HackTwat
MuscleChemistry Registered Member
Minimizing Weight Training Injuries in
Bodybuilders and Athlete
UNDERSTANDING BODYBUILDING TRAINING
A discussion of bodybuilding injuries must include a description of various routines and exercises performed by bodybuilders. Bodybuilding-style weight training is the type of weight training most commonly performed in the United States by both athletes and recreational lifters. This type of training involves multiple sets of various exercises performed with multiple repetitions. The intention is to isolate particular muscle groups. The amount of weight used is typically moderate (60% to 80% maximal strength). The goal is to promote muscular hypertrophy. This training is in contrast to power lifting and Olympic-style lifting.
Power lifting involves lifting very heavy or maximal weight (up to 100% maximal strength) using relatively few repetitions. Power lifters perform relatively small numbers of sets per workout and their training revolves around three lifts-the squat, the bench press, and the dead-lift. The goal is to achieve maximal strength. Olympic-style lifting, like power lifting, involves performing relatively small numbers of sets and exercises involving few repetitions. Training is focused around performing specific lifts-the clean, the clean and jerk, and the snatch. The weight is literally jerked up, largely using the powerful muscles of the back and legs. The goal is to develop maximal power.
While some athletes involved in strength training may perform Olympic lifts and/or power lifts, most of their training involves bodybuilding-style training. There are several reasons for this focus. Bodybuilding training helps to build the muscular hypertrophy necessary for many contact sports. This type of training can also facilitate a later strength training phase. A thicker muscle with greater cross-sectional area can generate more potential force.(2) Bodybuilding training also helps to provide balanced strength around joints by specifically isolating weak links that could otherwise allow excessive stress to the joint and subsequent injury.
COMMON BODYBUILDING ROUTINES
Bodybuilding routines tend to include a high volume of sets and exercises, repeated multiple times per week. For example, it would not be unusual for a bodybuilder to perform five different exercises for his or her chest with four to five sets of each exercise using 6 to 15 repetitions. At least two or three of these sets will typically be taken to failure (ie, the point at which no more repetitions [reps] can be performed). Advanced techniques are also often employed. These techniques include forced reps, cheating reps, drop the weight sets, negatives, and supersets (see Table 1). The full workout could involve 1,500 repetitions and take 2 to 3 hours to complete. Fatiguing workouts may be performed 5 to 7 days per week without a break. This schedule may result in overtraining and injury.
Many weight training injuries may be related to stressing the same joints repeatedly until muscular or tendinous failure occurs. Repeatedly training to failure without any periodization or cycling of the intensity or duration of the workouts increases the risk of tendinitis and other injuries. So, too, does the large volume and frequency of training. In addition, poor techniques may result in abnormal wear on joints and over time may lead to cartilage breakdown.
In contrast, power lifters and Olympic weight lifters tend to perform fewer sets and reps in each training session. They tend to periodize or cycle their workouts and slowly work up to their maximum lift over a period of weeks or months. They do not attempt to train to failure at each workout as bodybuilders typically do. Thus high-level lifters attempt to peak during the competitive season, avoiding the harmful effects of overtraining.
While there are no accurate statistics to compare, there is some evidence that power lifters and Olympic lifters may actually have a slightly lower rate of injuries than bodybuilders. For example, despite using much heavier weight in the bench press than bodybuilders, power lifters seem to have a lower incidence of pectoralis major tears. Reynolds and colleagues(5) concluded that part of the problem was the total volume of work that bodybuilders perform. Itresults in fatigue of the pectoralis muscle, predisposing the muscle to tearing.
This is not to say that many injuries do not occur with power lifting or Olympic lifting. The extremely heavy weights and the strenuous nature of the power lifts may result in substantial injury. Likewise, the explosive efforts involved in Olympic lifting exercises like the clean and jerk lead to a fair share of injuries.(6) At least one study(7) showed significantly increased disc degeneration among former Olympic weight lifters as compared to other athletes and controls.
Most bodybuilders do not warm up and spend little to no time stretching. However, some exercises require extreme ranges of motion in the shoulders and other joints. A few recommended bodybuilding routines actually involve these very stressful, potentially dangerous stretching exercises. For example, one popular training manual recommends fascial stretching.(8) One stretch involves hanging from a pull-up bar with the arms behind the back, a movement that could overstretch the anterior capsule of the shoulder, resulting in shoulder instability. Such fascial stretching is believed to increase muscle size, strength, and separation and lead to altered bone structure, such as an expanded rib cage and wider clavicles.(8) It is also claimed that tightness in the fascial sheath limits muscle growth and that forcefully stretching the fascia will increase the likelihood of muscle hypertrophy. There is no scientific basis for these claims; however, such advice is often followed by bodybuilders and may be a factor in causing excessive flexibility. Excessive flexibility, in turn, has been linked to an increased risk of injury.(9,10)
Some of the advanced techniques of bodybuilding (Table 1) designed to allow the lifter to exercise beyond failure and stimulate recruitment of additional muscle fibers may also lead to an increased risk of injury. For example, negative accentuated repetitions, where the emphasis is on lowering of the weight, may result in a greater chance of injury. Eccentric (negative) contractions, in which the muscle is lengthened while under tension, have been linked to both delayed onset muscle soreness(11-13) and increased muscle fiber damage.(12,13) Eccentric contractions are considered to be important for stimulating muscle growth(3) but may also lead to an increased risk of muscle or tendon injury.(12,14,15)
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Table 1. Advanced training techniques
Training to failure: Performing as many repetitions as can possibly be performed.
Forced reps: Having a training partner to assist (ie, active spotting) in performing additional reps past the point of failure.
Cheating reps: Performing as many reps as possible in good form and, when no more reps can be completed, modifying form to complete one or more additional reps. It is a method of going beyond failure without a spotter.
Negatives: This approach emphasizes the eccentric, negative portion of the repetition. To emphasize the negative portion of a full range-of-motion exercise, movement is slowed down as the weight is lowered. In other words, the muscle is still contracting as it is lengthening. It is possible to lower more weight slowly than can be raised, so this technique allows the muscle to be overloaded to a greater extent. A training partner helps raise the heavier weight. Note that eccentric contraction is important for muscular hypertrophy.(3)
Drop the weight sets (breakdown sets): Performing a set to failure and then reducing the weight by 10% to 20% and performing some additional repetitions to failure. It is believed that this type of training will recruit additional muscle fibers.(4)
Supersets: Performing two or more exercises in rapid succession with little or no rest in between. Exercises for the same or different body parts may be combined.
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GENERAL RECOMMENDATIONS TO PREVENT INJURIES
To prevent weight training injuries, the clinician should conduct a detailed consultation with the athlete in order to determine the specifics of his or her training program. To save time the clinician can have the athlete document his or her weekly workout, complete with exercises, sets, repetitions, and equipment used.
There are two main approaches to determining the amount of weight to use with a specific exercise. The oldest method is referred to as progressive resistance exercise (PRE). The general concept is to determine a 10 resistance maximum (RM)-the maximum amount of weight an individual can lift 10 times-and use it as the starting weight. For beginners or those on a rehabilitation program, it is often recommended to use half of the 10 RM weight and perform three sets of 10.
