EMG and muscle force: An introduction

Abstract

This paper is intended as an introduction to those methods of processing and presentation of the electromyogram (EMG) that give information about the muscle force or work in human movement. The physiological origin of the EMG is treated briefly, followed by a discussion of EMG recording and preprocessing: electrodes, preamplifier, rectifier, smoothing filter. Special attention is given to the prevention and suppression of interferences. The relation between EMG, muscle length and muscle force is explained on the basis of a three-component Hill muscle model. With this background, some possibilities on how to obtain quantitative information about muscle force, work and energy consumption in various categories of movement are summed up and discussed. Some possible applications in human movement studies are suggested.