Aging Affects the Demands and Patterns in Active Control Under Different Sensory-Conflicted Conditions

Area of Science:

• Biomechanics
• Gerontology
• Human Movement Science

Background:

• Falls are a major risk for older adults, often caused by unexpected slips and sensory system decline.
• Age-related sensory deterioration increases the need for active control to maintain balance.
• Current understanding of active control demands in older adults, particularly under perturbation, is limited.

Purpose of the Study:

• To quantify the levels and patterns of active control required by older adults during walking under varying sensory conditions.
• To investigate how sensory perturbations, such as slips and low light, affect active control demands across age groups.
• To introduce a novel assessment method for evaluating active control in the context of fall prevention.

Main Methods:

• A novel assessment was employed involving young and older adults walking under normal, slip, and slip with low light conditions.
• Step length variability, step width variability, and heel contact location ellipse area were measured.
• These metrics were used to quantify and differentiate levels and patterns of active control.

Main Results:

• Reduced sensory information significantly increased the demand for active control in both anterior-posterior and medial-lateral directions.
• Distinct patterns of active control were observed between different age groups and under various perturbation conditions.
• The findings suggest the existence of multiple patterns of active control.

Conclusions:

• Sensory perturbations necessitate higher active control, with age influencing these demands.
• The study proposes a novel, quantifiable method to assess active control under sensory challenges.
• This innovative approach can inform the development of targeted fall prevention training programs for older adults.