Abstract：
In current rehabilitation practice, exercise selection is commonly based on the amount of muscle recruitment demonstrated by electromyographic (EMG) analysis. A preponderance of evidence supports the concept that EMG of a muscle and torque output are positively correlated. This study was designed to investigate the relationship between surface EMG activity of the infraspinatus and torque production during exercises involving shoulder external rotation (ER). A total of 30 participants (average age = 24.6 y) performed maximum voluntary isometric contraction of ER at 5 points within the range of motion of 3 shoulder exercise positions with concomitant surface EMG recording. As a maximal internally rotated position was approached, maximum ER torque and minimum or near-minimum EMG recruitment were demonstrated. Conversely, at maximally externally rotated positions, EMG activity was greatest and torque values were lowest. An inverse relationship between joint torque output and EMG activity was established in each of the 3 exercises. The inverse relationship between EMG activity and torque output during Shoulder ER suggests that there may be additional factors warranting consideration during exercise selection. Further research may be needed to determine the relative value of electrical activity versus torque output to optimize the selection of rehabilitative exercises.
摘要：
在目前的康复实践中，运动选择通常基于肌电图(EMG)分析显示的肌肉募集量.大量证据支持以下概念：肌肉的EMG与扭矩输出呈正相关。这项研究旨在研究在涉及肩部外旋（ER）的运动中，冈下肌的表面EMG活动与扭矩产生之间的关系。共有30名参与者（平均年龄=24.6岁）在3个肩部运动位置的运动范围内的5个点进行了ER的最大自愿等距收缩，并进行了表面EMG记录。当接近最大内部旋转位置时，显示了最大ER扭矩和最小或接近最小的EMG募集。相反，在最大外部旋转位置，EMG活动最大，扭矩值最低。在3个练习中，关节扭矩输出与EMG活动之间建立了反比关系。肩关节ER期间肌电图活动和扭矩输出之间的反比关系表明，在运动选择期间可能需要考虑其他因素。可能需要进一步的研究来确定电活动与扭矩输出的相对值，以优化康复锻炼的选择。
