Mechanomyographic study of motor unit activation strategy in voluntary muscle actions

本研究的目的是利用短时傅立叶变换检查股直肌（RF）、肱二头肌（BB）和第一背骨间肌（FDI）自愿等距斜坡收缩期间的非平稳机械肌图（MMG），并获得关于连续MMG/力关系下运动单元（MU）激活策略的更详细信息。受试者被要求以10% MVC/s的恒定速率，在最大自主收缩（MVC）的5%至70%的范围内，对每块肌肉进行坡道收缩。mmg -振幅/力和mmg -平均频率/力的变化关系与各肌肉的MU激活策略一致。这里描述的估计方法被认为是一种有用的工具，可以更详细地检查MMG/force关系。

The aim of this study was to examine the non-stationary mechanomyogram (MMG) during voluntary isometric ramp contractions of the rectus femoris (RF), biceps brachii (BB) and first dorsal interosseouse muscle (FDI) using the short-time Fourier transform, and to obtain more detailed information on the motor unit (MU) activation strategy underling in the continuous MMG/force relationship. The subjects were asked to exert ramp contractions of each muscle from 5% to 70% of the maximal voluntary contraction (MVC) at constant rate of 10% MVC/s. The MMG-amplitude/force and MMG-mean-frequency/force relationships changed in agreement with the MU activation strategy of each muscle. The estimation method described here is considered to be a useful tool with which to examine in more detail the MMG/force relationship.