Another variation is the daily adjustable progressive resistance exercise (DAPRE) technique. Four sets are used. The weight used in the fourth set and the following workout are determined by how many repetitions are accomplished in the third set. In the first set half of the maximum weight (first determined by a PRE approach) is performed 10 times. In the second set three quarters of the maximum weight is lifted six times. In the third set, the maximum weight is lifted as many times as possible. If the weight is lifted only a few times, the athlete is instructed to decrease the maximum weight by 5 to I 0 lb. If the athlete lifts around five to six reps, he or she keeps the maximum weight the same. If he or she is able to lift more than six reps, the next set will use a weight with a 5- to 10-lb increase. A fourth set is performed, and the same principle for determining the working weight for the next workout is used based on the number of reps performed. This approach is most valuable when heavier weights are employed such as when training larger muscle groups, such as the legs, chest, or back.
It is important to remind the weight lifter that more is not necessarily better. Three to four sets of three exercises per body part is probably sufficient to stimulate the muscle hypertrophy response. At least 3, and as many as 7, days of rest should be taken between workouts of a body part. Some top level bodybuilders have made great gains training each body part only once per week.
It is recommended that workouts of lower intensity be alternated with workouts of higher intensity and lower volume in order to prevent overtraining. Periodization is a systematic method of training that involves preplanned periods or phases of training that allow the athlete to peak for competition or sport while avoiding overtraining. Strength coaches typically use such periodization programs when designing strength training programs for their athletes. Although there are many variations of the periodization approach, the general concept is to divide an annual training program into phases. The first phase usually includes high-volume, low-intensity workouts emphasizing technique. The second phase shifts the emphasis to power and strength workouts (for anaerobic sports) or high intensity, low-volume workouts (for aerobic sports). During competition the emphasis shifts to high-intensity, techniquefocused exercises using short workout periods. A fourth phase is often added emphasizing "active rest" where the athlete is not focusing on training, but is playing recreational sports. Viewed on a graph, it is apparent that the periodization approach is a gradual shift from high-volume, low-intensity work to low-volume, high-intensity work. In this author's experience it is a more rational way for bodybuilders to approach their training. The strategy of periodization should be recommended as a means of decreasing injuries and improving potential gains. (5,16)
A 5- to 10-minute warm-up on a stationary cycle or treadmill is a good way to raise body temperature and ready the body for high intensity exercise.(17) Some slow, static flexibility exercises following the warm-up will help to elongate muscles, tendons, and the surrounding connective tissue, and they will likely help prevent injury.(18) Such stretching should be gentle, and care should be taken not to overstretch. Flexibility exercises should be repeated after the workout as a cool-down to prevent shortening of the muscles and tendons. Stretches should be held for 15 to 30 seconds and may be repeated several times. Ballistic stretching should be avoided, as should bouncing at the end of the range of motion.
TYPES OF WEIGHT TRAINING INJURIES
A wide range of weight training injuries has been documented in the literature. These reports include a number of unusual injuries such as: subarachnoid aneurysmal hemorrhage (19); ruptures of the pectoralis major, (20) biceps,(21) triceps,(22) and quadriceps muscles (23); fracture of the dome of the talus(24); and Kienbock's syndrome (25) among others. This article will focus on some of the more common weight training injuries involving the lumbar spine, the cervical spine, the shoulder, and the knee.
The lower back is the site of greatest injury.(26-28) A number of reports point to the shoulder and the knee as the next most frequent sites of injury during weight training.(3,27-29) At least one epidemiologic study suggests a significant statistical link between weight training and cervical disc herniation.(30)
[Appendix D presents practical aids with recommendations for preventing various injuries while weight training.]
LUMBAR SPINE INJURIES
In both youths(26-29,31) and adults(32,33) the most common weight training injuries involve the lower back. The mechanisms of injury include hyperflexion, hyperextension, torsion, and overdevelopment and excessive tightening of the iliopsoas muscles. The most common back problems are mechanical sprains and strains; however, disc injury or spondylolisthesis may also occur. Spondylolisthesis may be due to the stress imposed at the neural arch while performing exercises that involve repetitive lumbar spine flexion and extension under load. It is particularly true of dead-lifts.(34)
The greatest number of weight training-related back injuries result from exercises in which the trainee is in the flexed posture, such as rows and dead-lifts. A bent barbell row is often performed standing with heavy weight held at arm's length while bent at the waist and the legs held straight. This position creates perhaps the greatest amount of contractile tension on the lumbar spine musculature and the greatest lumbar disc pressure.(35) A frequent error is to allow the back to round and then to jerk the weight up using the hip muscles to generate power. Lumbar flexion while lifting results in the load being shifted from the back muscles to the posterior ligaments, the thoracolumbar fascia, and the lumbar discs. The lower back muscles stop contracting when the spine is sufficiently flexed, a phenomenon known as the flexion relaxation response of the erector spinae.(36) It may result in injury to ligaments or discs.
The seated cable row exercise may also result in a hyperflexion injury to the lumbar spine, a problem often encountered in this author's practice. The injury usually results from leaning forward at the starting point of each rep, allowing the spine to flex, in an effort to get a good stretch (see Figs 1 and 2).
Extremely heavy weights are sometimes used in weightlifting exercises. As much as 1,000 lb can be used in the squat and dead-lift. While steadily applied compressive forces alone rarely injure the disc, rupture of the vertebral end plate or fatigue microfractures of the trabeculae of the vertebral bodies may result.(37,38) Research(39) reveals that retired heavyweight lifters exhibit significantly greater reduction of disc height on X-ray compared with controls.
Fig l. Unsafe technique in the seated row exercise-hyperflexion of the spine.
[** Illustrations(photos) have not been included in this on-line version, but are available on reprints of the original paper.]
Fig 2. The correct technique-maintain neutral (lordotic) positive.
Hyperextension injury to the spine may result from arching backward while performing unsupported overhead presses,(32) moving into a hyperextended position while performing the back extension exercise ballistically, or while performing prone leg curls. During the leg curl, there is a strong tendency for the spine to be pulled into hyperextension as the psoas comes into play to assist the hamstrings. Hyperextension can cause abnormal loading of the facet joints and the capsules, resulting in an inflammatory response. It can also increase the load on a preexisting spondylolisthesis, resulting in greater strain to the supporting tissues. The solution is to contract the abdominals while pulling the hips against the bench in order to maintain a neutral lumbar positive. In addition, patients should be advised to avoid using too heavy a weight or overstraining at the end of a set.
Injury to either the facets or the discs may occur from rotational exercises such as twists or from the rotary torso machine. The lumbar spine is particularly vulnerable to torsional forces. Due to the sagittal orientation of the facets, only a limited amount of rotation can occur in the lumbar spine. Additional rotation may result in injury to the facets or shearing of the discs.(40,41) Research (42) suggests a link between twisting while lifting and an increased risk of disc herniation.
