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

[研究1]探讨不同负荷和重复次数对肩关节旋转运动中肩肌肌电活动的影响。用表面电极记录冈下肌、三角肌后肌、三角肌中肌和正中肌的肌电活动，并以最大自主收缩率标准化，在负荷运动与%iEMG的关系中，冈下肌在20%IS ~ 60%IS时与无负荷运动时相比有显著性差异。在重复次数与%iEMG的关系中，冈下肌在10%IS时重复9 ~ 20次，差异有显著性等长肌力运动，20%IS时重复4 ~ 20次，30%IS时重复1 ~ 20次，与各无负荷运动比较，结果表明，10%IS负荷时重复20次以上，20%IS负荷训练7 ~ 10次，30%IS负荷训练3 ~ 7次为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至21岁男性的肩关节旋转强度和活动范围数据。从该数据可知，与现有的训练机所使用的负荷相比，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。本课题组进行了训练机的设计，并请专业厂家生产。

【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.