Muscle Sound Frequency Analysis From Fast And Slow Twitch Muscle

Abstract

Muscle sounds were recorded from human orbicularis oris and soleus muscles from 5 healthy subjects during isometric contraction. Frequency analysis of the signals revealed distinct power spectra for each muscle type. The peak frequency for soleus was 10.8 +/- 3.1 and for orbicularis oris was 22 +/- 5 Hz. The results indicate that muscle sound power spectra may reflect fibre type composition and/or motor unit firing frequency .