A double-blind placebo-controlled clinical investigation into pain reduction effect of placing the pain spot outside the intersection area of the two currents of interferential therapy compared to traditional method

Abstract

Background: Interferential therapy (IFT) is applied to intersect in the painful area but no confirmed effect with this method. Experimentally, the highest voltage of IFT is induced outside the intersection of the two currents. Placing the painful area outside the intersection point (external application) would reveal a better effect.

Objectives: To examine the effect of external application in pain compared to traditional method.

Design: A double-blind placebo-controlled clinical investigation.

Setting: A public hospital.

Participants: 168 LBP subjects.

Interventions: Assignment: (1) external IFT, (2) placebo external IFT, (3) traditional IFT and (4) placebo traditional IFT. Groups 1 and 3 received 20 min of IFT at 100 Hz and groups 2 and 4 received sham IFT.

Main outcome measures: Before and after IFT session, pain severity (VAS), pressure threshold (PPT), pain distribution and ROM were assessed.

Results: IFT changed all outcomes similarly. VAS and ROM improved statistically, P < 0.03. A trend of better VAS reduced with active IFTs.

Conclusions: No therapeutic difference between the two methods.