Effects of Aging and Task Prioritization on Split-Belt Gait Adaptation

Area of Science:

• Neuroscience
• Biomechanics
• Gerontology

Background:

• Age-related sensorimotor and cognitive decline impacts gait adaptation, particularly during dual-tasking.
• Dual-tasking necessitates attention shifting and task prioritization, especially in older adults.
• Understanding age-related sensorimotor changes is key to improving gait and preventing falls.

Purpose of the Study:

• To investigate how age and dual-tasking influence adaptive gait and task prioritization.
• To compare gait adaptation strategies between young and older adults on a split-belt treadmill.
• To assess the impact of a cognitive task on gait adaptation and performance in different age groups.

Main Methods:

• Young and older adults walked on a split-belt treadmill with a 2:1 speed ratio, with and without an Auditory Stroop task.
• Gait symmetry (step length, limb excursion, double support time) and strategy variables (swing time, swing speed) were analyzed.
• Cognitive task performance was measured alongside gait parameters during tied-belt and split-belt conditions.

Main Results:

• Both age groups adapted gait symmetry, but employed different strategies: older adults increased fast leg swing speed, while young adults increased fast leg swing time.
• Dual-tasking impacted limb excursion symmetry in the post-adaptation phase.
• Cognitive performance decreased during early adaptation, with older adults showing a more pronounced decline, indicating task prioritization.

Conclusions:

• Healthy older adults can adapt to split-belt perturbations, but use distinct strategies compared to younger adults, potentially to enhance stability.
• Age-related differences in adaptation strategy highlight the importance of gait stability in older individuals.
• The decline in cognitive performance during challenging motor tasks emphasizes the need for task prioritization, suggesting its relevance for fall prevention interventions in older adults.