Transcranial Direct Current Stimulation (tDCS) combined with virtual reality and muscle vibration
DevicetDCS will be delivered over the primary motor cortex (M1) to maximize the analgesic effect. The cathode will be positioned over the suborbital region, and the anode over M1 (position C3 or C4 of the international 10-20 system). A 2 mA direct current will be applied.
Participants will observe, through virtual reality goggles (HTC Vive), an avatar walking from a first-person perspective, synchronized with the vibration pattern. Twelve vibrators will be placed transversely and bilaterally over the tendons of the main flexors and extensors of the lower limbs.
The pattern used to trigger the vibrators is based on the natural sequence of gait movement. Muscle vibration induces a perception of movement in the direction of muscle elongation. The target frequency of the vibrators will be 80 Hz.
The session will begin with 5 minutes of tDCS alone, and then for the last 15minutes the investigators will combine tDCS, virtual reality and muscle vibration.