Department of Sport Social Management, KIBI International University, Takahashi, Okayama, Japan.
Department of Human Health and Wellbeing, University of Marketing and Distribution Science, Kobe, Hyogo, Japan.
PLoS One. 2022 Apr 22;17(4):e0261393. doi: 10.1371/journal.pone.0261393. eCollection 2022.
Depression of the sensory input during voluntary muscle contractions has been demonstrated using electrophysiological methods in both animals and humans. However, the association between electrophysiological responses of the sensory system and subjective peripheral sensation (SPS) during a voluntary muscle contraction remains unclear. This study aimed to describe the changes in SPS, spinal α-motoneuron excitability (F-wave to M-wave amplitude), and somatosensory evoked potentials (SEPs) during a unilateral pinch-grip task. Outcome variables were measured on the side ipsilateral and contralateral to the muscle contraction and at rest (control). Participants were 8 healthy men aged 20.9±0.8 years. The isometric pinch-grip task was performed at 30% of the maximum voluntary isometric force measured for the right and left hands separately. The appearance rate of the F-wave during the task was significantly higher for the ipsilateral (right) hand than for the contralateral (left) hand and control condition. Although there was no difference in the F-wave latency between hands and the control condition, the amplitude of the F-wave was significantly higher for the ipsilateral (right) hand than for the contralateral (left) hand and the control condition. There was no difference in the amplitude of the SEP at N20. However, the amplitude at P25 was significantly lower for the ipsilateral (right) hand than for the contralateral (left) hand and the control condition. The accuracy rate of detecting tactile stimulation, evaluated for 20 repetitions using a Semmes-Weinstein monofilament at the sensory threshold for each participant, was significantly lower during the pinch-grip task for both the ipsilateral (right) and contralateral (left) hands than in the control condition. Overall, our findings show that SPS and neurophysiological parameters were not modulated in parallel during the task, with changes in the subjective sensation preceding changes in electrophysiological indices during the motor task. Our findings provide basic information on sensory-motor coordination.
自愿肌肉收缩期间感觉输入的抑制已通过动物和人类的电生理方法得到证实。然而，感觉系统的电生理反应与自愿肌肉收缩期间的主观外周感觉（SPS）之间的关联尚不清楚。本研究旨在描述单侧捏夹任务期间 SPS、脊髓α运动神经元兴奋性（F 波至 M 波幅度）和体感诱发电位（SEP）的变化。在对侧和同侧（收缩侧）以及休息（对照）时测量结果变量。参与者为 8 名年龄 20.9±0.8 岁的健康男性。分别对右手和左手进行 30%的最大等长自主力测量，进行等长捏夹任务。在任务期间，同侧（右手）出现 F 波的频率明显高于对侧（左手）和对照条件。尽管 F 波潜伏期在手之间和对照条件之间没有差异，但 F 波幅度在同侧（右手）明显高于对侧（左手）和对照条件。SEP 在 N20 处的幅度没有差异。然而，同侧（右手）的 P25 幅度明显低于对侧（左手）和对照条件。使用每个参与者的感觉阈值的 Semmes-Weinstein 单丝评估触觉刺激的准确性，在捏夹任务期间，同侧（右手）和对侧（左手）的准确率均明显低于对照条件。总的来说，我们的发现表明，在任务期间，SPS 和神经生理参数没有平行调节，主观感觉的变化先于运动任务中电生理指标的变化。我们的发现提供了关于感觉运动协调的基本信息。
