双任务模式下楼梯时步态速度对动态步态稳定性的影响

Effects of dual-task paradigm and gait velocity on dynamic gait stability during stair descent

背景:发生在在步行楼梯行走过程的跌倒是人们意外死亡的主要原因之一。认知或身体任务的双任务范式对动态步态稳定性的影响仍不确定,步态的动态稳定性受步态速度的影响程度也还不清楚。方法:16名健康年轻女性在三种不同的任务状态下楼梯:下楼梯(单任务)、边计算减法边下楼梯(认知双任务)、端着一杯水下楼梯(身体双任务)。采用八摄像头的Vicon运动分析系统和Kistler测力台同步采集运动学和动力学数据。结果:在认知和身体双任务状态下,步态速度降低,步态动态稳定性增加。随着步态速度的增加,质心—压心倾角增大,与单任务相比,身体双任务状态倾角减小。结论:双任务引起的步态速度变化可以部分解释步态速度对双任务动态步态稳定性的影响。在双任务效果评估中,应考虑步态速度的影响。

Background:Falls during stair negotiation have become one of the leading causes of accidental death,the effects of a concurrent cognitive or manual dual-task paradigm on dynamic gait stability remain uncertain,and how much dynamic gait stability is influenced by gait velocity is also not clear.Methods:A total of 16 healthy young females descend a staircase under three different walking conditions:descend stairs only(single task);descend stairs while performing subtraction(cognitive dual-task),and descend stairs while carrying a glass of water(manual dual-task).An eight-camera Vicon motion analysis system and a Kistler force plate embedded into the third step of a staircase were used synchronously to collect kinematic and kinetic data.Results:Gait velocity decreased and dynamic gait stability increased,with both cognitive and manual dual-task conditions.The center of mass-center of pressure inclination angle increased with gait velocity but decreased with the manual dual-task condition compared to the single task condition.Conclusions:Changes in gait velocity,caused by the dual-task paradigm,can partially explain the effects of dual-task dynamic gait stability.The influence of gait velocity should be considered in the assessment of dual-task effects.