MECHANOMYOGRAPHIC RESPONSES TO MAXIMAL ECCENTRIC ISOKINETIC MUSCLE ACTIONS

The purpose of the present investigation was to examine the mechanomyo graphic (MMG) responses to maximal eccentric isokinetic muscle actions . Eight adult male volunteers [age 22 +/- 2 (SD) yr] performed maximal eccentric muscle actions of the leg extensors at 60, 90, 120, and 180 degrees/s on a Cybex 6000 isokinetic dynamometer. MMG was detected by a piezoelectric crystal contact sensor placed over the vastus lateral is muscle. Test-retest intraclass correlations ranged from R = 0.88 to 0.97 for peak torque and from R = 0.97 to 0.98 for root mean square M MG amplitude values. There was no significant (P > 0.05) velocity-rela ted change in eccentric peak torque; however, there was a significant (P < 0.05) increase in MMG between 60 [119 +/- 44 (SE) mV] and 180 deg rees/s (302 +/- 128 mV). These findings indicated a velocity-related d issociation between MMG and peak torque for maximal eccentric isokinet ic muscle actions.