Ankle muscle stiffness in the control of balance during quiet standing

J Neurophysiol. 2001 Jun;85(6):2630-3. doi: 10.1152/jn.2001.85.6.2630.

Abstract

This research presents new data and reanalyzed information to refute the criticisms of our model of stiffness control during quiet standing. A re-review of their references to biomechanical research on muscle ankle stiffness confirmed muscle stiffness estimates of the ankle series elastic elements that agreed closely with our estimates. A new technique is presented that directly estimates the muscle stiffness from the ankle moment (N. m) and sway angle (deg). The linear regression of 10 subjects standing quietly for 10 s estimated the stiffness (N x m/deg) to be safely above the gravitational spring. The R(2) scores for this linear regression averaged 0.92, confirming how closely the model approached a perfect spring that would have an R(2) = 1. These results confirm our model of a simple muscle stiffness control and refutes the criticisms.

MeSH terms

  • Adult
  • Ankle Joint / physiology*
  • Elasticity
  • Humans
  • Linear Models
  • Muscle Contraction / physiology*
  • Muscle, Skeletal / physiology*
  • Postural Balance / physiology*