We developed an active ankle-foot orthosis (AAFO) that controls dorsiflexion/plantarflexion of the ankle joint to prevent foot drop and toe drag during hemiplegic walking. To prevent foot slap after initial contact, the ankle joint must remain active to minimize forefoot collision against the ground. During late stance, the ankle joint must also remain active to provide toe clearance and to aid with push-off. We implemented a series elastic actuator in our AAFO to induce ankle dorsiflexion/plantarflexion. The activator was controlled by signals from force sensing register (FSR) sensors that detected gait events. Three dimensional gait analyses were performed for three hemiplegic patients under three different gait conditions: gait without AFO (NAFO), gait with a conventional hinged AFO that did not control the ankle joint (HAFO), and gait with the newly-developed AFO (AAFO). Our results demonstrate that our newly-developed AAFO not only prevents foot drop by inducing plantarflexion during loading response, but also prevents toe drag by facilitating plantarflexion during pre-swing and dorsiflexion during swing phase, leading to improvement in most temporal-spatial parameters. However, only three hemiplegic patients were included in this gait analysis. Studies including more subjects will be required to evaluate the functionality of our newly developed AAFO.

中文翻译：

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活动性踝足矫形器的开发，以防止偏瘫患者的脚下垂和脚趾阻力：一项初步研究

我们开发了一种主动型踝足矫形器（AAFO），它可以控制踝关节的背屈/足底屈曲，以防止偏瘫步行时脚下垂和脚趾阻力。为防止在初次接触后发生脚掌打伤，踝关节必须保持活动状态，以最大程度地减少前脚与地面的碰撞。在后期姿势中，踝关节还必须保持活动状态，以提供脚趾间隙并有助于下垂。我们在AAFO中实现了一系列弹性致动器，以引起踝背屈/足底屈曲。激活器由检测步态事件的力感应寄存器（FSR）传感器发出的信号控制。对三名偏瘫患者在三种不同的步态条件下进行了三维步态分析：无AFO的步态（NAFO），传统的铰链AFO不能控制踝关节的步态（HAFO），并与新开发的AFO（AAFO）保持步伐。我们的结果表明，我们新开发的AAFO不仅可通过在加载响应过程中诱发plant屈来防止脚下垂，而且还可以通过在预挥杆过程中促进plant屈和挥杆阶段中的背屈来防止脚趾阻力，从而改善大多数时空参数。但是，该步态分析仅包括三名偏瘫患者。需要评估包括更多科目在内的研究，以评估我们新开发的AAFO的功能。导致大多数时空参数得到改善。但是，该步态分析仅包括三名偏瘫患者。需要评估包括更多科目在内的研究，以评估我们新开发的AAFO的功能。导致大多数时空参数得到改善。但是，该步态分析仅包括三名偏瘫患者。需要评估包括更多科目在内的研究，以评估我们新开发的AAFO的功能。