Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai, 980-8575, Japan.
Department of Robotics, Graduate School of Engineering, Tohoku University, 6-6-01 Aoba, Aramaki, Aoba-ku, Sendai, 980-8579, Japan.
Gait Posture. 2020 Sep;81:27-32. doi: 10.1016/j.gaitpost.2020.06.029. Epub 2020 Jul 2.
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.
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.
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.
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).
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.
带跖屈阻力的踝足矫形器（AFO-Ps）可改善偏瘫患者支撑相患侧膝关节的屈曲。然而，AFO-Ps 会降低晚期支撑相的踝关节功率输出，并且由于晚期支撑相的推离不足，无法改善摆动相的膝关节屈曲，从而导致较低的足趾离地高度。
本研究旨在探讨一种带背屈阻力的 AFO 的效果，该 AFO 通过我们开发的带有弹簧凸轮机构的装置（步态解决方案；日本 Pacific Supply Co.，Ltd.）应用于 AFO-P，从而影响偏瘫患者步态中的下肢运动学和运动学。
11 名因中风导致偏瘫的患者在以下条件下以自感舒适的速度在 7 米步行道上行走：（a）使用带我们的弹簧凸轮机构的 AFO-P（AFO-PCAM）行走，（b）使用不带我们的装置的 AFO-P（AFO-P）行走，以及（c）不使用任何装置（赤脚条件）行走。使用三维运动分析系统和四个地面反力板收集步态运动学和动力学数据。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。
在 AFO-PCAM 条件下，晚期支撑相的最大踝关节功率输出减少明显小于 AFO-P 条件（p = 0.041）。与 AFO-P 条件相比，我们注意到 AFO-PCAM 条件下患侧摆动相的膝关节屈曲角度变化明显更大（p = 0.016）。比较变化的效应量较大（r ≧ 0.5）。
我们的装置由于背屈阻力而实现了晚期支撑相的踝关节跖屈力，从而增加了摆动相的膝关节屈曲角度。
