Influence of Noxious Electrical Stimulation on Chronic Pain From Knee Osteoarthritis

The NxES intervention will be applied with a pair of 2x3 inch electrodes placed orthogonally to the knee joint line with one electrode on the medial and lateral sides of the knee. The device is a commercially available unit(Chattanooga Continuum, DJO Global, Vista CA) and the parameters of the NxES include: 400 μs biphasic square wave pulses delivered at 50-100 pulses/second, using a cycle time of 10-seconds on, with a 2-second ramp-up in intensity, followed by a 10-second off period. The current intensity will be dosed over the first 2-minutes of stimulation to find the sensory perception threshold and the threshold for the first perception of a sharp, prickly buzzing sensation that they would identify as painful. Next, the current intensity will gradually be increased until the participant reports a sharp or prickly buzzing sensation that achieves a pain rating of not more than a 5/10 using a numeric pain rating scale.