Affordable Access

Publisher Website

Analyses of myo-electrical silence of erectors spinae

Authors
Journal
Journal of Biomechanics
0021-9290
Publisher
Elsevier
Publication Date
Volume
34
Issue
4
Identifiers
DOI: 10.1016/s0021-9290(00)00213-x
Keywords
  • Erector Spinae
  • Trunk Muscles
  • Electromyography
  • Electrical Silence
  • Flexion–Relaxation Phenomenon

Abstract

Abstract Electromyographic activity of the erector spinae was studied in 25 healthy, young individuals during forward bending and then coming back to erect posture. Sudden onset of electrical silence called the flexion – relaxation phenomenon was seen to occur in all at 57% of the maximum hip flexion and at 84% of the maximum vertebral flexion. Abrupt re-commencement of the activity was seen at almost similar flexion angle while coming back to erect position. The experiment was repeated with the buttocks held against the wall so as to prevent the posterior migration of the pelvis and also the hip flexion to some extent. The effect was to produce inhibition of the electrical activity earlier at 75% of maximum vertebral flexion ( p<0.001) while reactivation of erector spinae occurred soon after the extension started from the maximum trunk flexion. Eleven male subjects repeated the experimental task holding 22 lb weight in front and then on their back tied around the iliac crest. In both the instances the myo-electrical silence was found to occur at greater vertebral flexion. It is concluded that the passive equilibrium between gravity induced tensile torque and the extension torque of stretched posterior vertebral ligaments is responsible for the flexion–relaxation phenomenon than the stretch receptors.

There are no comments yet on this publication. Be the first to share your thoughts.