Department of Mechanical Engineering, Northern Arizona University, 15600 S McConnell Drive, NAU EGR Bldg 69, Flagstaff, AZ, 86011, USA.
College of Medicine - Phoenix, University of Arizona, Phoenix, AZ, USA.
Ann Biomed Eng. 2021 Sep;49(9):2522-2532. doi: 10.1007/s10439-021-02822-y. Epub 2021 Jun 29.
Lower-limb exoskeletons have the potential to improve mobility in individuals with movement disabilities, such as cerebral palsy (CP). The goal of this study was to assess the impact of plantar-flexor assistance from an untethered ankle exoskeleton on dynamic stability during unperturbed and perturbed walking in individuals with CP. Seven participants with CP (Gross Motor Function Classification System levels I-III, ages 6-31 years) completed a treadmill walking protocol under their normal walking condition and while wearing an ankle exoskeleton that provided adaptive plantar-flexor assistance. Pseudo-randomized treadmill perturbations were delivered during stance phase by accelerating one side of a split-belt treadmill. Treadmill perturbations resulted in a significant decrease in anteroposterior minimum margin-of-stability (- 32.1%, p < 0.001), and a significant increase in contralateral limb step length (8.1%, p = 0.005), integrated soleus activity during unassisted walking (23.4%, p = 0.02), and peak biological ankle moment (9.6%, p = 0.03) during stance phase. Plantar-flexor assistance did not significantly alter margin-of-stability, step length, soleus activity, or ankle moments during both unperturbed and perturbed walking. These results indicate that adaptive plantar-flexor assistance from an untethered ankle exoskeleton does not significantly alter dynamic stability maintenance during unperturbed and perturbed walking for individuals with CP, supporting future research in real-world environments.
下肢外骨骼有可能改善运动障碍患者（例如脑瘫患者）的移动能力。本研究旨在评估无束缚踝关节外骨骼提供的跖屈肌辅助对脑瘫患者在无干扰和受干扰步行时动态稳定性的影响。7 名脑瘫患者（粗大运动功能分级系统 I-III 级，年龄 6-31 岁）在正常步行条件下和穿着提供自适应跖屈肌辅助的踝关节外骨骼的情况下完成了跑步机步行方案。在支撑相期间，通过加速分带跑步机的一侧向跑步机施加伪随机跑步机扰动。跑步机扰动导致前后最小稳定性余量显著减少（-32.1%，p < 0.001），对侧肢体步长显著增加（8.1%，p = 0.005），无辅助行走时比目鱼肌活动的积分显著增加（23.4%，p = 0.02），以及支撑相时峰值生物踝关节力矩增加（9.6%，p = 0.03）。在无干扰和受干扰步行期间，跖屈肌辅助并没有显著改变稳定性余量、步长、比目鱼肌活动或踝关节力矩。这些结果表明，无束缚踝关节外骨骼提供的自适应跖屈肌辅助在无干扰和受干扰步行期间不会显著改变脑瘫患者的动态稳定性维持，支持未来在真实环境中的研究。
