Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
Department of Physical Medicine and Rehabilitation, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
Clin Biomech (Bristol). 2024 May;115:106263. doi: 10.1016/j.clinbiomech.2024.106263. Epub 2024 May 9.
Reduced ankle quasi-joint stiffness affects propulsion in the paretic side of patients with hemiparesis, contributing to gait asymmetry. We investigated whether the use of an ankle-foot orthosis with dorsiflexion resistance to compensate for reduced stiffness would increase quasi-joint stiffness and spatiotemporal symmetry in patients with hemiparesis.
Seventeen patients walked along a 7-m walkway in both ankle-foot orthosis with dorsiflexion resistance and control (i.e., ankle-foot orthosis) conditions. Dorsiflexion resistance by spring and cam was set to increase linearly from zero-degree ankle dorsiflexion. Gait data were analyzed using a three-dimensional motion analysis system.
Ankle-foot orthosis with dorsiflexion resistance significantly increased the quasi-joint stiffness in the early and middle stance phase (P = 0.028 and 0.040). Furthermore, although ankle power generation in the ankle-foot orthosis with dorsiflexion resistance condition was significantly lower than in the control condition (P = 0.003), step length symmetry significantly increased in the ankle-foot orthosis with dorsiflexion resistance condition (P = 0.016). There was no significant difference in swing time ratio between conditions.
Applying dorsiflexion resistance in the paretic stance phase increased quasi-joint stiffness but did not lead to an increase in ankle power generation. On the other hand, applying dorsiflexion resistance also resulted in a more symmetrical step length, even though the ankle joint power generation on the paretic side did not increase as expected. Future research should explore whether modifying the magnitude and timing of dorsiflexion resistance, considering the biomechanical characteristics of each patients' ankle joint during gait, enhances ankle joint power generation.
偏瘫患者患侧踝关节准关节僵硬度降低会影响推进力，导致步态不对称。我们研究了在偏瘫患者中使用带背屈阻力的踝足矫形器来补偿刚度降低是否会增加准关节刚度和时空对称性。
17 名患者分别在踝足矫形器带背屈阻力和对照（即踝足矫形器）条件下在 7 米的步行道上行走。通过弹簧和凸轮将背屈阻力设置为从零度踝关节背屈开始线性增加。使用三维运动分析系统分析步态数据。
踝足矫形器带背屈阻力显著增加了早期和中期站立阶段的准关节刚度（P=0.028 和 0.040）。此外，尽管踝足矫形器带背屈阻力条件下的踝关节功率生成明显低于对照条件（P=0.003），但踝足矫形器带背屈阻力条件下的步长对称性显著增加（P=0.016）。两种情况下的摆动时间比没有显著差异。
在患侧站立阶段施加背屈阻力会增加准关节刚度，但不会导致踝关节功率生成增加。另一方面，施加背屈阻力也会导致步长更对称，即使患侧踝关节的关节功率生成没有如预期那样增加。未来的研究应该探索通过考虑每个患者在步态过程中踝关节的生物力学特征来调整背屈阻力的大小和时机，是否可以增强踝关节的功率生成。
