Hip Angle and Limb Load Affect Reflexes Post-Stroke

髋部角度和肢体负荷影响中风后的反射

• 批准号: 7054264
• 负责人: MICHAEL D LEWEK
• 金额: $ 2.79万
• 依托单位: REHABILITATION INSTITUTE OF CHICAGO D/B/A SHIRLEY RYAN ABILITYLAB
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7054264
• 关键词: assistive device /technology; biomechanics; clinical research; electromyography; gait; hip; human subject; joint stiffness; knee; limb movement; muscle function; neurologic manifestations; neuromuscular disorder; orthotics; patient oriented research; postdoctoral investigator; posture; robotics; stretch receptors; stretch reflex; striated muscles; stroke

DESCRIPTION (provided by applicant): Following stroke, gait is often characterized by reduced flexion of the paretic limb accompanied by prolonged knee extension during late stance and swing. This movement pattern has been attributed to two competing origins: inadequate flexor activation and/or inappropriate extensor activation via excessive quadriceps activity. Evidence has demonstrated the dual importance of hip angle and limb load receptors in modulating muscle activity during the late stance phase of gait. Following stroke, however, the processing of afferent information may be disrupted by abnormal descending commands, which alter muscle activation and movement patterns. The primary goal of this proposal is to characterize the importance of hip angle sensors and load receptors in modulating activation patterns post-stroke to determine their respective role in contributing to abnormal gait. The primary hypothesis is that hyperexcitable heteronymous stretch reflexes from hip flexors onto knee extensors play a critical role in the mistiming of extensor activity and thus in gait abnormalities. The proposed experiments involve a careful examination of muscle activation patterns in response to isolated joint movements during passive conditions as well as during perturbed walking. Although appropriate afferent inputs associated with limb load and hip position are thought to be necessary for retraining 'normal' walking patterns after stroke, there are no quantitative studies which examine the role of hip angle and limb load in modulating muscle activity after stroke.

描述（由申请人提供）：中风后，步态的特征通常是瘫痪肢体的屈曲减少，并伴有后期站立和摆动期间膝关节延长。这种运动模式归因于两个相互竞争的根源：屈肌激活不足和/或由于股四头肌过度活动而导致的伸肌激活不当。有证据表明，髋部角度和肢体负荷受体在步态后期站立阶段调节肌肉活动方面具有双重重要性。然而，中风后，传入信息的处理可能会被异常的下行命令扰乱，从而改变肌肉激活和运动模式。该提案的主要目标是描述髋部角度传感器和负载感受器在调节中风后激活模式中的重要性，以确定它们各自在导致异常步态中的作用。主要假设是，从髋部屈肌到膝关节伸肌的过度兴奋的同向牵张反射在伸肌活动的错误时机以及步态异常中发挥着关键作用。所提出的实验包括仔细检查肌肉激活模式，以响应被动条件下以及扰动行走期间的孤立关节运动。尽管与肢体负荷和髋部位置相关的适当传入输入被认为对于中风后重新训练“正常”步行模式是必要的，但没有定量研究检验髋部角度和肢体负荷在中风后调节肌肉活动中的作用。