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首页> 外文学位 >Modulating the soleus Hoffmann reflex (H-reflex) during gait initiation.
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Modulating the soleus Hoffmann reflex (H-reflex) during gait initiation.

机译：在步态启动过程中调节比目鱼霍夫曼反射（H-reflex）。

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摘要

The purpose of this series of three studies was to investigate how the soleus (SOL) H-reflex was modulated during human gait initiation (GI) under various experimental situations.; Study 1 examined the role of peripheral influences from contracting tibialis anterior (TA) in modulation the SOL H-reflex during early phase of GI. To assess the H-reflex modulation when TA activation was eliminated, the stance limb of a person with complete peroneal nerve injury was tested during GI. Normal control subjects were also tested when they initiated walking after swaying forward without initial TA activation. The H-reflex was considerably depressed during initial GI without initial TA activation. This finding supports the view that reciprocal inhibition of the SOL H-reflex during GI, which normally involves TA activation, is due to a centrally mediated process; and not due to peripheral influences from TA.; In Study 2, patterns of SOL H-reflex modulation as a function of posture, task, and reflex activation history were assessed with three experimental paradigms: lying prone compared with standing unsupported, standing compared with the initiation of walking, and standing compared with the (mid) stance phase of walking. Paired H-reflexes were evoked under each condition. When different postures and tasks were compared, paired reflex depression (a measure of the relative influence of the reflex activation history on reflex excitability) was modulated independently of the first H-reflex (a representation of the task or phase dependent modulation). These experiments demonstrated divergent patterns of segmental reflex modulation.; Study 3 was done to investigate SOL H-reflex for swing limb and stance limb during the reaction time (RT) period and during the early phase of GI relative to the kinetic events in the process of GI. Both stance and swing limb H-reflexes were significantly and gradually depressed during RT, however, the stance limb H-reflexes were significantly lower and their depression started earlier on than the swing limb. Although there was some inhibition of the H-reflex due to TA contraction, the H-reflexes for both limbs after the TA EMG onset were more closely modulated with the ground reaction forces.
机译：这一系列三项研究的目的是研究在各种实验情况下，人的步态起始（GI）期间比目鱼（SOL）H反射如何被调节。研究1研究了在GI早期，胫骨前部收缩（TA）对周围环境的影响在调节SOL H反射中的作用。为了评估消除TA激活后的H反射调制，在GI期间测试了完全腓骨神经损伤的人的站立肢体。正常对照组在向前倾斜但没有初始TA激活的情况下开始行走时也进行了测试。在没有最初的TA激活的情况下，最初的GI期间H反射明显降低。这一发现支持了这样的观点，即GI过程中对SOL H反射的相互抑制（通常涉及TA激活）是由于中央介导的过程所致。而不是由于TA的外围影响。在研究2中，通过三种实验范式评估了SOL H反射调制的模式与姿势，任务和反射激活历史的关系：俯卧与无支撑站立比较，站立与行走开始比较以及站立与行走比较（中）站立阶段的步行。在每种情况下都会引起配对的H反射。当比较不同的姿势和任务时，成对的反射抑制（反射激活历史对反射兴奋性的相对影响的度量）独立于第一个H反射（任务或相位相关调制的表示）进行调制。这些实验证明了分段反射调制的不同模式。进行了研究3，以研究相对于GI过程中的动力学事件，在GI的反应时间（RT）期间和GI早期，摆动肢和站立肢的SOL H反射。在RT期间，姿态和挥肢H-反射均显着并逐渐抑制，但是，姿态肢H-反射显着降低，并且其压抑开始于摇摆肢。尽管由于TA收缩而对H反射有一定的抑制作用，但TA EMG发作后双肢的H反射受地面反作用力的影响更紧密。

著录项

  • 作者

    Jeon, Hye-Seon.;

  • 作者单位

    University of Florida.;

  • 授予单位 University of Florida.;
  • 学科 Health Sciences Rehabilitation and Therapy.; Biology Animal Physiology.
  • 学位 Ph.D.
  • 年度 2003
  • 页码 80 p.
  • 总页数 80
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 康复医学;生理学;
  • 关键词

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