Effect of Posterior-Anterior Mobilization of the Thoracic Spine on Pain, Respiratory Function, and Thoracic Circumference in Patients With Chronic Low Back Pain

Background: Posterior-anterior (PA) vertebral mobilization, a manual therapy technique has been used for relieving pain or stiffness treating in spinal segment for in clinical practice, however evidence to gauge efficacy is yet to be synthesised. Objects: This study aimed to investigate the effect of PA mobilization of the thoracic spine on the respiratory function in patients with low back pain (LBP). Methods: The study participants included 30 patients with chronic LBP. They were randomly allocated to the experimental and control groups. The experimental and control groups received PA mobilization of the T1-T8 level of the thoracic spine and placebo mobilization, respectively. All patients received interventions for 35 minutes a day, five times a week, over 2-week period, respectively. Forced vital capacity (FVC), forced expiratory volume in 1 second ($FEV_1$), peak expiratory flow (PEF), forced expiratory flow 25~75% ($FEF_{25{\sim}75%}$), and chest wall expansion were measured before and after the intervention. Statistical analysis was performed using independent t-test and two-way analysis of variance, and Pearson's correlation analysis was used to compare the correlation between respiratory function and chest measurement. Results: The experimental group showed significant improvements in FVC, $FEV_1$, PEF, $FEF_{25{\sim}75%}$ (p<.05), and chest wall expansion (p<.05) compared with the control group. Conclusion: PA mobilization of the upper thoracic spine may be beneficial for improving respiratory function parameters including FVC, $FEV_1$, PEF, $FEF_{25{\sim}75%}$, and chest wall expansion in patients with chronic LBP.