Effects of Myofascial Chain-Based Radial Extracorporeal Shock Wave Therapy in Chronic Non-Specific Low Back Pain: A Randomized Controlled Trial

Background: Chronic non-specific low back pain (NSLBP) is a leading cause of disability worldwide. While radial extracorporeal shock wave therapy (rESWT) is commonly utilized, conventional protocols primarily target localized pain sites and may overlook global myofascial dysfunction. This study compared the clinical effectiveness of myofascial chain-based rESWT with conventional localized rESWT in patients with chronic NSLBP receiving standardized conservative therapy. Methods: In this prospective, assessor- and participant-blinded randomized controlled trial, 30 adults with chronic NSLBP were randomly assigned (1:1) to either a myofascial chain-based rESWT group (n = 15) or a localized rESWT group (n = 15). Both groups received four weekly sessions of active rESWT (3000 pulses/session) combined with identical physical therapy and home-based stabilization exercises. Primary outcomes were pain intensity (10-cm Visual Analog Scale, VAS) and functional disability (Oswestry Disability Index, ODI, 0–50 scale). The secondary outcome was lumbar flexion excursion assessed by the Modified Schober Test (MST). Assessments occurred at baseline (Week 0), immediately post-treatment (Week 5), and at 8-, 12-, and 16-week follow-ups, with the 16-week follow-up designated as the primary trial endpoint. Analyses were conducted based on the intention-to-treat (ITT) principle using repeated-measures ANOVA and ANCOVA. Results: All 30 participants were included in the primary ITT analysis. Both groups showed significant improvements over time across all outcomes (p < 0.001). Significant Group × Time interaction effects favored the myofascial chain group for VAS (F = 20.31, p < 0.001, ηp2 = 0.42) and ODI (F = 16.68, p < 0.001, ηp2 = 0.37). At the primary 16-week endpoint, repeated-measures model contrasts favored the myofascial chain group for VAS (mean difference: −0.65, 95% CI [−1.31 to 0.02], p = 0.057) and ODI (mean difference: −3.20, 95% CI [−5.62 to −0.78]). For lumbar mobility, ANCOVA adjusting for baseline imbalance demonstrated greater improvement in the myofascial chain group at 3 months (F = 5.54, p = 0.026, ηp2 = 0.170; adjusted mean difference: 0.19 cm, 95% CI [0.03 to 0.36]). Symptom recurrence did not significantly differ between groups (6.7% vs. 13.3%, p = 1.00). Expected mild procedure-related soreness and erythema were observed, but no severe treatment-related adverse events occurred. Conclusions: When added to standard rehabilitation, myofascial chain-based rESWT yielded greater reductions in pain and disability and better restoration of lumbar mobility than localized rESWT. Trial registration: Clinical Research Information Service (CRIS, KCT0011599; retrospectively registered on 13 February 2026). However, worst-case sensitivity analyses indicated that superiority at the 16-week endpoint was sensitive to missing data assumptions among participants who experienced recurrence. Therefore, these comparative findings should be interpreted cautiously as exploratory, and larger multicenter trials with higher retention rates are required to definitively establish long-term superiority.