Mechanomyography changes during different isometric contraction forces at different muscle lengths

Mechanomyography (MMG), a low frequency sound signal, can be used to record muscle internal mechanical movements. In this study, we use MMG to measure muscle vibrations of human medial gastrocnemius (MG) during isometric plantarflexion at different contraction forces and at different ankle joint positions. The results linked median frequency of MMG signals (fmed) to plantarflexion torque at different muscle lengths.