Little Leaguer's Shoulder

Aka: Little Leaguer's Shoulder

1. Definition
   1. Proximal Humerus physis injury with open Growth Plate
2. Epidemiology
   1. Age distribution: 9 to 16 years old (mean age 14)
   2. Seen in young athletes involved with overhead activity
      1. Racquet sports
      2. Volleyball
      3. Baseball
      4. Swimming
      5. Gymnastics
   3. Most common occurence in young pitchers
      1. Especially with breaking pitches (e.g. curve balls)
3. Pathophysiology
   1. Stress injury to proximal humeral physis
   2. Injury secondary to throwing sports (esp. pitching)
      1. Stress occurs before Growth Plate closure
         1. Stress transmitted to proximal physis of Humerus
      2. Contrast with after Growth Plate closure (adults)
         1. Stress transmitted to rotator cuff
4. Symptoms
   1. Gradual pain onset (often over months)
   2. Pain located at lateral proximal Humerus
   3. Pain provoked by overhead activity
5. Signs
   1. Tenderness over proximal lateral Humerus
6. Imaging
   1. Bilateral three view Shoulder XRay (comparison)
      1. Proximal Humerus physis widening
   2. Other imaging (e.g. MRI) only needed in uncertain cases
7. Management
   1. See Prevention below
   2. Relative rest from throwing for 3 months
   3. Strengthening Exercises when pain decreased
   4. Throwing Exercises in intervals once pain-free
8. Prevention
   1. Allow for adequate recovery between outings
   2. Consider throwing mechanics evaluation
   3. New guidelines recommend no throwing for 3 months of every year
   4. Limit number of pitches per week and per outing
      1. Guidelines adjusted for age and pitch type
      2. AAP: 200 pitches/week and 90 pitches/outing
      3. USA-BMSAC: 125 pitches/week and 75 pitches/outing
9. References
   1. Carson (1998) Am J Sports Med 26:575-80 [PubMed]
   2. Cassas (2006) Am Fam Physician 73:1014-22 [PubMed]