The Research of EMG activity of the rotator cuff muscles and the optimal training machine production to train those muscles.

【study1】本研究旨在探讨不同负荷和重复对肩部旋转运动中肩部肌肉肌电活动的影响。用表面电极记录冈下肌、后三角肌、中三角肌和中斜方肌的肌电活动，用最大自愿收缩归一化。在负荷与%iEMG的关系中，与无负荷运动时相比，20%IS和60%IS时冈下肌表现出显著差异。在重复与%iEMG的关系中，10%IS（等距力量）运动时9 ~ 20次重复、20%IS运动时4 ~ 20次重复和30%IS运动时1 ~ 20次重复的冈下肌与各无负荷运动时的差异显著。结果表明，10% IS负荷下重复20次以上、20%IS负荷下重复7 ~ 10次、30%IS负荷下重复3 ~ 7次是冈下肌的适宜训练范围。【研究2】本研究的目的是开发肩袖训练机。首先，收集了12 - 21岁男性的肩关节旋转强度和活动范围数据。从这些数据可以看出，与现有的训练机相比，肩袖训练机所需的负荷较轻。此外，每几百克的负载调整是必要的。本课题组对训练机进行了设计，并询问了专业厂家的生产情况。

【study1】The purpose of this study was to investigate the effect of the difference load and repetition on the EMG activity of shoulder muscles during the performance of the shoulder rotation exercise. EMG activity for the infraspinatus, posterior deltoid, middle deltoid and middle trapezius were recorded using surface electrode and normalized using maximum voluntary contraction.In the relationship between load and %iEMG, the infraspinatus showed significant differences at 20%IS to 60%IS in comparison with that during non-load movement. In the relationship between repetition and %iEMG, the infraspinatus showed significant differences 9 to 20 repetition during 10%IS(isometric strength) movement, 4 to 20 repetition during 20%IS and 1 to 20 repetition during 30%IS in the comparison with that during each non-load monement.These results suggest that 20 repetition and more at 10% IS load, 7 to 10 repetitions at 20%IS load and 3 to 7 repetition at 30%IS load are the appropriate range of training for the infraspinatus muscle.【Study 2】The purpose of this study was to develop the rotator cuff training machine. First, the shoulder rotational strength and range of motion data for males from 12 to 21 years old were collected. From this data, it understood that the load needed for the rotator cuff training machine is light in comparison with the load that is used with an existing training machine. Furthermore, load adjustment for each several hundreds gram is necessary. This research group did the design of the training machine and asked the production of the machine of the manufacturer of the speciality.