Wavelet analysis of quadriceps power spectra and amplitude under varying levels of contraction intensity and velocity.

Academic Article

Abstract

  • INTRODUCTION: We investigated the effect of contraction intensity [100%, 75%, 50%, and 25% maximum voluntary contraction (MVC)] and movement velocity (50°, 100°, 200°, and 400°/s) on surface electromyography root mean square amplitude (SEMGRMS ) and median frequency (SEMGMDF ) of rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM). METHODS: SEMGs during knee extension were resolved into their respective frequencies using wavelet transformations. RESULTS: RF, VL, and VM muscles displayed increased SEMGMDF as contraction intensity increased from 25% to 50% MVC and from 75% to 100% MVC, and each muscle displayed its own unique frequency shifting patterns. The SEMGMDF was not influenced by movement velocity. SEMGRMS increased in all 3 muscles as contraction intensity increased and was influenced by movement velocity, with the highest values observed at 400° and 200°/s. CONCLUSIONS: We infer that increasing contraction intensity facilitates greater recruitment of fast-twitch muscle fibers, but there are differing responses in RF, VL, and VM muscles.
  • Authors

  • Croce, Ronald
  • Miller, John
  • Chamberlin, Kent
  • Filipovic, David
  • Smith, Wayne
  • Status

    Publication Date

  • November 2014
  • Published In

  • Muscle and Nerve  Journal
  • Keywords

  • Action Potentials
  • Adult
  • Analysis of Variance
  • Electromyography
  • Female
  • Humans
  • Knee
  • Male
  • Median Nerve
  • Movement
  • Muscle Contraction
  • Muscle Strength
  • Muscle Strength Dynamometer
  • Quadriceps Muscle
  • Wavelet Analysis
  • Young Adult
  • electromyography
  • isokinetic
  • power spectrum
  • quadriceps
  • wavelet transform
  • Digital Object Identifier (doi)

    Pubmed Id

  • 24590658
  • Start Page

  • 844
  • End Page

  • 853
  • Volume

  • 50
  • Issue

  • 5