The Research Of Static And Dynamic Muscle Contraction Fatigue Features Based On Mechanomyographic Signal

Muscle fatigue by doing sports,is a phenomenon of the decrease of the maximum voluntary contraction(MVC),which could be used in the fields of the prevention of occupational diseases in physiology or medicine and of the training of athletes in physical engineering.Previously many investigators have been doing researches about muscle fatigue with electromyography(EMG).As a new analysis tool of investigating muscle contract and muscle fatigue,mechanomyography(MMG)has distinct advantages and attracts more attention.In this thesis,researches for muscle fatigue phenomenon that being general seen in daily life have done with MMG,and also static and dynamic contractions trials for flexor carpi radialis have been designed based on the predecessors' research methods.Under the condition of two kinds of muscle contraction,the frequency-domain features,discrete wavelet decomposition-reconstruction and wavelet packet decomposition-reconstruction of MMG were investigated to find variation of MMG frequency-band information.MMG were treated by short time Fourier transform(STFT),and the two frequency-domain features were extracted,and then amplitude of variation of feature value was quantitative calculated.This thesis illustrated that MMG is an effective tool of analyzing muscle activation and estimating muscle fatigue by the way of static and dynamic muscle contraction.According to research results,mean power frequency(MPF)and median frequency(MDF)are effective feature parameters and show some certain regularity according to the two styles of muscle contraction.The method and conclusion of research play a role in promoting future quantitative research for measuring muscle fatigue.