Bilodeau M, Arsenault A B, Gravel D, Bourbonnais D
Research Centre, Montreal Rehabilitation Institute, Quebec, Canada.
Electromyogr Clin Neurophysiol. 1994 Apr-May;34(3):149-58.
In order to be considered a potential tool for the characterization of muscle activity, the reliability of EMG power spectral analysis should be demonstrated. In this study, the reliability of the mean power frequency (MPF) and of the median frequency (MF) of power spectra (triceps brachii (TB), anconeus (AN)) obtained at different force levels from both ramp and stepwise isometric contractions was tested across three similar sessions performed on three different days (N = 9). Two-way ANOVAs for repeated measures did not disclose any significant differences (p > 0.05) in the value of either the MF or the MPF across the different sessions for either type of contraction. In contrast, significant changes (p < 0.05) in both the MF and the MPF were found across force levels. No significant interactions (p > 0.05) were found between the session and the force factors, for any of the analyses performed. The present results indicate that the MPF and the MF of the EMG power spectrum, taken at a specific force level, are reliable measures across sessions performed on different days. Consequently, this supports the possible use of power spectral analysis of EMG signals as an evaluation technique that could monitor changes in the neuromuscular system that can occur over a given period.
为了被视为一种用于表征肌肉活动的潜在工具，肌电图功率谱分析的可靠性应得到验证。在本研究中，对9名受试者在不同日期进行的三个相似实验中，测试了从不同力量水平的斜坡式和逐步等长收缩中获得的肱三头肌（TB）和肘肌（AN）功率谱的平均功率频率（MPF）和中位数频率（MF）的可靠性。重复测量的双向方差分析未发现两种收缩类型在不同实验中MF或MPF值有任何显著差异（p>0.05）。相比之下，在不同力量水平上发现MF和MPF均有显著变化（p<0.05）。对于所进行的任何分析，在实验和力量因素之间均未发现显著交互作用（p>0.05）。目前的结果表明，在特定力量水平下获取的肌电图功率谱的MPF和MF在不同日期进行的实验中是可靠的测量指标。因此，这支持了将肌电图信号的功率谱分析用作一种评估技术的可能性，该技术可以监测在给定时间段内可能发生的神经肌肉系统变化。
