ISSN:
1741-0444
Keywords:
EMG
;
Fatigue
;
Firing statistics
;
Spectrum
;
Zero crossing
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract EMG was recorded during short test contractions performed during occupational work. Mean power frequency (MPF) and median frequency (MF), calculated from EMG spectra, and zero crossing rate (ZC) of the EMG signal were compared as estimators of local muscular fatigue. The results show that there is a systematic difference between the three estimates. The difference can be explained by dividing the effect of muscle fatigue on EMG spectra into a motor unit action potential velocity effect and a firing statistics effect. Furthermore, it is shown that the phenomenon of increasing estimators of EMG spectrum shift is unlikely to be caused by motor unit action potential velocity increase. Successive recruitment of new motor units is suggested as a feasible explanation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02442323