title: A comparison of critical force and electromyographic fatigue threshold for isometric muscle actions of the forearm flexors.
abstract: The purpose of this study was twofold: (1) to determine if the mathematical model used for estimating the EMG(FT) during cycle ergometry was applicable to isometric muscle actions; and (2) to compare the mean torque level from the CF test to that of the EMG(FT) test. The CF was defined as the slope coefficient of the linear relationship between total "isometric work" (W (lim) in N m s) and time to exhaustion (T (lim)). The EMG(FT) was defined as the y-intercept of the isometric torque versus EMG fatigue curve slope coefficient relationship. There was a significant (p < 0.05) mean difference between CF (6.6 +/- 3.2 N m) and EMG(FT) (10.9 +/- 4.7 N m). The results of the present study suggested that, during isometric muscle actions of the forearm flexors, fatigue thresholds estimated from the W (lim) versus T (lim) relationship (CF) are different from those estimated from electromyographic fatigue curves (EMG(FT)).
authors.affiliation: Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, NE 68583-0806, USA. rhendri7@unlserve.unl.edu
authors.forename: C Russell
authors.initials: CR
authors.lastname: Hendrix
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Housh
authors.forename: Glen O
authors.initials: GO
authors.lastname: Johnson
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Weir
authors.forename: Travis W
authors.initials: TW
authors.lastname: Beck
authors.forename: Moh H
authors.initials: MH
authors.lastname: Malek
authors.forename: Michelle
authors.initials: M
authors.lastname: Mielke
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schmidt
mesh_terms: D004576:Electromyography / Q000379:methods*; D016552:Ergometry / Q000379:methods; D005080:Exercise Test; D005260:Female; D005542:Forearm / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology; D005082:Physical Exertion; D019415:Torque; D055815:Young Adult