Effect of transcutaneous electrical nerve stimulation at auricular points on experimental cutaneous pain threshold

The purposes of this study were 1) to examine the effect of high intensity, low frequency transcutaneous electrical nerve stimulation at auricular acupuncture points on experimental pain threshold measured at the wrist and 2) to determine the changes in effect over time. Forty-four healthy adult men and women were assigned randomly to one of three treatment groups. Group 1 (n = 15) received TENS to appropriate auricular points for wrist pain, Group 2 (n = 14) received TENS to inappropriate (placebo) auricular points, and Group 3 (n = 15) received no TENS. We measured experimental pain threshold at the wrist after an electrical stimulus during one pretreatment and three posttreatment time periods. Group 1 was the only group that had a statistically significant increase (p less than .05) in pain threshold after testing. This increase remained significant for all posttreatment measurements for Group 1. These results suggest that high intensity, low frequency TENS applied to appropriate auricular acupuncture points can increase pain threshold.