The effects of concentric isokinetic strength training of the quadriceps femoris on mechanomyography and muscle strength

The purpose of the present investigation was to examine the effect of concentric isokinetic leg extension training on peak torque (PT) and mechanomyographic (MMG) responses. Twenty-one males were assigned into a training (TRN, n = 12) or control (CTL, n = 9) group. The training group performed six sets of ten leg extensions three days per week for twelve weeks at a velocity of 90°.s^-1. All subjects were tested every four weeks for PT and MMG responses at a velocity of 90°.s^-1. The two-way mixed factorial ANOVA indicated a significant increase (p < 0.05) in PT over the twelve weeks for the TRN group but no significant change (p > 0.05) in PT for the CTL group. For the MMG there was no significant (p > 0.05) interaction, therefore, the TRN and CTL groups exhibited the same pattern of responses over the twelve-week training period. The reason for the increase in PT in the absence of a change in MMG may be due to hypertrophy and/or changes in other muscles involved in leg extension.