Assessing age-related balance deterioration: Visual or mechanical tasks?

Area of Science:

• Gerontology
• Biomechanics
• Motor Control

Background:

• Mediolateral balance assessment (MELBA) tracks targets using center-of-mass feedback and is sensitive to age-related balance decline.
• Ground-level tasks may offer greater sensitivity to balance deterioration compared to existing MELBA protocols.

Purpose of the Study:

• To compare the age sensitivity of visual and mechanical mediolateral balance assessments.
• To investigate differences in tracking strategies between visual and mechanical balance tasks in older and younger adults.

Main Methods:

• Developed a mechanical mediolateral balance assessment using surface translations.
• Recruited 15 older adults and 12 young adults to perform both visual and mechanical MELBA tasks.
• Calculated phase-shift and gain between center-of-mass and target/surface, and trunk-leg angle phase-shift to assess tracking strategies.

Main Results:

• Older adults performed worse than young adults on both visual and mechanical tasks.
• A significant age-task interaction was found for mean phase-shift, with older adults showing greater age differences in the visual task.
• Tracking strategies differed, with greater trunk-leg decoupling observed in the mechanical task compared to the visual task.

Conclusions:

• The visual mediolateral balance assessment is more sensitive to age-related balance deterioration than the mechanical version.
• Visual tracking may engage motor strategies more susceptible to the effects of aging, explaining the observed differences in sensitivity.