Design and Evaluation of a Biarticular Prosthesis to Reduce Gait Compensations

项目总结/摘要 我提出的研究和培训计划旨在提高退伍军人的流动性和生活质量， 通过开发一种新型的双关节假体来进行经胫骨（TT）截肢，并训练我 神经肌肉生物力学，假肢工程，并通过指导和支持步态模拟 一个强大的多学科导师团队，使我能够成为一个成功的独立研究 科学家我的长期职业目标是设计、开发和评估新型假肢、矫形器和辅助器具 为行动不便的人提供的设备。根据这一目标，我提议设计、开发和 评估一种新型双关节假体，解决了当前下肢假体的一些局限性。 在美国，大约有100万人患有下肢丧失。流动性的一个重要原因 这一人群的损伤是踝跖屈肌的丧失， 在正常行走过程中有助于身体支撑、向前推进和摆动腿启动。双关节 腓肠肌（GAS）具有与比目鱼肌不同的作用;它提供主要的能量来源， 使腿进入摆动阶段。如果没有GAS，剩余腿部肌肉的代偿性变化是 这是必要的，包括增加髂腰肌的向心力，以加速腿部进入摆动阶段。 目前的假肢不能复制踝跖屈肌的生理功能。行走时 使用传统的假肢足踝系统，TT截肢者显示出有限的推离力， 自适应步态策略，例如在预摆动期间增加假体侧的髋屈肌工作， 弥补双关节GAS的不足。这些补偿被认为有助于增加 截肢者行走的代谢成本。 为了减少TT截肢者典型的步态补偿，我建议开发一种新的双关节 假肢（BP）带有一个跨越踝关节和膝关节的离合弹簧。BP将有能力 以产生净正踝关节功并提供能量来驱动腿摆动。我会用 肌肉骨骼建模和模拟TT截肢者步态，以优化BP的设计，我将使用 步态分析以评估BP对步态的影响。BP有可能减少步态代偿 并改善TT截肢退伍军人的功能活动性。该提案有三个具体目标： 目标1：使用模拟，确定特定于主题的最佳BP参数。 目的2：证明TT截肢者步态补偿通常与传统的被动- 弹性假体在一定范围的步行速度内随着受试者特定的最佳BP而降低。 目标3：确定最佳BP是否降低步行的代谢成本。 为了加快我的训练，促进我成为一名独立的研究科学家，我带来了 与具有不同专业知识的导师一起。Czerniecki博士是退伍军人事务部的理疗师和康复教授 专门从事截肢者康复和步态分析的医学。克鲁特博士是一名退伍军人事务部研究职业科学家 有一个充满活力的研究计划，专注于假肢工程和截肢者的流动性。Thelen博士是一位 机械和生物力学工程教授，步态计算模拟专家。博士 斯蒂尔是机械工程的助理教授，也是OpenSim研究员， 肌肉骨骼建模在指导下开展拟议的研究项目和培训计划 这些导师将使我成为步态神经肌肉生物力学，假肢， 工程和步态的计算模拟，并建立一个独立的研究生涯。

Project Summary / Abstract My proposed research and training program aims to improve the mobility and quality of life of veterans with transtibial (TT) amputation through the development of a novel biarticular prosthesis, and to train me in neuromuscular biomechanics, prosthetic engineering, and gait simulations through the guidance and support of a strong multidisciplinary team of mentors, so that I can become a successful independent research scientist. My long-term career goal is to design, develop and evaluate novel prosthetic, orthotic and assistive devices for people with reduced mobility. Consistent with this goal, I am proposing to design, develop and evaluate a novel biarticular prosthesis that addresses some of the limitations of current lower limb prostheses. Approximately one million people in the US are living with lower limb loss. An important cause of mobility impairment in this population is the loss of the ankle plantar flexors since these muscles are the primary contributors to body support, forward propulsion and swing leg initiation during normal walking. The biarticular gastrocnemius (GAS) has a role distinct from that of the soleus; it provides the dominant source of energy to power the leg into swing phase. Without the GAS, compensatory changes of the remaining leg muscles are necessary, including an increase in the concentric iliopsoas force to accelerate the leg into swing phase. Current prosthetic limbs cannot replicate the physiologic function of the ankle plantar flexors. When walking with conventional prosthetic foot-ankle systems, TT amputees show limited push-off power, and they use adaptive gait strategies, such as increased hip flexor work on the prosthetic side during pre-swing, to compensate for the lack of a biarticular GAS. These compensations are thought to contribute to the increased metabolic cost of amputee walking. To reduce the gait compensations typical of TT amputees, I am proposing to develop a novel biarticular prosthesis (BP) with a clutched spring that spans the ankle and knee joint. The BP will have the ability to generate net positive ankle joint work and to provide energy to power the leg into swing. I will use musculoskeletal modeling and simulations of TT amputee gait to optimize the design of the BP, and I will use gait analysis to evaluate the effect of the BP on gait. The BP has the potential to reduce gait compensations and improve functional mobility in veterans with TT amputation. The proposal has three specific aims: Aim 1: Using simulation, determine subject-specific optimal BP parameters. Aim 2: Demonstrate that the TT amputee gait compensations typically seen with conventional passive- elastic prostheses are reduced with the subject-specific optimal BP across a range of walking speeds. Aim 3: Determine if the Optimal BP reduces the metabolic cost of walking. To accelerate my training and facilitate my development into an independent research scientist, I have brought together mentors with diverse expertise. Dr. Czerniecki is a VA physiatrist and professor of rehabilitation medicine specializing in amputee rehabilitation and gait analysis. Dr. Klute is a VA research career scientist with a vibrant research program focused on prosthetic engineering and amputee mobility. Dr. Thelen is a professor of mechanical and biomechanical engineering and an expert in computational simulations of gait. Dr. Steele is an assistant professor of mechanical engineering and an OpenSim fellow with detailed knowledge or musculoskeletal modeling. Conducting the proposed research project and training program under the guidance of these mentors will allow me to become an expert in the neuromuscular biomechanics of gait, prosthetic engineering, and computational simulations of gait and to establish an independent research career.