Relationship between shoulder complex alignment and standing posture control in the mimicked cocking phase of pitching motion

Studying purpose was to assess the relation between trunk and foot COP at the cocking phase during pitching motion. Subjects were 22 healthy men. We measured using goniometer and electronic vernier caliper at the cocking posture the horizontal abduction angle of humeral articulation (HABD), scapula spine distance (SSD), body rotation angle and horizontal abduction angle of humerus against a line of PSIS (cocking angle), and we estimated ratios of the horizontal abduction angle of humeral articulation (HABDR) and scapula spine distance (SSDR) to the cocking angle. We measured COPs feet using stabilometer. Correlation coefficients between upper trunk alignments and COPs both feet were as follows: HABDR vs both foot COP; and SSDR vs. both foot COP.Results suggest anterior and inner placements of foot COP associate with the movements of scapula and body trunk to reduce the horizontal abduction stress of shoulder joint at the cocking phase of pitching motion.