Purpose: In physical therapy for post-stroke patients, we often experience cases in which unpleasant emotions cause abnormal muscle tonus. Previously, we suggested that the magnitude of spinal motor neuron excitability was correlated with the grade of muscle tonus. Therefore, spinal motor neuron excitability was considered to be a useful index to evaluate the influence of unpleasant emotions on muscle tonus. In this study, we investigated whether unpleasant emotions evoked by visual stimuli affected the excitability of spinal motor neurons.Materials and Methods: The F-waves, an indicator of spinal motor neuron excitability, were measured in 19 healthy adult volunteers. Firstly, for the rest trial, F-waves were measured during relaxation to determine the baseline of spinal motor neuron excitability. Following the rest trial, the unpleasant trial was conducted in which F-waves were measured while the subjects viewed an unpleasant picture for 1 min. After the unpleasant trial, F-waves were measured during relaxation. For the control condition, F-waves were measured while the subjects viewed a neutral picture instead of the unpleasant picture. The recorded F-wave data were analysed for persistence and the F/M amplitude ratio.Results: Persistence and the F/M amplitude ratio were significantly greater during the unpleasant trial than during the rest trial. In the control condition, there was no significant difference in persistence and the F/M amplitude ratio compared with the three trials.Conclusions: Our findings indicate that unpleasant emotions may affect spinal motor neuron excitability. Therefore, learning how to control emotions should be important aspect of physical therapy.

中文翻译：

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令人不快的视觉刺激会增加脊髓运动神经元的兴奋性。

目的：在中风后患者的物理治疗中，我们经常遇到不愉快的情绪导致异常肌肉紧张的情况。以前，我们建议脊髓运动神经元兴奋性的大小与肌肉紧张程度相关。因此，脊髓运动神经元兴奋性被认为是评估不愉快情绪对肌张力影响的有用指标。在这项研究中，我们调查了视觉刺激引起的不愉快情绪是否会影响脊髓运动神经元的兴奋性。材料和方法：在 19 名健康成人志愿者中测量了 F 波，这是脊髓运动神经元兴奋性的指标。首先，对于休息试验，在放松期间测量 F 波以确定脊髓运动神经元兴奋性的基线。在休息试验之后，进行了不愉快的试验，其中测量 F 波，同时受试者观看不愉快的图片 1 分钟。在不愉快的试验之后，在放松期间测量了 F 波。对于控制条件，在受试者观看中性图片而不是令人不快的图片时测量 F 波。对记录的 F 波数据进行持续性和 F/M 振幅比分析。结果：在令人不快的试验期间，持续性和 F/M 振幅比显着大于休息试验期间。在对照条件下，与三个试验相比，持续性和F/M振幅比没有显着差异。结论：我们的研究结果表明，不愉快的情绪可能会影响脊髓运动神经元的兴奋性。所以，