Evaluation of wet-cupping therapy for persistent non-specific low back pain: a randomised, waiting-list controlled, open-label, parallel-group pilot trial

This randomized controlled pilot study investigated the efficacy of wet-cupping therapy for persistent non-specific low back pain, a condition that affects up to 85% of the population at some point in life. The research was conducted at the Korea Institute of Oriental Medicine, recruiting 32 participants through local advertisements. Participants were randomized in a 2:1 ratio to the treatment group (n=21) or the waiting-list group (n=11). The main inclusion criterion was non-specific low back pain for at least 3 months, without identifiable structural causes such as disc herniation or infection.

The intervention consisted of wet-cupping sessions three times per week for two weeks, totaling six sessions. Treatment points were selected from BL-23, BL-24, and BL-25 bilaterally, with practitioners choosing the two most painful points on palpation at each session. The procedure followed a strict sterilization protocol using disposable 40 cc cups and self-disposing lancets to ensure safety. Primary outcomes included the numerical rating scale for pain (NRS 0-100), the Present Pain Intensity (PPI) index of the McGill Pain Questionnaire, the Oswestry Disability Questionnaire (ODQ), and acetaminophen use.

Results showed a clinically significant reduction on the NRS in the wet-cupping group (-16.0 points) compared with the control group (-9.1 points), although the between-group difference did not reach statistical significance (p=0.37). However, the PPI showed statistically significant differences (-1.2 vs -0.2, p<0.01), indicating substantial improvement in present pain. Acetaminophen use was notably lower in the treatment group (0.9 vs 5.7 tablets over 4 weeks, p=0.09). No procedure-related adverse events were reported.

The clinical implications suggest that wet-cupping may be a safe and potentially effective intervention for reducing present pain in patients with chronic low back pain. The study highlighted the importance of adequate sterilization protocols, contrasting with traditional practices that reuse equipment. Limitations include the small sample size, the absence of a sham group to control for placebo effects, and inconsistencies among different pain measures. The study calculated that 115 participants per group would be needed for a definitive clinical trial.