Differences of Spinal Curvature, Thoracic Mobility, and Respiratory Strength Between Chronic Neck Pain Patients and People Without Cervical Pain

OBJECTIVE: To investigate the differences of spinal curvature, thoracic sagittal mobility, and respiratory strength between patients with chronic neck pain (CNP) and people without cervical pain, and to determine the correlation between respiratory strength and thoracic mobility in CNP patients. METHODS: A total of 78 participants were finally included in this study, of whom 30 had no cervical pain and 48 had CNP. The Neck Disability Index (NDI), cervical lordotic curvature, thoracic kyphotic curvature, thoracic sagittal range of motion (ROM), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were measured and analyzed. RESULTS: In males, thoracic sagittal ROM(MEP-MIP) and MEP showed a significant difference between the no cervical pain group and the CNP group. In females, thoracic kyphotic curvature, thoracic sagittal ROM(MEP-MIP), MIP, and MEP were significantly different between the no cervical pain group and the CNP group. Thoracic kyphotic curvature was significantly correlated with MEP and MIP in all population groups, and significantly correlated with NDI in the female group. Thoracic sagittal ROM(MEP-MIP) had a significant linear relationship with NDI, MEP, and MIP in all population groups. CONCLUSION: The thoracic mobility during forced respiration was reduced in patients with CNP and was correlated with respiratory strength. Changes in the biomechanics of the cervicothoracic spine and rib cage due to CNP may contribute to impairment of respiratory strength.