Zeng Ziwei, Ho Cheuk-Yin, Zhou Junhong, Shen Jiahao, Yang Yijian
Department of Sports Science and Physical Education, The Chinese University of Hong Kong, N.T. Hong Kong SAR, China.
Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Roslindale, Massachusetts, USA.
Innov Aging. 2025 May 24;9(6):igaf055. doi: 10.1093/geroni/igaf055. eCollection 2025.
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.
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.
Task-specific adaptations were observed: MDT prompted greater stride length adjustments, while CDT led to more balanced cadence and stride length adjustments ( = 8.346, = .010, p = .317). Fallers exhibited more anti-phase coordination in hip flexion-knee flexion than non-fallers during dual-task conditions ( ≤ .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 ( ≤ .044). Coordination variability decreased during MDT for hip flexion-ankle dorsiflexion in both groups compared to ST ( ≤ .027).
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.
跌倒在老年人中是一个主要的公共卫生问题，常导致受伤、行动能力受损和失去独立性。双任务行走是指在行走时执行一项次要任务，它模拟了现实生活中的挑战，并且与跌倒风险相关。本研究旨在调查双任务对有跌倒史和无跌倒史的老年人行走过程中的步行动作策略、关节间协调性以及协调变异性的影响。
20名65岁及以上的社区居住老年人（10名有跌倒史者，10名无跌倒史者）在三种条件下完成了一项2分钟的行走测试：单任务（ST）行走、运动双任务（MDT）行走（手持一杯水）和认知双任务（CDT）行走（连续减法运算）。使用惯性测量单元收集步态数据。步行动作策略通过步频和步长的变化来量化，而关节间协调性则使用矢量编码进行分析。采用双向重复测量方差分析来评估任务和组对变量的影响。
观察到特定任务的适应性变化：MDT促使步长有更大的调整，而CDT导致步频和步长调整更加平衡（F = 8.346，p = 0.010，η² = 0.317）。在双任务条件下，有跌倒史者在髋部屈曲 - 膝部屈曲方面比无跌倒史者表现出更多的反相位协调性（p ≤ 0.042）。在CDT行走中，与ST相比，有跌倒史者在髋部屈曲 - 膝部屈曲中远端相位的频率较低，而在髋部屈曲 - 踝背屈中反相位的频率较高（p ≤ 0.044）。与ST相比，两组在MDT期间髋部屈曲 - 踝背屈的协调变异性均降低（p ≤ 0.027）。
本研究更好地理解了有跌倒史和无跌倒史的老年人在步行动作策略和特定相位协调模式上的差异，特别是在双任务行走条件下。有跌倒史者保守的运动控制策略表明其在稳定性和适应性之间优先考虑稳定性，这可能会增加复杂行走任务期间跌倒的风险。
