Mechanomyographic responses to maximal eccentric isokinetic muscle
actions.
Smith, Douglas B., Jeffrey R. Stout, Terry J. Housh, Glen O. Johnson,
Tammy Evetovich, and Kyle T. Ebersole.
Center for Youth Fitness and Sports Research, School of Health and
Human Performance, University of Nebraska-Lincoln, Lincoln, NE 68588
-0229; Exercise Science Department, Creighton University, Omaha, NE
68178, Center for Youth Fitness and Sports Research, School of Health
and Human Performance, University of Nebraska-Lincoln, Lincoln, NE
68588-0229
APStracts 3:0512A, 1996.
The purpose of the present investigation was to examine the
mechanomyographic (MMG) responses to maximal eccentric isokinetic
muscle actions. Eight adult male volunteers (Mean ? + ? SD ? age ? =
? 22 ? + ? 2 ? yrs) performed maximal eccentric muscle actions of the
leg extensors at 60, 90, 120, and 180 . s -1 on a Cybex ? 6000
isokinetic dynamometer. MMG was detected by a piezoelectric crystal
contact sensor placed over the vastus lateralis muscle. Test-retest
intraclass correlations ranged from R ? = ? 0.88-0.97 for peak torque
and R ? = ? 0.97 ? - ? 0.98 for root mean square (rms) MMG amplitude
values, respectively. There was no significant (p ? > ? 0.05)
velocity-related change in eccentric peak torque, however, there was
a significant (p ? < ? 0.05) increase in MMG between 60 . s -1 (Mean
? + ? SEM ? = ? 119 ? + ? 44 ? mV) and 180 . s -1 (Mean ? + ? SEM ? =
? 302 ? + ? 128 ? mV). These findings indicated a velocity-related
dissociation between MMG and peak torque for maximal eccentric
isokinetic muscle actions.
Received 14 June 1996; accepted in final form 29 October 1996.
APS Manuscript Number A556-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996