Contralateral Effects of Unilateral Arm Movement on the Mean Power Frequency of sEMG Signals

Objective:The aim of this study was to examine the effects of fatiguing the muscles of a single arm on the contralateral muscles in the mean power frequency(MPF)of sEMG signals and to explore the central control contributing to the change of MPF.Method:10 male subjects completed the two trials by turns.The subjects relaxed the right arm naturally and performed the isometric contractions with 4kg load in the left arm in the first trial.In the second trial,the subjects performed the fatiguing elbow flexion and elbow extension with 5kg load in the right arm and the isometric contractions with 4kg load in the left arm.The sEMG signals were recorded from biceps brachii(BB),triceps brachii(TB)and trapezius muscles of the left arm as the observed arm and MPF,AEMG,C(n)and %DET were calculated.Result:The differences of the mean MPF from the left BB,TB and trapezius muscle were significant between in the first trial and in the second trial.The slope of MPF from the left TB was significantly different between in the first trial and in the second trial.Conclusions:It is concluded that the fatiguing elbow flexion and elbow extension from right arm resulted in the change in MPF from the left arm during isometric contractions.The change in MPF during fatigue cannot be explained only by the changes in peripheral metabolic acidosis and central control mechanism may contribute to the signal variations.