The aim of this study was to evaluate the effects of an 8-week local vibration training (LVT) program on functional and corticospinal properties of dorsiflexor muscles. Forty-four young subjects were allocated to a training (VIB, n = 22) or control (CON, n = 22) group. The VIB group performed twenty-four 1-h sessions (3 sessions/week) of 100-Hz vibration applied to the right tibialis anterior (TA). Both legs were tested in each group before training (PRE), after 4 (MID) and 8 (POST) weeks of training, and two weeks after training (POST2W). Maximal voluntary contraction (MVC) torque was assessed and transcranial magnetic stimulation (TMS) was used to evaluate cortical voluntary activation (VATMS), motor evoked potential (MEP), cortical silent period (CSP) and input-output curve parameters. MVC was significantly increased for VIB at MID for right and left legs (+7.4%, p=0.001 and +6.2%, p<0.01, respectively) and remained significantly greater than PRE at POST (+12.0%, p<0.001 and +10.1%, p<0.001, respectively). VATMS was significantly increased for right and left legs at MID (+4.4%, p<0.01 and +4.7%, p<0.01, respectively) and at POST (+4.9%, p=0.001 and +6.2%, p=0.001, respectively). These parameters remained enhanced in both legs at POST2W. MEP and CSP recorded during MVC and input-output curve parameters did not change at any time points for either leg. Despite no changes in excitability or inhibition being observed, LVT seems to be a promising method to improve strength through an increase of maximal voluntary activation, i.e. neural adaptations. Local vibration may thus be further considered for clinical or aging populations.
- Local vibration
- Transcranial magnetic stimulation
- Cortical voluntary activation
- corticospinal excitability and inhibition
- Boltzmann modelling
- Copyright © 2016, Journal of Applied Physiology