These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Differences in coordination of elbow flexor muscles in force tasks and in movement tasks.
    Author: Tax AA, Denier van der Gon JJ, Erkelens CJ.
    Journal: Exp Brain Res; 1990; 81(3):567-72. PubMed ID: 2226689.
    Abstract:
    Motor-unit activity in m. biceps brachii, m. brachialis and m. brachioradialis during isometric contractions has been compared with motor-unit activity during slow voluntary (extension and flexion) movements made against external loads. During these slow movements the recruitment threshold of m. biceps motor units is considerably lower than it is during isometric contractions but the recruitment threshold of both m. brachialis and m. brachioradialis motor units is considerably higher. For all three elbow flexor muscles the motor-unit firing frequency seems to depend on the direction of movement: the firing frequency is higher during flexion movements (3 deg/s) and lower during extension movements (-3 deg/s) than during isometric contractions. The relative contribution of the biceps to the total exerted flexion torque during slow voluntary movements is estimated to increase from 36% to about 48% and that of the brachialis/brachioradialis is estimated to decrease from 57% to about 45% compared to the relative contribution of these muscles during isometric contractions. This difference in the relative contribution of the three major elbow flexor muscles is shown to be caused by differences in the central activation in force tasks and movement tasks.
    [Abstract] [Full Text] [Related] [New Search]