Article

The aim of this study was to investigate how and why age and localized muscle
fatigue affect postural control using model-based simulations. A balance control
model, based on an optimal control strategy, was used to simulate trials of quiet
upright stance both pre-fatigue and following induced ankle plantarflexor
fatigue. Empirical data were obtained from an earlier study that included both
younger and older participants. Effects of age and ankle fatigue were determined
from center-of-pressure (COP) measures and fitted model parameters. Though some
discrepancies existed, the simulated effects of age and ankle fatigue were
consistent with experimental findings in terms of trends in COP-based measures
with age and ankle fatigue. Changes in both COP-based measures and model
parameters were used to infer potential underlying causal mechanisms for the
observed effects of age and ankle fatigue. For example, the model-based
simulations indicated that sensory delay time increased with age and ankle
fatigue by 31.1% and 2.9%, respectively, suggesting a potentially important role
for such delay in postural control and fall risks.

Langue : ANGLAIS