Twisting exercises are often performed in an attempt to isolate the transverse abdominus muscle and create a thinner waistline. However, the transverse abdominus does not contract while rotating the torso, and twisting exercises will not trim the waist. Despite its horizontal fiber orientation, the transverse abdominus functions mainly to compress the abdomen during functions such as forced expiration and defecation.(43,44)
Many commonly performed abdominal exercises may contribute to lower back injury through overdevelopment and tightening of the hip flexor, iliopsoas muscles. When the iliopsoas Muscle contracts, it exerts both increased compressive and shear forces on the lumbar spine.(45) Many abdominal exercises are actually exercises in which the hip flexor muscles rather than the abdominals perform much or all of the work. These exercises include full sit-ups, straight leg raises, high chair and hanging leg raises, crunches with the feet hooked under a sofa or an apparatus in the gym, V-ups, Roman Chair rocking crunches, and most abdominal machines. Hooking the feet under a stationary object for support increases the tendency for the hip flexors to be recruited during sit-ups.
CERVICAL SPINE INJURIES
While not as common as back injuries, neck injuries occur fairly frequently in weight lifters. Cervical spine problems include mechanical sprains and strains, disc injuries, and brachial plexus injuries. Soft tissue injuries may result from protruding the head forward or from unnecessarily tensing the neck while weight training. Some problems result from a muscle imbalance syndrome similar to the "upper crossed syndrome" described by Janda.(46) This problem occurs because of imbalance in training programs that involve an inordinate amount of exercise for the pectorals, the front delts, the lats, and the biceps and very little training of antagonist muscle groups. The result can be overly developed and tight pectoralis major and minor, latissimus dorsi, front deltoids, trapezium, biceps, and stemocleidomastoid muscles, especially if proper attention has not been given to maintaining flexibility in these muscle groups. It is often accompanied by relative weakness of the middle and lower trapezium, rhomboids, the upper thoracic extensors, the deep neck flexors, the rear delts, and the external shoulder rotators (the infraspinatus and the teres minor).(33) It results in the rounded shoulder, forward head posture frequently seen in bodybuilders.
Exercises in which the head is allowed to nod or protrude forward may contribute to cervical spine injury by either promoting the postural defect noted previously, or by predisposing the athlete to cervical disc problems. The tendency to jut the head forward in exercises such as shrugs (Figs 3 and 4), behind the neck presses (Fig 5), behind the neck pulldowns, lateral shoulder raises (Fig 6), triceps extensions, curls, incline leg presses, and abdominal crunches promotes the development of the rounded shoulder, forward head posture. This posture is associated with abnormal mechanical function of the cervical spine. It is characterized by adaptive shortening of the suboccipital muscles, the stemocleidomastoid and the anterior scalene muscles, and excessive tension and weakening of the long cervical extensor muscles, the levator scapulae and the scapular retractor muscles. Trigger points and/or muscle strain may result in any of these muscles. Either upper cervical or cervico-thoracic joint dysfunction may result. Not only do cervical pain syndromes occur, but also temporomandibular joint dysfunction and headache. (47,48)
[Fig 3. Shrugs with protruding head posture (unsafe)]
Protraction (protrusion) of the head during exercises in which the neck muscles are under load has also been linked with an increased risk of cervical disc derangement (herniation).(49) The forward head posture results in anterior shearing and increased compression of the lower cervical discs as the head slides forward and the upper cervical spine becomes hyperextended. Forceful contraction of the trapezium, the sternocleidomastoid, and the other cervical muscles will increase the load on the cervical discs and the facets. This finding correlates with an epidemiologic study that found that weight training, particularly with free weights, was associated with an increased risk of cervical disc herniation.(30) Cailliet(5O) claims that this forward head posture also leads to accelerated degenerative changes in the cervical spine. He notes that each inch the head protrudes forward of the trunk results in the equivalent load of an extra head that the neck must support.
[Fig 4. Shrugs while maintaining neutral cervical spine posture(safe technique).]
[Fig 5. The behind the neck press may result in strain to the cervical spine and the anterior capsule of the shoulder.]
It should be noted that during the performance of some exercises, untrained lifters commonly not only protract the head but also tense and flex the neck forward during the performance of exercises. This action occurs most frequently with curls, lateral raises, and leg presses. This habit may be even more damaging than simply protruding the head. Beginning with the novice athlete, bench presses-both flat and incline-are commonly incorporated into weight training and may be involved in the cause of cervical spine injury. It is not clear whether the injury occurs from protrusion of the head as the bar is lowered or from forcibly hyperextending the neck (ie, driving the head backward into the bench) as the weight is pushed up.
Neck strengthening is a controversial topic. Little research has investigated the role of neck strengthening in injury prevention. Mobility of the cervical spine is important and may be emphasized to the exclusion of strengthening. Some experts(48) recommend that rehabilitative exercises be directed toward strengthening the scapular muscles with the cervical spine held in the neutral position. However, others(51,52) have achieved good results with direct neck strengthening exercises, especially those directed at the cervical extensors.
[Fig 6. Lateral raise with internal shoulder rotation and head protrusion may result in impingement of the rotator cuff and cervical spine strain.]
SHOULDER INJURIES
As a trade-off for mobility, the shoulder lacks some of the stability found in other joints.(53) The shoulder is under considerable stress during many commonly performed weight training exercises and, as a result, is frequently injured.(3,31,54,55) Shoulder pain is often taken for granted or ignored by many bodybuilders. For example, anterior shoulder pain felt secondary to performing bench presses (ie, achieving a "burn") is frequently assumed to be a sore anterior deltoid muscle from a hard workout. It may, in fact, represent a sign of rotator cuff strain or impingement.
Impingement syndrome and anterior instability are the most common types of shoulder conditions associated with weight training. It is important to recognize that these conditions often coexist.(54) Rotator cuff strain/tendinitis/tear, proximal biceps tendinitis, and subacromial bursitis frequently result from subacromial impingement. However, primary tendinitis resulting from overload may also occur. Less common types of shoulder injuries include brachial plexus neuropathy, suprascapular nerve impingement, posterior glenohumeral instability (due to heavy bench presses), acromio-clavicular joint sprains (AC), proximal biceps tendon tears, pectoralis major strains or tears, and osteolysis of the distal clavicle.
Impingement syndrome
Impingement syndrome refers to impingement of the rotator cuff tendons, especially the supraspinatus tendon, under the subacromial arch. The biceps tendon or the subacromial bursa may also be impinged under the subacromial arch. The position that appears to be most damaging is abduction with internal rotation. It is not clear whether rotator cuff muscle/ tendon overload precedes impingement or is caused by it.(53,56)
A major factor in shoulder impingement injuries in weight lifters is the muscle imbalance syndrome mentioned earlier, highlighted by overly tight shoulder internal rotators and weak shoulder external rotators.(53,57) A substantial portion of the typical training program is dedicated to training the pectorals and the lats. Both tend to produce internal rotation of the shoulders. The external shoulder rotators (the infraspinatus and the teres minor) are often neglected.
There is considerable stress imposed on the rotator cuff muscles during the performance of many exercises, such as the bench press. Too many sets of exercises for the same body part with excessive weight can result in fatigue and overload injury to the rotator cuff. Therefore, weight lifters should be encouraged to perform fewer sets and no more than 12 sets per body part, including warm-ups.
A common exercise is the lateral raise with the shoulder in internal rotation (Fig 6). The lifter is often instructed to point the thumb down as though pouring water from a pitcher in an effort to better isolate the side deltoid. It may be true, but there is a risk of accelerating or aggravating an impingement syndrome. The clinician should suggest that lateral raises be performed face down on an incline bench positioned at about 75 degrees up from the ground. This position will isolate the side delts without creating impingement (Fig 7).
