Gender comparisons of the mechanomyographic responses to maximal concentric and eccentric isokinetic muscle actions

Abstract

Gender comparisons of the mechanomyographic responses to maximal concentric and eccentric isokinetic muscle actions. Med. Sci. Sports Exerc., Vol. 30, No. 12, pp. 1697-1702, 1998. The purpose of this study was to determine whether there is a gender difference in the velocity-related patterns of mechanomyographic (MMG) responses to maximal isokinetic concentric (CON) and eccentric (ECC) muscle actions. Adult males (N = 15) and females (N = 16) performed maximal CON and ECC muscle actions of the leg extensors on a calibrated Cybex 6000 dynamometer at velocities of 30, 90, and 150°·s−1. MMG was detected by a piezoelectric crystal contact sensor placed over the vastus lateralis muscle. The results indicated that there were decreases in CON peak torque (PT) across velocities, while ECC PT remained constant with increasing velocity for both genders. MMG amplitude increased significantly (P The gender difference in CON MMG responses may be attributed to the greater percent decline in CON PT across velocity for the females than the males. In addition, the males displayed greater CON and ECC MMG amplitudes at all muscle action velocities than the females, possibly because of gender differences in muscle mass and/or thickness of the adipose tissue layer.