Tanino Yoshitsugu, Suzuki Toshiaki
Clinical Physical Therapy Laboratory, Kansai University of Health Sciences, Japan.
J Phys Ther Sci. 2014 Jan;26(1):101-4. doi: 10.1589/jpts.26.101. Epub 2014 Feb 6.
[Purpose] The gross morphology of the vastus medialis (VM) muscle has been thoroughly described. However, there is insufficient evidence of physiological differentiation between the VM obliquus (VMO) and VM longus (VML). To elucidate spinal reflex arc excitability in two divisions of the VM, we compared H-reflexes and T-waves in VMO and VML. [Subjects] Twenty-three healthy male volunteers participated in this study. [Methods] The H-reflex was evoked from the VMO and VML by electrical stimulation of the femoral nerve during knee extension at 10% maximal voluntary isometric contraction. Also, the patellar tendon was tapped by an examiner using an electrical tendon hammer, and a component of the compound muscle action potential (T-wave) was recorded. [Results] The configurations of the H-reflex and T-wave were sharp and slow in VMO and VML, respectively. No significant differences in the amplitudes of the H-reflexes and T-waves were observed between VMO and VML. The durations of VML H-reflexes and T-waves were significantly longer than those in VMO. [Conclusion] Spinal reflex arc excitability corresponding to VMO and VML was similar. However, the configurations and durations of the H-reflex and T-wave were differentiated with electromyography. On the basis of these findings, we suggest that VMO and VML are electrophysiologically distinct entities.
[目的] 股内侧肌（VM）的大体形态已得到充分描述。然而，股内侧斜肌（VMO）和股内侧长肌（VML）之间生理分化的证据不足。为了阐明VM两个部分的脊髓反射弧兴奋性，我们比较了VMO和VML中的Hoffmann反射（H反射）和T波。[对象] 23名健康男性志愿者参与了本研究。[方法] 在膝关节伸展时，以最大自主等长收缩的10%进行电刺激股神经，从VMO和VML诱发H反射。此外，检查者使用电动肌腱锤轻敲髌腱，并记录复合肌肉动作电位的一个成分（T波）。[结果] VMO中H反射和T波的形态分别为尖锐和缓慢。VMO和VML之间的H反射和T波振幅未观察到显著差异。VML的H反射和T波持续时间明显长于VMO。[结论] 与VMO和VML相对应的脊髓反射弧兴奋性相似。然而，通过肌电图可区分H反射和T波的形态及持续时间。基于这些发现，我们认为VMO和VML在电生理上是不同的实体。
