Robotic Ankle to Restore Symmetry and Reduce Energy Cost of Walking Post-Stroke

描述(由申请人提供)：中风是美国慢性残疾的主要原因，每年有近610,000例新病例。在慢性中风患者中，缓慢、令人精疲力竭的步行是限制日常生活活动的主要有害结果。此外，行走障碍会导致继发性损伤，如肌肉无力和平衡不良，这两个因素都是摔倒的危险因素。因此，旨在改善中风后步行功能的干预措施可能会对数百万人的生活质量产生重大积极影响。在健康步行中，脚踝伸肌在关键的步行次级任务中起主要作用，包括(1)推进(2)体重支持和(3)摆动启动。慢性中风患者通常在这些子任务中的每一个都有问题，可能是由于他们瘫痪肢体的踝关节机械功能薄弱和不协调所致。单侧踝关节功能受损导致高度不对称的步态，限制了最高行走速度，并增加了代谢能量消耗。这项拟议研究的主要目标是使用可穿戴的机器人设备来辅助中风后偏瘫患者的瘫痪肢体，并改善步态对称性和经济性。我们将招募20名慢性中风患者，并为他们的瘫痪肢体构建轻型机器人踝关节外骨骼。然后，我们将测试以踝关节伸展为重点的机器人辅助是否可以改善瘫痪肢体的功能-将其推向尺寸/年龄配对的健康对照组。我们假设，有针对性的单侧踝关节机械辅助将恢复从四肢到下肢关节的多个肌肉骨骼组织尺度上的步态对称性，并降低中风后患者行走的代谢成本。如果 机器人脚踝外骨骼可以恢复正常的行走机制，降低新陈代谢成本，那么中风后有严重障碍的人可以受益于便携式版本，作为社区步行期间的永久辅助。

DESCRIPTION (provided by applicant): Stroke is a leading cause of chronic disability in the United States, with nearly 610,000 new cases annually. In chronic stroke patients, slow, exhausting walking is a primary deleterious outcome that limits activities of daily living. Furthermore, impaired walking can lead to secondary impairments such as muscle weakness and poor balance, both risk factors for falls. Therefore, interventions designed to improve walking function post-stroke could have significant positive impact on the quality of life of millions. In healthy walking, the ankle extensor muscles play a major role in key walking sub-tasks including (1) propulsion (2) body-weight support and (3) swing initiation. Chronic stroke patients typically have problems with each of these sub-tasks, likely due to weak and uncoordinated ankle mechanical function in their paretic limb. Impaired unilateral ankle function results in highly asymmetric gait that limits top walking speed and elevates metabolic energy expenditure. The primary objective of the proposed research is to use a wearable robotic device to assist the paretic limb in patients with post-stroke hemiplegia and improve both gait symmetry and economy. We will recruit 20 patients with chronic stroke and construct lightweight robotic ankle exoskeletons for their paretic limb. Then we will test whether robotic assistance focused on ankle joint extension can improve paretic limb function - driving it towards that of size/age paired healthy controls. We hypothesize that targeted, unilateral ankle joint mechanical assistance will restore gait symmetry across multiple scales of musculoskeletal organization - from limbs to lower-limb joints- and reduce the metabolic cost of walking in people post-stroke. If robotic ankle exoskeletons can restore normal walking mechanics and reduce metabolic cost, then people with severe impairments post-stroke could benefit from a portable version as a permanent aid during community ambulation.