Citation

Qu X, Nussbaum MA, Madigan ML. Gait Posture 2009; 30(4): 518-522.

Affiliation

School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.

Copyright

(Copyright © 2009, Elsevier Publishing)

DOI

10.1016/j.gaitpost.2009.07.127

PMID

19726189

Abstract

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 plantar-flexor 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.

Language: en