The effects of transcutaneous electrical nerve stimulation on skin temperature in asymptomatic subjects.

Abstract

Several studies have evaluated the effects of transcutaneous electrical nerve stimulation (TENS) on skin temperature. The results of these studies, however, remain controversial. This study examined the effects of two modes of TENS, compared with a control condition, on skin temperature of the hand and finger. Twenty-four asymptomatic subjects (23 female, 1 male) with no previous experience with TENS participated. The subjects ranged in age from 19 to 28 years (means = 23.0, SD = 2.44). All subjects participated in a 4-Hz TENS session, a 100-Hz TENS session, and a control (no TENS) session. Electrodes were placed on the medial and lateral aspects of the dorsal surface of the left hand. Each session consisted of a 60-minute stabilization period, a 30-minute stimulation period, and a 30-minute follow-up period. Hand temperature was measured using infrared thermography, and finger temperature was measured using a skin thermistor. Mean hand temperature after low-frequency TENS was 1.69 degrees C warmer than the mean hand temperature following the high-frequency TENS and 1.60 degrees C warmer than after the control condition. No differences in the finger temperature were found among the three conditions. High-intensity, low-frequency TENS prevented cooling of the hand. High- and low-frequency TENS had no effect on finger temperature.