Velocity-Specific Coactivation and Neuromuscular Responses to Fatiguing, Reciprocal, Isokinetic, Forearm Flexion, and Extension Muscle Actions

Tyler J. Neltner; John Paul V. Anders; Joshua L. Keller; Robert W. Smith; Terry J. Housh; Richard J. Schmidt; Glen O. Johnson

Ayuda

Velocity-Specific Coactivation and Neuromuscular Responses to Fatiguing, Reciprocal, Isokinetic, Forearm Flexion, and Extension Muscle Actions

Tyler J. Neltner ^[1] ; John Paul V. Anders ^[1] ; Joshua L. Keller ^[2] ; Robert W. Smith ^[1] ; Terry J. Housh ^[1] ; Richard J. Schmidt ^[1] ; Glen O. Johnson ^[1]
1. [1] University of Nebraska System
  
  University of Nebraska System
  
  Estados Unidos
2. [2] University of South Alabama
  
  University of South Alabama
  
  Estados Unidos
Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 36, Nº. 3, 2022, págs. 649-660
Idioma: inglés
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Resumen
- The purpose of this study was to examine the effects of fatiguing, reciprocal, maximal, isokinetic, forearm flexion, and extension on coactivation. Ten recreationally trained women (mean +/- SD: age = 21 +/- 1.63 years) performed 50 maximal, reciprocal, isokinetic, forearm flexion, and extension muscle actions at 60 and 180[degrees][middle dot]s-1 on separate days. Electromyographic (EMG) and mechanomyographic (MMG) signals from the biceps brachii (BB) and triceps brachii (TB) were recorded. A 2 (time) x 2 (velocity) x 2 (movement) and 4 separate 2 (time) x 2 (velocity) x 2 (muscle) x 2 (movement) repeated-measures analysis of variances were used to examine normalized torque and normalized EMG and MMG amplitude (AMP) and mean power frequency, respectively, with an alpha of p < 0.05. There were no significant interactions for torque but a main effect for time (p < 0.001, d = 3.29) such that it decreased. There was a significant four-way interaction for EMG AMP (p = 0.004, = 0.61) which revealed parallel responses between the BB and TB during both movements, with no changes at 60[degrees][middle dot]s-1 and increases at 180[degrees][middle dot]s-1. The current findings suggested a common drive between agonist and antagonist muscles during fatiguing forearm flexion and extension muscle actions, with velocity-specific activation strategies. In addition, both EMG and MMG are viable techniques for assessing coactivation during fatiguing exercise.