肩関節外転位における内旋運動での肩甲骨周囲筋群の変化

抄録

To measure and evaluate changes of the scapular muscles by MRI at the shoulder internal rotation in shoulder abduction quantatively. The subjects were 8 overhead varsity athletes. Before and after performing shoulder internal rotation exercise of 30 deg / sec in 90 degree-abduction in Biodex, MRI was taken and T2 relaxation time of the rotator cuff (infraspinatus muscles (ISP)) and scapular muscles (trapezius muscle upper (TU), trapezius muscle middle (TM), trapezius muscle lower (TL), rhomboid muscle major (RMJ) pectoralis major (PEC)) were calculated. TM and RMJ revealed significant elongation of T2 relaxation time after internal rotation exercise, which meant not only rotator muscles but also scapula stabilizer muscles functioned during internal rotation motion of shoulder at 90 degree-abduction position. The scapular stabilizer, especially trapezius muscle middle and rhomboid muscle major could play important roles for shoulder rotation at abduction position in the overhead athletes.