Proactive and reactive perturbation training to reduce falls and improve gait stability in people with chronic stroke

项目摘要/摘要 中风后，独立活动能力不足是导致生活质量下降的主要原因，如 许多慢性中风(PWCS)患者无法恢复到原来的活动水平 参与或参与社区。行动不便的一个主要原因是步态不稳定，这可能 增加跌倒风险，限制自主功能。而几种常见的康复方法(例如 运动训练、传统的平衡训练、力量训练)可以改善某些方面的机能，他们有 未能解决PWCS中的跌倒发生率。在一定程度上，这种不成功很可能是由于目前的干预措施 没有针对导致中风后步态不稳定的特定机制。 这项研究的一个长期目标是开发一个基于机制的干预工具箱，以改善各种 中风后功能的几个方面。作为迈向这一目标的一步，本提案的目标是确定 靶向扰动训练能否通过提高步态稳定性来减少PWCS患者的跌倒。当摄动时 训练以前在其他临床人群中被用来降低跌倒风险，到目前为止 在工务小组委员会中未能做到这一点。这种不成功可能是由于应用程序的性质造成的 摄动，传统上被设计成引起离散的反应，以避免失去平衡。 相比之下，本提案将采用机械扰动，以便在以下方面进行主动调整 用于确保每一步步行稳定性的神经机械策略。这种主动的扰动 可能更适合于防止固有的运动错误，这些错误是造成损失的主要因素 PWCS之间的平衡和下降。这项工作的中心假设是，与反应性方法不同， 主动扰动训练将重新训练普遍的步态稳定策略，降低摔倒的风险。这 假说将通过三个具体目标来阐述。 第一个具体目标是确定是否通过主动性或反应性训练降低了PWCS的跌倒发生率， 对开发可应用于现实世界的干预措施具有直接的临床意义。 第二个特别的目标是描述步态变化背后的神经机械机制。 摄动训练，揭示稳定策略是否通常用于确保步行平衡 可以通过适当的有针对性的扰动来加强。最后，第三个具体目标是确定 无论是主动训练还是反应性训练都会产生普遍的步态稳定，理想的干预方式是这样的 提高对现实世界行走中可能经历的未经训练的干扰的适应能力。 拟议的项目是基于两足步行控制的神经机械框架，因此允许 对临床相关结果(跌倒发生率)和用于治疗的策略的机械措施的调查 确保稳定。该项目所产生的知识有可能有助于发展 一个更大规模的康复范例，解决中风后跌倒的重要问题。

PROJECT SUMMARY / ABSTRACT Following a stroke, deficits in independent mobility are a primary contributor to decreased quality of life, as many people with chronic stroke (PwCS) are prevented from returning to their prior levels of activity participation or involvement in the community. A major cause of mobility deficits is gait instability, which can increase the risk of falls and limit independent function. While several common rehabilitation methods (e.g. locomotor training, traditional balance training, strengthening) can improve some aspects of function, they have failed to address fall incidence among PwCS. In part, this lack of success is likely due to current interventions not being targeted toward the specific mechanisms causing post-stroke gait instability. A long-term goal of this research is to develop a toolbox of mechanism-based interventions to improve various aspects of post-stroke function. As a step toward this goal, the objective of the present proposal is to determine whether targeted perturbation training can reduce falls in PwCS by improving gait stability. While perturbation training has previously been used to reduce fall risk in other clinical populations, it has thus far been unsuccessful at doing so among PwCS. This lack of success may be due to the nature of the applied perturbations, which are traditionally designed to elicit discrete Reactive responses to avoid a loss of balance. In contrast, the present proposal will apply mechanical perturbations designed to elicit Proactive adjustments in the neuromechanical strategies used to ensure walking stability with every step. Such Proactive perturbations may be better suited to prevent the intrinsic movement errors that are a primary contributor to losses of balance and falls among PwCS. The central hypothesis of this work is that that unlike Reactive methods, Proactive perturbation training will retrain generalized gait stabilization strategies, reducing the risk of falls. This hypothesis will be addressed through three Specific Aims. The first Specific Aim is to determine whether fall rate in PwCS is reduced by Proactive or Reactive training, with immediate clinical implications for the development of interventions that can be applied in the real world. The second Specific Aim is to characterize the neuromechanical mechanisms that underlie gait changes with perturbation training, revealing whether the stabilization strategies normally used to ensure walking balance can be strengthened with appropriately targeted perturbations. Finally, the third Specific Aim is to determine whether Proactive or Reactive training produces generalized gait stabilization, as an ideal intervention would improve resilience even to untrained perturbations that may be experienced in real world walking. The proposed project is based on a neuromechanical framework of bipedal walking control, and thus allows investigation of both clinically relevant outcomes (fall rate) and mechanistic measures of the strategies used to ensure stability. The knowledge resulting from this project has the potential to contribute to the development of a larger-scale rehabilitation paradigm addressing the important problem of post-stroke falls.