Abstract
The purpose of this study is to examine the usefulness to evaluate a muscle fatigue in three kinds of the surface electromyography(bipolar-lead, monopolar-lead and source derivation method). The subjects were 8 healthy college students (19.5±0.5 years; mean±S.D.). In an attempt to cause a muscle fatigue, the subjects were forced to maintain a forearm levelly for 120 seconds in having the iron array (2kg, 5kg, 7kg, 10kg) in their hands and the surface electromyograms (sEMG) of the biceps brachii were recorded with three kinds of leads (bipolar-lead, monopolar-lead and source derivation method) at the same time. The powere spectrums of each sEMGs were gotten by Fast Fourier Transform (FFT). The center frequencys and integral values of the power spectrums were compared in sEMG recorded by each derivations. It was more remarkable of both of the decline of the center frequency elapse and the increase of the integral value of power spectrums with a muscle fatigue in the sEMG by the source derivation (SD) method than in sEMG by other leads(p<0.05). When judging a muscle fatigue from the power spectrum of sEMG from these results, it thought that the SD method was a valid method. [J Physiol Sci. 2008;58 Suppl:S160]
