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Affiliation
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Department of Human Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands. |
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Abstract
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BACKGROUND: Mediolateral balance assessment (MELBA) comprises tracking of predictable and unpredictable targets moving at increasing frequencies, using centre-of-mass feedback. The mediolateral-balance-assessment was shown to be sensitive to subtle age-related balance deterioration. However, it has been suggested that performance during ground-level tasks can be more sensitive to balance deterioration.
METHODS: we developed a modified mediolateral-balance-assessment using tracking of surface translations with comparable waveforms (mechanical mediolateral-balance-assessment) to compare age sensitivity of the visual and mechanical mediolateral-balance-assessment, 15 older adults (68 SD 5 yr) and 12 young adults (30 SD 4 yr) performed both tasks. Phase-shift and gain between the CoM and either the visual target or the surface displacement for the visual and the mechanical mediolateral-balance-assessment, respectively, were calculated. To identify differences in tracking strategies between the visual and mechanical mediolateral-balance-assessment, phase-shift between trunk and leg angles was calculated.
FINDINGS: Overall, older adults performed worse than young across the predictable and unpredictable tracking and visual and mechanical tasks. Of all mediolateral-balance-assessment performance descriptors, a significant interaction between age and task (visual or mechanical) was only found for the mean phase-shift. Post-hoc comparisons revealed significant age differences in the visual but not in the mechanical mediolateral-balance-assessment. Significant differences in tracking strategies were found between visual and mechanical mediolateral-balance-assessment with a greater decoupling of trunk and legs during the mechanical than the visual mediolateral-balance-assessment.
INTERPRETATION: the visual mediolateral-balance-assessment was more sensitive to age-related balance deterioration than the mechanical mediolateral-balance-assessment, possibly because visual tracking elicits motor strategies that are more affected by ageing.
Copyright © 2019. Published by Elsevier Ltd.
Language: en |