Nishihara Ken, Chiba Yu, Moriyama Hideki, Hosoda Masataka, Suzuki Yosuke, Gomi Toshiaki
Department of Physical Therapy, Saitama Prefectural University, Koshigaya, Saitama, Japan.
Med Sci Monit. 2009 Sep;15(9):MT113-20.
Electromyography (EMG) is useful in investigating muscle activation; however, noninvasive evaluation of surface EMG is limited due to its complicated waveform. This study investigated muscle structure and activation using an analysis technique for surface EMG.
MATERIAL/METHODS: Surface array electrodes were used in 17 healthy male subjects to record eight-channel EMGs from each biceps brachii muscle during voluntary isometric contraction with a 1-kg weight band with the subjects seated. The peaks detected by referenced EMGs were normalized and averaged as averaged pulses (APs) and the innervation zone (IZ) was estimated from the APs. Muscle fiber conduction velocities (MFCVs), estimated by the time difference of the peaks (method P) and by cross-correlation (method CC) by APs, were compared. Time periods with positive values around the central peak in AP (PP) were measured and the contribution of MFCVs by motor unit action potentials (MUAPs) was estimated.
IZs were estimated in 12 subjects. Near the IZ, correlation between MFCVs by methods P and CC was lower than in other locations; MFCV was significantly larger by method P than by method CC in the vicinity of the IZ. PP of the comparison AP was significantly larger than that of the reference AP. The distribution of the MFCVs by different MUAPs was verified by computer simulation.
Surface EMG was used to demonstrate the diversity of MFCVs, with some increased MFCVs, for several MUAPs in the vicinity of the IZ. This method could be applied to the evaluation of neuromuscular disorders.
肌电图（EMG）在研究肌肉激活方面很有用；然而，由于其复杂的波形，表面肌电图的无创评估受到限制。本研究使用一种表面肌电图分析技术来研究肌肉结构和激活情况。
材料/方法：对17名健康男性受试者使用表面阵列电极，在受试者坐着并使用1千克重量带进行自愿等长收缩时，记录每块肱二头肌的八通道肌电图。将参考肌电图检测到的峰值进行归一化并平均为平均脉冲（APs），并从APs估计神经支配区（IZ）。比较通过峰值时间差（方法P）和通过APs的互相关（方法CC）估计的肌肉纤维传导速度（MFCVs）。测量AP中中心峰值周围正值的时间段，并估计运动单位动作电位（MUAPs）对MFCVs的贡献。
在12名受试者中估计了IZ。在IZ附近，方法P和方法CC测得的MFCVs之间的相关性低于其他位置；在IZ附近，方法P测得的MFCV明显大于方法CC测得的。比较AP的PP明显大于参考AP的PP。通过计算机模拟验证了不同MUAPs的MFCVs分布。
表面肌电图用于证明MFCVs的多样性，在IZ附近的几个MUAPs中，一些MFCVs有所增加。该方法可应用于神经肌肉疾病的评估。
