Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan.
Muscle Nerve. 2012 Jul;46(1):86-95. doi: 10.1002/mus.23268.
We quantified the alternate muscle activity among four synergists of the quadriceps femoris (QF), including the vastus intermedius (VI), during low-level sustained contraction.
Surface electromyograms (EMGs) were recorded from the VI, vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) in 11 healthy men during isometric knee extension at 2.5% maximum voluntary contraction for 60 min to determine alternate muscle activity among the four synergists of the QF.
Alternate activity was primarily found between the RF and VI, VL, or VM, and rarely found among the vasti muscles. Multiple muscle comparison revealed the duration of alternate activity in the RF/VI+VL+VM combination remained high throughout the experiment, although the frequency of that combination did not.
These results suggested that there is a fixed muscle combination, i.e., RF and the 3 vasti muscles, to perform low-intensity sustained contraction in the human QF.
本研究旨在量化股四头肌（QF）四个协同肌（包括中间肌 VI）在低水平持续收缩下的交替活动。
11 名健康男性在进行等长膝关节伸展时，以 2.5%最大自主收缩的强度持续 60 分钟，记录来自 VI、股外侧肌（VL）、股内侧肌（VM）和股直肌（RF）的表面肌电图（EMG），以确定 QF 的四个协同肌之间的交替活动。
交替活动主要发生在 RF 和 VI、VL 或 VM 之间，而在 vasti 肌肉之间很少发生。多肌肉比较显示，尽管该组合的频率没有变化，但在整个实验过程中，RF/VI+VL+VM 组合的交替活动持续时间仍然很高。
这些结果表明，在人类 QF 中，存在一个固定的肌肉组合，即 RF 和 3 个 vasti 肌肉，用于进行低强度持续收缩。
