Mechanism-based Strategies to Restore Post-Stroke Gait Stability through Targeted Motor Adaptation

项目摘要/摘要 独立机动性，即个体在其环境中成功导航的能力，是一种 生活质量的主要贡献者。不幸的是，中风后的机动性通常会降低，从而导致许多 中风患者的活动参与度恢复到典型水平。减少的主要贡献者 移动性是指步态不稳定，它可以通过增加跌倒的风险或通过减少运动能力来限制功能。 个人对自身平衡的信心。现有的康复技术已被证明改善了某些 中风后步态功能的几个方面，例如增加自我选择的步行速度。然而，这些 干预措施普遍未能解决步态不稳定问题，跌倒风险缺乏改善就是明证。 这一系列研究的长期目标是开发一个工具箱，用于改善中风后的干预 步态不稳定，允许临床医生为个别患者选择最合适的选择。这个项目将 重点关注不稳定的潜在机械原因，初步工作表明 在对照组中确定了一致的神经机械步态稳定策略。目前的方法 与步态不稳定的典型研究不同，步态不稳定的典型研究主要集中在量化非因果指标 而不是理解潜在的机制。 中心假设是中风后的步态不稳定通常是由于缺乏机械性的- 适当调整脚的摆放位置。步态模式稳定的个体始终使用一种策略，即 根据重心的机械状态，主动控制脚的内侧摆放。 然而，这种积极稳定的证据在中风幸存者中缺乏。 增加了跌倒的风险。这项拟议的工作将调查一种新的力场的影响，该力场旨在允许 在不干扰步态进展的情况下实时操作足部内侧放置。第一个具体 目的是确定足部放置辅助是否促进了典型步态稳定策略的使用。 当中风幸存者行走时，这个力场将被用来鼓励机械适当的脚放置， 这可以通过允许参与者练习所需的运动模式来驱动步态稳定性的恢复 一个具有适当挑战性的环境。第二个具体目标是确定脚的位置是否 扰动促进了典型步态稳定策略的使用。这个力场将被用来扰乱脚 远离机械上适当的目标位置，可能导致错误驱动的适应 当参与者试图抵消这些错误时，朝着所需的步态模式前进。 建议的项目是基于对人类步态力学的定量理解，并利用 最近开发的一种力场，旨在允许以前不可行的步态操作。这个 由此产生的知识有可能为更大规模的发展做出重要贡献 治疗干预针对患者的特定限制的康复范例。

Project Summary / Abstract Independent mobility, the ability of an individual to successfully navigate through their environment, is a primary contributor to quality of life. Unfortunately, mobility often decreases following a stroke, preventing many people with stroke from returning to typical levels of activity participation. A major contributor to reduced mobility is gait instability, which can limit function either by increasing the risk of falls or by decreasing an individual's confidence in their balance. Existing rehabilitation techniques have been shown to improve certain aspects of post-stroke gait function, such as increasing self-selected walking speed. However, these interventions have generally failed to address gait instability, as evidenced by a lack of improvement in fall risk. The long term objective of this line of research is to develop a toolbox of interventions for improving post-stroke gait instability, allowing clinicians to select the most appropriate option for individual patients. This project will focus on a potential mechanistic cause of instability, which has been suggested by preliminary work that identified a consistent neuromechanical gait stabilization strategy among controls. The present approach contrasts with typical investigations of gait instability, which largely focus on quantifying non-causal indicators of stability rather than understanding the underlying mechanism. The central hypothesis is that post-stroke gait instability is commonly caused by a lack of mechanically- appropriate adjustments in foot placement. Individuals with stable gait patterns consistently use a strategy of actively controlling their mediolateral foot placement based on the mechanical state of their center of mass. However, this evidence of active stabilization is lacking in a sub-population of stroke survivors with an increased fall risk. The proposed work will investigate the effects of a novel force-field designed to allow the real-time manipulation of mediolateral foot placement without interfering with gait progression. The first Specific Aim is to determine whether foot placement assistance promotes use of the typical gait stabilization strategy. The force-field will be used to encourage mechanically-appropriate foot placement while stroke survivors walk, which may drive restoration of gait stability by allowing participants to practice the desired movement pattern in an appropriately challenging environment. The second Specific Aim is to determine whether foot placement perturbation promotes use of the typical gait stabilization strategy. The force-field will be used to perturb foot placement away from mechanically-appropriate target locations, potentially causing error-driven adaptation toward the desired gait pattern as participants seek to cancel out these errors. The proposed project is based on a quantitative understanding of human gait mechanics, and takes advantage of a recently developed force-field designed to allow gait manipulations that were previously not feasible. The resultant knowledge has the potential to make an important contribution to the development of a larger-scale rehabilitation paradigm in which therapeutic interventions are targeted to a patient's specific limitations.