Increases in trunk velocity during lifting are associated with improvements in disability and self-efficacy in people with chronic low back pain during cognitive functional therapy: a longitudinal analysis of the RESTORE trial

Abstract

Objectives Lifting is a common self-reported aggravating factor associated with individuals experiencing low back pain (LBP). However, there is a paucity of longitudinal studies with multiple measures on lifting spinal kinematics, pain, disability and pain-related cognitions. This study investigated the relationship between changes in these factors in people with lifting-related chronic LBP undergoing cognitive functional therapy (CFT). Methods 141 people with chronic LBP aggravated by lifting received a course of CFT over 13 weeks (average 4.8 sessions) and performed the same lifting task before each treatment session. Measures included range of motion (ROM) and velocity from trunk and pelvis inertial measurement units independently and the relative angle between units (lumbar angle). Participants reported (1) average pain intensity, (2) pain-related disability and (3) pain-related cognitions (pain catastrophising and pain self-efficacy) via online questionnaires at baseline, 3, 6 and 13 weeks. Multivariate multilevel models evaluated associations between individual rates of changes over time for three selected kinematic measures (trunk velocity, trunk ROM or lumbar ROM) with pain, disability, pain catastrophising and pain self-efficacy. Results Increased trunk velocity showed potentially large correlations with reduced disability (r=-0.60, 95% CI: -0.90, 0.09) and improved pain self-efficacy (r=0.64, 95% CI: -0.17, 0.93) over time, although there was statistical uncertainty for these estimates. Conclusions In people with lifting-related LBP undergoing CFT, increased trunk velocity during lifting showed potentially large correlations with reductions in disability and improvements in pain self-efficacy. These findings highlight the potential clinical importance of trunk velocity as both a monitoring measure and treatment target.