Another common mistake is raising the arms above 90 degrees while performing side raises. Unless the thumb is pointing up, this position may increase the risk of impinging the rotator cuff tendons under the subacromial arch. Shoulder protraction is associated with narrowing of the subacromial space.(58) Allowing the shoulders to become protracted forward beyond the neutral position during the performance of exercises such as bench presses may increase the strain to this area.
Anterior instability of the glenohumeral joint
Instability may be due to a single-event trauma where the capsule and glenoid labrum are torn or may be atraumatic representing a tendency toward a loose joint capsule. When either inherently loose or torn loose, the capsule may be unable to support the shoulder in the extremes of abduction and external rotation. Therefore, exercises that place the shoulder in this position should be modified or avoided such as the behind-the-neck press, the behind-the-neck pulldown, and the pec deck(59) (Figs 5, 9, and 10). It may also occur from repeatedly hyperextending the shoulder during the performance of bench presses, flyes, and the pec deck by lowering the bar or dumbbells to the point where the elbows are behind the back. Weight lifters not only place their shoulders in an abducted/externally rotated or hyperextended position, but also do it with considerable weight held in their hands. The general principle to use in advising patients is to avoid positions in which the elbows extend behind the coronal plane of the body. It is important to remind the patient that overhead positions are less stable and therefore more risky. While instability is often caused by gradual repetitive capsular stretching injury, Olympic lifters tend to suffer instability resulting from a single-event traumatic injury. They often lose control of a weight while holding the weight in an overhead position.(54)
[Fig 7. A safer technique for performing the lateral raise while still isolating the side deltoid.]
[Fig 8. The upright row involves abducting the shoulder with internal rotation-potential impingement.]
It should be noted that the diagnosis of anterior instability may be overlooked due to a misleading response to testing. Patients often experience pain in the posterior shoulder when the arm is placed in an abducted/externally rotated position. It is thought that this posterior pain arises from traction or compression of the posterior structures as the shoulder subluxates forward. Also, anterior instability may be misdiagnosed as a rotator cuff strain.
The load and shift test is a form of instability testing that involves passively translating the humeral head while stabilizing the glenoid. This test may be performed with the patient in various positions, including seated with arm by the side, seated with the arm in the abducted and externally rotated position, and supine with the arm abducted and externally rotated. Excessive forward excursion of the humerus associated with either pain, apprehension, or clicking may all be considered positive signs. The relocation test should reduce the positive findings. This test involves restabilizing the humerus by pushing the head of the humerus from anterior to posterior while placing the arm in the "apprehension" position of abduction/external rotation. The relocation test is performed with the patient supine. Care should be taken to support the arm to avoid protective muscle spasm.(53)
Impingement may occur secondary to shoulder instability.(60) The response to testing includes pain felt with the apprehension test that is relieved by the relocation test. Apprehension is usually not the primary response to testing. In such cases, the underlying instability and the subsequent impingement should both be addressed.
[Fig 9. This technique in the pec deck exercise may result in overworking the anterior capsule of the shoulder.]
[Fig 10. This modified technique on the pec deck exercise is safer because it eliminates the externally rotated and extended position.]
Less common shoulder injuries related to weight training
There have been a number of reports in the literature of suprascapular nerve injury either via stretch or compression. Abduction of the arm against resistance has been implicated as the mechanism of injury.(61) The lateral raise and the shoulder press are two exercises that involve abduction against resistance.
A number of reports(5,20,62) document the occurrence of tears of the pectoralis major muscle or tendon, usually from bench pressing. The tendon may either avulse from the bone, tear at the musculotendinous junction, or tear in the muscle itself, usually near the musculotendinous junction. Most of these injuries occur while the arms are extended behind the chest.(20) To prevent such injuries the lifter should avoid lowering the bar to the point at which the shoulder is hyperextended.(5,20,62) Regular stretching may be helpful.
An entity known as atraumatic osteolysis of the distal clavicle has been reported in a number of studies as being related to weight training. This condition, referred to as weight lifter's shoulder, is marked by pain at the acromioclavicular joint while performing the dip, bench press, clean-and-jerk, and overhead presses. Radiographs show osteoporosis and loss of subchondral bony detail at the distal clavicle. In addition, cystic changes may also be present.(63,64) Atraumatic osteolysis is believed to result from repetitive loading of the acromioclavicular joint resulting in neurovascular compromise to the distal clavicle. Management is difficult given that most patients are serious lifters. Either a dramatic reduction in weight, elimination of the offending maneuver, or substitution of exercises may be suggested. Alternatives to the bench press include a narrow grip bench, cable crossovers, and the incline or decline press. If unsuccessful, elimination of heavy lifting for 6 months is recommended. There is some evidence that those treated surgically with amputation of the distal I to 2 cm of the clavicle are able to return to some lifting. However, many athletes are not able to return to a pre-injury level of lifting.(63)
KNEE INJURIES
Knee pain secondary to weight lifting is often caused by an overuse injury involving the patellofemoral joint, or the quadriceps or patellar tendons. However, tears to the menisci may also occur. Patellofemoral pain syndrome may or may not include chondromalacia. Ligamentous problems are rare except when caused by trauma during Olympic weight lifting.
One study(65) found that former elite weight lifters had a 31% incidence of osteoarthritis of the knee as compared with former runners who had only a 14% increased incidence of osteoarthritis of the knee. The patellofemoral joint was the most common location. One should keep in mind that Olympic lifts require ballistically dropping into a very deep squat, to the point where the hamstrings rest against the calves. Such extreme squatting positions result in very high meniscal compressive forces and patellofemoral contact forces. Also, competitive lifters often lift maximal weights. Elastic knee wraps are frequently worn while performing squats and other heavy leg exercises with the intention of protecting the knee joint. Such wraps may increase the friction between the patella and the underlying cartilage, thus increasing the risk of knee injury.(9,40)
Some general rules of thumb for athletes with patellofemoral pain are:
If the weight lifter has had damage to the anterior cruciate ligament it is important to:
This author has seen the greatest number of knee injuries occur as the result of hack squats. However, regular squats, leg presses, knee extensions, lunges, step-ups, and leg curls may all play a role in overuse injuries. In particular, bouncing at the bottom of a squat has been implicated as a cause of patellar tendon strain due to the high eccentric forces generated during this technique.(9) One case report even documents a bilateral quadriceps tendon rupture that occurred while squatting.(23)
CONCLUSION
Weight training is a wonderful form of exercise when practiced sensibly and in moderation. Helping athletes and other patients to continue performing their strength training exercises by modifying their programs in an attempt to prevent injuries is a great benefit. We should consider the advice given by Hippocrates 2,400 years ago: "Exercise should be mild at first, gradually increasing, gently warming and not taking too much from the available strength . . . exercise should be as far as possible natural and there should be plenty of them; violent exercise should be sparingly used, and only when necessary."(66, p.289)
Bodybuilders and Athlete
UNDERSTANDING BODYBUILDING TRAINING
A discussion of bodybuilding injuries must include a description of various routines and exercises performed by bodybuilders. Bodybuilding-style weight training is the type of weight training most commonly performed in the United States by both athletes and recreational lifters. This type of training involves multiple sets of various exercises performed with multiple repetitions. The intention is to isolate particular muscle groups. The amount of weight used is typically moderate (60% to 80% maximal strength). The goal is to promote muscular hypertrophy. This training is in contrast to power lifting and Olympic-style lifting.
