Calf muscle-tendon properties and postural balance in old age

J Appl Physiol (1985). 2006 Jun;100(6):2048-56. doi: 10.1152/japplphysiol.01442.2005. Epub 2006 Feb 2.


We tested the hypothesis that compromised postural balance in older subjects is associated with changes in calf muscle-tendon physiological and mechanical properties. Trial duration and center of pressure (COP) displacements were measured in 24 younger (aged 24+/-1 yr), 10 middle-aged (aged 46+/-1 yr), and 36 older (aged 68+/-1 yr) healthy subjects under varying levels of postural difficulty. Muscle-tendon characteristics were assessed by dynamometry, twitch superimposition, and ultrasonography. In tandem and single-leg stances, trial duration decreased (<or=65% lower, P<0.001) and COP displacements increased (<or=90% higher, P<0.05) with age. Muscle strength, size, activation capacity, and tendon mechanical properties decreased with age by 55, 13, 13, and 36-48%, respectively (P<0.05). Regressions with these parameters and balance indexes were significant (P<0.05) for single-leg and tandem (0.69<r2<0.90) postures only, indicating that the age-related changes in muscle-tendon characteristics may explain the majority of the variance in balance performance during tasks more difficult than habitual bipedal stance.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Accidental Falls
  • Adult
  • Aged
  • Aging / physiology*
  • Biomechanical Phenomena
  • Feedback / physiology
  • Female
  • Humans
  • Leg / anatomy & histology
  • Leg / physiology
  • Male
  • Middle Aged
  • Muscle, Skeletal / diagnostic imaging*
  • Muscle, Skeletal / physiopathology
  • Postural Balance / physiology*
  • Regression Analysis
  • Tendons / diagnostic imaging*
  • Tendons / physiopathology
  • Time Factors
  • Torque
  • Ultrasonography