Stretch Reflex Contributions to Multijoint Coordination

牵张反射对多关节协调的贡献

• 批准号: 7487843
• 负责人: ERIC JON PERREAULT
• 金额: $ 20.79万
• 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: 2006-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7487843
• 关键词: Accounting; Address; Animals; Attention; Biomechanics; Central Nervous System Diseases; Complex; Condition; Coupled; Coupling; Data; Deafferentation procedure; Distal; Elbow; Freedom; Grant; Hand; Human; Individual; Intervention; Investigation; Joint structure of shoulder region; Joints; Length; Limb structure; Link; Mechanics; Mediating; Modeling; Motor Neurons; Movement; Muscle; Neural Pathways; Output; Pathway interactions; Pattern; Positioning Attribute; Posture; Property; Purpose; Reflex action; Regulation; Rehabilitation therapy; Relative (related person); Research Personnel; Robot; Robotics; Role; Shoulder; Skeleton; Spinal; Spinal cord injury; Stretching; Stroke; System; Techniques; Upper Extremity; Upper arm; abnormal reflex; base; electric impedance; human study; neuropathology; response; sensory neuropathy; stretch reflex; tool

DESCRIPTION (provided by applicant): Abnormal interjoint coordination is a hallmark of neuropathologies such as stroke and spinal cord injury, and there is evidence that changes in stretch reflex function may contribute to this discoordination. Understanding the significance of these changes and how they might be reversed or reduced through rehabilitation is best done in the context of the unimpaired state. However, there is little information regarding the role of stretch reflexes in the unimpaired control of multijoint movement and posture. Rather, most human studies have focused on the stretch response to single joint perturbations, which allow for unambiguous regulation of muscle length, but do not address the complexities of real perturbations and real movements involving multiple muscles acting in multiple degrees of freedom. This purpose of this grant is to examine stretch reflex contributions to multijoint coordination in the unimpaired human arm. Specifically we will determine if the muscle activation patterns generated in response to whole limb perturbations arise from neurally-mediated, intermuscular (heteronymous) connections or if they simply represent the autogenic (homonymous) responses of individual muscles linked via the skeleton. In addition, the functional consequences of these actions will be addressed by quantifying the mechanical impact of any observed reflex actions. Our Aims are: 1) To examine the heteronymous reflexes connecting the elbow and shoulder by applying single joint perturbations to a single joint, and recording the changes in muscle activity elicited at both joints. These results will provide a "model-free" assessment of heteronymous linkages. 2) To examine the relative contributions of homonymous and heteronymous stretch reflex pathways in coordinating the response to whole limb perturbations. This will be investigated using a 3DOF robot to perturb limb posture and a 3D biomechanical model to estimate the resulting muscle length changes. Changes in muscle activation that are not directly linked to homonymous length changes are likely to represent the output of heteronymous pathways. 3) To examine the influence of reflexively evoked changes in muscle activity on the regulation of multijoint mechanics. The first two Aims are important for assessing the existence and connectivity of stretch reflex responses, but alone do not establish their functional consequences. The latter requires an assessment of how reflex responses influence the mechanical properties of a limb. This will be accomplished using nonlinear system identification techniques to estimate stretch reflex contributions to multijoint impedance. This study will be the first to investigate the role of multijoint stretch reflexes for coordinating arm posture in the 3DOF relevant to normal function. Our results will provide the essential basis for our further investigations into abnormal reflex function following stroke and will elucidate the degree to which spinal mechanisms should be targeted by rehabilitation interventions.

描述（由申请人提供）：异常的间交互配位是诸如中风和脊髓损伤之类的神经病理学的标志，并且有证据表明，拉伸反射功能的变化可能会导致这种脱节。最好在不受影响的状态下完成这些变化的意义以及如何通过康复来逆转或减少它们。但是，关于拉伸反射在对多焦点运动和姿势无损控制中的作用的信息很少。相反，大多数人类研究都集中在对单个关节扰动的伸展运动上，这允许对肌肉长度进行明确调节，但并不能解决实际扰动的复杂性和涉及多种自由度作用的多种肌肉的真实运动的复杂性。这笔赠款的这一目的是检查对未损坏的人类手臂中多关节协调的伸展反射贡献。具体而言，我们将确定肌肉激活模式是否是响应整个肢体扰动而产生的，是由神经介导的，肌间（异义）连接产生的，还是仅表示通过骨架链接的单个肌肉的自体（同型）反应。此外，这些动作的功能后果将通过量化任何观察到的反射作用的机械影响来解决。我们的目标是：1）检查通过将单个关节扰动施加到单个关节上，并记录两个关节引起的肌肉活动的变化，以检查连接肘部和肩部的异源反射。这些结果将对异义链接提供“无模型”评估。 2）检查同义和异义伸展反射途径在协调对整个肢体扰动的响应时的相对贡献。这将使用3DOF机器人进行研究以考虑到肢体姿势和3D生物力学模型，以估计所得的肌肉长度变化。与同义长度变化无直接相关的肌肉激活的变化可能代表异义途径的输出。 3）检查肌肉活性反射诱发的变化对多聚期力学调节的影响。前两个目标对于评估拉伸反射响应的存在和连通性很重要，但仅凭就不能确定其功能后果。后者需要评估反射反应如何影响肢体的机械性能。这将使用非线性系统识别技术来估计对多聚期阻抗的伸展反射贡献。这项研究将是第一个研究多期拉伸反射在与正常功能相关的3DOF中协调臂姿势的作用。我们的结果将为我们对中风后异常反射功能的进一步研究提供基本基础，并将阐明应通过康复干预措施将脊柱机制作为目标的程度。