Muscle coordination changes affecting impaired balance control post-stroke.

 描述(申请人提供)：这项研究的长期目标是通过改善康复努力的发展和处方来提高中风后的生活质量。这项建议的重点是获得有关神经肌肉机制的基础知识，这些机制损害了中风后的步态和平衡，并导致摔倒风险增加和活动能力下降。这一点很重要，因为再训练、步态和平衡的康复范例由于缺乏对导致功能损害的潜在神经肌肉机制的了解而受到限制。因此，这个项目将研究中风后行走和平衡过程中肌肉协调性是如何受损的。此外，我们还将研究在成功的步态康复计划后肌肉协调性是如何改变的。在目标1中，我们将识别和比较中风后个体在平衡和步态过程中肌肉协调性的损害。在目标2中，我们将通过一种新的步态康复计划来研究改善肌肉协调性的机制。我们将使用肌电图(EMG)记录在以自己选择的速度行走和反应性平衡(站立时对支撑面平移的反应)时的肌肉活动。我们将使用运动模块来表征肌肉的协调性，运动模块识别一起被激活的肌肉组。中风后瘫痪腿在步态过程中运动模块的数量减少，这与步态和平衡的临床测量得分较低有关。在这些人中，许多人的运动模块数量减少是由于踝趾屈肌与髋关节和膝关节伸肌的异常耦合。即使在那些没有这种异常耦合的个体中，踝趾屈肌的招募也往往是不适当的时机。我们不知道这种不适当的时机或异常耦合是否也会在平衡过程中发生。我们预计瘫痪腿上的运动模块的数量、组成和时间将因步态和平衡的异常肌肉耦合和不适当的招募时机而改变。我们还将利用正在进行的康复计划作为平台，了解如何改善平衡和步态控制的神经肌肉机制。这项康复计划的目标是通过功能性电刺激改善脚踝肌肉的招募，并已被证明改善了步态和平衡能力的生物力学和临床测量。然而，肌肉活动尚未被检查，因此，尚不清楚这些改善是否与恢复适当的踝关节活动和/或全肢肌肉协调有关。我们希望这个康复计划能在步态和平衡过程中恢复适当的全肢肌肉协调性。拟议项目的结果将有助于我们了解肌肉耦合异常和不适当的招募时机如何导致中风后步态和平衡的功能障碍，并将有助于理解康复如何改善这些功能障碍，推动此类干预措施的改进和特异性，以改善结果和生活质量。

 DESCRIPTION (provided by applicant): The long-term goal of this research is improve quality of life post-stroke by improving the development and prescription of rehabilitation efforts. This proposal is focused on gaining fundamental knowledge about neuromuscular mechanisms that impair gait and balance post-stroke and lead to increased risk of falls and decreased mobility. This is important because rehabilitation paradigms for retraining gait and balance have been limited by a lack of understanding of the underlying neuromuscular mechanisms leading to functional impairments. Therefore, this project will examine how muscle coordination is impaired across both walking and balance post-stroke. Further, we will also examine how muscle coordination is changed after a successful gait rehabilitation program. In Aim 1, we will identify and compare impairments in muscle coordination during balance and gait in individuals post-stroke. In Aim 2, we will examine mechanisms of improved muscle coordination through a novel gait rehabilitation program. We will record muscle activity using electromyography (EMG) while walking at self-selected speed and during reactive balance (responses to support-surface translations while standing). We will characterize muscle coordination using motor modules, which identify groups of muscles that are activated together. A reduction has been shown post-stroke in the number of motor modules in the paretic leg during gait that is related to lower scores on clinical measures of both gait and balance. In many of these individuals, the reduced number of motor modules was due to abnormal coupling of the ankle plantarflexors with the hip and knee extensors. Even in those individuals without this abnormal coupling, recruitment of the ankle plantarflexors were often inappropriately timed. We do not know if this inappropriate timing or abnormal coupling also occurs during balance. We expect that the number, composition and timing of motor modules on the paretic leg will be altered due to abnormal muscle coupling and inappropriate recruitment timing in both gait and balance. We will also take advantage of an ongoing rehabilitation program as a platform to understand how neuromuscular mechanisms underlying the control of balance and gait can be improved. This rehabilitation program targets improving ankle muscle recruitment through functional electrical stimulation and has been shown to improve biomechanical and clinical measures of gait and balance performance. However, muscle activity has yet to be examined and thus it is unknown if these improvements are related to restoration of appropriate ankle activity and/or whole-limb muscle coordination. We expect that this rehabilitation program restores appropriate whole-limb muscle coordination during both gait and balance. The results of the proposed project will help us to understand how abnormal muscle coupling and inappropriate recruitment timing leads to functional impairments in gait and balance post- stroke and will contribute to the understanding of how rehabilitation ameliorates these functional impairments, driving the improvement and specificity of such interventions to improve outcomes and quality of life.