The Effect of a Cognitive Dual Task on the Control of Minimum Toe Clearance While Walking.

The aim of the current study was to evaluate the effect of a cognitive dual task on minimum toe clearance (MTC) variability while walking. In a randomized cross-over design, gait kinematics of 25 older (70 ± 6 years) and 45 younger adults (25 ± 2 years) were captured during normal walking and dual-task walking. Variability of stride time, stride length, and MTC were calculated. Differences between normal versus dual-task walking were assessed using Wilcoxon tests. Compared with normal walking, dual-task walking caused an increase in stride time variability (older adults: p < .001 and younger adults: p < .001), while the variability of MTC decreased (older adults: p = .032 and younger adults: p = .012). MTC seems to be a task-relevant gait parameter that is controlled with high priority to preserve its variability under challenging conditions.