背景:匆忙和转弯都与老年人跌倒有关。转弯时侧向失去平衡会增加髋部骨折的可能性。然而,99%的意外转弯失败都可以追溯到无论年龄大小都无法遏制前进的势头。
目的:在转弯时,与内侧-外侧(M-L)平衡和前后(P-A)推进相关的时空步态适应存在基于年龄的差异吗?
方法:健康的年轻人(n=10)和老年人(n=10)以首选和较快的测试速度行走,同时随机提示方向,无论是在开始步态的早期还是在进入空间定义的转弯区域之前的1-2步后期。在转弯900或继续直行之前,仪器化的4.6m地毯记录了时空变化,直到倒数第二个脚步声。
结果:当通过步行测试速度的相互作用接近转弯区时,提示时间和方向,除了老年人的步幅较短之外,在管理P-A减速扰动时,两个年龄组在步态速度和步幅上显示出相似的调整,在管理M-L平衡不稳定力方面,右和左脚跟到脚跟支撑基础(BOS)的类似适应。三向互动(p<.027)表明,当提示方向较早快速行走(p<.020)和较晚行走首选速度(p<.014)时,可以使用类似的BOS缩小的脚部策略,使其相对于直线行走接近转弯。
结论:这些发现是在调节质心加速度和处理环境监管条件以保持个人空间安全裕度的背景下进行解释的。该研究支持在其他健康的老年人中,转弯的步态训练包括练习,不仅要管理使身体侧向加速的扰动,还要管理使前进减速的扰动。
BACKGROUND: Hurrying and turning are each associated with falls in older adults. Losing balance sideways when turning increases the likelihood of hip fracture. Yet 99 % of failures when turning unexpectedly have been traced to an inability to curb forward momentum regardless of age.
OBJECTIVE: Do age-based differences exist in spatial-temporal gait adaptations related to medial-lateral (M-L) balance and posterior-anterior (P-A) propulsion upon approach of turns relative to continuing straight, across walking speeds and whether direction is known in advance?
METHODS: Healthy young (n=10) and older adults (n = 10) walked at preferred and fast test speeds while randomly cued for direction either early upon initiating gait or late 1-2 steps before entering a spatially defined turning area. An instrumented 4.6 m carpet recorded spatial-temporal changes up to the penultimate footfall prior to turning 900 or continuing straight.
RESULTS: When approaching the turning zone across interactions of walking test speed, cue time and direction, other than stride-length being shorter in older adults, both age-groups showed similar adjustments in gait speed and stride-length in managing P-A deceleration perturbations, and similar adaptations in right and left heel-to-heel base of support (BOS) in managing M-L balance destabilizing forces. A three-way interaction (p<.027) suggests a similar foot strategy of BOS narrowing may be used approaching turns relative to straight walks when direction is cued early walking fast (p<.020) and late walking preferred speed (p<.014).
CONCLUSIONS: The findings were interpreted within the context of regulating center of mass acceleration and processing environmental regulatory conditions to maintain a personal space safety margin. The study supports that in otherwise healthy older adults, gait training for turns include practice to not only manage perturbations which accelerate the body sideways but also those which decelerate forward progression.