Reliability of surface polyelectromyographic recordings of motor unit activity

Recordings of electrical activity from muscles provides the best means of studying motor control. Quantitation of surface electromyograms (SEMGs) is problematic due to the ill-posed nature of the inverse problem. As a first step towards establishing methods for comparing across muscles and across subjects, the authors examined the repeatability of activity recorded during a comprehensive protocol. To facilitate overview of the protocol, a motor control profile was developed. Results from comparisons in 50 spinal cord injured subjects are presented.