Tashiro Hideyuki, Hirosaki Sota, Sato Yui, Toki Megumi, Ihira Hikaru, Kozuka Naoki
Department of Physical Therapy, School of Health Sciences, Sapporo Medical University, S-1, W-17, Chuo-ku, Sapporo, Hokkaido 060-8556, Japan.
Graduate School of Health Sciences, Sapporo Medical University, S-1, W-17, Chuo-ku, Sapporo, Hokkaido 060-8556, Japan.
Gait Posture. 2023 Oct 26. doi: 10.1016/j.gaitpost.2023.10.018.
Divided attention is commonly required in daily life, and to prevent falls, balance must be recovered when a person experiences unexpected perturbations. Previous studies have shown that additional cognitive tasks in postural responses negatively affect automatic postural responses. However, the effect of dual-tasking on reactive stepping performance is still not clearly understood. This study investigated the effect of dual-tasking on reactive stepping induced by a large perturbation in older adults and characterized the effect of dual-tasking by comparison with young adults.
How does the effect of dual-tasking on reactive stepping performance differ between young and older adults?
Twenty-nine older adults and twenty-two young adults were prospectively exposed to external perturbations to induce forward reactive steps. Perturbations were delivered under simple front fixed gaze (single-task condition) and modified Stroop task (dual-task condition). Measures of the time to foot-off and reach stability, step length, velocity, and number of steps were based on force plate data for both the single- and dual-task conditions.
Young and older adults showed a delay in foot-off time during the dual-task condition compared with that during the single-task condition. The reach stability time, step length, and number of steps were worse in the dual-task condition than in the single-task condition for older adults, but not for young adults. The deficits in reactive stepping performance during dual-tasking could reflect the reactive balance capacity in real life.
The findings of this study highlight the increased risk of falls with age.
日常生活中通常需要分散注意力，为防止跌倒，当人经历意外扰动时必须恢复平衡。先前的研究表明，姿势反应中的额外认知任务会对自动姿势反应产生负面影响。然而，双任务对反应性跨步表现的影响仍未完全清楚。本研究调查了双任务对老年人因大扰动诱发的反应性跨步的影响，并通过与年轻人比较来表征双任务的影响。
双任务对反应性跨步表现的影响在年轻人和老年人之间有何不同？
前瞻性地让29名老年人和22名年轻人暴露于外部扰动以诱发向前的反应性跨步。在简单的前方固定注视（单任务条件）和改良的斯特鲁普任务（双任务条件）下施加扰动。基于单任务和双任务条件下的测力台数据测量离地时间、达到稳定的时间、步长、速度和步数。
与单任务条件相比，年轻人和老年人在双任务条件下的离地时间均出现延迟。对于老年人，双任务条件下的达到稳定时间、步长和步数比单任务条件下更差，但年轻人并非如此。双任务期间反应性跨步表现的缺陷可能反映了现实生活中的反应性平衡能力。
本研究结果突出了随年龄增长跌倒风险增加的问题。
