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These common overuse injuries are usually a minor problem but, if ignored, they can end a young athlete's playing days and lead to long-term problems. Here's what you need to know about evaluation, treatment, and prevention.
Baseball is one of the most popular sports in the United States, with nearly 5 million children 5 to 14 years of age participating annually (during both Spring, and more and more, Fall programs) in organized and recreational baseball and softball,1 and a total of more than 20 million amateur players.2 This number is likely to increase as more children have the opportunity to participate in organized sports. Increasing participation has been accompanied by growth in specialization in a particular sport and elite levels of training and competition.3
Young athletes who focus on one sport, and play that sport year round, are at high risk for overuse injuries. Thirty percent to 50% of all pediatric sports injuries are thought to be caused by overuse; the incidence of baseball-related injuries is 2% to 8%.4 The true incidence of injury is unknown, however, because many athletes receive home treatment or do not report their injury.
Little League shoulder and Little League elbow are two common overuse injuries associated with baseball. They occur most often in pitchers but also in other frequent throwers on the team. Little League elbow, which is more common than Little League shoulder, also may occur in young tennis players and football quarterbacks. These injuries cause pain and disability and may lead to problems later in life.
Each phase has distinct movement patterns, which may be related to Little League shoulder and elbow.
The wind-up phase consists of positioning the body to throw and a high knee kick. This phase sets the body in forward momentum and involves minimal use of the throwing arm.
The cocking phase begins when the front foot makes contact with the ground and ends when the pitching arm is abducted and extended as far as possible behind the body. The shoulder is in maximum external rotation, the elbow is flexed, and the forearm is supinated. The deltoid, rotator cuff, and elbow musculature are very active in this phase.7
The acceleration phase begins when the throwing arm starts to rotate internally and adduct at the shoulder, while the elbow extends. This very rapid phase ends with the release of the ball. A large valgus force stresses the medial ligaments at the elbow.8
Follow-through is the deceleration of the arm and return of balance so the pitcher can resume defensive play. The antagonist muscles contract to slow the arm, and the external rotators of the shoulder contract strongly to maintain the stability of the glenohumeral joint.8
Elite-level pitchers have well-established throwing mechanics. In younger athletes, who are still developing throwing mechanics, improper mechanics can lead to differences from ideal mechanics in the forces generated during each phase and increase the risk of injury.
Age. The age range for Little League shoulder and elbow is about 9 to 16 years. Older adolescents are skeletally mature and not at risk for apophysitis or avulsion fractures.
Initial onset and duration of pain. Overuse injuries usually have an insidious and progressive course rather than immediate pain after a single event. Athletes complain of pain with throwing; the discomfort may last for days. The patient does not often complain of symptoms in the office because he must throw to induce the discomfort.
What sports the athlete plays and when. Find out all the sports the athlete plays and what months of the year he (or she) participates in them. Athletes who play the same sport in more than one season have a higher risk of developing overuse injury than those who play in only one season. The proliferation of indoor facilities in cold weather states has turned baseball, and other "outdoor" sports, into year-round activities.
What position(s) the athlete plays. Athletes who play heavy throwing positions are more prone to overuse throwing injuries. In baseball, the positions with the greatest risk of such injuries, ranked from highest to lowest, are pitcher, catcher, third baseman, shortstop, and outfielder. 7
Skilled pitchers often are at higher risk of overuse injuries because they usually pitch more often and for a longer duration than their teammates. When not pitching, they play heavy throwing positions like shortstop and third base, or even rotate to one of those positions after pitching several innings in the same game. This increases the number of maximum-effort throws and decreases the athlete's time for rest. Many such pitchers have learned advanced pitches too early in their skeletal development.
Time each week spent practicing and playing in games and number of pitches thrown. Practice time includes practice outside of organized baseball, such as in the backyard or pickup games. Little League and most other youth baseball organizations have rules regulating the amount young athletes should pitch. However, coaches often do not consider overlap with other leagues and backyard practice. Pitch counting enumerates maximum-effort, game-quality pitches. Pitchers should detail the number of pitches thrown per game and per week. Also ask what types of pitches the athlete is throwing and at what age he or she began to use them. Note any recent changes in training because a sudden increase in throwing may make a player more susceptible to injury. Many coaches have described the "full throttle" phenomenon, which means that young pitchers tend to throw every pitch "all out" every game without pacing themselves. This can contribute to overuse injury.
