The Association between Age-Related Cognitive Changes and Obstacle Avoidance: Focusing on Memory-Guided Limb Movements

An association between cognitive impairment and tripping over obstacles during locomotion in older adults has been suggested. However, owing to its memory-guided movement, whether this is more pronounced in the trailing limb is poorly known. We examined the age-related changes in stepping-over, focusing on trailing limb movements, and their association with cognitive performance. Age-related change in obstacle avoidance was examined by comparing the foot kinematics of 105 older and 103 younger adults when stepping over an obstacle. The difference in clearance between the leading limb and trailing limb (Δ clearance) was calculated to determine the degree of decrement in the clearance of the trailing limb. A cognitive test battery was used to evaluate cognitive function among older adults for assessing their association with Δ clearance. Older adults showed a significantly lower clearance of the trailing limb than younger adults, resulting in a greater Δ clearance. The significant correlations between greater Δ clearance and scores of Montreal Cognitive Assessment and delayed recall of the Wechsler Memory Scale-Revised Logical Memory. Our results suggest that memory functions may contribute to the control of trailing limb movements, which can secure a safety margin to avoid stumbling on an obstacle, during obstacle avoidance locomotion.