No announcement yet.

muscle twitch peak time as a function of activation level

This topic is closed.
  • Filter
  • Time
  • Show
Clear All
new posts

  • muscle twitch peak time as a function of activation level

    In an experiment involving single-pulse TMS of the hand
    area when the subject produced various finger forces in
    isometric condition, I observed that the peak times of the finger
    twitches were shorter for larger initial levels of force. The peak
    times did not depend on the intensity of the TMS. Finally,
    as expected, peak force depended on both factors.

    My guess is that the shorter peak time observed with
    an increased initial level of muscle contraction is
    essential a mechanical effect due to the increased stiffness
    of the muscle (stiffer springs must have a higher-cut off frequency
    when viewed as low-pass filters since they transmit better
    higher frequencies).

    I have done a research in pubmed and I have not found
    studies reporting the peak time of the muscle impulse
    response for various levels of baseline activation and
    impulse intensity. I also don't know if it is a well-known
    property of Hill-like models of the muscles.

    I would be grateful if somebody could point a reference
    to me that shows (theoretically and/or experimentally)
    that the peak time of a muscle twitch in isometric conditions
    depends primarily on the initial activation level and less
    (or not at all) on the impulse intensity.

    Gabriel Baud-Bovy
    UHSR University