The Relation between the Number of Impulses and the Integrated Electric Activity in Electromyogrsm

Abstract

Abstract. In order to evaluate electrical parameters of gross response electro‐myograms, the interrelationship between the integrated electric activity and the number of motor impulses of the myograms obtained from human forefinger abductor muscle in voluntary, non‐isometric contractions was studied. The integrated activity was determined by planimetry. The number of motor impulses were counted irrespective of location and size. The relationship between the integrated activity and the number of motor impulses was found to be linear in contraotions up to a spike frequency of 500 cps. It was concluded that, as far as small muscles are concerned, counting of the motor impulses in the electromyogram, recorded with non‐selective electrodes, can be used in estimating the electric activity of the whole muscle.