Journal of the National Strength Training Association, and the Journal of the National Athletic Trainers’ Association. ’Selection of Articles
Articles on musculoskeletal injuries caused by weight training, weight and power lifting, body building, and recreational weight use in subjects aged 6-21 years were included in the search, as were all cohort studies and case series on children, adolescents, and college students, including case reports on adolescents and case series involving mainly adults only if they contained useful information not present in the other articles. Data for 1986 was obtained from the National Electronic Injury Surveillance System (NEISS) of the U.S. Consumer Product Safety Commission. NEISS obtains injury reports from a probability sample of 64 emergency rooms in the U.S. and its territories. From these data, the system makes a projection of the total number of visits for injuries to all emergency rooms in this area. NEISS only reports injuries that are associated with specific consumer products, for example weight training equipment, that it is evaluating for safety. Assessment of Articles
The articles had
demonstrate convincingly the associated sports activities, following: weight caused the injuries; competent professionals determined the type of injury; the data supported any claims that a specific weight training activity caused an injury; and the studies of injury rates ascertained the numbers of injuries reasonably completely, and made accurate determinations of the total numbers of subjects exposed to risk of injury and the mean duration of this exposure. to
use, not
Basis for Guidelines
The brief guidelines for safe weight use by children and adolescents are based on the data in the research reports; position papers of the American Academy of Pediatrics2 and the National Strength
Training Association;3~4 a report on a recent consensus conference on weight training in the prepubescent athlete;’ and one textbook on weight training.’ These sources provide additional information on this topic for the interested reader.
306 Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
TABLE 1.
*
See
text
for
Injuries in
Case
Reports and Series
description. that used self-administered questionobtain data. Faulty recall on the part of the athletes, the majority of whom had not seen a physician, may have affected the validity of the information. Brown and Kimba117 counted all injuries that resulted in one or more days of missed participation; some, therefore, were minor. The mean time lost per injury was 11.5 days. For the more serious ones, this value was nerve injuries (3 injuries), 89.0 days; frac-
investigations
Results
naires
Nature and
Quality
of the Data
Published research was scanty. Case reports or series on adolescent athletes provided much of the information in addition to two cohort studies of adolescent athleteS7 (Risser WL, Risser JMH, Preston D, unpublished data, 19XX) and three of small numbers of children in short-term training programs.8-lo The NEISS data’ apparently described a mixture of recreational weight users, athletes, and children who were injured while playing with weight equipment. Except when noted below, orthopedists evaluated the injuries. The data provided convincing support for the cause-effect relationship between specific exercises and acute injuries. For overuse problems, which are usually gradual in onset, this relationship was sometimes less clear. A variety of types of physicians presumably saw the patients described in the NEISS data, which provided enough information to allow a detailed assessment of kind, severity, and causes of specific injuries in only a small percent of
to
TABLE 2.
Injuries in Cohort Studies
cases.
Kind and
The
Severity
case
of
Injuries
reports and series1-17 dealt with serious
injuries in adolescents (Table 1). They indicated that weight use can cause a variety of significant acute and overuse problems as well as death. The two cohort studies of adolescents, ours (Risser, unpublished data) and Brown and Kimball’s7 gave a more complete picture of the range of possible injuries (Table 2). The design of these investigations was almost identical, they were historical (retrospective) cohort
*
Risser WL,
Risser JMH,
Preston D.
Unpublished data. 307
Downloaded from cpj.sagepub.com at Universitats-Landesbibliothek on December 13, 2013
and dislocations ( 1 ), 113. For others, time lost was muscle strains (60 injuries), 10.1 days; tendonitis (12), 14.6; muscle cramps (10), 3.8; ligament sprains (4), 7.0; and abrasions (4), l.l. Risser used a definition of injury that was more restrictive: disability exceeding 7 days. Of the 27 injuries, three caused disability of more than 21 days. In both studies, the most common type of injury was the muscle strain, and the most common site was the tures
the
(2), 41.7;
mean
lower back. In preadolescent athletes, Rians et al.8 reported one injury, a shoulder strain causing 1 week of disability, among 18 boys aged 8.3 ± 1.2 years (mean ± standard deviation) engaged in a 14-week training program. Sewall and Micheli9 noted no injuries among eight boys and girls age 10-11 years who trained for 9 weeks. Servedio et al. 10 detected no problems during an 8-week program involving six boys aged 11.9 ± 0.5 years. In the NEISS report, injuries caused by weight lifting exercises or equipment resulted in an estimated 43,397 visits to emergency rooms in 1986. This number is approximately 25% of all product-associated injuries. Children age 2-4 years had 2,2711 injuries, children age 5-14 years had 5,943, and adolescents and young adults age 15-24 years had 21,242. NEISS gave few details on the kinds of injury but categorized them by severity. For the three age groups combined, 81 % of injuries were mild (for example sprains, contusions to lower trunk, dislocated arms, arm fractures, and sprained necks); 17% were moderate (crushed fingers, head lacerations, punctured eyes, concussion, neck fractures); and 2% were severe (amputations, anoxia, crushed arms). One boy age 4 years died after falling off a weight training bench and striking his head on the concrete floor.
