A comparison between young and old adults in their ability to rapidly sidestep during gait when attention is divided
A comparison between young and old adults in their ability to rapidly sidestep during gait when attention is divided
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DOI：
10.1159/000118603
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发表时间：
2008-01-01
期刊：
影响因子：
3.5
通讯作者：
White, Scott
中科院分区：
文献类型：
--
作者：
Cho, Chiung-Yu;Gilchrist, Louise;White, Scott
背景：老年人跌倒的发生率高，其危险因素往往是复杂的。为了更好地理解跌倒风险的增加，人们在与年龄相关的平衡变化领域进行了大量研究。然而，对认知变化的研究表明，老年人在两项或两项以上活动中分散注意力的能力较差。这种无法分散注意力的情况可以解释老年人跌倒风险增加的原因。目的：探讨注意力分散、年龄和对运动路径的先验知识对步行时的动态测量和骶骨标记相对于压力中心(COP)位置的影响。方法：青年组和老年组各32例。受试者在不中断前进的情况下行走和后退一步。在一半的步行试验中，执行了一项算术任务，其中有预先计划好的或未知的步进方向。测量最大侧向地面反作用力、COP到骶骨的平均距离、行走速度、操作速度和认知任务的准确度。结果：两组受试者在双任务试验中均显著减小了骶骨标记与COP之间的内侧距离(p=0.04)。在双重任务试验中，两组受试者的步行速度都显著降低(p<；0.0001)。对台阶方向的先验知识显着影响最大侧向地面反作用力和骶骨标记到COP距离，但差异是年龄相关的。年轻人在未知条件下比在预先计划的条件下有更大的价值(p<；0.0001)。对于认知任务，两组都降低了操作速度(p<；0.0001)，但与基线数据相比，保持了操作的准确性(p>；005)。结论：我们的结果显示，老年人在面对双重任务试验或未知测试条件时，倾向于保守。目前研究中的老年人的表现与年轻人不同，这一事实表明，当面临具有挑战性的平衡任务时，他们可能会害怕摔倒。版权所有(C)2008 S.Karger AG，巴塞尔。
Background: The incidence of falls among older adults is high and the risk factors are often complex in nature. Considerable research has been done in the area of age-related changes of balance in an attempt to better understand the increased risk of falls. Studies of cognitive changes, however, suggest that the elderly are less able to divide their attention between two or more activities. This inability to divide attention could explain the increased risks of falls in the elderly. Objective: To investigate the effects of divided attention, age and prior knowledge of movement path, on kinetic measures and the position of the sacral marker relative to the center of pressure (COP) when individuals perform a rapid sidestep during walking. Methods: 32 young and 32 old adults participated in this study. Subjects walked and took a sidestep without interrupting forward progression. An arithmetic task was performed during half of the walking trials with the sidestep direction preplanned or unknown. Peak lateral ground reaction force, mean distance between COP and sacrum, walking velocity, performance speed and accuracy of the cognitive task were measured. Results: Both groups significantly decreased their mediolateral distance between the sacral marker and the COP in the dual-task trials (p = 0.04). Both groups significantly decreased their walking speed in the dual-task trials (p < 0.0001). Prior knowledge of the sidestep direction significantly affected the peak lateral ground reaction force and the sacral marker to COP distance but the differences were age-dependent. Young adults had a larger value in the unknown condition than in the preplanned condition (p < 0.0001). For the cognitive task, both groups decreased their performance speed (p < 0.0001) but maintained their performance accuracy as compared to the baseline data (p > 0.05). Conclusions: Our results revealed that old adults tended to be conservative, when facing the dual-task trials or unknown test condition. The fact that the older adults in the current study did not perform similarly to the younger adults suggests that they might have a fear of fall when facing a challenging balance task. Copyright (c) 2008 S. Karger AG, Basel.