Background

Adaptation of lower limb function to different gait tasks is inherently not as effective among individuals with lower limb amputation as compared to able-bodied individuals. Varying stiffness of a prosthetic foot may be a way of facilitating gait tasks that require larger ankle joint range of motion.

Methods

Three stiffness settings of a novel prosthetic foot design were tested for level walking at three speeds as well as for 7,5° incline and decline walking. Outcome measures, describing ankle range of motion and ankle dynamic joint stiffness were contrasted across the three stiffness settings. Standardized mechanical tests were done for the hindfoot and forefoot.

Findings

Dorsiflexion angle was incrementally increased with a softer foot and a faster walking speed / higher degree of slope. The concurrent dynamic joint stiffness exhibited a less systematic change, especially during INCLINE and DECLINE walking. The small difference seen between the stiffness settings for hindfoot loading limits analysis for the effects of stiffness during weight acceptance, however, a stiffer foot significantly restricted plantarflexion during DECLINE.

Interpretations

Varying stiffness settings within a prosthetic foot does have an effect on prosthetic foot dynamics, and differences are task dependent, specifically in parameters involving kinetic attributes. When considering the need for increased ankle range of motion while performing more demanding gait tasks, a foot that allows the users themselves to adjust stiffness according to the task at hand may be of benefit for active individuals, possibly enhancing the user's satisfaction and comfort during various daily activities.

中文翻译：

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机械和生物力学测量的任务相关变化是由于操纵假足的刚度设置造成的

背景

与身体健全的个体相比，下肢截肢患者的下肢功能适应不同的步态任务本身就没有那么有效。改变假脚的刚度可能是促进需要更大踝关节运动范围的步态任务的一种方式。

方法

针对三种速度下的水平行走以及 7.5° 上斜和下斜行走测试了新型假足设计的三种刚度设置。结果测量，描述踝关节运动范围和踝关节动态关节刚度在三种刚度设置中进行对比。对后足和前足进行了标准化的机械测试。

发现

背屈角度随着脚的柔软和更快的步行速度/更高的坡度而逐渐增加。同时发生的动态关节刚度表现出较少的系统性变化，尤其是在 INCLINE 和 DECLINE 步行期间。后足负荷刚度设置之间的微小差异限制了对重量接受期间刚度影响的分析，然而，较硬的脚在下降期间显着限制了跖屈。

解释

假足内的不同刚度设置确实会对假足动力学产生影响，并且差异取决于任务，特别是在涉及动力学属性的参数中。当考虑在执行更苛刻的步态任务时增加脚踝运动范围的需要时，允许用户自己根据手头任务调整刚度的脚可能对活跃的个体有益，可能会提高用户在各种情况下的满意度和舒适度日常活动。