Power lifting involves lifting very heavy or maximal weight (up to 100% maximal strength) using relatively few repetitions. Power lifters perform relatively small numbers of sets per workout and their training revolves around three lifts-the squat, the bench press, and the dead-lift. The goal is to achieve maximal strength. Olympic-style lifting, like power lifting, involves performing relatively small numbers of sets and exercises involving few repetitions. Training is focused around performing specific lifts-the clean, the clean and jerk, and the snatch. The weight is literally jerked up, largely using the powerful muscles of the back and legs. The goal is to develop maximal power.
While some athletes involved in strength training may perform Olympic lifts and/or power lifts, most of their training involves bodybuilding-style training. There are several reasons for this focus. Bodybuilding training helps to build the muscular hypertrophy necessary for many contact sports. This type of training can also facilitate a later strength training phase. A thicker muscle with greater cross-sectional area can generate more potential force.(2) Bodybuilding training also helps to provide balanced strength around joints by specifically isolating weak links that could otherwise allow excessive stress to the joint and subsequent injury.
COMMON BODYBUILDING ROUTINES
Bodybuilding routines tend to include a high volume of sets and exercises, repeated multiple times per week. For example, it would not be unusual for a bodybuilder to perform five different exercises for his or her chest with four to five sets of each exercise using 6 to 15 repetitions. At least two or three of these sets will typically be taken to failure (ie, the point at which no more repetitions [reps] can be performed). Advanced techniques are also often employed. These techniques include forced reps, cheating reps, drop the weight sets, negatives, and supersets (see Table 1). The full workout could involve 1,500 repetitions and take 2 to 3 hours to complete. Fatiguing workouts may be performed 5 to 7 days per week without a break. This schedule may result in overtraining and injury.
Many weight training injuries may be related to stressing the same joints repeatedly until muscular or tendinous failure occurs. Repeatedly training to failure without any periodization or cycling of the intensity or duration of the workouts increases the risk of tendinitis and other injuries. So, too, does the large volume and frequency of training. In addition, poor techniques may result in abnormal wear on joints and over time may lead to cartilage breakdown.
In contrast, power lifters and Olympic weight lifters tend to perform fewer sets and reps in each training session. They tend to periodize or cycle their workouts and slowly work up to their maximum lift over a period of weeks or months. They do not attempt to train to failure at each workout as bodybuilders typically do. Thus high-level lifters attempt to peak during the competitive season, avoiding the harmful effects of overtraining.
While there are no accurate statistics to compare, there is some evidence that power lifters and Olympic lifters may actually have a slightly lower rate of injuries than bodybuilders. For example, despite using much heavier weight in the bench press than bodybuilders, power lifters seem to have a lower incidence of pectoralis major tears. Reynolds and colleagues(5) concluded that part of the problem was the total volume of work that bodybuilders perform. Itresults in fatigue of the pectoralis muscle, predisposing the muscle to tearing.
This is not to say that many injuries do not occur with power lifting or Olympic lifting. The extremely heavy weights and the strenuous nature of the power lifts may result in substantial injury. Likewise, the explosive efforts involved in Olympic lifting exercises like the clean and jerk lead to a fair share of injuries.(6) At least one study(7) showed significantly increased disc degeneration among former Olympic weight lifters as compared to other athletes and controls.
Most bodybuilders do not warm up and spend little to no time stretching. However, some exercises require extreme ranges of motion in the shoulders and other joints. A few recommended bodybuilding routines actually involve these very stressful, potentially dangerous stretching exercises. For example, one popular training manual recommends fascial stretching.(8) One stretch involves hanging from a pull-up bar with the arms behind the back, a movement that could overstretch the anterior capsule of the shoulder, resulting in shoulder instability. Such fascial stretching is believed to increase muscle size, strength, and separation and lead to altered bone structure, such as an expanded rib cage and wider clavicles.(8) It is also claimed that tightness in the fascial sheath limits muscle growth and that forcefully stretching the fascia will increase the likelihood of muscle hypertrophy. There is no scientific basis for these claims; however, such advice is often followed by bodybuilders and may be a factor in causing excessive flexibility. Excessive flexibility, in turn, has been linked to an increased risk of injury.(9,10)
Some of the advanced techniques of bodybuilding (Table 1) designed to allow the lifter to exercise beyond failure and stimulate recruitment of additional muscle fibers may also lead to an increased risk of injury. For example, negative accentuated repetitions, where the emphasis is on lowering of the weight, may result in a greater chance of injury. Eccentric (negative) contractions, in which the muscle is lengthened while under tension, have been linked to both delayed onset muscle soreness(11-13) and increased muscle fiber damage.(12,13) Eccentric contractions are considered to be important for stimulating muscle growth(3) but may also lead to an increased risk of muscle or tendon injury.(12,14,15)
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Table 1. Advanced training techniques
Training to failure: Performing as many repetitions as can possibly be performed.
Forced reps: Having a training partner to assist (ie, active spotting) in performing additional reps past the point of failure.
Cheating reps: Performing as many reps as possible in good form and, when no more reps can be completed, modifying form to complete one or more additional reps. It is a method of going beyond failure without a spotter.
Negatives: This approach emphasizes the eccentric, negative portion of the repetition. To emphasize the negative portion of a full range-of-motion exercise, movement is slowed down as the weight is lowered. In other words, the muscle is still contracting as it is lengthening. It is possible to lower more weight slowly than can be raised, so this technique allows the muscle to be overloaded to a greater extent. A training partner helps raise the heavier weight. Note that eccentric contraction is important for muscular hypertrophy.(3)
Drop the weight sets (breakdown sets): Performing a set to failure and then reducing the weight by 10% to 20% and performing some additional repetitions to failure. It is believed that this type of training will recruit additional muscle fibers.(4)
Supersets: Performing two or more exercises in rapid succession with little or no rest in between. Exercises for the same or different body parts may be combined.
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GENERAL RECOMMENDATIONS TO PREVENT INJURIES
To prevent weight training injuries, the clinician should conduct a detailed consultation with the athlete in order to determine the specifics of his or her training program. To save time the clinician can have the athlete document his or her weekly workout, complete with exercises, sets, repetitions, and equipment used.
There are two main approaches to determining the amount of weight to use with a specific exercise. The oldest method is referred to as progressive resistance exercise (PRE). The general concept is to determine a 10 resistance maximum (RM)-the maximum amount of weight an individual can lift 10 times-and use it as the starting weight. For beginners or those on a rehabilitation program, it is often recommended to use half of the 10 RM weight and perform three sets of 10.
