Elucidation of the Motor unit firing behaviors in various human muscles

点击翻译按钮获取中文摘要

Purpose of the present research was to elucidate the motor unit firing behaviors in various human muscles during voluntary isometric force exertion. First, I improved the quadrifilar needle electrode which is used in the precision decomposition technique. As a result, the quadrifilar wire electrode which can detect the intra-muscular myoelectric signal of vastus medialis muscle was produced. Next, the recruitment threshold, the de-recruitment threshold, and the firing rate of the motor unit in the vastus medialis muscle were verified. The positive correlation was observed between the recruitment and de-recruitment threshold of the motor units. The negative correlation was observed between the recruitment threshold and the firing frequency of the motor units. These results indicate that the concept of the "Onion skin phenomenon" is also adapted in the vastus medialis muscle.