Muir B C, Haddad J M, van Emmerik R E A, Rietdyk S
Department of Mechanical Engineering, University of Washington, Seattle, WA, USA; RR&D Center for Limb Loss and MoBility (CLiMB), Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA.
Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA; Center for Aging and the Life Course, Purdue University, West Lafayette, IN, USA.
Gait Posture. 2019 May;70:254-259. doi: 10.1016/j.gaitpost.2019.01.035. Epub 2019 Mar 16.
Age-associated physiological changes result in modified gait, such as slower speed, for older adults. Identifying the onset of age-related gait changes will provide insight into the role of aging on locomotor control. It is expected that a more challenging gait task (obstacle crossing) puts more demands on physiological systems, and may reveal gait modifications in a middle-aged group that are not evident in an easier gait task (level walking).
To identify the effect of advancing age on gait as a function of increasing locomotor challenge during an obstacle crossing task.
Three age groups (young, middle-aged, and older adults) stepped over an obstacle placed in a 15 m walkway. Task challenge ranged from low to high in four conditions: unobstructed gait, 3, 10, and 26 cm obstacles. Gait measures were calculated during the approach and crossing steps.
Significant interactions were observed for gait speed (age by height by step, p < 0.01), foot placement variability (age by step, p < 0.01) and foot clearance (age by height, p = 0.05). Relative to young adults, older adults walked slower in all conditions and had higher foot clearances for the 10 and 26 cm obstacles. Middle-aged adults walked with speeds and foot clearances that were not different from young adults in the lower gait challenge conditions, and changed to values that were not different from older adults in the highest gait challenge conditions. Foot placement variability was greater for the middle-aged and older groups, but only in the last two steps before the obstacle.
Multiple gait changes were observed as early as middle-age, and changes in speed and foot clearance became more evident as task difficulty increased. The increased gait challenge placed more demands on the neuromuscular system, revealing age-related gait modifications that were not evident in the level walking gait task.
与年龄相关的生理变化会导致老年人的步态发生改变，比如速度变慢。确定与年龄相关的步态变化的起始点，将有助于深入了解衰老在运动控制中的作用。预计更具挑战性的步态任务（跨越障碍物）会对生理系统提出更高要求，并且可能揭示中年人群中在较简单的步态任务（平地行走）中不明显的步态改变。
确定在跨越障碍物任务中，随着运动挑战增加，年龄增长对步态的影响。
三个年龄组（年轻人、中年人、老年人）跨过放置在15米长通道中的障碍物。任务挑战在四种条件下从低到高变化：无障碍步态、3厘米、10厘米和26厘米的障碍物。在接近和跨越步骤中计算步态指标。
观察到步态速度（年龄×身高×步幅，p < 0.01）、足部放置变异性（年龄×步幅，p < 0.01）和足部间隙（年龄×身高，p = 0.05）存在显著交互作用。相对于年轻人，老年人在所有条件下行走速度都较慢，并且在跨越10厘米和26厘米障碍物时足部间隙更大。中年成年人在较低步态挑战条件下的行走速度和足部间隙与年轻人没有差异，而在最高步态挑战条件下则变为与老年人没有差异的值。中年和老年组的足部放置变异性更大，但仅在障碍物前的最后两步中如此。
早在中年就观察到多种步态变化，并且随着任务难度增加，速度和足部间隙的变化变得更加明显。增加的步态挑战对神经肌肉系统提出了更高要求，揭示了在平地行走步态任务中不明显的与年龄相关的步态改变。
