Document Detail

EMG spectral shift as an indicator of fatigability in an heterogeneous muscle group.
MedLine Citation:
PMID:  2289502     Owner:  NLM     Status:  MEDLINE    
Changes in electromyogram (EMG) power spectra were investigated in the triceps surae muscles of two classes of individuals (untrained subjects and athletes) maintaining a plantarflexion torque of 80% of maximal voluntary contraction until exhaustion. A set of 23 parameters describing changes in the frequency content and power of EMG was defined. For most experiments, classical changes were found, indicating a shift of the EMG spectra towards lower frequencies and an increase in the total power of the signals. In 12% of the experiments, alternations in activity between synergistic muscles were found, leading to a large variability in the spectral parameters. After the expression of each experiment in terms of a reduced data matrix and matrix to vector transformations, three methods of discrimination were used to classify subjects with respect to changes in the EMG signal during sustained contraction: (1) evaluation of the most discriminating parameter, (2) principal components analysis, (3) transformation maximizing differences between classes. Method (3) was found to be preferable since it led to good separation of the two classes in a reference group of subjects and a satisfactory projection of each individual from a group of unknowns into the appropriate class. These results suggest using a method such as this for ergonomic or athletic training purposes rather than the usual method of monitoring the frequency shift of the EMG.
J Duchêne; F Goubel
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  European journal of applied physiology and occupational physiology     Volume:  61     ISSN:  0301-5548     ISO Abbreviation:  Eur J Appl Physiol Occup Physiol     Publication Date:  1990  
Date Detail:
Created Date:  1991-04-01     Completed Date:  1991-04-01     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0410266     Medline TA:  Eur J Appl Physiol Occup Physiol     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  81-7     Citation Subset:  IM    
Département de Génie Biologique, URA CNRS 858, Université de Technologie, Compiègne, France.
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MeSH Terms
Fatigue / physiopathology*
Isometric Contraction / physiology
Muscles / physiology*
Regression Analysis

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