Adaptive demodulation of muscular force from myoelectric signals obtained during locomotion

A demodulation scheme is proposed for estimating dynamic muscular force from the corresponding electromyographic (EMG) signal. In order to test the scheme, computer simulations were performed based on the theoretical model of integral pulse frequency and amplitude modulation (IPFAM) for EMG signals. The demodulator was also used for reconstructing the muscle force of dynamically contracting muscles from direct measurements of EMG signals in cat plantaris muscles during locomotion. The performance of the adaptive demodulator was found to be superior to that of conventional low-pass filtering schemes which are commonly used for muscular force estimation