Quadriceps mechano- and electromyographic time-frequency responses during muscular contractions to volitional exhaustion.

Academic Article


  • INTRODUCTION: Surface electromyography (SEMG) and mechanomyography (SMMG) responses of the quadriceps during muscular contractions to exhaustion were computed and analyzed by analysis of variance and polynomial regression analyses. METHODS: Participants performed maximum flexion-extension movements at 180°/s until volitional exhaustion, rested for 2 minutes, and then completed a second bout of movements until exhaustion. Torque and SEMG/SMMG median frequencies and amplitudes were examined at 9 points across repetitions completed. RESULTS: (1) Torque decreased precipitously; (2) SEMG amplitude displayed an initial increase, then a steady decrease, and SMMG amplitude showed a continuous decrease; and (3) SEMG and SMMG median frequencies displayed a continual decrease over repetitions completed. Fractional polynomial and quadratic models explained the fatigue process with the highest precision. CONCLUSIONS: Changes in electrical and mechanical properties of the quadriceps during fatigue reflect alterations in neuromuscular activation strategies and/or muscle wisdom. SEMG frequency modeled muscle fatigue more effectively than amplitude, whereas SMMG frequency and amplitude were equally effective.
  • Authors

  • Croce, Ronald
  • Craft, Amber
  • Miller, John
  • Chamberlin, Kent
  • Filipovic, David
  • Status

    Publication Date

  • March 2016
  • Published In

  • Muscle and Nerve  Journal
  • Keywords

  • Accelerometry
  • Analysis of Variance
  • Electric Stimulation
  • Electromyography
  • Evoked Potentials, Motor
  • Exercise
  • Fourier Analysis
  • Humans
  • Male
  • Muscle Contraction
  • Muscle Strength Dynamometer
  • Muscle, Skeletal
  • Physical Stimulation
  • Regression Analysis
  • Time Factors
  • Torque
  • Young Adult
  • electromyography
  • fatigue
  • isokinetics
  • mechanomyography
  • wavelet transform
  • Digital Object Identifier (doi)

    Pubmed Id

  • 26172571
  • Start Page

  • 452
  • End Page

  • 463
  • Volume

  • 53
  • Issue

  • 3