School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
Department of Rehabilitation Sciences, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hong Kong SAR, China.
Exp Aging Res. 2022 May-Jun;48(3):295-310. doi: 10.1080/0361073X.2021.1982343. Epub 2021 Sep 30.
This study first examined whether real-time conscious postural control (reinvestment) and postural sway increase with different postural difficulties on a compliant surface among older adults. The second objective was to investigate the effect of an externally focused dual-task on real-time reinvestment and postural sway under a relatively challenging standing position.
Thirty-two community-dwelling older adults (mean age = 72.09, SD = 4.18 years) were recruited. Participants performed balance tasks in four standing positions in a randomized order on a balance foam pad. The four positions included wide-based standing on foam (WBF), narrow-based standing on foam (NBF), tandem-based standing on foam (TBF) and tandem-based standing on foam with an externally focused dual-task (TBFE). Throughout all the balance tasks, participants' real-time reinvestment and body sway were indicated by the Alpha2 T3-Fz Electroencephalogram (EEG) coherence and the total sway length (TSL), respectively.
Our results revealed no significant difference in real-time reinvestment among different standing positions while postural sway increased from WBF to NBF and reduced from NBF to TBF. We also demonstrated that when performing a relatively challenging standing task on a compliant surface, an externally focused dual-task (TBFE), compared to a baseline single task (TBF), can neither mitigate real-time reinvestment nor improve balance performance in community-dwelling older adults with good balance capability. Potential explanations and implications are discussed.
本研究首先考察了在顺应性表面上，老年人在不同的姿势难度下，实时姿势控制（再投资）和姿势摆动是否会增加。第二个目的是研究在相对具有挑战性的站立位置下，外部焦点双重任务对实时再投资和姿势摆动的影响。
招募了 32 名社区居住的老年人（平均年龄=72.09，标准差=4.18 岁）。参与者以随机顺序在平衡泡沫垫上进行四种站立姿势的平衡任务。这四个姿势包括在泡沫上宽基础站立（WBF）、在泡沫上窄基础站立（NBF）、在泡沫上串联基础站立（TBF）和在泡沫上串联基础站立同时执行外部焦点双重任务（TBFE）。在所有平衡任务中，参与者的实时再投资和身体摆动分别由 Alpha2 T3-Fz 脑电图（EEG）相干性和总摆动长度（TSL）指示。
我们的结果表明，在不同的站立姿势下，实时再投资没有显著差异，而姿势摆动从 WBF 增加到 NBF，然后从 NBF 减少到 TBF。我们还表明，在顺应性表面上执行相对具有挑战性的站立任务时，与基线单任务（TBF）相比，外部焦点双重任务（TBFE）既不能减轻实时再投资，也不能改善具有良好平衡能力的社区居住老年人的平衡性能。讨论了潜在的解释和影响。
