Estimation of a Muscle Force from a Mechanomyographic Signal During a Contraction of a Single Motor Unit

Abstract

In this paper an estimation method of a muscle force generated during a single Motor Unit (MU) contraction from a mechanomyographic signal (MMG) is described. The MMG signal has been recorded with a microphone immersed in a paraffin oil, placed above the medial gastrocnemius muscle of a rat. The estimation process evaluates the muscle surface displacement and thus indirectly the force. In estimation procedure the oil medium model have been used. This model describes the propagation of the acoustic wave generated by the muscle surface displacement and recorded with the microphone. The estimation procedure uses the model as a reference model enabling estimation of the muscle surface acceleration being the model input, from the MMG signal which is the model output. The method have been applied to the signals recorded in vivo. The results obtained with the method reveal a good correspondence between the estimated and the directly measured force signals.