A study on the MU number estimation of ADM muscle using surface EMG

Abstract

This study suggested a new method to estimate the motor unit (MU) of abductor digiti minimi (ADM) muscle using surface electromyogram and muscle modeling. First, this study detected single motor unit action potential (SMUAP) by inducing voluntary contraction of ADM muscle with less than 1% MVC for the estimation of the number of muscle fibers. This study estimated the number of muscle fibers as 93±16 by varying the depth of SMUAP and number of muscle fibers with 1,271 steps using the designed ADM simulator. Second, this study designed the ADM simulator for ADM muscle with physiological parameters such as the estimated number of muscle fibers, conduction velocity, and muscle length of each experiment subject, and probable and statistical parameters for the MU number estimation of ADM muscle. Third, this study used compound muscle action potential (CMAP) detected through electric stimulus to the ulnar nerve, which is the dominant nerve of the ADM muscle for MU number estimation. The CMAP was simulated with the ADM simulator using the detected CMAP and the number of muscle fibers estimated above. This study estimated the MU number as 109±18 using the method to find the minimum mean square error (MSE) value that takes into account the simulated CMAP and the shape and amplitude of signals from the CMAP detected from surface electrodes. © 2017 International Information Institute.