The regularity of the fluctuations present in torque signals represent the adaptability of the motor control. While previous research showed how it is affected by neuromuscular fatigue and ageing, the underlying mechanisms remain unclear. It is currently under debate whether these changes are explained by central or peripheral neuromuscular mechanisms. Here, we experimentally manipulated the sleep of thirteen young adults through a supervised 24 h-sleep deprivation protocol. This study aimed to investigate the effect of sleep deprivation on the regularity of torque fluctuations, and other standard torque-related outcomes (Peak Torque – PT – and Rate of Torque Development – RTD). The participants were asked to perform knee extension maximal voluntary contractions (MVC) and submaximal knee extensions at 40% of MVC for 30 s. PT and RTD were calculated from the MVC and the regularity of the torque fluctuations was determined on the submaximal task through Sample Entropy (SampEn). In addition, rate of perceived effort (RPE) was collected. We found no significant changes in PT and RTD. The regularity of torque fluctuations significantly increased (i.e., a decrease in SampEn) after 24 h-sleep deprivation (PRE = 1.76 ± 0.268, POS24 = 1.71 ± 0.306; p = 0.044). Importantly, we found a negative correlation between RPE and SampEn relative changes after sleep deprivation. This study brings new insights towards the understanding of the underlying mechanisms that explain changes in torque fluctuations, demonstrating that these changes are not limited to neuromuscular processes but are also likely to be affected by other domains, such as psychological profile, which can indirectly affect the neural drive to the muscles.

扭矩信号波动的规律性代表了电机控制的适应性。虽然之前的研究表明神经肌肉疲劳和衰老如何影响它，但其潜在机制仍不清楚。目前尚不清楚这些变化是由中枢神经肌肉机制还是外周神经肌肉机制解释的。在这里，我们通过监督的 24 小时睡眠剥夺方案实验性地操纵了 13 名年轻人的睡眠。本研究旨在调查睡眠剥夺对扭矩波动规律性以及其他标准扭矩相关结果（峰值扭矩 - PT - 和扭矩发展率 - RTD）的影响。参与者被要求进行膝关节伸展最大自主收缩 (MVC) 和次最大膝关节伸展 (MVC 的 40%)，持续 30 秒。PT 和 RTD 是根据 MVC 计算的，扭矩波动的规律性是通过样本熵 (SampEn) 在次最大任务上确定的。此外，还收集了感知努力率（RPE）。我们发现 PT 和 RTD 没有显着变化。24 小时睡眠剥夺后，扭矩波动的规律性显着增加（即 SampEn 减少）（PRE = 1.76 ± 0.268，POS24 = 1.71 ± 0.306；p  = 0.044）。重要的是，我们发现睡眠剥夺后 RPE 和 SampEn 相对变化之间呈负相关。这项研究为理解解释扭矩波动变化的潜在机制带来了新的见解，表明这些变化不仅限于神经肌肉过程，还可能受到其他领域的影响，例如心理状况，这可以间接影响扭矩波动的变化。神经对肌肉的驱动。