Watanabe Kohei, Kouzaki Motoki, Moritani Toshio
School of International Liberal Studies, Chukyo University, Nagoya, Yagotohonmachi, Showa-ku, Nagoya, 466-8666, Japan.
Muscle Nerve. 2014 Nov;50(5):794-802. doi: 10.1002/mus.24232. Epub 2014 Sep 17.
Our recent studies have demonstrated region-specific neural activation within the rectus femoris (RF) muscle. However, these studies involved a fixed joint angle or posture. In this study we investigated the effect of hip and knee joint angles on neural activation within RF using multichannel surface electromyography (SEMG).
Eleven healthy men performed isometric maximal voluntary contraction (MVC) during knee extension and hip flexion at different hip or joint angles. During the contractions, SEMG of the RF was recorded using 46 electrode pairs covering most of the superficial area of the muscle.
During knee extension MVC, an increase in the hip joint angle was associated with a significant increase in SEMG amplitude in the proximal region and a decrease in the distal region (P < 0.05). Higher SEMG amplitude during hip flexion MVC compared with knee extension MVC was observed in proximal regions with the flexed knee and hip joint angles. This task-dependent spatial distribution of SEMG amplitude was seen at the extended hip, but not at the extended knee.
SEMG amplitudes within the RF muscle are not modified uniformly with changes in joint position.
我们最近的研究已经证明股直肌（RF）内存在特定区域的神经激活。然而，这些研究涉及固定的关节角度或姿势。在本研究中，我们使用多通道表面肌电图（SEMG）研究了髋关节和膝关节角度对RF内神经激活的影响。
11名健康男性在不同髋关节或关节角度进行膝关节伸展和髋关节屈曲的等长最大自主收缩（MVC）。在收缩过程中，使用覆盖该肌肉大部分浅表区域的46对电极记录RF的SEMG。
在膝关节伸展MVC期间，髋关节角度增加与近端区域SEMG振幅显著增加和远端区域减少相关（P < 0.05）。在膝关节和髋关节屈曲角度的近端区域，观察到髋关节屈曲MVC期间的SEMG振幅高于膝关节伸展MVC。在髋关节伸展时观察到这种与任务相关的SEMG振幅空间分布，但在膝关节伸展时未观察到。
RF肌肉内的SEMG振幅不会随着关节位置的变化而均匀改变。
