Glinka Michal N, Weaver Tyler B, Laing Andrew C
Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.
Hum Mov Sci. 2015 Dec;44:246-57. doi: 10.1016/j.humov.2015.09.004. Epub 2015 Sep 26.
While epidemiologic data suggests that one in four older adults have difficulty performing stooping and crouching (SC) tasks, little is known about how aging affects SC performance. This study investigated differences between young and older adults in lower limb kinematics and underfoot center of pressure (COP) measures when performing a series of SC tasks. Twelve healthy younger and twelve healthy older participants performed object-retrieval tasks varying in: (1) initial lift height, (2) precision demand, and (3) duration. Whole-body center of mass (COM), underfoot COP, and hip and knee angular kinematics (maximum angles and velocities) were analyzed. Compared to younger, older participants moved slower when transitioning into and out of pick-up postures that were characterized by less hip and knee flexion. Older participants also showed a diminished ability to adapt to the changing postural demands of each set of tasks. This was especially evident during longer tasks, whereby older individuals avoided high knee flexion crouching postures that were commonly used by younger participants. Older adults also tended to exhibit faster and more frequent COP trajectory adjustments in the anterior-posterior direction. It is likely that limitations in physical characteristics such as lower limb strength and range of motion contributed to these differences.
虽然流行病学数据表明，四分之一的老年人在进行弯腰和下蹲（SC）任务时存在困难，但关于衰老如何影响SC表现却知之甚少。本研究调查了年轻人和老年人在执行一系列SC任务时下肢运动学和足底压力中心（COP）测量值的差异。12名健康的年轻人和12名健康的老年人进行了物体取回任务，这些任务在以下方面有所不同：（1）初始举升高度，（2）精度要求，以及（3）持续时间。分析了全身质心（COM）、足底COP以及髋部和膝部的角运动学（最大角度和速度）。与年轻人相比，老年人在进入和离开以较少髋部和膝部屈曲为特征的拾取姿势时移动较慢。老年人还表现出适应每组任务不断变化的姿势要求的能力下降。这在较长时间的任务中尤为明显，在此期间，老年人避免了年轻人常用的高膝屈曲下蹲姿势。老年人在前-后方向上也倾向于表现出更快、更频繁的COP轨迹调整。下肢力量和运动范围等身体特征的限制可能导致了这些差异。
