Motor unit action potential counts in surface electrode array EMG

The number of motor unit action potentials (MUAPs) appearing in the surface electromyogram (EMG) signal offers potentially valuable information about both motor unit recruitment and firing rates. Estimates of the numbers of MUAPs are likely to be a more accurate reflection of the neural command to muscle than are current EMG quantification methods. In this paper, we describe a method to estimate the number of MUAPs present in the surface EMG signals. The four-step procedure for MUAP counting takes advantage of the high selectivity and resolution of a two dimensional surface electrode array recording system [2]. We illustrate the performance of the method of MUAP counting from surface EMG recordings at different contraction levels.