Background

The inability to adjust step length can lead to falls in older people when navigating everyday terrain. Precisely targeted forward placement of the leading foot, constituting step length adjustment, is required for adaptive gait control, but this ability may reduce with ageing. The objective of this study was to investigate ageing effects on step length adaptation using real-time biofeedback.

Research question

Does ageing affect the ability to adapt step length to match a target using real-time biofeedback?

Methods

Fifteen older adults (67 ± 3 years; 8 females) and 27 young adults (24 ± 4 years; 13 females) completed a step length adaptation test while walking at preferred speed on a treadmill. The test involved walking while viewing a monitor at the front of the treadmill that showed a real-time signal of absolute left-right foot displacement. The task was to match the local maxima of the signal (i.e. step length) to two target conditions, at 10 % longer or 10 % shorter than mean baseline step length. When the target was displayed, it remained unchanged for a set of 10 consecutive step attempts. Three sets of 10 attempts for each target condition were allocated in random order, for a total of 30 step attempts per target. Average absolute error and average error (bias) of step length accuracy was computed for each target condition and compared between groups.

Results

: The step adaptation test identified that older adults had greater mean absolute error for both short and long step targets and showed a step length-dependent bias significantly different to the young.

Significance

Real-time foot position feedback could be a useful tool to train and evaluate step adaptation in older people.

中文翻译：

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年龄对连续走步生物反馈的跑步机行走过程中步调适应的影响。

背景

在日常地形上导航时，无法调整步长会导致老年人跌倒。自适应步态控制需要将前脚精确定向向前放置，以构成步长调节，但是这种能力可能会随着年龄的增长而降低。这项研究的目的是利用实时生物反馈研究衰老对步长适应的影响。

研究问题

老化是否会影响通过实时生物反馈调整步长以匹配目标的能力？

方法

15名老年人（67±3岁； 8名女性）和27名年轻人（24±4岁； 13名女性）在跑步机上以理想速度行走时完成了步长适应性测试。该测试包括在跑步机前部的监视器上行走，该监视器显示实时的左右脚绝对位移信号。任务是使信号的局部最大值（即步长）与两个目标条件相匹配，比平均基线步长长10％或短10％。显示目标时，在连续10次尝试步骤中，目标保持不变。为每个目标条件随机分配了三组10次尝试，每个目标总共进行了30步尝试。计算每个目标条件的步长精度的平均绝对误差和平均误差（偏差），并在组之间进行比较。

结果

：阶跃适应性测试确定，成年人的短步和长步目标均具有更大的平均绝对误差，并且显示出步长依赖性偏差与年轻人明显不同。

意义

实时脚部位置反馈可能是训练和评估老年人步适应性的有用工具。