Effects of Dual-Tasking on Stepping Strategy and Inter-Joint Coordination During Walking in Older Fallers and Non-Fallers.

Abstract

Background and objectives: Falls are a major public health concern among older adults, often leading to injuries, impaired mobility, and loss of independence. Dual-task walking, where a secondary task is performed while walking, simulates real-life challenges and is linked to fall risk. This study aimed to investigate how dual-tasking affects stepping strategies, inter-joint coordination, and coordination variability during walking in older adults with and without a history of falls.

Research design and methods: Twenty community-dwelling older adults (10 fallers, 10 non-fallers), aged 65 and older, completed a 2-min walking test under three conditions: single-task (ST) walking, motoric dual-task (MDT) walking (holding a glass of water), and cognitive dual-task (CDT) walking (serial subtractions). Gait data were collected using inertial measurement units. Stepping strategies were quantified by the changes in cadence and stride length, while inter-joint coordination was analyzed using vector coding. Two-way repeated measures ANOVA was used to assess task and group effects on variables.

Results: Task-specific adaptations were observed: MDT prompted greater stride length adjustments, while CDT led to more balanced cadence and stride length adjustments (F = 8.346, p = .010, η ²p = .317). Fallers exhibited more anti-phase coordination in hip flexion-knee flexion than non-fallers during dual-task conditions (p ≤ .042). In CDT walking, fallers showed a lower frequency of distal phase in hip flexion-knee flexion and a higher frequency of anti-phase in hip flexion-ankle dorsiflexion compared to ST (p ≤ .044). Coordination variability decreased during MDT for hip flexion-ankle dorsiflexion in both groups compared to ST (p ≤ .027).

Discussion and implications: This study provided better understanding on the differences of stepping strategies and phase-specific coordination patterns between older adult fallers and non-fallers, particularly under dual-task walking conditions. The conservative motor control strategies in fallers suggest a prioritization of stability over adaptability, potentially increasing fall risk during complex walking tasks.