Differences in Scapular Upward Rotation between Baseball Pitchers and Position Players

Abstract

Background Baseball pitchers have been reported to have an increased prevalence of shoulder injury compared with position players such as infielders and outfielders. Furthermore, insufficient scapular upward rotation has been empirically linked with several of these shoulder disorders. However, the difference in scapular upward rotation between pitchers and position players is not known. Hypothesis Pitchers will have decreased scapular upward rotation of their dominant shoulders compared with position players. Study Design Descriptive laboratory study. Methods Dominant shoulder scapular upward rotation was measured with the arm at rest and at 60°, 90°, and 120° of humeral elevation among 15 professional baseball pitchers and 15 position players with no recent history of upper extremity injury. Results Independent t tests showed pitchers have significantly less scapular upward rotation at 60° (3.9°, P = .011) and 90° (4.4°, P = .009) of humeral elevation compared with position players. Conclusion Baseball pitchers have less scapular upward rotation than do position players, specifically at humeral elevation angles of 60° and 90°. Clinical Relevance This decrease in scapular upward rotation may compromise the integrity of the glenohumeral joint and place pitchers at an increased risk of developing shoulder injuries compared with position players. As such, pitchers may benefit from periscapular stretching and strengthening exercises to assist with increasing scapular upward rotation.