Little League shoulder Proximal humeral epiphysitis, or Little League shoulder, is most often seen in high-performance pitchers between 11 and 16 years of age.9 Athletes in this age range are undergoing a rapid growth spurt, and many are beginning to develop and practice new pitching skills and techniques. It is not known whether Little League shoulder is caused by inflammation of the proximal humeral physis from overuse or a stress fracture of the physis, similar to a Salter-Harris Type I fracture.9
The proximal humeral physis appears at about 6 months of age and fuses between 19 and 22 years. It accounts for approximately 80% of humeral growth. 5 It fuses earlier in girls than in boys. Proximal humeral epiphysitis is not limited to baseball; it also occurs in athletes who play racquet sports, like tennis, and sports such as swimming and gymnastics.
High-level baseball pitchers have greater external rotation and less internal rotation in their dominant shoulder compared to the nondominant shoulder and the shoulders of nonthrowers.10 The difference is created by adaptive remodeling. It occurs at the proximal humeral physis of skeletally immature athletes in response to muscular forces and torques that accompany pitching. Adaptive remodeling of the humerus increases external rotation and reduces impingement of the rotator cuff on the glenoid rim.11 Although adaptive remodeling helps create the anatomy necessary to become an elite pitcher as an adult, that does not mean that it allows unlimited throwing in the skeletally immature athlete. It means that a young thrower's safe and successful development straddles the fine line between overuse and appropriate use.
The chief complaint of athletes with Little League shoulder is usually pain in the proximal humerus while throwing. The pain increases as the velocity and duration of throwing increases. The athlete may or may not have residual soreness that lasts more than a day after throwing. Onset of symptoms is usually gradual, and athletes often wait several months before coming in for medical evaluation. Many of these youngsters throw four to five times a week in practice, games, and at home, and only seek help when the pain does not allow them to continue throwing.9 They also may notice loss of velocity or control of pitches.
Diagnosis. The physical exam may be negative or relatively unremarkable. This does not rule out Little League shoulder because the hallmark of the disorder is pain while throwing. An athlete who has rested a few days or refrained from throwing may not have symptoms in the office. Athletes with Little League shoulder have tenderness to palpation of the proximal humerus. [Editor's note: For a more detailed discussion of the physical exam, see "An overview of overuse injuries" in the November 2001 issue of Contemporary Pediatrics.]
Begin the shoulder examination with inspection. The athlete should wear a tank top or no shirt so that you can observe any asymmetry in the shoulder and its musculature. Palpate the proximal humerus. It will be tender in an athlete with Little League shoulder.
Evaluate range of motion in both shoulders, especially with forward flexion and abduction. External rotation can be measured by having the athlete place his elbows at his side, flexed to 90° and rotated outward. Measure internal rotation by asking the patient to place his arm behind his back and reach up as high as possible along his spine. This is best accomplished by examining the arms one at a time. Although high-level throwers have increased external rotation and decreased internal rotation in the dominant arm compared with the nondominant arm, the total arc of motion should be similar for each shoulder if the shoulder is healthy.12
Strength testing of the shoulder and rotator cuff is also important to rule out a rotator cuff tear. Only about 25% of athletes with Little League shoulder demonstrate rotator cuff weakness with external rotation.9 Discomfort with resistance testing is much more common, however. Patients often complain of discomfort with supraspinatus testing and shoulder abduction and external rotation against resistance. Shoulder abduction testing is done by abducting the arms to 90° and applying a downward force. This maneuver tests the deltoid muscle, which may be uncomfortable in Little League shoulder.
The physical exam should also rule out referred pain caused by cervical spine pathology. The athlete should have full, pain-free range of motion in the neck. Spurling's test uses axial loads to compress the cervical spine. A positive result yields discomfort with radicular symptoms. The patient should also have a brief neurovascular exam of the affected extremity.
Treatment is almost always nonsurgical and includes a rest period of approximately two or three months. The athlete should undergo a physical therapy program with low weights and high repetitions to enhance strength and flexibility of the rotator cuff and scapular stabilizer musculature. Anti-inflammatory medications usually help relieve acute pain, but they should be used only for a few days to a couple of weeks. A thorough warm-up before activity and therapy followed by ice and rest also are helpful.
Once these criteria have been met, the athlete should begin a functional throwing progression under the direction of an experienced physical therapist or certified athletic trainer. The goal is a safe, carefully planned progression of the number, distance, and velocity of throws, including detailed rules regarding soreness and return of symptoms.13,14 The progression begins with short, low-velocity throws. As tolerated, the athlete increases the number of throws, velocity, and distance. If the athlete experiences soreness, he should rest and decrease throwing or remain at the same level.
An athlete may be able to return to play earlier if he changes to a position that involves minimal throwing, such as first base or designated hitter. Educating the athlete, family, and coaches about level of participation, pitch counts, and pitch types is paramount. The athlete should also be encouraged to play on only one team and avoid year-round throwing.
