Kilohertz-frequency interferential current induces hypoalgesic effects more comfortably than TENS

Abstract

Abstract This study aims to demonstrate the hypoalgesic effect of the tibial nerve using transcutaneous interferential-current nerve inhibition (TINI), which injects the kilohertz frequency produced by the interferential currents. Thirty-one healthy adults participated in this cross-over repeated measures study. The hypoalgesic effects of TINI were compared with transcutaneous electrical nerve stimulation (TENS). The washout period was 24 hours or more. Stimulus intensity was set at the pain threshold level. TINI and TENS were applied for 20 minutes each. The ankle passive dorsiflexion range of motion, pressure pain threshold (PPT), and tactile threshold were measured at the baseline, pretest, test (immediately before ceasing intervention), and posttest (30 min after ceasing intervention) sessions. After the interventions, the participants evaluated the level of discomfort for TINI and TENS on a 10 cm visual analog scale (VAS). As a result, PPT significantly increased compared to baseline in test and posttest sessions of TINI, but not in those of TENS. Also, participants reported that TENS was 36% more discomfort than TINI. In conclusion, we found that TINI inhibited mechanical pain sensitivity and that the inhibitory effect persisted long after electrical stimulation ceased. Our study also shows that TINI provides the hypoalgesic effect more comfortably than TENS.