Effect of low frequency transcutaneous electrical nerve stimulation of TE5 (waiguan) and PC6 (neiguan) acupoints on cold-induced pain

[Purpose] This study assesse the effect of low frequency transcutaneous electrical nerve stimulation (TENS) of theTE5 (waiguan) and PC6 (neiguan) acupoints on cold-induced pain. [Subjects and Methods] Forty-eight subjects were divided by convenience into three groups: TENS with electrodes of 1 cm(2) area, TENS with electrodes of area 15 cm(2) and a placebo group. The study consisted of three phases: cold-induced pain without electroanalgesia, cold-induced pain with electroanalgesia or placebo, and cold-induced pain post-electroanalgesia or placebo. [Results] Acupuncture like TENS increased the pain threshold latency during treatment (45.7 ± 11.7s) compared to pre-treatment (30.9 ± 8.9s) in the TENS group with 1 cm(2) electrodes. In the TENS group with 15 cm(2) electrodes, the pain threshold latency increased at post-treatment (36.2 ± 12.9s) compared to pre-treatment (25.5 ± 7.4s). The placebo group showed no significant changes. The group with 1 cm(2) electrodes showed a significantly higher pain threshold latency (45.7 ± 11.7s) than the other two groups. At post-treatment, the pain threshold latencies of both the 1 cm(2) (39.4 ± 11.5s) and 15 cm(2) (36.2 ± 12.9s) TENS group were higher than that of the placebo group (22.4 ± 7.4s). [Conclusion] Acupuncture like TENS applied to PC6 and TE5 acupoints increased the pain threshold latency. The pain intensity was reduced by TENS with an electrode area of 1 cm(2).