Little League shoulder is generally a self-limited injury. However, untreated athletes may develop growth plate injuries, avascular necrosis,15 and permanent loss of velocity and accuracy of throwing.
Little League elbow As noted, Little League elbow, or medial epicondylar apophysitis, is a more common injury than Little League shoulder. The incidence of elbow pain in 9- to 12-year-old baseball players is 26% to 40% in a given year.16,17 The classic injury is a stress reaction in the medial epicondyle of the humerus. The term Little League elbow describes the spectrum from stress reaction to the more advanced stages of the disorder. They include osteochondritis dessicans of the capitellum, avulsion fractures of the medial epicondyle, loose bodies or bone chips, and early arthritis with bone spurring and narrowing.
Little League elbow is most common in pitchers and other high-risk baseball players, but it also affects players of racquet sports, such as tennis and badminton.18 It is most often seen in athletes between 8 and 15 years of age. Symptoms occur in the athlete's dominant extremity.
There are six ossification centers in the elbow. The olecranon, medial, and lateral epicondyle ossification centers appear by 10 years of age and fuse by 16 or 17 years in boys. The radius appears at 4 years and fuses at about 16 years. The capitellum appears at 4 years and fuses at around 14 years. Finally, the trochlea appears by about 8 years and fuses at about 13 years. Fusion occurs one or two years earlier in girls than in boys.
The acceleration phase of throwing places a large force on the elbow, causing a valgus tension, which stresses the medial structures and compresses the lateral osseous anatomy.19 Sidearm throwing and improper mechanics increase the forces on the elbow. The medial epicondyle is the weakest structure in a skeletally immature elbow, and it is the site of most of the pathology.20 In adolescence, valgus stress overload may result in an avulsion fracture of the medial epicondyle. After physeal fusion, ulnar collateral ligament or ulnar nerve injury is more common.
The athlete complains of pain in the medial elbow and proximal forearm while throwing. The onset of pain is usually gradual, and the athlete cannot recall a distinct injury. Harder and farther throws and long periods of throwing exacerbate the pain. The athlete often has soreness after throwing that lasts longer than 24 hours. He also may complain of difficulty "loosening up" his elbow. Acute-onset pain or pain caused by a single pitch in a skeletally immature athlete is more suggestive of an avulsion fracture.
The physical exam may be normal or reveal minimal discomfort. As with Little League shoulder, this does not rule out Little League elbow because the hallmark is pain with throwing. An athlete who has not thrown for some time may have minimal symptoms at rest in the office.
Diagnosis. Examination of the elbow should begin with inspection and comparison to the opposite elbow. Note any swelling or asymmetry as well as overall alignment and carrying angle. The patient with Little League elbow usually has medial swelling and a flexion contracture to 15°.19 Assess flexion and extension range of motion as well as pronation/ supination. Young throwers should not have any extension deficits; decreased range of motion indicates significant disease.
Palpation of the medial epicondyle often elicits tenderness. Classic physical exam findings include point tenderness over the medial epicondyle and pain with resisted wrist flexion and pronation. The wrist flexors originate at the medial epicondyle. Also assess the lateral epicondyle, ulnar nerve, radial head, and olecranon process. The patient with classic Little League elbow should not have discomfort at these structures.
Ulnar nerve injury can cause medial elbow pain resulting from stretching or compression in the groove or a subluxing ulnar nerve. Patients usually complain of radiculopathy, or numbness in the fourth and fifth digits. Palpate the ulnar nerve throughout elbow flexion and extension to assess for discomfort and subluxation. Tinel's test (tap test) is very useful to reproduce symptoms. Athletes with chronic Little League elbow and ulnar nerve symptoms are likely to have ulnar neuritis.
Panner disease, or osteochondrosis of the capitellum, causes lateral elbow pain in athletes under 10 years of age. This benign disease ends in reossification of the epiphysis with no residual deformity or late sequelae. 20 The pain is usually mild and activity-related; it resolves quickly with rest. The patient often has discomfort proximal to the radial head accompanied by minimal effusion and flexion contracture. Radiographs show global fragmentation of the capitellar epiphysis. Panner disease is treated by restricting activity until symptoms resolve and ossification of the epiphysis occurs.
Osteochondritis dessicans (OCD) of the capitellum can be a debilitating disorder. The valgus compressive forces on the lateral elbow associated with throwing cause vascular insufficiency and resultant avascular necrosis.21 OCD presents as lateral elbow pain that gets worse with activity. The athlete often has swelling and a flexion contracture greater than 15°. He may complain of locking if there is a detached bone fragment. Radiographs show a focal lesion in the subchondral bone of the capitellum, and an MRI or CT scan may be needed to determine the size of the lesion and the condition of the cartilage.20 Treatment consists of rest and immobilization, but these lesions may require arthroscopic drilling and referral to an orthopedic specialist.
