Hisao Tokushima

Effective parameters derived from multiresolution analysis of surface electromyograms

Purpose of this study is to extract effective parameters for explaining muscle state based on multiresolution analysis of surface electromyograms (EMGs). The EMGs were decomposed into five levels using the Daubechies orthogonal wavelet of order 5 (db5). Two kinds of surface EMG were recorded from biceps brachii in five healthy males during muscle fatigue test and increasing load test. Selected parameters for analyzing EMGs were as follows; 1) PD(j): power of the details at level j ; 2) TPw: total power of the details concerning all levels; 3) RPD(j): power ratio of the PD(j) to TPw at level j. On muscle fatigue test, RPD(1), RPD(2), RPD(3) decreased after the test and RPD(4), RPD(5) increased contrarily. On increasing load test, RPD(3) showed a curve with two peaks at 25% MVC 30% MVC and at 45% MVC. On the contrary, RPD(4) showed inversed curve of the RPD(3) . This suggests activity of recruited fast muscle fibers.

Detection of Fast Fiber Recruitment by Multiresolution Analysis of Surface Electromyograms

This paper suggests possibility for detecting recruitment of fast muscle fiber on increasing load tests by multiresolution analysis of surface electromyograms (sEMGs). Recruitment of the muscle fiber can be guessed from a graph of power ratio vs. % maximum voluntary contraction concerning the detail at each level, RPD(j). RPD(j)s are extracted parameters from multiresolution analysis of sEMGs. The sEMGs were recorded from the biceps brachii in five healthy males