Xiao Fangxin, Noort Wendy, Lévénez Juliette, Han Jia, van Dieën Jaap H, Maas Huub
Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Van der Boechorststraat 7, Amsterdam, 1081 BT, The Netherlands.
School of Exercise and Health, Shanghai University of Sport, Shanghai, China.
Exp Brain Res. 2025 Apr 28;243(5):132. doi: 10.1007/s00221-025-07041-8.
Nociception resulting in pain perception might be one of the factors contributing to the motor control changes in people with low-back pain. However, limited evidence exists regarding the effects of acute pain on trunk motor control during locomotion. This study aimed to evaluate the effects of hypertonic saline induced nociception on trunk movement and back muscle activity during locomotion in a rat model. Spine and pelvis kinematics, EMG signals from bilateral multifidus (MF) and medial longissimus (ML) muscles of the rats were collected during treadmill locomotion before and after hypertonic saline (5.8%) injection into the MF. We found that both the locomotion and EMG patterns remained unchanged after hypertonic saline injection. No significant changes were found in stride duration, pelvic, lumbar and spine angle changes, variability, or movement asymmetry. The overall EMG activation patterns and intermuscular coordination remained unchanged after hypertonic saline injection and there was synchronized activation of bilateral MF muscles with two peaks per stride cycle, and alternating activation of left and right ML. The only significant effects of hypertonic saline injection were the decrease in the normalized peak amplitude of the left MF and EMG variability in right ML, no effects were detected in other EMG outcomes or muscles. These results suggest that the changes in EMG activity reflect localized neuromuscular response to nociception rather than broader alterations in control of locomotion.
导致疼痛感知的伤害感受可能是导致腰痛患者运动控制变化的因素之一。然而，关于急性疼痛对运动过程中躯干运动控制的影响，现有证据有限。本研究旨在评估在大鼠模型中，高渗盐水诱导的伤害感受对运动过程中躯干运动和背部肌肉活动的影响。在向多裂肌（MF）注射5.8%高渗盐水前后，于跑步机运动期间收集大鼠的脊柱和骨盆运动学数据，以及双侧多裂肌（MF）和内侧最长肌（ML）的肌电图信号。我们发现，注射高渗盐水后，运动和肌电图模式均保持不变。步幅持续时间、骨盆、腰椎和脊柱角度变化、变异性或运动不对称性均未发现显著变化。注射高渗盐水后，整体肌电图激活模式和肌肉间协调性保持不变，双侧MF肌肉在每个步幅周期有两个峰值的同步激活，左右ML交替激活。注射高渗盐水的唯一显著影响是左侧MF归一化峰值幅度降低以及右侧ML的肌电图变异性降低，在其他肌电图结果或肌肉中未检测到影响。这些结果表明，肌电图活动的变化反映了对伤害感受的局部神经肌肉反应，而非运动控制的更广泛改变。
