Neuromuscular effects of warm needle acupuncture versus mild moxibustion in knee osteoarthritis: An active-controlled randomized trial

Background: Knee osteoarthritis (KOA) is associated with neuromuscular dysfunction and impaired quadriceps activation. This study compared the short-term neuromuscular effects of warm needle acupuncture (WNA) and mild moxibustion (MM). Methods: In this single-center, assessor- and statistician-blinded randomized controlled trial, 60 patients with KOA were randomized 1:1 to WNA or MM for 4 weeks. Thirty healthy participants provided an exploratory physiological reference at baseline. Co-primary outcomes were isokinetic quadriceps peak torque (PT) and average power (AP). Secondary outcomes included VAS, WOMAC, thigh circumference asymmetry, and surface electromyography (sEMG). Between-group effects were assessed using baseline-adjusted ANCOVA. Results: At week 4, WNA showed greater baseline-adjusted improvements than MM in PT (adjusted difference 18.38 N·m, 95% CI 11.69–25.06; Holm-adjusted p<0.001) and AP (10.45 W, 95% CI 6.61–14.29; Holm-adjusted p<0.001). VAS and WOMAC also favored WNA, whereas thigh circumference asymmetry was not significantly different. Selected absolute sEMG parameters differed between groups. Credibility and expectancy were comparable, and no serious adverse events occurred. Conclusions: WNA was associated with greater short-term improvements than MM in quadriceps strength, pain, and function. These findings support comparative effectiveness of WNA versus MM but do not isolate thermal-specific, placebo-specific, or expectancy-independent effects. Trial registration: ITMCTR2025001238; registered on 16 May 2025 after completion of participant recruitment and follow-up (late/retrospective registration).