Practical to Demonstrate Electromyographic Changes Associated With Phenomena of Fatigue Due to Isometric Exercise

ABSTRACT

Purpose of the study Teaching the physiology of motor unit recruitment as a strategy for force generationand changes in the recruitment patterns as a consequence of fatigue.Methodology: A protocol was designed to study fatigue developed as a consequence of graded isometricexercise and the surface electromyographic (sEMG) features associated with development of fatigue.Main findings: Fatigue can be quantified by reduction in grip force in isometric hand grip. During maximalexercise, sEMG amplitude declined with time as a consequence of fatigue. The sEMG amplitude wasobserved to increase in the case of submaximal exercise representing recruitment of additional motor unitsto compensate for declining force production in fatigued motor units.Conclusion: The proposed practical exercise fulfils the teaching goal of acquainting the students with themotor unit recruitment patterns as reflected in sEMG associated with fatigue development.