Another variation is the daily adjustable progressive resistance exercise (DAPRE) technique. Four sets are used. The weight used in the fourth set and the following workout are determined by how many repetitions are accomplished in the third set. In the first set half of the maximum weight (first determined by a PRE approach) is performed 10 times. In the second set three quarters of the maximum weight is lifted six times. In the third set, the maximum weight is lifted as many times as possible. If the weight is lifted only a few times, the athlete is instructed to decrease the maximum weight by 5 to I 0 lb. If the athlete lifts around five to six reps, he or she keeps the maximum weight the same. If he or she is able to lift more than six reps, the next set will use a weight with a 5- to 10-lb increase. A fourth set is performed, and the same principle for determining the working weight for the next workout is used based on the number of reps performed. This approach is most valuable when heavier weights are employed such as when training larger muscle groups, such as the legs, chest, or back.
It is important to remind the weight lifter that more is not necessarily better. Three to four sets of three exercises per body part is probably sufficient to stimulate the muscle hypertrophy response. At least 3, and as many as 7, days of rest should be taken between workouts of a body part. Some top level bodybuilders have made great gains training each body part only once per week.
It is recommended that workouts of lower intensity be alternated with workouts of higher intensity and lower volume in order to prevent overtraining. Periodization is a systematic method of training that involves preplanned periods or phases of training that allow the athlete to peak for competition or sport while avoiding overtraining. Strength coaches typically use such periodization programs when designing strength training programs for their athletes. Although there are many variations of the periodization approach, the general concept is to divide an annual training program into phases. The first phase usually includes high-volume, low-intensity workouts emphasizing technique. The second phase shifts the emphasis to power and strength workouts (for anaerobic sports) or high intensity, low-volume workouts (for aerobic sports). During competition the emphasis shifts to high-intensity, techniquefocused exercises using short workout periods. A fourth phase is often added emphasizing "active rest" where the athlete is not focusing on training, but is playing recreational sports. Viewed on a graph, it is apparent that the periodization approach is a gradual shift from high-volume, low-intensity work to low-volume, high-intensity work. In this author's experience it is a more rational way for bodybuilders to approach their training. The strategy of periodization should be recommended as a means of decreasing injuries and improving potential gains. (5,16)
A 5- to 10-minute warm-up on a stationary cycle or treadmill is a good way to raise body temperature and ready the body for high intensity exercise.(17) Some slow, static flexibility exercises following the warm-up will help to elongate muscles, tendons, and the surrounding connective tissue, and they will likely help prevent injury.(18) Such stretching should be gentle, and care should be taken not to overstretch. Flexibility exercises should be repeated after the workout as a cool-down to prevent shortening of the muscles and tendons. Stretches should be held for 15 to 30 seconds and may be repeated several times. Ballistic stretching should be avoided, as should bouncing at the end of the range of motion.
TYPES OF WEIGHT TRAINING INJURIES
A wide range of weight training injuries has been documented in the literature. These reports include a number of unusual injuries such as: subarachnoid aneurysmal hemorrhage (19); ruptures of the pectoralis major, (20) biceps,(21) triceps,(22) and quadriceps muscles (23); fracture of the dome of the talus(24); and Kienbock's syndrome (25) among others. This article will focus on some of the more common weight training injuries involving the lumbar spine, the cervical spine, the shoulder, and the knee.
The lower back is the site of greatest injury.(26-28) A number of reports point to the shoulder and the knee as the next most frequent sites of injury during weight training.(3,27-29) At least one epidemiologic study suggests a significant statistical link between weight training and cervical disc herniation.(30)
[Appendix D presents practical aids with recommendations for preventing various injuries while weight training.]
LUMBAR SPINE INJURIES
In both youths(26-29,31) and adults(32,33) the most common weight training injuries involve the lower back. The mechanisms of injury include hyperflexion, hyperextension, torsion, and overdevelopment and excessive tightening of the iliopsoas muscles. The most common back problems are mechanical sprains and strains; however, disc injury or spondylolisthesis may also occur. Spondylolisthesis may be due to the stress imposed at the neural arch while performing exercises that involve repetitive lumbar spine flexion and extension under load. It is particularly true of dead-lifts.(34)
The greatest number of weight training-related back injuries result from exercises in which the trainee is in the flexed posture, such as rows and dead-lifts. A bent barbell row is often performed standing with heavy weight held at arm's length while bent at the waist and the legs held straight. This position creates perhaps the greatest amount of contractile tension on the lumbar spine musculature and the greatest lumbar disc pressure.(35) A frequent error is to allow the back to round and then to jerk the weight up using the hip muscles to generate power. Lumbar flexion while lifting results in the load being shifted from the back muscles to the posterior ligaments, the thoracolumbar fascia, and the lumbar discs. The lower back muscles stop contracting when the spine is sufficiently flexed, a phenomenon known as the flexion relaxation response of the erector spinae.(36) It may result in injury to ligaments or discs.
The seated cable row exercise may also result in a hyperflexion injury to the lumbar spine, a problem often encountered in this author's practice. The injury usually results from leaning forward at the starting point of each rep, allowing the spine to flex, in an effort to get a good stretch (see Figs 1 and 2).
Extremely heavy weights are sometimes used in weightlifting exercises. As much as 1,000 lb can be used in the squat and dead-lift. While steadily applied compressive forces alone rarely injure the disc, rupture of the vertebral end plate or fatigue microfractures of the trabeculae of the vertebral bodies may result.(37,38) Research(39) reveals that retired heavyweight lifters exhibit significantly greater reduction of disc height on X-ray compared with controls.
Fig l. Unsafe technique in the seated row exercise-hyperflexion of the spine.
[** Illustrations(photos) have not been included in this on-line version, but are available on reprints of the original paper.]
Fig 2. The correct technique-maintain neutral (lordotic) positive.
Hyperextension injury to the spine may result from arching backward while performing unsupported overhead presses,(32) moving into a hyperextended position while performing the back extension exercise ballistically, or while performing prone leg curls. During the leg curl, there is a strong tendency for the spine to be pulled into hyperextension as the psoas comes into play to assist the hamstrings. Hyperextension can cause abnormal loading of the facet joints and the capsules, resulting in an inflammatory response. It can also increase the load on a preexisting spondylolisthesis, resulting in greater strain to the supporting tissues. The solution is to contract the abdominals while pulling the hips against the bench in order to maintain a neutral lumbar positive. In addition, patients should be advised to avoid using too heavy a weight or overstraining at the end of a set.
Injury to either the facets or the discs may occur from rotational exercises such as twists or from the rotary torso machine. The lumbar spine is particularly vulnerable to torsional forces. Due to the sagittal orientation of the facets, only a limited amount of rotation can occur in the lumbar spine. Additional rotation may result in injury to the facets or shearing of the discs.(40,41) Research (42) suggests a link between twisting while lifting and an increased risk of disc herniation.
Twisting exercises are often performed in an attempt to isolate the transverse abdominus muscle and create a thinner waistline. However, the transverse abdominus does not contract while rotating the torso, and twisting exercises will not trim the waist. Despite its horizontal fiber orientation, the transverse abdominus functions mainly to compress the abdomen during functions such as forced expiration and defecation.(43,44)
Many commonly performed abdominal exercises may contribute to lower back injury through overdevelopment and tightening of the hip flexor, iliopsoas muscles. When the iliopsoas Muscle contracts, it exerts both increased compressive and shear forces on the lumbar spine.(45) Many abdominal exercises are actually exercises in which the hip flexor muscles rather than the abdominals perform much or all of the work. These exercises include full sit-ups, straight leg raises, high chair and hanging leg raises, crunches with the feet hooked under a sofa or an apparatus in the gym, V-ups, Roman Chair rocking crunches, and most abdominal machines. Hooking the feet under a stationary object for support increases the tendency for the hip flexors to be recruited during sit-ups.
