Task space control of normal & pathological locomotion

描述(由申请人提供)：这项建议的广泛、长期目标是定量描述、比较和模拟任务空间控制在正常步态和因下肢截肢引起的病理性步态中的使用。广泛的研究已经对人体运动和运动控制的关节运动学和动力学进行了详细的研究，并有正常和各种运动功能障碍的研究。然而，关于人类如何将关节水平的信息与更高水平的运动目标联系起来，人们知之甚少。了解损伤前后控制腿部控制的基本生物力学原理将为创建病理性步态障碍的新治疗干预措施提供一般理论框架。该项目建议使用行为运动实验来研究健康完好无损的受试者以及膝下(经胫骨)和膝上(经股)假肢行走的截肢者的任务空间控制。这个项目将使用广泛的数据分析来量化和表征运动过程中的任务空间控制，使用从生物力学模型和特征分析中确定的变量。基于分析结果，进一步的研究将创建一个基于物理的病理性截肢者步态的计算机模拟，根据正常步态和截肢者步态之间的差异计算出校正的关节扭矩。该项目的一般假设是，人类通过精确地引导他们的腿通过预定义的任务空间来控制运动，同时允许关节水平的动力学的灵活性，而且更近端的肢体截肢将导致这种利用任务空间冗余的能力的更大损失。研究任务空间控制在运动过程中的应用有三个具体目标：正常人类运动(AIM1)；截肢引起的病理性步态(AIM2)；从正常步态到病态步态的评估和模拟(AIM3)。实现这三个目标将通过量化正常人类步态的功能相关任务变量，并从理论上理解这些控制变量在神经机械病理(如下肢截肢)后的变化，从而提供立即可交付的结果。这项工作将开发新的分析工具来定量分析正常步态和截肢步态，但它也将普遍适用于所有步态病理的研究。它可能进一步影响未来使用任务级而不是关节级康复目标的步态康复治疗方法，并启发快速增长的康复机器人设备领域的控制系统。这项拟议的工作还将为未来研究运动过程中腿部控制的神经机制提供一个理论框架。

DESCRIPTION (provided by applicant): The broad, long-term objectives of this proposal are to quantitatively characterize, compare, and simulate the use of task space control in normal and pathological gait due to lower limb amputation. Extensive research has detailed joint kinematics and kinetics of human locomotion and movement control with normal and various motor function disorders. Yet, relatively little is known about how humans relate joint-level information to higher-level locomotor goals. Understanding basic biomechanical tenets governing leg control before and after injury will provide a general theoretical framework for creating new therapeutic interventions for pathological gait disabilities. This project proposes to use behavioral locomotion experiments to study task space control in both healthy intact human subjects and in both Below-Knee (transtibial) and Above-Knee (transfemoral) amputees walking on prosthetic legs. This project will use extensive data analysis to quantify and characterize task space control during locomotion using variables identified from biomechanical models and by eigenanalysis. Based on the analytical results, a further study will create a physics-based computer simulation of pathological amputee gait with corrective joint torques computed from the differences discovered between normal and amputee gait. The general hypothesis of the project is that humans control locomotion by precisely guiding their legs through a predefined task space while allowing flexibility in joint-level dynamics and that more proximal limb amputations will result in greater losses in this ability to exploit task space redundancy. Three specific aims to study the use of task space control during locomotion are addressed: normal human locomotion (Aim1); pathological gait due to lower limb amputation (Aim2); and, the evaluation and simulation of the changes from normal to pathological human walking (Aim3). Achieving these three aims will provide immediate deliverables by quantifying functionally relevant task variables for normal human gait and a theoretical understanding of how these control variables change after a neuromechanical pathology such as lower limb amputation. This work will develop new analytical tools to quantitatively assay normal and amputee gait, however, it will also be generally applicable to the study of all gait pathologies. It could further impact future therapeutic approaches for gait rehabilitation that use task-level rather than joint-level rehabilitation goals and inspire control systems for the rapidly growing field of rehabilitative robotic devices. The proposed work will also form a theoretical framework for future studies of the neural mechanisms underlying leg control during locomotion.