Laboratorio di Ingegneria del Sistema Neuromuscolare, Politecnico di Torino, 10129 Torino, Italy.
IEEE Trans Neural Syst Rehabil Eng. 2010 Jun;18(3):221-9. doi: 10.1109/TNSRE.2010.2041593. Epub 2010 Feb 8.
The aim of this study was to compare the decomposition results obtained from high-density surface electromyography (EMG) and concurrently recorded intramuscular EMG. Surface EMG signals were recorded with electrode grids from the tibialis anterior, biceps brachii, and abductor digiti minimi muscles of twelve healthy men during isometric contractions ranging between 5% and 20% of the maximal force. Bipolar intramuscular EMG signals were recorded with pairs of wire electrodes. Surface and intramuscular EMG were independently decomposed into motor unit spike trains. When averaged over all the contractions of the same contraction force, the percentage of discharge times of motor units identified by both decompositions varied in the ranges 84%-87% (tibialis anterior), 84%-86% (biceps brachii), and 87%-92% (abductor digiti minimi) across the force levels analyzed. This index of agreement between the two decompositions was linearly correlated with a self-consistency measure of motor unit discharge pattern that was based on coefficient of variation for the interspike interval (R(2) = 0.68 for tibialis anterior, R(2) = 0.56 for biceps brachii, and R(2) = 0.38 for abductor digiti minimi). These results constitute an important contribution to the validation of the noninvasive approach for the investigation of motor unit behavior in isometric low-force tasks.
本研究旨在比较高密度表面肌电图（EMG）和同时记录的肌内 EMG 的分解结果。表面 EMG 信号通过电极网格从 12 名健康男性的胫骨前肌、肱二头肌和小趾展肌记录，在 5%至 20%最大力的等长收缩期间。双极肌内 EMG 信号通过一对线电极记录。表面和肌内 EMG 分别分解为运动单位尖峰序列。当对相同收缩力的所有收缩进行平均时，两种分解方法识别的运动单位放电时间的百分比在分析的力水平范围内变化范围为 84%-87%（胫骨前肌）、84%-86%（肱二头肌）和 87%-92%（小趾展肌）。这两种分解方法之间的一致性指数与基于肌间间隔变异系数的运动单位放电模式的自一致性度量呈线性相关（胫骨前肌的 R²=0.68，肱二头肌的 R²=0.56，小趾展肌的 R²=0.38）。这些结果为非侵入性方法在等长低力任务中研究运动单位行为的验证做出了重要贡献。
