Beauchamp James A, Patterson Jacqueline R, Heckman C J, Dewald Julius P A
Annu Int Conf IEEE Eng Med Biol Soc. 2019 Jul;2019:2302-2306. doi: 10.1109/EMBC.2019.8857014.
The tonic vibration reflex (TVR), a reflexive muscle contraction resulting from muscle or tendon vibration, is a useful tool in assessing spinal motoneuron excitability, particularly in hyperexcitable conditions, such as in chronic hemiparetic stroke. The influence of experimental parameters, for example the type of vibratory stimulus and limb configuration, and their interactions on the TVR response in chronic stroke is unknown, yet this knowledge is crucial for designing experiments with reliable TVR responses. Therefore, we conducted a screening experiment of six potential driving factors affecting the TVR response, with a D-optimal split plot fractional design matrix consisting of thirty-two combinations for each of the four participants with chronic hemiparetic stroke. Our results suggest that pre-vibration muscle activation level, vibration frequency, and stimulus application force, are all significant contributors to the TVR response in chronic hemiparetic stroke, along with an interaction between elbow flexion angle and muscle activity level. This investigation highlights the sensitivity of the TVR response in chronic hemiparetic stroke and motivates future designed experiments in understanding this reflex as it relates to motoneuron excitability.
强直性振动反射（TVR）是一种由肌肉或肌腱振动引起的反射性肌肉收缩，是评估脊髓运动神经元兴奋性的有用工具，特别是在慢性偏瘫性中风等过度兴奋的情况下。实验参数的影响，例如振动刺激的类型和肢体配置，以及它们对慢性中风中TVR反应的相互作用尚不清楚，但这些知识对于设计具有可靠TVR反应的实验至关重要。因此，我们进行了一项筛选实验，研究影响TVR反应的六个潜在驱动因素，采用D最优裂区分数设计矩阵，由四名慢性偏瘫性中风患者的32种组合组成。我们的结果表明，振动前肌肉激活水平、振动频率和刺激施加力，都是慢性偏瘫性中风中TVR反应的重要因素，同时肘部屈曲角度和肌肉活动水平之间存在相互作用。这项研究突出了慢性偏瘫性中风中TVR反应的敏感性，并激发了未来旨在理解这种与运动神经元兴奋性相关的反射的设计实验。
