步行双任务对健康老年人和青年人足廓清功能的影响

关键词：双任务  平地步行  足廓清  最小趾间距  步态分析

Keywords:dual-task  level walking  foot clearance  minimum toe clearance  gait analysis

摘要：

      摘要 目的：观察步行双任务对健康青年人和健康老年人足廓清功能的影响，为减少可能的绊倒风险提供依据。 方法：老年组（健康老年人）25例，青年组（健康青年人）21例，使用三维运动分析系统收集和建模分析软件分析两组受试者在单、双任务步行过程中的时空参数和运动学参数，比较优势侧腿足廓清时的步态参数变化及其变异性。 结果：在单、双任务步行对比中，两组受试者最小趾间距（MTC）未发生明显改变（P>0.05），但老年组和青年组跨步长时间均明显增加，步速减慢（P<0.05）。老年组双任务时从足趾离地到MTC对应时刻的时间占整个步态周期时间百分比（nMTC-TIME）缩短（P<0.05），但青年组双任务时此参数未发生明显变化。步态各参数变异性在单、双任务间均无显著性差异（P>0.05）。两组间各参数注意力消耗比较也无显著性差异（P>0.05）。 结论：步行双任务中健康老年人和青年人均进行步态调整，包括增加跨步长时间，减慢步速。老年人虽然表现与健康青年人类似的MTC和步态变异性，但可能为保证此高度，即有效的足廓清采取相应的调整策略，尤其是缩短足廓清阶段，这可能是其预防绊倒的策略之一。

Abstract:

      Abstract Objective： To observe the effect of single-task walking and dual-task walking on the foot clearance in healthy elderly and healthy youth， and to provide evidence for preventing tripping. Method：Twenty-five healthy older adults (elderly group) and twenty-one healthy younger adults (young group) participated in this study. The Three-dimensional Motion Analysis system was used to collect the gait data and the Visual 3D Professional V6 was used to analyze temporal-spatial parameters and kinematic data on dominant lower limb during single-task walking and dual-task walking in the two groups. The differences of gait parameters and their variability during foot clearance of dominant lower limb were compared within and between these two groups. Result： Compared with the single-task walking， both healthy young and elderly people showed longer stride time and slower velocity(P<0.05)， though the height of toe minimum clearance(MTC) didn't show significant difference during dual-task walking. Elderly participants also showed less percentage from toe off to MTC (nMTC-TIME)(P<0.05)，but the young group didn't show such difference during dual-task walking. All the variation of gait indexes didn't show significant difference between the single-task walking and the dual-task walking(P>0.05). And no significant difference was found on attention cost of all the gait indexes between the two groups(P>0.05). Conclusion： During the dual-task walking， both young and elderly people adopted adjustment strategies including increasing stride time and slowing down stride speed. Although the toe height at MTC and gait variability in the elderly group kept similar to the young group， the elderly subjects may adopt strategy for effective foot clearance， especially shortened the phase of foot clearance， which may be one of the strategies for trip prevention.