Scapular position and orientation in throwing athletes

Background: Despite the recognized importance of proper 3-dimensional motion of the scapula in throwers, minimal research has quantified scapular position and orientation in throwing athletes. Hypothesis: Throwing athletes exhibit scapular position and orientation differences when compared to nonthrowing control subjects. Study Design: Descriptive laboratory study. Methods: Scapular position and orientation during scapular plane humeral elevation were assessed with electromagnetic tracking in a group of 21 throwing athletes and 21 control subjects. Scapular upward/downward rotation, internal/external rotation, anterior/posterior tipping, elevation/depression, and protraction/retraction were assessed. Results: The throwing athletes demonstrated significantly increased upward rotation, internal rotation, and retraction of the scapula during humeral elevation. No differences in anterior/posterior tipping and elevation/depression were present. Conclusions: The results indicate that throwing athletes have scapular position and orientation differences compared to nonthrowing athletes. This suggests that throwers develop chronic adaptation for more efficient performance of the throwing motion. Clinical Relevance: Clinicians evaluate scapular position, orientation, and movement in throwing athletes as part of the evaluation of shoulder injuries associated with the throwing motion. The current study provides clinicians with an understanding of the types of adaptations that may be observed in normal, healthy throwing athletes.