Thermographic outcomes of auricular laser acupuncture and auricular seed acupressure in older adults with chronic shoulder pain: an exploratory nonrandomized, nonconcurrent comparison

Purpose: Compare pain, quality of life, and cutaneous temperature changes within predefined anterior, lateral, and posterior shoulder regions of interest between auricular laser acupuncture and seed acupressure in older adults with chronic shoulder pain. Methods: This exploratory, nonrandomized, open-label study enrolled 20 adults aged 60–90 years, allocated by order of entry to consecutive, nonconcurrent cohorts of auricular laser acupuncture (n = 10) or seed acupressure (n = 10), treated twice weekly for five weeks. VAS, McGill, SF-36, and thermography were assessed before the first (A1) and fifth sessions (A2) and after the tenth (A3) and analyzed using linear mixed-effects models. Results: From A1 to A3, VAS decreased by − 2.70 points in Laser (95% CI − 4.37 to − 1.03) and − 2.50 in Seed (95% CI − 4.17 to − 0.83); the between-group difference was − 0.20 points (Laser − Seed; 95% CI − 2.54 to 2.14). Selected McGill and SF-36 outcomes changed; McGill affective A1-to-A2 change differed between groups (Laser − Seed: −2.70; 95% CI − 4.86 to − 0.55; p = 0.017). Anterior thermal range (ΔT) showed a TIME × GROUP interaction (p = 0.007); the A1-to-A3 between-group difference was − 1.941 °C (Seed − Laser; 95% CI − 3.097 to − 0.785), although Seed ΔT was higher at baseline (+ 1.496 °C; 95% CI 0.607 to 2.385). Lateral ΔT showed a TIME effect (p = 0.033); posterior ΔT showed none. Conclusion: Clinical outcomes improved over time without evidence of differential changes between interventions. Thermography identified region-specific ΔT trajectories, warranting further investigation as a complementary method. Clinical trial registration: ClinicalTrials.gov NCT07010627.