Bio-Inspired Ankle-Knee Coupling to Enhance Walking for Individuals with Transtibial Amputation

仿生踝膝关节可增强小腿截肢患者的行走能力

• 批准号: 1705714
• 负责人: Karl Zelik
• 金额: $ 32.99万
• 依托单位: Vanderbilt University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1705714&HistoricalAwards=false
• 关键词: Bio; Inspired; Ankle; Knee; Coupling

Despite advances in prosthetic foot technology over the last decade, there is growing evidence that individuals with lower-limb amputation (ILLA) are still at a physical disadvantage based on how a prosthetic foot is attached to its leg. ILLA's are missing a physical coupling between their prosthetic ankle and biological knee joint. In non-amputees, this ankle-knee coupling is provided by the gastrocnemius (calf) muscle, which helps a person to transfer power from their ankle to the rest of their body. But this important coupling mechanism is cut during transtibial amputation, which may prevent ILLA's from being able to effectively use power provided by their prosthetic foot. This then forces ILLA's to change their gait in such a way that it may increase their risk of secondary health impairments, like chronic back pain and knee osteoarthritis. The purpose of this research is to test if restoring ankle-knee coupling with an artificial gastrocnemius will improve the way power is transferred from the prosthesis to the body, and thereby improve health and mobility outcomes for ILLA's. First, this study will focus on identifying optimal artificial gastrocnemius properties, for use with both passive (carbon fiber) and powered (motorized) prosthetic feet. Next, the researchers will compare ILLA walking with vs. without the artificial gastrocnemius. During this portion of the study, biomechanical measurements will be used to assess benefits. The proposed artificial gastrocnemius design will be lightweight and comfortably fit underneath clothing, such that it can be easily integrated with existing prosthetic feet to broadly impact the health and mobility of ILLA. These improved outcomes may then help to reduce secondary health comorbidities that contribute to $8 billion in amputation-related medical expenses in the U.S. each year. The research team brings together interdisciplinary expertise in biomechanics, prosthetic design and clinical care, and students will be involved in all stages of this research. Outreach activities are planned to enhance understanding of the K12 population about working with individuals with disabilities, biomechanics, and prosthetics.The specific objectives of this proposal are (a) to characterize the effect of gastrocnemius-like ankle-knee coupling dynamics on human walking, then (b) to test the hypothesis that restoring this coupling for individuals with transtibial amputation will improve their gait symmetry and economy while also reducing unhealthy joint loading. Case study data, exoskeleton experiments, and walking simulations provide preliminary evidence that restoring this ankle-knee coupling may be beneficial to ILLA's; however, this has not yet been tested experimentally and it is currently unknown how individual ankle-knee coupling behaviors affect gait, or which are optimal. This study combines various measurement modalities to systematically evaluate biomechanics and mobility outcomes for ILLA walking with a range of ankle-knee coupling behaviors, followed by comparison between walking with vs. without an optimized artificial gastrocnemius. The artificial gastrocnemius will be controlled using a programmable, off-board prosthesis emulator. This study will generate new biomechanical data that provide insight into the functional benefits of ankle-knee coupling in bipedal walking and how these dynamics facilitate power transfer from the ankle. A feasibility study will be performed, with clinical partners, to assess if adding an artificial gastrocnemius will improve health- and mobility-related outcomes for ILLA's while they walk on passive and powered foot prostheses. This approach is innovative because it seeks to improve the function of all prosthetic feet by focusing on the transmission/interface with the body, rather than solely on the prosthetic foot itself. By enhancing walking performance, this research aims to improve mobility and physical activity outcomes for ILLA's.

尽管假肢脚技术在过去十年中取得了进步，但越来越多的证据表明，下肢截肢（ILLA）患者仍然处于身体劣势，这是基于假肢脚与腿的连接方式。假体踝关节和生物膝关节之间缺少物理耦合。在非截肢者中，这种踝关节-膝关节耦合是由腓肠肌（小腿）提供的，它帮助人们将力量从脚踝转移到身体的其他部位。但是这种重要的耦合机制在经胫骨截肢时被切断，这可能会阻止ILLA能够有效地利用假足提供的动力。这就迫使ILLA改变他们的步态，这可能会增加他们继发性健康损害的风险，比如慢性背痛和膝关节骨关节炎。本研究的目的是测试用人工腓肠肌恢复踝膝耦合是否会改善从假体到身体的力量传递方式，从而改善ILLA的健康和活动结果。首先，本研究将重点确定最佳的人造腓肠肌性能，用于被动（碳纤维）和动力（电动）假肢脚。接下来，研究人员将比较使用人工腓肠肌和不使用人工腓肠肌的ILLA行走。在这部分研究中，生物力学测量将用于评估益处。拟议的人造腓肠肌设计将是轻量级的，舒适地适合在衣服下，这样它可以很容易地与现有的假肢脚集成，以广泛影响ILLA的健康和活动。这些改善的结果可能有助于减少次级健康合并症，这些合并症每年在美国造成80亿美元的截肢相关医疗费用。研究团队汇集了生物力学、假肢设计和临床护理方面的跨学科专业知识，学生将参与这项研究的各个阶段。计划开展外展活动，以提高K12人口对残疾人，生物力学和假肢工作的理解。本提案的具体目标是：(a)表征腓骨样踝关节-膝关节耦合动力学对人类行走的影响，然后(b)验证这样一个假设，即恢复腓骨样踝关节-膝关节耦合可以改善患者的步态对称性和经济性，同时减少不健康的关节负荷。案例研究数据、外骨骼实验和步行模拟提供了初步证据，证明恢复这种踝关节-膝关节耦合可能对ILLA有益；然而，这尚未经过实验测试，目前尚不清楚个体踝关节-膝关节耦合行为如何影响步态，或者哪种行为是最佳的。本研究结合了各种测量方法，系统地评估了具有一系列踝关节-膝关节耦合行为的ILLA行走的生物力学和活动结果，然后比较了使用和不使用优化的人工腓肠肌行走的情况。人造腓肠肌将使用一个可编程的外载假体模拟器进行控制。这项研究将产生新的生物力学数据，为两足行走中踝关节-膝关节耦合的功能益处以及这些动力学如何促进踝关节的能量传递提供见解。将与临床合作伙伴进行可行性研究，以评估添加人工腓肠肌是否会改善ILLA使用被动和动力足假体行走时的健康和活动相关结果。这种方法是创新的，因为它试图通过关注与身体的传输/接口来改善所有假肢脚的功能，而不仅仅是假肢脚本身。通过提高步行能力，本研究旨在改善ILLA患者的行动能力和身体活动结果。