School of Rehabilitation, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada; Research Center, Montreal Rehabilitation Institute, Montreal, Quebec, Canada.
J Electromyogr Kinesiol. 1992;2(3):121-9. doi: 10.1016/1050-6411(92)90009-8.
The aim of the present study was to contrast, between men and women, the behavior of EMG power spectrum statistics (median frequency (MF) and mean power frequency (MPF) obtained across increasing force levels. Thirteen men and sixteen women produced ramp (single contractions with the force increasing linearly) elbow flexions and extensions from 0 to 100% of the maximum voluntary contraction (MVC). Each ramp was produced in a 5-s period. Surface EMG signals from triceps brachii (TB), anconeus (AN), and biceps brachii (BB) were recorded with miniature surface electrodes placed 6 mm apart. These signals were sampled at 2,000 Hz. The MPF and MF of power spectra, obtained from single 256-ms windows, were computed for each muscle at 10, 20, 40, 60, and 80% MVC. Significant differences (two-way analyses of variance (ANOVAs); p < 0.05) in the behaviors of the MPF and MF across force levels were found between men and women. In general, the MPF and MF showed more pronounced increases across increasing force levels for men than for women. It is proposed that this gender effect could be explained by differences in skinfold thickness and fiber type characteristics between the two groups of subjects.
本研究旨在对比男性和女性在递增力量水平下肌电图（EMG）功率谱统计量（中值频率（MF）和平均功率频率（MPF））的行为。13 名男性和 16 名女性进行了从 0 到 100%最大自主收缩（MVC）的斜坡式（单次收缩，力线性增加）肘屈伸运动。每个斜坡在 5 秒内完成。使用微型表面电极以 6 毫米的间隔记录肱三头肌（TB）、肘肌（AN）和肱二头肌（BB）的表面肌电图信号。这些信号以 2000 Hz 的频率进行采样。从每个肌肉的单个 256 毫秒窗口中获取的功率谱的 MPF 和 MF，在 10、20、40、60 和 80%MVC 下进行计算。在男女之间，在力量水平上 MPF 和 MF 的行为存在显著差异（双向方差分析（ANOVA）；p<0.05）。一般来说，男性的 MPF 和 MF 在递增的力量水平上的增加比女性更为明显。这一性别效应可以用两组受试者的皮肤褶皱厚度和纤维类型特征的差异来解释。
