The Thrower’s Shoulder

1 Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA Throwers, or athletes who engage in repetitive overhead motions, are a unique subset of athletes that experience distinct injuries of the shoulder. The majority of athletes who present with a throwing related injury are baseball players. Pitchers and fielders alike engage in drills and game scenarios where throws are made at high velocities, long distances, and in a repetitive nature, all of which increase the strain on the arm of the young athlete. Baseball remains one of America’s favorite pastimes and youth engage in this sport often by the age of six or seven. This early participation in overhead throwing increases the likelihood that orthopedic surgeons may encounter patients with shoulder pain. Injuries peculiar to throwers most commonly involve the labrum and the undersurface of the rotator cuff. Material changes in both the anterior and posterior glenohumeral capsule can occur with repetitive overhead motions. These capsular changes may change shoulder kinematics and subsequently contribute to both labral and rotator cuff injury. Furthermore, the glenohumeral joint and the scapula are inextricably linked – what effects one will affect the other. Abnormal scapular kinematics may herald the development of tissue breakdown in the shoulder. This article will discuss the pathomechanics of injuries to throwers, examine the throwing motion, and correlate this to its long term effects on the glenohumeral joint and scapular kinematics.