title: An Examination of Fatigue Index and Velocity-Related Force Loss for the Forearm Flexors.
abstract: The purpose of this study was to examine the relationship between the fatigue index from an isokinetic fatigue test and the velocity-related decrease in peak torque for the forearm flexors. After a familiarization session, 13 habitually active males (mean ± SD, age = 23.8 ± 3.1 years) reported to the laboratory to perform either 50 repeated, maximal, concentric isokinetic muscle actions of the dominant forearm flexors at a velocity of 180°·s(-1) or 6 separate sets of 3 maximal concentric isokinetic muscle actions at randomly ordered velocities of 30, 90, 150, 270, and 330°·s(-1). The correlation between the relative percent declines in peak torque during the 2 isokinetic tests was then examined. The results indicated an inverse relationship (r = -0.75, p < 0.01) between these 2 variables. That is, the subjects who demonstrated the greatest fatigue indexes (i.e., those who were most susceptible to fatigue) were generally the most resistant to a velocity-related torque loss. These findings support the possibility of using a multiple-velocity isokinetic test to estimate fiber type composition, just as fatigue-based tests have been used.
authors.affiliation: Biophysics Laboratory, Department of Health and Exercise Science, University of Oklahoma, Norman, Oklahoma.
authors.forename: Joshua C
authors.initials: JC
authors.lastname: Carr
authors.forename: Travis W
authors.initials: TW
authors.lastname: Beck
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.forename: Nathan P
authors.initials: NP
authors.lastname: Wages
mesh_terms: D000328:Adult; D005542:Forearm; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D019415:Torque; D055815:Young Adult