title: Mechanomyographic responses to maximal eccentric isokinetic muscle actions.
abstract: The purpose of the present investigation was to examine the mechanomyographic (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 lateralis 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 MMG amplitude values. 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 [119 +/- 44 (SE) mV] and 180 degrees/s (302 +/- 128 mV). These findings indicated a velocity-related dissociation between MMG and peak torque for maximal eccentric isokinetic muscle actions.
authors.affiliation: Center for Youth Fitness and Sports Research, School of Health and Human Performance, University of Nebraska at Lincoln 68588-0229, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Smith
authors.forename: T J
authors.initials: TJ
authors.lastname: Housh
authors.forename: J R
authors.initials: JR
authors.lastname: Stout
authors.forename: G O
authors.initials: GO
authors.lastname: Johnson
authors.forename: T K
authors.initials: TK
authors.lastname: Evetovich
authors.forename: K T
authors.initials: KT
authors.lastname: Ebersole
mesh_terms: D000328:Adult; D004576:Electromyography; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*