Incidence of Injury
Only two articles on adolescents, the cohort studies7 (Risser, unpublished data), had information on the number of subjects at risk of injury, permitting the determination of incidence rates. The incidence measure is the cumulative incidence, which is the number of persons in the cohort injured during the follow-up period. It is a measure of the individual’s risk of injury. Twenty-eight of 71 power lifters were injured for a cumulative incidence of 39.4% (95% confidence interval: 32.0%, 46.8%).7 These 28 had 98 injuries, so that several boys had at least two. The
duration of participation in the program was 17.1 months. Twenty-five of 354 junior and senior high school football players were injured (Risser, unpublished data) for a cumulative incidence of injury of 7.1 % (95% confidence interval: 4.3%, 9.5%); two of 25 had a second injury. These athletes had a mean duration of weight training experience of 11.2 months. As mentioned previously, Risser et al. used a more restrictive definition of injury. The three studies8-10 of preadolescent athletes described only a few subjects in short-term programs. The cumulative incidence of injury was low: one injured boy among the 32 participants. mean
Causes of Injury
The
of injury in the case reports and series in presented Table 1. Aggressive use of the major lifts led to significant injuries to the lower back, 12,17 as well as avulsion fractures of the anterior iliac spine (dead lift),17 osteolysis of the clavicle (bench press),&dquo; and meniscus tears (dead lift).17 Overhead lifts 13, 11 caused fractures of the forearm or wrist when the athlete lost control of the barbell and it hyperextended the wrists as it fell backwards behind the lifter’s head. The cohort studies of adolescents also blamed the major lifts for most of the significant injuries. Brady et a1.17 incriminated a machine called the Leaper in severe injuries to the back, pelvis, and neck. To use this device, the athlete places its padded lever arms on his shoulders and leaps upward against resistance. These researchers also found that injuries occurred during use of other machines, in particular the Universal Gym (back injuries and avulsions of the anterior iliac spine during hyperextension exercises) and leg machines (meniscus tears during knee causes
are
flexion)..
/
The NEISS report* provided limited information about the causes of injury. Children age 2-4 years most often fell over, against, or from equipment or they or an older person dropped weights onto their hands or feet. These accidents also happened frequently among older children and adolescents, as did injuries during actual lifting exercises. Prevention of
Injury
This is a complicated topic that I can introduce only in a brief review. Before starting a weight training program, athletes should probably have a physical examination, although only a few will have prob-
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lems that contraindicate participation. A coach with appropriate training should then help them plan their activities. These should be appropriate to their level of physical and emotional maturity and to their sport; a distance runner does not need the same kind of approach as a lineman in football. Unfortunately, coaches skilled in guiding young athletes are scarce. No good data indicate at what age athletes may safely train or compete using the major lifts and maximal amounts of weight. The U.S. Weight Lifting and Power Lifting Federations allow participation at age 14. Some experts have recommended an older age, for example 16 yearns. When adolescents reach Tanner stage 5 of their secondary sexual development, they have passed their period of maximal velocity of height growth,18,19 during which the epiphyses may be especially vulnerable to injury.2° The American Academy of Pediatrics has recently suggested2 that this milestone be used to determine the age at which aggressive use of the major lifts may begin. They remain dangerous at any age, as Tables 1 and 2 indicate, and care in their use remains essential. Athletes who are not yet mature enough to use these lifts with maximal amounts of weight can learn proper form at low weight. Athletes must learn proper technique for the exercises they use, and they must be supervised so that they maintain good form consistently. Errors in method, particularly during the major lifts, can cause injuries.11-17 Trained, attentive spotters must assist athletes when they perform a major lift, so that the spotter can catch the barbell if the lifter loses control. Safety equipment is available for some of these exercises, for example the step-down rack for the squat lift. Although the safety rules are important, many children and adolescents lift weights at home without supervision or spotters. Such individuals should avoid using the major lifts, particularly at high loads. Athletes should warm up and cool down before and after training with stretching exercises, calisthenics, and jogging. When they begin lifting, they should start with small amounts of weight and progress to those they will use for their maximal training effort. They will need to move weights from place to place around the training room, and so they must learn how to lift and carry heavy objects. They should wear shoes that will provide good traction. Beginning lifters are particularly likely to exceed their limits and must be cautioned to avoid this. They must learn not to perform exercises with a hyperextended back, and not to hyperventilate or perform a
