Differences of shoulder function between pitching side and non-pitching side of patients with throwing shoulder injuries

Abstract

[Purpose] To compare the shoulder functions of the pitching and non-pitching sides of patients with throwing shoulder injuries. [Subjects and Methods] The subjects were 44 male baseball players. Scapulohumeral and scapulothoracic shoulder-joint functions (7 ROM items, 13 strength measures) of the pitching and non-pitching sides were compared. [Results] On the pitching side, the retroversion angle of the humeral head and the secondary external rotation angle were significantly large, whereas the values of the secondary internal rotation angle, horizontal flexion test, scapular retraction test, inner muscle strength, and the strength of the muscle fibers of the lower trapezius muscle were either significantly lower, or smaller. [Conclusion] The results suggest that characteristic differences in shoulder functions related to ROM and muscle strength of the pitching and non-pitching sides seen in cases of throwing shoulder injury are strongly related to shoulder pain at the time of throwing.