CERVICAL SPINE INJURIES
While not as common as back injuries, neck injuries occur fairly frequently in weight lifters. Cervical spine problems include mechanical sprains and strains, disc injuries, and brachial plexus injuries. Soft tissue injuries may result from protruding the head forward or from unnecessarily tensing the neck while weight training. Some problems result from a muscle imbalance syndrome similar to the "upper crossed syndrome" described by Janda.(46) This problem occurs because of imbalance in training programs that involve an inordinate amount of exercise for the pectorals, the front delts, the lats, and the biceps and very little training of antagonist muscle groups. The result can be overly developed and tight pectoralis major and minor, latissimus dorsi, front deltoids, trapezium, biceps, and stemocleidomastoid muscles, especially if proper attention has not been given to maintaining flexibility in these muscle groups. It is often accompanied by relative weakness of the middle and lower trapezium, rhomboids, the upper thoracic extensors, the deep neck flexors, the rear delts, and the external shoulder rotators (the infraspinatus and the teres minor).(33) It results in the rounded shoulder, forward head posture frequently seen in bodybuilders.
Exercises in which the head is allowed to nod or protrude forward may contribute to cervical spine injury by either promoting the postural defect noted previously, or by predisposing the athlete to cervical disc problems. The tendency to jut the head forward in exercises such as shrugs (Figs 3 and 4), behind the neck presses (Fig 5), behind the neck pulldowns, lateral shoulder raises (Fig 6), triceps extensions, curls, incline leg presses, and abdominal crunches promotes the development of the rounded shoulder, forward head posture. This posture is associated with abnormal mechanical function of the cervical spine. It is characterized by adaptive shortening of the suboccipital muscles, the stemocleidomastoid and the anterior scalene muscles, and excessive tension and weakening of the long cervical extensor muscles, the levator scapulae and the scapular retractor muscles. Trigger points and/or muscle strain may result in any of these muscles. Either upper cervical or cervico-thoracic joint dysfunction may result. Not only do cervical pain syndromes occur, but also temporomandibular joint dysfunction and headache. (47,48)
[Fig 3. Shrugs with protruding head posture (unsafe)]
Protraction (protrusion) of the head during exercises in which the neck muscles are under load has also been linked with an increased risk of cervical disc derangement (herniation).(49) The forward head posture results in anterior shearing and increased compression of the lower cervical discs as the head slides forward and the upper cervical spine becomes hyperextended. Forceful contraction of the trapezium, the sternocleidomastoid, and the other cervical muscles will increase the load on the cervical discs and the facets. This finding correlates with an epidemiologic study that found that weight training, particularly with free weights, was associated with an increased risk of cervical disc herniation.(30) Cailliet(5O) claims that this forward head posture also leads to accelerated degenerative changes in the cervical spine. He notes that each inch the head protrudes forward of the trunk results in the equivalent load of an extra head that the neck must support.
[Fig 4. Shrugs while maintaining neutral cervical spine posture(safe technique).]
[Fig 5. The behind the neck press may result in strain to the cervical spine and the anterior capsule of the shoulder.]
It should be noted that during the performance of some exercises, untrained lifters commonly not only protract the head but also tense and flex the neck forward during the performance of exercises. This action occurs most frequently with curls, lateral raises, and leg presses. This habit may be even more damaging than simply protruding the head. Beginning with the novice athlete, bench presses-both flat and incline-are commonly incorporated into weight training and may be involved in the cause of cervical spine injury. It is not clear whether the injury occurs from protrusion of the head as the bar is lowered or from forcibly hyperextending the neck (ie, driving the head backward into the bench) as the weight is pushed up.
Neck strengthening is a controversial topic. Little research has investigated the role of neck strengthening in injury prevention. Mobility of the cervical spine is important and may be emphasized to the exclusion of strengthening. Some experts(48) recommend that rehabilitative exercises be directed toward strengthening the scapular muscles with the cervical spine held in the neutral position. However, others(51,52) have achieved good results with direct neck strengthening exercises, especially those directed at the cervical extensors.
[Fig 6. Lateral raise with internal shoulder rotation and head protrusion may result in impingement of the rotator cuff and cervical spine strain.]
SHOULDER INJURIES
As a trade-off for mobility, the shoulder lacks some of the stability found in other joints.(53) The shoulder is under considerable stress during many commonly performed weight training exercises and, as a result, is frequently injured.(3,31,54,55) Shoulder pain is often taken for granted or ignored by many bodybuilders. For example, anterior shoulder pain felt secondary to performing bench presses (ie, achieving a "burn") is frequently assumed to be a sore anterior deltoid muscle from a hard workout. It may, in fact, represent a sign of rotator cuff strain or impingement.
Impingement syndrome and anterior instability are the most common types of shoulder conditions associated with weight training. It is important to recognize that these conditions often coexist.(54) Rotator cuff strain/tendinitis/tear, proximal biceps tendinitis, and subacromial bursitis frequently result from subacromial impingement. However, primary tendinitis resulting from overload may also occur. Less common types of shoulder injuries include brachial plexus neuropathy, suprascapular nerve impingement, posterior glenohumeral instability (due to heavy bench presses), acromio-clavicular joint sprains (AC), proximal biceps tendon tears, pectoralis major strains or tears, and osteolysis of the distal clavicle.
Impingement syndrome
Impingement syndrome refers to impingement of the rotator cuff tendons, especially the supraspinatus tendon, under the subacromial arch. The biceps tendon or the subacromial bursa may also be impinged under the subacromial arch. The position that appears to be most damaging is abduction with internal rotation. It is not clear whether rotator cuff muscle/ tendon overload precedes impingement or is caused by it.(53,56)
A major factor in shoulder impingement injuries in weight lifters is the muscle imbalance syndrome mentioned earlier, highlighted by overly tight shoulder internal rotators and weak shoulder external rotators.(53,57) A substantial portion of the typical training program is dedicated to training the pectorals and the lats. Both tend to produce internal rotation of the shoulders. The external shoulder rotators (the infraspinatus and the teres minor) are often neglected.
There is considerable stress imposed on the rotator cuff muscles during the performance of many exercises, such as the bench press. Too many sets of exercises for the same body part with excessive weight can result in fatigue and overload injury to the rotator cuff. Therefore, weight lifters should be encouraged to perform fewer sets and no more than 12 sets per body part, including warm-ups.
A common exercise is the lateral raise with the shoulder in internal rotation (Fig 6). The lifter is often instructed to point the thumb down as though pouring water from a pitcher in an effort to better isolate the side deltoid. It may be true, but there is a risk of accelerating or aggravating an impingement syndrome. The clinician should suggest that lateral raises be performed face down on an incline bench positioned at about 75 degrees up from the ground. This position will isolate the side delts without creating impingement (Fig 7).
Another common mistake is raising the arms above 90 degrees while performing side raises. Unless the thumb is pointing up, this position may increase the risk of impinging the rotator cuff tendons under the subacromial arch. Shoulder protraction is associated with narrowing of the subacromial space.(58) Allowing the shoulders to become protracted forward beyond the neutral position during the performance of exercises such as bench presses may increase the strain to this area.
