Study on Neural Effects of Whole-Body Vibration Training

<p>Whole-body vibration (WBV) training is widely used as a training method for athletes, older adults, and people with central nervous system injuries. Although it has been shown that WBV can strongly suppress H-reflex excitability of the soleus muscle, the effects on other muscles remain unknown. Therefore, the purpose of this study was to determine the effects of WBV on the spinal reflex circuits of the flexor and extensor muscles of the thigh and lower leg muscles. Seven healthy adult male individuals participated in this study and underwent assessments before, during and after WBV and a control condition that included standing only. Surface electromyography signals were recorded unilaterally in the right leg during the experiments. In the WBV condition, the intervention was applied for 1 minute and in the control condition participants stood still for 1 minute. Posterior root muscle (PRM) reflexes were measured in four lower extremity muscles, including the tibialis anterior (TA), soleus (SOL), vastus medialis (VM), and biceps femoris (BF) before, during, and after the interventions. Our results showed that the peak-to-peak amplitudes of PRM-reflexes of the TA, SOL, and BF muscles decreased significantly during the WBV intervention, compared to before the intervention. However, no effect was observed in the control condition. These results indicate that WBV has widespread inhibitory effects on reflex circuits in muscles other than the SOL, but this effect is not sustained following a short duration intervention. Overall, our results suggest that WBV can be used effectively to temporarily decrease spasticity in neurological disorder population.</p>