Kashiwagi K, Tanaka M, Kawazoe T, Furuichi K, Takada H
Department of Fixed Prosthodontics, Osaka Dental University, Japan.
J Osaka Dent Univ. 1995 Apr;29(1):19-28.
Various amplitude normalization procedures for surface electromyographic (EMG) signals have been utilized to reduce the inter- and intrasubject variability of data collected on gait analysis. We examined two normalization methods (normalization to mean of ensemble average: NME, and normalization to peak of ensemble average: NPE) for intersubject variability and reproducibility surface EMG profiles for the masticatory muscles during unilateral gum chewing. The EMG profiles for the anterior temporal (Ta), posterior temporal (Tp), masseter (M) and anterior belly of the digastric (Da) muscles on the chewing side from five normal subjects were made at three different sessions. Coefficients of variation and intraclass correlation coefficients were used to assess variability and reproducibility. Each normalization procedure the intersubject variability of unnormalized EMG profiles for Ta, Tp and M. The NME procedure provided lower intersubject variability for Da. The reproducibility of unnormalized profiles for Ta, Tp and M was significantly improved by both procedures (p < 0.05). NME on Da was more effective in its reproducibility (p < 0.05). We found that the phasic characteristics of muscular activity influenced the outcome of amplitude normalization.
表面肌电图（EMG）信号的各种幅度归一化程序已被用于减少步态分析中收集的数据在受试者间和受试者内的变异性。我们研究了两种归一化方法（归一化到总体平均值的均值：NME，以及归一化到总体平均值的峰值：NPE），以探讨单侧咀嚼口香糖时咀嚼肌的受试者间变异性和表面肌电图轮廓的可重复性。在三个不同的时间段对五名正常受试者咀嚼侧的颞前肌（Ta）、颞后肌（Tp）、咬肌（M）和二腹肌前腹（Da）的肌电图轮廓进行了测量。变异系数和组内相关系数用于评估变异性和可重复性。每种归一化程序都降低了Ta、Tp和M未归一化肌电图轮廓的受试者间变异性。NME程序降低了Da的受试者间变异性。两种程序均显著提高了Ta、Tp和M未归一化轮廓的可重复性（p<0.05）。NME对Da的可重复性更有效（p<0.05）。我们发现肌肉活动的相位特征会影响幅度归一化的结果。