Anterior instability of the glenohumeral joint
Instability may be due to a single-event trauma where the capsule and glenoid labrum are torn or may be atraumatic representing a tendency toward a loose joint capsule. When either inherently loose or torn loose, the capsule may be unable to support the shoulder in the extremes of abduction and external rotation. Therefore, exercises that place the shoulder in this position should be modified or avoided such as the behind-the-neck press, the behind-the-neck pulldown, and the pec deck(59) (Figs 5, 9, and 10). It may also occur from repeatedly hyperextending the shoulder during the performance of bench presses, flyes, and the pec deck by lowering the bar or dumbbells to the point where the elbows are behind the back. Weight lifters not only place their shoulders in an abducted/externally rotated or hyperextended position, but also do it with considerable weight held in their hands. The general principle to use in advising patients is to avoid positions in which the elbows extend behind the coronal plane of the body. It is important to remind the patient that overhead positions are less stable and therefore more risky. While instability is often caused by gradual repetitive capsular stretching injury, Olympic lifters tend to suffer instability resulting from a single-event traumatic injury. They often lose control of a weight while holding the weight in an overhead position.(54)
[Fig 7. A safer technique for performing the lateral raise while still isolating the side deltoid.]
[Fig 8. The upright row involves abducting the shoulder with internal rotation-potential impingement.]
It should be noted that the diagnosis of anterior instability may be overlooked due to a misleading response to testing. Patients often experience pain in the posterior shoulder when the arm is placed in an abducted/externally rotated position. It is thought that this posterior pain arises from traction or compression of the posterior structures as the shoulder subluxates forward. Also, anterior instability may be misdiagnosed as a rotator cuff strain.
The load and shift test is a form of instability testing that involves passively translating the humeral head while stabilizing the glenoid. This test may be performed with the patient in various positions, including seated with arm by the side, seated with the arm in the abducted and externally rotated position, and supine with the arm abducted and externally rotated. Excessive forward excursion of the humerus associated with either pain, apprehension, or clicking may all be considered positive signs. The relocation test should reduce the positive findings. This test involves restabilizing the humerus by pushing the head of the humerus from anterior to posterior while placing the arm in the "apprehension" position of abduction/external rotation. The relocation test is performed with the patient supine. Care should be taken to support the arm to avoid protective muscle spasm.(53)
Impingement may occur secondary to shoulder instability.(60) The response to testing includes pain felt with the apprehension test that is relieved by the relocation test. Apprehension is usually not the primary response to testing. In such cases, the underlying instability and the subsequent impingement should both be addressed.
[Fig 9. This technique in the pec deck exercise may result in overworking the anterior capsule of the shoulder.]
[Fig 10. This modified technique on the pec deck exercise is safer because it eliminates the externally rotated and extended position.]
Less common shoulder injuries related to weight training
There have been a number of reports in the literature of suprascapular nerve injury either via stretch or compression. Abduction of the arm against resistance has been implicated as the mechanism of injury.(61) The lateral raise and the shoulder press are two exercises that involve abduction against resistance.
A number of reports(5,20,62) document the occurrence of tears of the pectoralis major muscle or tendon, usually from bench pressing. The tendon may either avulse from the bone, tear at the musculotendinous junction, or tear in the muscle itself, usually near the musculotendinous junction. Most of these injuries occur while the arms are extended behind the chest.(20) To prevent such injuries the lifter should avoid lowering the bar to the point at which the shoulder is hyperextended.(5,20,62) Regular stretching may be helpful.
An entity known as atraumatic osteolysis of the distal clavicle has been reported in a number of studies as being related to weight training. This condition, referred to as weight lifter's shoulder, is marked by pain at the acromioclavicular joint while performing the dip, bench press, clean-and-jerk, and overhead presses. Radiographs show osteoporosis and loss of subchondral bony detail at the distal clavicle. In addition, cystic changes may also be present.(63,64) Atraumatic osteolysis is believed to result from repetitive loading of the acromioclavicular joint resulting in neurovascular compromise to the distal clavicle. Management is difficult given that most patients are serious lifters. Either a dramatic reduction in weight, elimination of the offending maneuver, or substitution of exercises may be suggested. Alternatives to the bench press include a narrow grip bench, cable crossovers, and the incline or decline press. If unsuccessful, elimination of heavy lifting for 6 months is recommended. There is some evidence that those treated surgically with amputation of the distal I to 2 cm of the clavicle are able to return to some lifting. However, many athletes are not able to return to a pre-injury level of lifting.(63)
KNEE INJURIES
Knee pain secondary to weight lifting is often caused by an overuse injury involving the patellofemoral joint, or the quadriceps or patellar tendons. However, tears to the menisci may also occur. Patellofemoral pain syndrome may or may not include chondromalacia. Ligamentous problems are rare except when caused by trauma during Olympic weight lifting.
One study(65) found that former elite weight lifters had a 31% incidence of osteoarthritis of the knee as compared with former runners who had only a 14% increased incidence of osteoarthritis of the knee. The patellofemoral joint was the most common location. One should keep in mind that Olympic lifts require ballistically dropping into a very deep squat, to the point where the hamstrings rest against the calves. Such extreme squatting positions result in very high meniscal compressive forces and patellofemoral contact forces. Also, competitive lifters often lift maximal weights. Elastic knee wraps are frequently worn while performing squats and other heavy leg exercises with the intention of protecting the knee joint. Such wraps may increase the friction between the patella and the underlying cartilage, thus increasing the risk of knee injury.(9,40)
Some general rules of thumb for athletes with patellofemoral pain are:
- Do not perform squats through a painful range of motion(often in the midrange).
- Do not perform lunges or squats with the knees caving inward (keep the knees over the toes).
- Focus on the last 10' to 15' of knee extension when performing knee extension exercises.
- Take care not to press the kneecaps into the bench when performing leg curls (or any prone position of exercise). In other words, move toward the foot of the bench so that the patellae are not compressed while the knees are extended.
If the weight lifter has had damage to the anterior cruciate ligament it is important to:
- Avoid knee extension exercises (especially from 70' of flexion to full extension).
- Substitute seated knee extensions with closed chain exercises such as partial squats and leg presses.
- Focus on hamstring development (adds some dynamic support).
This author has seen the greatest number of knee injuries occur as the result of hack squats. However, regular squats, leg presses, knee extensions, lunges, step-ups, and leg curls may all play a role in overuse injuries. In particular, bouncing at the bottom of a squat has been implicated as a cause of patellar tendon strain due to the high eccentric forces generated during this technique.(9) One case report even documents a bilateral quadriceps tendon rupture that occurred while squatting.(23)
CONCLUSION
Weight training is a wonderful form of exercise when practiced sensibly and in moderation. Helping athletes and other patients to continue performing their strength training exercises by modifying their programs in an attempt to prevent injuries is a great benefit. We should consider the advice given by Hippocrates 2,400 years ago: "Exercise should be mild at first, gradually increasing, gently warming and not taking too much from the available strength . . . exercise should be as far as possible natural and there should be plenty of them; violent exercise should be sparingly used, and only when necessary."(66, p.289)
