SOLEUS H-REFLEX GAIN, THRESHOLD, AND AMPLITUDE AS FUNCTION OF BODY POSTURE AND LOAD IN SPINAL CORD INTACT AND INJURED SUBJECTS
SOLEUS H-REFLEX GAIN, THRESHOLD, AND AMPLITUDE AS FUNCTION OF BODY POSTURE AND LOAD IN SPINAL CORD INTACT AND INJURED SUBJECTS
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DOI：
10.1080/00207450903139747
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发表时间：
2009-01-01
影响因子：
2.2
通讯作者：
Harkema, Susan J.
中科院分区：
文献类型：
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作者：
Knikou, Maria;Angeli, Claudia A.;Harkema, Susan J.
在这项研究中，我们建立了8名慢性脊髓损伤(SCI)患者和10名脊柱正常受试者比目鱼肌H反射兴奋性随体位和负荷变化的参数。在所有受试者中，当他们仰卧、坐着和站在稳定的跑步机上时，比目鱼肌H反射募集曲线被建立。站立时，通过上半身安全带提供体重支持(BWS)，SCI受试者的体重支持范围为20%-50%，脊柱完整受试者的BWS设置为0%和50%。根据比目鱼肌H反射募集曲线上肢的Sigmoid函数，估计对应于H阈值(H TH)、最大H反射幅度(H Max)、H max的50%以及反射增益的刺激。无论体位和负荷如何，SCI受试者的比目鱼肌H反射增益、H最大波幅和对应于H-TH、H-max的50%和H-max的刺激均增加。此外，在SCI受试者的负重状态下，反射增益没有得到适当的调节。脊髓损伤受试者的脊髓反射兴奋性受损伴随着H反射募集曲线参数的变化，无论是否有身体负荷。
In this study, we established parameters of the soleus H-reflex excitability in response to changes of posture and load in 8 chronic spinal cord injured (SCI) and 10 spinal-intact subjects. The soleus H-reflex recruitment curve was established in all subjects while they were supine, seated, and standing on a stable treadmill. During standing, body weight support (BWS) was provided via an upper body harness and ranged in SCI subjects from 20%-50% and in spinal-intact subjects was set at 0% and 50%. Stimuli corresponding to the H-threshold (H-th), maximal H-reflex amplitude (H-max), and 50% of H-max as well as the reflex gain were estimated based on a sigmoid function of the ascending limb of the soleus H-reflex recruitment curve. The soleus H-reflex gain, H-max amplitude, and stimuli corresponding to H-th, 50% of H-max, and H-max were increased in SCI subjects regardless of the body position and loading. Further, the reflex gain was not modulated appropriately during conditions of weight bearing in SCI subjects. Impaired spinal reflex excitability in SCI subjects is accompanied by changes of the H-reflex recruitment curve parameters regardless of presence or absence of body loading.