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

项目概要/摘要 独立移动性，即个人成功地在其环境中导航的能力，是一种 生活质量的主要贡献者。不幸的是，中风后活动性往往会下降， 中风患者恢复到典型的活动参与水平。一个主要原因是， 活动性是步态不稳，它可以通过增加福尔斯的风险或减少 个人对平衡的信心。现有的康复技术已被证明可以改善某些 中风后步态功能方面，如增加自主选择的步行速度。但这些 干预措施通常不能解决步态不稳定，这可以从跌倒风险缺乏改善中得到证明。 这项研究的长期目标是开发一套干预措施， 步态不稳，允许临床医生为个体患者选择最合适的选择。该项目将 重点放在一个潜在的机械原因的不稳定性，这已经提出了初步工作， 确定了一个一致的神经力学步态稳定控制策略。本方法 与步态不稳定的典型调查形成对比，步态不稳定主要集中在量化非因果指标 而不是理解潜在的机制。 中心假设是中风后步态不稳通常是由于缺乏机械- 适当调整脚部位置。具有稳定步态模式的个体一贯使用以下策略： 基于他们的质心的机械状态主动控制他们的中外侧脚放置。 然而，这种主动稳定的证据在中风幸存者的亚群中缺乏， 增加跌倒风险。这项拟议中的工作将调查一种新的力场的影响，这种力场的设计是为了让 在不干扰步态进展的情况下实时操纵中外侧足部放置。第一特定 目的是确定脚放置辅助是否促进典型步态稳定策略的使用。 力场将用于鼓励中风幸存者行走时机械适当的足部放置， 这可以通过允许参与者练习期望的运动模式来驱动步态稳定性的恢复， 适当的挑战环境。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。力场将用来干扰脚 放置远离机械适当的目标位置，可能导致错误驱动的适应 当参与者试图消除这些错误时，朝向期望的步态模式。 拟议的项目是基于对人类步态力学的定量理解，并利用 最近开发的力场，旨在允许步态操纵，以前是不可行的。的 由此产生的知识有可能为更大规模的发展做出重要贡献。 康复模式，其中治疗干预针对患者的具体局限性。

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.