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，步态通常的特征是偏长的肢体的屈曲减少，伴随着晚点和挥杆期间长时间的膝盖伸展。这种运动模式归因于两个竞争的起源：屈肌激活不足和/或通过过度的股四头肌活性激活不适当。证据表明，在步态晚期姿势阶段调节肌肉活性中，髋角和肢体负荷受体的双重重要性。然而，在中风后，传入信息的处理可能会因异常的降命令而破坏，从而改变肌肉激活和运动模式。该提案的主要目标是表征髋部传感器和负载受体在调节激活模式中的重要性，以确定它们在促进异常步态中的作用。主要的假设是，从髋屈肌到膝盖伸肌的过度异义异，在伸肌活性以及步态异常中起着至关重要的作用。提出的实验涉及对被动条件下孤立的关节运动以及在扰动行走期间的孤立关节运动进行仔细检查。尽管认为与肢体负荷和髋关节位置相关的适当传入输入对于在中风后进行“正常”步行模式是必需的，但尚无定量研究来检查髋部角和肢体负荷在中风后调节肌肉活动中的作用。