Neuromuscular and Biomechanical Control of Lower Limb Loading in Individuals with Chronic Stroke

项目总结/摘要 中风是导致长期残疾的主要原因，是美国个人因中风而导致的偏瘫经常发生 在麻痹下肢上承受重量和将重量从一条腿转移到另一条腿上有困难。 重量转移和肢体负荷受损导致外侧不稳定， 步行速度和跌倒的风险增加。因此，恢复肢体负荷能力是一个重要的目标， 中风后的康复尽管有相当多的康复努力旨在提高瘫痪肢体负荷， 它们在改善神经运动和功能结果方面的有效性仍然有限，可能是由于 了解肢体负荷机制和不愿使用麻痹肢体。协调 在重量接受期间调节负荷力的神经肌肉动作是 功能性肢体负荷.因为改变的神经肌肉控制在中风患者中很常见， 这些异常可能会损害肢体负荷能力。该项目的长期目标是 开发一个基于机制的框架，用于设计和测试新型康复的有效性 干预措施，以加强下肢重量转移和肢体负荷，以改善平衡和流动性。这 项目旨在（1）识别肢体负荷中的神经肌肉和生物力学异常 反应在个人中风后，（2）确定负责的潜在机制， 肢体负荷的缺陷，以及（3）测试6周扰动诱导肢体的短期有效性 改善肢体负荷反应和活动功能的负荷训练计划。我们建议申请 突然单侧降低支撑面，引起侧向重量转移，迫使肢体负荷。 将记录动力学、运动学和下肢肌肉激活模式。我们预计，与 与健康对照组相比，中风患者的膝关节肌肉组织的肌肉协同激活增加 随着膝关节屈曲和扭矩产生的减少，以及在负荷期间不规则的冲击力调节， 干扰轻瘫肢体的重量转移和负荷。此外，我们假设，与一个 常规临床负重康复训练方案，施加肢体负荷组将显示 在训练后的随意踏步和行走中有更大的改善。具体来说，我们希望 膝关节肌肉共同激活持续时间将减少，膝关节扭矩增加， 站立/双支撑时间将增加，反映出步态跟随期间麻痹肢体负荷能力的改善 训练

Project Summary/Abstract Stroke is the leading cause of long-term disability is the U.S. Individuals with hemiparesis due to stroke often have difficulty bearing weight on the paretic lower extremity and transferring weight from one leg to the other. Impaired weight transfer and limb loading contribute to lateral instability and are associated with decreased walking speed and increased risk of falling. Consequently, restoring limb loading ability is an important goal for rehabilitation post-stroke. Despite considerable rehabilitation efforts aimed at enhancing paretic limb loading, their effectiveness on improving neuromotor and functional outcomes remains limited possibly due to poorly understood limb loading mechanisms and the reluctance to use the paretic limb. The coordination of neuromuscular actions to regulate loading force during weight acceptance is an important component of functional limb loading. . Because altered neuromuscular control is common in persons with stroke, it is possible that these abnormalities may impair limb loading ability. The long term objective of this project is to develop a mechanism-based framework for designing and testing the effectiveness of novel rehabilitation interventions to enhance lower limb weight transfer and limb loading to improve balance and mobility. This project aims to (1) identify the neuromuscular and biomechanical abnormalities in limb loading responses in individuals post-stroke, (2) determine the underlying mechanisms responsible for the deficits in limb loading, and (3) test the short-term effectiveness of a 6-week perturbation-induced limb load training program on improving limb loading responses and mobility function. We propose to apply a sudden unilateral lowering of support surface to induce lateral weight transfer that forces limb loading. Kinetic, kinematic, and lower extremity muscle activation patterns will be recorded. We expect that, compared to healthy controls, individuals with stroke will show increased muscle co-activation of the knee musculature with decreased knee flexion and torque production, and irregular impact force regulation during loading that will disrupt weight transfer and loading of the paretic limb. Furthermore, we hypothesize that compared to a conventional clinical weight-shift rehabilitation training program, the imposed limb loading group will show greater improvements during voluntary stepping and walking following training. Specifically, we expect the knee muscle co-activation duration will be reduced, with increased knee joint torque, and the paretic single stance/double support time will increase, reflecting improved paretic limb loading ability during gait following training.