Amiez Nicolas, Martin Alain, Paizis Christos
Inserm UMR1093-CAPS, Université de Bourgogne, UFR des Sciences du Sport, F-21000, Dijon, Institut National de la Santé et de la Recherche Médicale: UMR1093, Université de Bourgogne, France.
Universite Lyon 1, UCBL-Lyon 1, Laboratoire Interuniversitaire de Biologie de la Motricité, Villeurbanne, France.
J Physiol. 2025 May;603(9):2741-2762. doi: 10.1113/JP286689. Epub 2025 Apr 1.
Stimulation of muscle afferents by local vibration (LV) can lead to two distinct perceptual and motor responses: the tonic vibration reflex (TVR) or the movement illusion. This study aimed to evaluate the effect of TVR and movement illusion on corticospinal excitability. In two experiments, EMG activity of the vibrated flexor carpi radialis (FCR) muscle (80 Hz, 6 min) and the extensor carpi radialis (ECR) muscle were recorded. Illusion was assessed using questionnaires. LV conditions were adjusted to favour either TVR (visual attention focused on the vibrating wrist) or ILLUSION (hidden hand, visual attention focused on the EMG of the FCR muscle). Motor-evoked potential (MEP) and cervicomedullary motor-evoked potential (CMEP) were recorded at rest for both muscles before (10 and 0 min) and after (0 and 30 min) each LV condition. Only the TVR condition increased EMG of the FCR muscle (+490% compared to resting, P = 0.005), while movement illusion was greater in the ILLUSION condition (P < 0.001). Concerning the vibrated muscle at P0, TVR reduced the amplitude of CMEP (-13.8 ± 15.8%, P = 0.011) without altering MEP (0.3 ± 27.9%, P = 1), whereas the opposite occurred with movement illusion (i.e. CMEP: -4.5 ± 13.7%, P = 0.891; MEP: -25.1 ± 17.2%, P = 0.002). Cortical excitability (MEP/CMEP ratio) of the vibrated muscle was reduced by 24 ± 13.3% on average compared to values obtained before LV, only in the ILLUSION condition. In conclusion, this study highlights the relevance of measuring and reporting the perceptual and motor responses induced during LV, demonstrating that TVR and movement illusion partly determine the acute effects on the neural network. KEY POINTS: Tonic vibration reflex and movement illusion are rarely controlled and measured in studies investigating the effect of LV on corticospinal excitability. The application of LV with visual attention focused on the vibrated muscle promotes the presence of a tonic vibration reflex (TVR). The absence of visual feedback on the latter promotes the presence of an illusion of movement. The cortical excitability of the vibrated muscle is influenced differently according to the perceptual and motor responses induced during LV, with an opposite effect on the cortical excitability of the antagonist muscle. Improved control of LV application conditions, quantification of perceptual and motor responses, and reporting of results (e.g. EMG activity of the vibrated muscle or illusion of movement during the protocol) are required to enhance our understanding of the physiological mechanisms associated with LV use and, consequently, the effectiveness of LV as a therapeutic modality.
局部振动（LV）刺激肌肉传入神经可导致两种不同的感知和运动反应：紧张性振动反射（TVR）或运动错觉。本研究旨在评估TVR和运动错觉对皮质脊髓兴奋性的影响。在两个实验中，记录了振动的桡侧腕屈肌（FCR）肌肉（80Hz，6分钟）和桡侧腕伸肌（ECR）肌肉的肌电图活动。使用问卷评估错觉。调整LV条件以利于TVR（视觉注意力集中在振动的手腕上）或错觉（隐藏手部，视觉注意力集中在FCR肌肉的肌电图上）。在每种LV条件之前（10和0分钟）和之后（0和30分钟），记录两块肌肉在静息状态下的运动诱发电位（MEP）和颈髓运动诱发电位（CMEP）。只有TVR条件增加了FCR肌肉的肌电图（与静息相比增加490%，P = 0.005），而运动错觉在错觉条件下更大（P < 0.001）。关于P0处振动的肌肉，TVR降低了CMEP的幅度（-13.8±15.8%，P = 0.011），而未改变MEP（0.3±27.9%，P = 1），而运动错觉则相反（即CMEP：-4.5±13.7%，P = 0.891；MEP：-25.1±17.2%，P = 0.002）。与LV之前获得的值相比，仅在错觉条件下，振动肌肉的皮质兴奋性（MEP/CMEP比值）平均降低了24±13.3%。总之，本研究强调了测量和报告LV期间诱导的感知和运动反应的相关性，表明TVR和运动错觉部分决定了对神经网络的急性影响。关键点：在研究LV对皮质脊髓兴奋性的影响时，紧张性振动反射和运动错觉很少得到控制和测量。将视觉注意力集中在振动肌肉上应用LV会促进紧张性振动反射（TVR）的出现。对后者缺乏视觉反馈会促进运动错觉的出现。根据LV期间诱导的感知和运动反应，振动肌肉的皮质兴奋性受到不同影响，对拮抗肌的皮质兴奋性有相反作用。需要改进LV应用条件的控制、感知和运动反应的量化以及结果报告（例如方案期间振动肌肉的肌电图活动或运动错觉），以增强我们对与LV使用相关的生理机制的理解，从而提高LV作为治疗方式的有效性。
