• KOLs Community
    • Voluntary Contraction
    • Effect Of Antagonistic...
    • Key People For Voluntary Contraction

      Top KOLs in the world
      Simon Charles Gandevia
      voluntary activation motor cortex muscle fatigue
      John Christine Rothwell
      motor cortex magnetic stimulation corticospinal excitability
      HALLETT Hallett
      essential tremor motor cortex magnetic stimulation
      Brian L Day
      motor cortex magnetic stimulation parkinsons disease
      C David Marsden
      parkinsons disease basal ganglia substantia nigra
      Roger Maro Enoka
      motor units muscle fatigue multiple sclerosis

      Effect of antagonistic voluntary contraction on motor responses in the forearm


      OBJECTIVE: We investigated the effects of voluntary contraction of agonist and antagonist muscles on motor evoked potentials (MEP) and on myoelectric activities in the target (agonist) muscle following transcranial magnetic stimulation (TMS).

      METHODS: The left extensor carpi radialis (ECR) and flexor carpi radialis (FCR) muscles were studied in 16 healthy subjects. H reflexes, MEP induced by TMS, and background electromyographic (EMG) activity were recorded using surface electrodes at rest and during voluntary contraction of either agonist or antagonist muscles.

      RESULTS: Voluntary contraction of antagonist muscles (at 10% of maximum contraction) enhanced the amplitudes of MEP for both muscles. The H reflex of the FCR muscle was inhibited by contraction (10% of maximum) of the ECR muscle. Background EMG activity did not differ between H-reflex trials and TMS trials. Enhancement of MEP amplitudes and background EMG activity during voluntary antagonist contraction was comparable in the two muscles. Appearance rate of MEP recorded by needle electrodes in response to subthreshold TMS was increased by antagonistic voluntary contraction.

      CONCLUSION: Facilitation occurs during voluntary contraction of antagonist muscles. Differences between the effects of voluntary contraction of the ECR muscle for the MEP and the H reflex of the FCR suggest that cortical facilitatory spread occurs between agonist and antagonist muscles.

      Sign-in to see all concepts, it's free!


    Download on the App StoreGet it on Google Play

    Copyright © 2023 - KOL means Key Opinion Leaders .

    KOL does not provide medical advice, diagnosis or treatment.