Richer Natalie, Polskaia Nadia, Lajoie Yves
a School of Human Kinetics, Faculty of Health Sciences , University of Ottawa , Ottawa , Ontario , Canada.
Exp Aging Res. 2017 Jan-Feb;43(1):21-33. doi: 10.1080/0361073X.2017.1258214.
Background/Study Context: Recent evidence suggests that removing attention from postural control using either an external focus or a cognitive task will improve stability in healthy young adults. Due to increases in attentional requirements of upright stance in older adults, it is unclear if similar benefits would be observed in this population. The aim of the present study was to examine the effect of attentional focus and of a continuous cognitive task on postural control in older adults.
Sixteen healthy older adults (71.9 ± 4.32 years) were asked to stand quietly on a force platform with feet together in three different conditions: internal focus (minimizing movement of the hips), external focus (minimizing movement of markers placed on the hips), and cognitive task (silently counting the occurrence of a single digit in a 3-digit number sequence). A one-way analysis of variance with repeated measures on condition was performed for each postural control measure.
Hypotheses were partially supported because the cognitive task led to greater stability than both focus conditions, as evidenced by a smaller sway area (p < .01, η = .41), reduced sway variability (anterior-posterior: p = .001, η = .37; medial-lateral: p < .0001, η = .49), and higher mean power frequency in the anterior-posterior direction (p = .01, η = .78). However, no difference was observed between internal and external focus conditions.
A continuous, attention-demanding cognitive task significantly improved stability in older adults compared with an internal or external focus of attention. This suggests that older adults were able to effectively allocate their attention away from postural control, allowing a more automatic type of control to operate. Future studies should investigate a variety of cognitive tasks to determine the degree of postural improvement that can be observed in older adults.
背景/研究背景：最近的证据表明，通过外部焦点或认知任务转移对姿势控制的注意力，将改善健康年轻成年人的稳定性。由于老年人直立姿势的注意力需求增加，尚不清楚在该人群中是否会观察到类似的益处。本研究的目的是检查注意力焦点和持续认知任务对老年人姿势控制的影响。
16名健康老年人（71.9±4.32岁）被要求在三种不同条件下双脚并拢安静地站在测力平台上：内部焦点（尽量减少臀部运动）、外部焦点（尽量减少放置在臀部的标记物的运动）和认知任务（默默数三位数序列中单个数字的出现次数）。对每个姿势控制测量进行了条件重复测量的单因素方差分析。
假设得到部分支持，因为认知任务比两种焦点条件都导致更大的稳定性，摆动面积更小（p<.01，η=.41）、摆动变异性降低（前后方向：p=.001，η=.37；内外方向：p<.0001，η=.49）以及前后方向更高的平均功率频率（p=.01，η=.78）证明了这一点。然而，内部和外部焦点条件之间未观察到差异。
与内部或外部注意力焦点相比，持续的、需要注意力的认知任务显著提高了老年人的稳定性。这表明老年人能够有效地将注意力从姿势控制上转移开，从而使一种更自动的控制类型得以运行。未来的研究应该调查各种认知任务，以确定在老年人中可以观察到的姿势改善程度。
