Comparison the efficacy of diclofenac phonophoresis and ultrasound therapy on pressure pain threshold in healthy volunteer

Abstract

Phonophoresis is a technique commonly used in physical therapy practice. However, evidence to support the effectiveness of this technique on pain relief is still unclear. In addition, there is no study about the difference between the application of diclofenac before and after phonophoresis technique. This study aimed to compare the effects of 4 treatments, including phonophoresis with the application of diclofenac before  (PH1) and after (PH2) the treatment, ultrasound therapy (US), and placebo ultrasound therapy (placebo US) on pressure pain threshold (PPT). Forty healthy volunteers, age between 18 to 25 years old participated in this randomized, double-blind, placebo controlled cross-over trial study. Each participant received each treatment in a random order with a 1 week washout period. Participants were assessed for the levels of PPT 3 times which were before, immediately after and 15 minutes after the treatments. The results showed that the PPT was significantly increased in both PH1 and PH2 groups after treatment for 15 minutes (p<0.05).The increment of PPT after the treatments in PH1 and PH2 groups was significantly greater than the US and placebo US groups (P<0.01) However, there was no significant difference between the PH1 and PH2 groups. The finding indicate that diclofenac phonophoresis can increase PPT as compared to ultrasound therapy or using diclofenac only. Therefore therapists can apply diclofenac either before or after the phonophoresis treatment.