Peripheral Stimulation Neural Response

TENS is performed using a commercially available device (ProStim, Alimed Inc, Dedham, Massachusetts, USA). One pair of 2 x 3.5 inches rectangular electrodes (Vermed ChroniCare TENS Electrodes, Vermed, Buffalo, NY, USA) are placed to simultaneously stimulate both median and ulnar nerves at the wrist, while a second pair of round 2 inch diameter electrodes are used to stimulate the radial nerve on the forearm. Bursts of electrical stimulation at 10 Hz (100 microsecond pulse width duration) are delivered to all nerves simultaneously for 2 hours.