Background

Ankle–foot orthoses with plantarflexion resistance (AFO-Ps) improve knee flexion in the stance phase on the paretic side in patients with hemiparesis. However, AFO-Ps decrease ankle power generation in the late stance phase and do not improve the knee flexion in the swing phase based on insufficient push-off at the late stance, resulting in lower toe clearance.

Research question

This study sought to investigate the effect of an AFO with dorsiflexion resistance, which was implemented by our developed device with spring–cam mechanism attached to the AFO-P (Gait Solution; Pacific Supply Co., Ltd., Japan), on kinetics and kinematics in the lower limb during gait in patients with hemiparesis.

Methods

Eleven patients with hemiparesis due to stroke walked on a 7-m walkway at a self-selected comfortable pace in the following conditions: (a) walking using the AFO-P with the proposed device with a spring–cam mechanism (AFO-PCAM), (b) walking using the AFO-P without our device (AFO-P), and (c) walking using no device (barefoot condition). Gait kinematics and kinetics were collected using a three-dimensional motion analysis system and four ground-reaction force plates. Changes in all parameters from the barefoot to AFO-PCAM and AFO-P conditions were compared using the Wilcoxon signed-rank test.

Results

In the AFO-PCAM condition, decrease in the maximum ankle power generation in the late-stance phase was significantly smaller than that in the AFO-P condition (p = 0.041). We noted a significant higher change in knee flexion in the paretic swing phase in the AFO-PCAM condition relative to that in the AFO-P condition (p = 0.016). The effect size for the comparisons of change was large (r ≧ 0.5).

Significance

Our device facilitated the realization of the ankle plantarflexion power in the late-stance phase because of dorsiflexion resistance, increasing the knee flexion angle during the swing phase.

中文翻译：

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偏瘫患者在步行过程中使用弹簧凸轮机制抵抗背屈的踝足矫形器会增加膝部屈曲。

背景

偏瘫患者在足底屈曲性踝足矫形器（AFO-Ps）可以改善坐骨侧站立阶段的膝关节屈曲。但是，AFO-Ps会在后期站立时减少脚踝力量的产生，并且由于后期站立时的推力不足而不能改善挥杆阶段中的膝盖屈曲，从而导致较低的脚趾间隙。

研究问题

本研究试图研究具有背屈阻力的AFO，这是由我们开发的带有弹簧凸轮机构的装置实现的，该装置附接到AFO-P（步态解决方案；日本太平洋供应有限公司），对动力学和偏瘫患者步态下肢运动学。

方法

11名因中风而导致偏瘫的患者在以下情况下以自行选择的舒适步速在7米长的步道上行走：（a）使用带有弹簧凸轮机构（AFO-PCAM）的拟议设备，使用AFO-P行走，（b）在没有我们的设备（AFO-P）的情况下使用AFO-P行走，以及（c）在没有设备的情况下（赤脚状态）行走。使用三维运动分析系统和四个地面反作用力板来收集步态运动学和动力学。使用Wilcoxon符号秩检验比较从赤脚到AFO-PCAM和AFO-P条件的所有参数的变化。

结果

在AFO-PCAM条件下，后期阶段最大踝关节发电量的下降显着小于AFO-P条件下（p = 0.041）。我们注意到，相对于AFO-P情况，膝关节屈曲在AFO-PCAM情况下膝关节屈曲变化显着更高（p = 0.016）。变化比较的效应量大（r≥0.5）。

意义

由于背屈阻力，我们的设备有助于在后期站立阶段实现踝关节屈曲力，从而增加了摆动阶段的膝盖屈曲角度。