Over recent years, a growing body of research has highlighted the neural plastic effects of spinal manipulation on the central nervous system. Recently, it has been shown that spinal manipulation improved outcomes, such as maximum voluntary force and limb joint position sense, reflecting improved sensorimotor integration and processing. This study aimed to further evaluate how spinal manipulation can alter neuromuscular activity. High density electromyography (HD sEMG) signals from the tibialis anterior were recorded and decomposed in order to study motor unit changes in 14 subjects following spinal manipulation or a passive movement control session in a crossover study design. Participants were asked to produce ankle dorsiflexion at two force levels, 5% and 10% of maximum voluntary contraction (MVC), following two different patterns of force production (“ramp” and “ramp and maintain”). A significant decrease in the conduction velocity (p = 0.01) was observed during the “ramp and maintain” condition at 5% MVC after spinal manipulation. A decrease in conduction velocity suggests that spinal manipulation alters motor unit recruitment patterns with an increased recruitment of lower threshold, lower twitch torque motor units.

中文翻译：

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脊柱操纵对运动单位行为的影响

近年来，越来越多的研究突出了脊柱操纵对中枢神经系统的神经可塑性作用。近来，已经显示出脊柱操纵改善了结果，例如最大的自发力和四肢关节位置感，反映了感觉运动的整合和处理的改善。这项研究旨在进一步评估脊柱操纵如何改变神经肌肉活动。记录并分解来自胫骨前肌的高密度肌电图（HD sEMG）信号，以便研究交叉操纵设计中的脊柱操作或被动运动控制后14名受试者的运动单位变化。要求参与者在两种力量水平下产生踝背屈，最大自愿收缩（MVC）的5％和10％，遵循两种不同的力量产生方式（“斜坡”和“斜坡与维持”）。传导速度显着降低（p = 0.01）在“倾斜和维持”状态下在脊髓操纵后5％MVC期间观察到。传导速度的降低表明，脊柱操纵会随着较低阈值，较低抽搐扭矩马达单元的增加而改变马达单元的募集模式。