Inserm UMR 1093-CAPS, UFR des Sciences du Sport, Institut National de la Santé et de la Recherche Médicale: UMR 1093, Université de Bourgogne, Dijon, France.
Centre d'Expertise de la Performance, UFR des Sciences du Sport, Université de Bourgogne, Dijon, France.
J Neurophysiol. 2024 Feb 1;131(2):379-393. doi: 10.1152/jn.00258.2023. Epub 2024 Jan 10.
Local vibration (LV) applied over the muscle tendon constitutes a powerful stimulus to activate the muscle spindle primary (Ia) afferents that project to the spinal level and are conveyed to the cortical level. This study aimed to identify the neuromuscular changes induced by a 30-min LV-inducing illusions of hand extension on the vibrated flexor carpi radialis (FCR) and the antagonist extensor carpi radialis (ECR) muscles. We studied the change of the maximal voluntary isometric contraction (MVIC, ) for carpal flexion and extension, motor-evoked potentials (MEPs, ), cervicomedullary motor-evoked potentials (CMEPs, ), and Hoffmann's reflex (H-reflex, ) for both muscles at rest. Measurements were performed before (PRE) and at 0, 30, and 60 min after LV protocol. A lasting decrease in strength was only observed for the vibrated muscle. The reduction in CMEPs observed for both muscles seems to support a decrease in alpha motoneurons excitability. In contrast, a slight decrease in MEPs responses was observed only for the vibrated muscle. The MEP/CMEP ratio increase suggested greater cortical excitability after LV for both muscles. In addition, the H-reflex largely decreased for the vibrated and the antagonist muscles. The decrease in the H/CMEP ratio for the vibrated muscle supported both pre- and postsynaptic causes of the decrease in the H-reflex. Finally, LV-inducing illusions of movement reduced alpha motoneurons excitability for both muscles with a concomitant increase in cortical excitability. Spinal disturbances confound the interpretation of excitability changes in motor areas and compromise the conclusions reached by previous studies using only a corticospinal marker for both vibrated and antagonist muscles. The time course recovery suggests that the H-reflex perturbations for the vibrated muscle do not only depend on changes in alpha motoneurons excitability. Local vibration induces neuromuscular changes in both vibrated and antagonist muscles at the spinal and cortical levels.
局部振动（LV）施加于肌肉肌腱会构成一种强有力的刺激，从而激活投射到脊髓水平并传递到皮质水平的肌梭初级（Ia）传入纤维。本研究旨在确定 30 分钟 LV 诱导的手部伸展错觉对振动的屈指浅肌（FCR）和拮抗伸指浅肌（ECR）肌肉引起的神经肌肉变化。我们研究了腕部屈肌和伸肌的最大自主等长收缩（MVIC，）、运动诱发电位（MEPs，）、颈髓运动诱发电位（CMEPs，）和双侧肌肉静息时的 Hoffmann 反射（H 反射，）的变化。在 LV 方案之前（PRE）和 0、30 和 60 分钟后进行测量。仅观察到振动肌肉的力量持续下降。观察到的两种肌肉的 CMEPs 减少似乎支持α运动神经元兴奋性降低。相比之下，仅观察到振动肌肉的 MEPs 反应略有下降。MEP/CMEP 比值增加表明两种肌肉的皮质兴奋性增加。此外，H 反射对于振动和拮抗肌肉均大大减少。振动肌肉的 H/CMEP 比值降低支持 H 反射降低的突触前和突触后原因。最后，LV 诱导的运动错觉降低了两种肌肉的α运动神经元兴奋性，同时增加了皮质兴奋性。脊髓干扰使运动区域的兴奋性变化的解释变得复杂，并使以前仅使用振动和拮抗肌肉的皮质脊髓标记的研究得出的结论受到影响。恢复时间过程表明，振动肌肉的 H 反射干扰不仅取决于α运动神经元兴奋性的变化。局部振动在脊髓和皮质水平引起振动和拮抗肌肉的神经肌肉变化。
