Effects of carrier frequency of interferential current on pressure pain threshold and sensory comfort in humans.

Abstract

To assess the effect of carrier frequency of interferential current (IFC) on pressure pain threshold (PPT) and sensory comfort in healthy subjects. A double-blind randomized trial. University research laboratory. Healthy subjects (N=150). Application of the IFC for 20 minutes and measures of PPT collected in the regions of the nondominant hand and forearm. We measured PPT and comfort at frequencies of 1kHz, 2kHz, 4kHz, 8kHz, and 10kHz. There was a significant increase in PPT in the 1-kHz group when compared with the 8-kHz and 10-kHz groups. There was a greater discomfort in the 1-kHz and 2-kHz groups. IFC with a carrier frequency of 1kHz promotes a higher hypoalgesic response during and after stimulation than IFC with carrier frequencies of 8kHz and 10kHz. Carrier frequencies of 1kHz and 2kHz are perceived as more uncomfortable than carrier frequencies of 4kHz, 8kHz, and 10kHz.