Relationships between changes in forward bending, pain catastrophizing, and pain self-efficacy during cognitive functional therapy for people with chronic low back pain

OBJECTIVE: To investigate whether improvements in forward bending were related to reductions in pain catastrophizing (PC) and improvements in pain self-efficacy (PSE) in people with chronic low back pain (CLBP) who were undergoing cognitive functional therapy (CFT). DESIGN: Longitudinal observational study. METHODS: Two hundred sixty-one participants with CLBP received CFT. Forward bending was assessed at each treatment session over 13 weeks (average of 4.3 time points per participant [range, 1-8]). Inertial measurement units placed on T12 and S2 measured spinal range of movement (ROM) and velocity. Participants completed the Pain Catastrophizing Scale and the Pain Self-Efficacy Questionnaire online at 0, 3, 6, and 13 weeks. Multivariate, multilevel models evaluated the associations between individual rates of change over time for 3 spinal movement measures (trunk velocity, trunk ROM, and lumbar ROM) as well as PC/PSE. RESULTS: Strong correlations were observed for increased trunk velocity with reduced PC (r = -0.56; 95% confidence interval [CI]: -0.82, -0.01) and increased PSE (r = 0.63; 95% CI: 0.18, 0.87). There was no evidence of an association between changes in trunk ROM and PC (r = -0.06; 95% CI: 0.38, 0.28) or PSE (r = 0.36; 95% CI: -0.27, 0.65) as well as no evidence of an association between lumbar ROM and PC (r = -0.07; 95% CI: -0.63, 0.55) or PSE (r = 0.16; 95% CI: -0.49, 0.69). CONCLUSION: Improvements in PC and PSE were strongly correlated with increased trunk velocity-but not trunk or lumbar ROM-in people with CLBP who were undergoing CFT. These findings are consistent with CFT that explicitly trains "nonprotective" spinal movement in conjunction with positively reframing pain cognitions.