Inserm UMR1093-CAPS, Institut National de la Santé et de la Recherche Médicale, UFR des Sciences du Sport, Université de Bourgogne, Dijon, France.
Centre d'Expertise de la Performance, UFR des Sciences du Sport, Université de Bourgogne, Dijon, France.
J Appl Physiol (1985). 2024 Oct 1;137(4):800-813. doi: 10.1152/japplphysiol.00192.2024. Epub 2024 Aug 8.
Local vibration (LV) mainly stimulates primary afferents (Ia) and can induce a tonic vibration reflex (TVR) and an illusion of movement. This study aimed to evaluate the effect of these two phenomena on maximal voluntary isometric contraction (MVIC) capacity. LV (80 Hz) was applied to the wrist flexor muscles in two randomized experiments for 6 min. LV conditions were adjusted to promote either TVR (visual focus on the vibrated wrist) or ILLUSION [hand hidden, visual focus on electromyographic activity of the flexor carpi radialis muscle (FCR)]. Mechanical and electromyographic (EMG) responses of the FCR and extensor carpi radialis muscles were recorded during MVIC in flexion and extension and during electrically evoked contractions at supramaximal intensity. Measurements were performed before (10 min and just before) and after (0 and 30 min) LV protocol. An increase in FCR EMG was observed during LV in the TVR condition (+340%) compared with the illusion condition ( = 0.003). In contrast, the movement illusion was greater in the ILLUSION condition (assessed through subjective scales) ( = 0.004). MVIC was reduced in flexion only after the TVR condition ([Formula: see text], all < 0.034). Moreover, the decrease in force was correlated with the amount of TVR recorded on the FCR muscle ( = -0.64, = 0.005). Although potentiated doublets of each muscle did not evolve differently between conditions, a decrease was observed between the first and the last measure. In conclusion, when conducting research to assess maximal strength, it is necessary to have better control and reporting of the phenomena induced during LV. The maximal force production of the vibrated muscle is reduced after 6 min of LV only in TVR condition. Furthermore, the amount of TVR is negatively correlated with this force decrease. When measuring the effects of LV on maximal force production, it is important to control and report any phenomena induced during vibration, such as TVR or movement illusion, which can be achieved by recording EMG activity of vibrated muscle and quantifying illusion.
局部振动（LV）主要刺激初级传入纤维（Ia），可引起紧张性振动反射（TVR）和运动错觉。本研究旨在评估这两种现象对最大自主等长收缩（MVIC）能力的影响。在两项随机实验中，将 LV（80Hz）施加于腕屈肌，持续 6 分钟。LV 条件调整为促进 TVR（视觉聚焦于振动腕部）或错觉[手隐藏，视觉聚焦于桡侧腕屈肌（FCR）的肌电图活动]。在屈/伸位进行 MVIC 时以及在最大刺激强度下进行电诱发收缩时，记录 FCR 和桡侧伸腕肌的机械和肌电图（EMG）反应。在 LV 方案之前（10 分钟和之前）和之后（0 分钟和 30 分钟）进行测量。在 TVR 条件下，与错觉条件相比（ = 0.003），LV 期间 FCR EMG 增加（+340%）。相比之下，错觉条件下的运动错觉更大（通过主观量表评估）（ = 0.004）。仅在 TVR 条件下，MVIC 在屈位时降低（[公式：见文本]，所有 <0.034）。此外，力的下降与 FCR 肌肉上记录的 TVR 量呈负相关（ = -0.64， = 0.005）。尽管各肌肉的增强偶联在不同条件下没有不同的演变，但在第一次和最后一次测量之间观察到下降。总之，在进行评估最大强度的研究时，有必要更好地控制和报告 LV 过程中引起的现象。仅在 TVR 条件下，6 分钟 LV 后振动肌肉的最大力输出降低。此外，TVR 的量与这种力下降呈负相关。在测量 LV 对最大力输出的影响时，控制和报告振动过程中引起的任何现象（如 TVR 或运动错觉）非常重要，可以通过记录振动肌肉的肌电图活动并量化错觉来实现。
