Relationship between Muscle Force, Length and Myo-Electric Activity in Vivo

Abstract

A vast amount of physiological data exists for the mechanical and electrical behaviour of voluntary skeletal muscles. The data, however, are almost exclusively obtained under conditions of artificial stimulation and also are usually only concerned with the static properties of the muscle. 

This paper presents an experimental procedure aimed at the development of a dynamic model relating the tendon force output of the muscle to its myo-electric activity. Transducers for the measurement of the muscle force and length in vivo are described as well as the electrodes used to measure the myo-electric activity.

The determination of the experimental model is guided by a theroetical model. The theoretical model uses the motor unit as a basic block with the neural signal to the muscle as an input. The theoretical model indicates that a suitable system between the myo-electric signal and force is that of an instantaneous nonlinearity followed by a linear system. To this end a modification of a known modelling technique is used.