Effect on range and strength of shoulder rotation of repeated shadow pitching exercise

Abstract

[Purpose] The purpose of this study was to clarify the effect on the range and strength of shoulder rotation of repeated shadow pitching exercise. [Subjects] The subjects were 9 male high-school baseball club pitchers. [Methods] Before and after consecutive normal pitching and shadow pitching, we compared the shoulder internal and external rotation range of motion (ROM) with or without the scapula fixed, shoulder internal and external rotation strength, and subjective fatigue on the throwing side between the two tasks. [Results] Normal pitching and shadow pitching decreased shoulder internal and external rotation strength. However, decrease of shoulder internal rotation ROM was found only in normal pitching, and shadow pitching increased shoulder external rotation. [Conclusion] The results suggest that the contribution of the scapulothoracic joint to shoulder rotation during the pitching motion of shadow pitching is large, possibly decreasing the risk of throwing injury.