Valsalva
when lifting. These breathing induce patterns may fainting, with loss of control of the weight and consequent injury. Athletes should exhale when straining. If they have pain when performing an exercise, they must be sure that their form is correct. If pain persists even with proper technique, they should decrease the amount of weight they are using, or stop that particular exercise for several days. Athletes should train a particular muscle group no more than three times a week. Coaches must plan and supervise the training area carefully. The room must be large enough so that the athletes will not be in each other’s way, and it must be well lit and ventilated. The floor must have a padded, nonslippery surface. Loose weights must not be scattered around. The equipment must be of good quality, inspected regularly for defects, and suitable to the size and age of the athletes. For example, standard models of equipment such as the Universal Gym are designed for persons of average adult height, although some machines are now devised for the small athlete. Casual users and children must not have access to the weight room. The researchers who have studied weight training in prepubescent athletes8.9 urge particular attention to safety. They advise against competitive lifting and recommend training with low loads using high numbers of sets and repetitions. They also suggest that weight training be only one part of an activity and fitness program, and that the amount of time devoted to it be limited, for example no more than 20-30 minutes per session, no more than four times per week. Coaches must be competent to train children, maintain a low athlete-to-coach ratio, and ensure that each child is mature enough to follow instructions and preserve an appropriate level of concentration. maneuver
References
Injury Information Clearinghouse. 1986 data summary on injuries caused by weight lifting. Washington, DC: National Electronic Injury Surveillance System, U.S. Consumer Product Safety Commission. American Academy of Pediatrics. Strength training, weight and power lifting, and body building by children and adolescents. Pediatrics (in press). Lincoln, Nebraska National Strength and Conditioning Assoc. Position paper on prepubescent strength training. 1985. Lincoln, Nebraska National Strength and Conditioning Assoc. How to build a strength training and conditioning program in your high school. Cahill BR, ed. Proceedings of the conference on strength
1. National
2.
3. 4.
5.
training and the prepubescent athlete. Chicago: Orthopedic Society for Sports Medicine, 1988.
American
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6. Fleck
SJ, Kraemer WJ. Designing resistance training programs. Champaign, IL: Human Kinetics Books, 1987. 7. Brown EW, Kimball RG. Medical history associated with adolescent powerlifting. Pediatrics 1983;72:636-44. 8. Rians CB, Weltman A, Cahill BR, et al. Strength training for prepubescent males: is it safe? Am J Sports Med 1987;15:483-9. 9. Sewall L, Micheli
10.
11.
LJ. Strength training for children. J Pediatr Orthop 1986;6:143-6. Servedio FJ, Bartels RL, Hamlin RL, et al. The effects of weight training, using Olympic style lifts, on various physiologic variables in prepubescent boys (abstract). Med Sci Sports Exerc 1985;17:288. George DH, Stakiw K, Wright CJ. Fatal accident with weightlifting equipment: implications for safety standards. Can
Med Assoc J 1989;140:925-6. 12. Jackson FE, Sazima HJ, Pratt RA II,
ries. J Am College
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13. Gumbs VL, Segal D, Halligan JB, et al. Bilateral distal radius and ulnar fractures in adolescent weight lifters. AmJ Sports Med 1982;10:375-9. 14. Ryan JR, Salciccioli GG. Fractures of the distal radial epiphysis in adolescent weight lifters. Am J Sports Med 1976;4:26-7. 15. Cahill BR. Osteolysis of the distal part of the clavicle in male athletes. J Bone Joint Surg 1982A;64:1053-8. 16. Kotani PT, Ichikawa N, Wakabayashi W, et al. Studies of spondylolysis found among weight lifters. Br J Sports Med
1971 ;6 :4-7. 17. 18. 19.
20.
Brady TA, Cahill BR, Bodnar LM. Weight training-related injuries in the high school athlete. 1982;10:1-5. Marshall WA, Tanner JM. Variations in the patterns of pubertal change in girls. Arch Dis Child 1969;44:291-303. Marshall WA, Tanner JM. Variations in the pattern of pubertal change in boys. Arch Dis Child 1970;45:13-23. Smith NJ, Stanitski CL. Sports medicine. Philadelphia: WB Saunders Co, 1987:33.
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