The physical exam for Little League elbow also should rule out referred pain from cervical spine and shoulder pathology.
Avulsion fractures with less than 5 mm displacement can be immobilized with the elbow at 90° of flexion for two to three weeks.22 After immobilization, the athlete should regain full range of motion through exercises and therapy. If the avulsed fragment is greater than 5 mm, refer the patient to an orthopedist.
Treatment. Initial treatment of Little League elbow is conservative. Immediate complete rest from throwing activities is the backbone of therapy. Athletes may take a nonsteroidal anti-inflammatory medication and should ice the medial elbow for 15 minutes three or four times a day. Ice massage is an effective method. To do this, the athlete should fill small paper cups with water and freeze them, then peel down the paper rim and gently massage the entire medial elbow.
Individualized physical therapy programs that concentrate on elbow range of motion and strengthening may be beneficial. Progressive strengthening programs should include the shoulder girdle and trunk. Players can be allowed to return to throwing when they display full range of motion and full strength (earlier if they play low-frequency throwing positions such as first base or designated hitter and keep maximum-effort throws to a minimum). As with Little League shoulder, functional progression of throwing overseen by an experienced physical therapist or certified athletic trainer is important. Education of the patient, family, and coaching staff mirrors what should be taught for Little League shoulder.
Most cases of classic Little League elbow resolve with rest and conservative management. Improper management may lead to functional disability or permanent deformity. Osteoarthritis is a potential long-term complication.7
Preventing shoulder and elbow injuries How many players have been lost to the major leagues, not to mention high school and college baseball, because of shoulder and elbow injuries suffered as children?23 No one can say, of course, but we can work toward protecting youthful players and preventing further injuries. In the quest for victory, it seems that the best young pitchers always pitch more often and longer than others, putting them at greater risk of injury. Educating athletes, parents, coaches, and sports medicine staff is a must.
Players need to recognize the benefits of year-round physical fitness. They must develop fundamental fitness skills before they can develop sport-specific skills.23 Resistance training is important for all athletes. Young athletes in a sport that requires repetitive throwing should use low weights, while doing high repetitions (10 to 12). Power lifting and so-called maxing out are not healthy for skeletally immature youth. Once an athlete turns 16 or 17, he can begin adult resistance training programs, taking care to use proper technique and form. Athletes who throw should focus lifting exercises on their lower extremities and trunk to build overall strength and not just concentrate on the upper extremities.
Athletes need a period of "active rest" every year.24 The rest period should be at least three months long to give the body time to rest and recover. During active rest, throwers should not participate in any throwing drills or other activities that involve extending arms over head, such as swimming, playing quarterback in football, and javelin throwing.
Young pitchers often start a game on the mound, then move to third base or shortstop. To reduce maximum-effort throws after pitching, a young thrower should not play any other heavy throwing positions during the same game. Nor should he pitch again that day. He should rest his arm over the next 24 hours. A pitcher should be discouraged from pitching for more than one team in a season and from "backyard practice" after a game.24 When not pitching, he needs to reduce maximum-effort throws during practice or while playing other positions.
Most organized leagues have rules regarding the amount a player can pitch. These rules should be enforced, and pitch counts should include every pitch an athlete throws in all leagues. The main contributors to shoulder and elbow injuries are pitch counts, pitch types, and pitch mechanics.25 Young athletes should avoid breaking pitches, such as a curveball or slider, until after they are 14 years old.25 The skeletally immature elbow and shoulder cannot handle the repetitive forces and torque produced by these pitches. Pitchers under 14 years old should rely instead on the fastball and change-up. The Guide for Patients and Parents on page 91 gives age-appropriate pitching guidelines.
Pain but no gain Like many other overuse or overload injuries, Little League shoulder and Little League elbow are an increasingly common diagnosis in general pediatric practice and sports medicine clinics. A careful history and physical examination, along with radiographs, often can pinpoint the problem.26 The physician should offer the athlete, the family, and the coaching and training staff information on return to play and injury prevention.
Athletes should never pitch or play through pain. An athlete who complains of tenderness around the joint or popping or discomfort with throwing should no longer throw that day. He should be watched closely for a return of symptoms and decrease the number of throws and pitches over the next several days. If symptoms return, he should be evaluated by a physician.
Overuse injuries generally respond well to the conservative treatment described here. Players should return to activity only after they have recovered full strength and full pain-free range of motion in the affected extremity and can throw without pain. Little League elbow and Little League shoulder are usually minor problems, but they often end a career when they are ignored.
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