Muijres Wouter, Arnalsteen Sylvie, Daenens Cas, Afschrift Maarten, De Groote Friedl
Department of Movement Sciences, KU Leuven, Leuven, Belgium.
Department of Human Movement Sciences, Vrije Universiteit, Amsterdam, Netherlands.
Front Aging Neurosci. 2023 Mar 16;15:1130707. doi: 10.3389/fnagi.2023.1130707. eCollection 2023.
Stepping accuracy, speed, and stability are lower in older compared to young adults. Lower stepping performance in older adults may be due to larger accuracy-speed-stability trade-offs because of reduced ability to simultaneously fulfill these task-level goals. Our goal was to evaluate whether trade-offs are larger in older compared to young adults in a targeted stepping task. Since sensorimotor function declines with age, our secondary goal was to evaluate whether poorer sensorimotor function was associated with larger trade-offs.
Twenty-five young (median 22 years old) and 25 older (median 70 years old) adults stepped into projected targets in conditions with various levels of accuracy, speed, and stability requirements. We determined trade-offs as the change in performance, i.e., foot placement error, step duration, and mediolateral center of pressure path length, between each of these conditions and a control condition. To assess age-related differences in the magnitude of trade-offs, we compared the change in performance between age groups. Associations between trade-offs and measures of sensorimotor function were tested using correlations.
We found an accuracy-speed and an accuracy-stability trade-off in both young and older adults, but trade-offs were not different between young and older adults. Inter-subject differences in sensorimotor function could not explain inter-subject differences in trade-offs.
Age-related differences in the ability to combine task-level goals do not explain why older adults stepped less accurate and less stable than young adults. However, lower stability combined with an age-independent accuracy-stability trade-off could explain lower accuracy in older adults.
与年轻人相比，老年人的步幅准确性、速度和稳定性较低。老年人较低的步幅表现可能是由于同时实现这些任务级目标的能力下降，导致准确性 - 速度 - 稳定性之间的权衡更大。我们的目标是评估在有针对性的步幅任务中，老年人与年轻人相比，这种权衡是否更大。由于感觉运动功能会随着年龄下降，我们的次要目标是评估较差的感觉运动功能是否与更大的权衡相关。
25名年轻人（中位数年龄22岁）和25名老年人（中位数年龄70岁）在具有不同准确性、速度和稳定性要求的条件下步入预计目标。我们将权衡确定为每种条件与对照条件之间性能的变化，即脚放置误差、步幅持续时间和压力中心在内外侧方向的路径长度。为了评估年龄组之间权衡幅度的差异，我们比较了不同年龄组之间的性能变化。使用相关性测试权衡与感觉运动功能测量之间的关联。
我们在年轻人和老年人中都发现了准确性 - 速度以及准确性 - 稳定性之间的权衡，但年轻人和老年人之间的权衡没有差异。感觉运动功能的个体间差异无法解释权衡的个体间差异。
与年龄相关的组合任务级目标能力的差异并不能解释为什么老年人的步幅比年轻人更不准确和更不稳定。然而，较低的稳定性加上与年龄无关的准确性 - 稳定性权衡可以解释老年人较低的准确性。
