The Effectiveness of Cervical Spine and Diaphragm Manual Therapy Combined with Breathing Re-Education Exercises on Musculoskeletal, Respiratory and Psychophysiological Outcomes in Patients with Non-Specific Chronic Neck Pain: A Randomized Controlled Trial

Background/Objectives: Dysfunctional breathing interacts with common impairments in patients with non-specific chronic neck pain. This study aimed to assess the effect of combining manual therapy with breathing re-education. Methods: A randomized controlled trial with concealed allocation and intention-to-treat analysis, including ninety patients with non-specific chronic neck pain, was employed. Participants were allocated to undertake 10 sessions of either cervical spine and diaphragmatic MT (specifically, Mulligan concept techniques and diaphragmatic doming/release) combined with breathing re-education (experimental group 1, EG1) or cervical spine MT alongside sham diaphragmatic MT (experimental group 2, EG2) or conventional physiotherapy (control group—CG). Interventions lasted 1 month. Primary outcomes were the pain intensity assessed on a 0-to-10 numeric rating scale and the Neck Disability Index percentage. Data were collected at baseline, 1 month, and 4 months post randomization. Results: Pain intensity improved more in the EG1 compared to the CG (mean difference −2.15, 95% CI −2.50 to −1.79) and to a lesser extent relative to the EG2 (mean difference −0.42, 95% CI −0.78 to −0.07) at 1 month. Neck disability equally improved in the EG1 (mean difference −14.72, 95% CI −17.55 to −11.89) and the EG2 (mean difference −13.06, 95% CI −15.93 to −10.19) compared to the CG at 1 month. All significant differences for pain and disability noted at one month remained significant at 4 months. EG1 significantly improved in all respiratory-related secondary outcomes compared to EG2 and the CG, both at 1 and 4 months. Conclusions: Combining diaphragm manual therapy with breathing re-education led to superior improvements in pain and dysfunctional breathing-related outcomes. Trial Registration: NCT05229393.