Comparison of Forward Scapular Posture and Glenohumeral Range of Motion between Baseball Pitchers and Nonoverhead Athletes

Abstract

Background and Purpose: Pitchers have anecdotally been described as having a shoulder are increased external rotation (ER) and decreased internal rotation (IR), horizontal adduction, and total range of motion (ROM). Alternations in these physical characteristics and the demands placed on the shoulder during throw training may predispose pitchers to history of upper extremity injury. However, little data exist that compare these specific adaptations between pitchers and nonoverhead athletes. Therefore, the purpose of this study was to compare forward scapular posture and glenohumeral ROM between baseball pitchers and nonoverhead athletes. Methods: Twenty collegiate baseball pitchers and twenty-four nonoverhead athletes with no recent history of upper extremity injury participated. Nonoverhead athletes were recruited from collegiate track and soccer players. Dominant glenohumeral horizontal adduction, and IR ROM, ER ROM, and total arc of motion were measured with a standard goniometric. Forward scapular posture was measured with a double square. Results: Pitchers presented with less glenohumeral IR ROM (pitchers = 77.08° ± 3.96°, nonoverhead = 82.75° ± 3.74°; p = 0.002) and horizontal adduction ROM (pitchers = 14.66° ± 1.87°, nonoverhead = 22.25° ± 2.49°; p = 0.001) than nonoverhead athletes. However, pitchers had significantly more forward scapular posture compared with nonoverhead athletes (p = 0.001). No significant differences existed between pitchers and nonoverhead athletes for ER ROM and total glenohumeral ROM. Conclusions: Repetivive throwing motion creates increased forward scapular posture, decreased glenohumeral internal rotation ROM and horizontal adduction ROM. It is important to take part in internal rotation stretching program and minimize risk factor for shoulder injury in throwers. Clinical Relevance: Understanding the physical adaption will help clinicians to develop injury-prevention programs specific to baseball pitchers.