Trunk�pelvis kinematics variability during gait and its association with trunk muscle endurance in patients with chronic low back pain

The first purpose was to investigate the trunk muscle endurance, the second aim was to evaluate the trunk�pelvis kinematics during gait, and the third was to evaluate the relationship between trunk�pelvis kinematics and the trunk muscle endurance. Thirty participants (15 nonspecific chronic low back pain NCLBP and 15 healthy) were included. The authors first assessed trunk muscle endurance on endurance testing protocols. The authors next measured the trunk�pelvis kinematics during gait using a 3-dimensional motion capture system. Angular displacement, waveform pattern (CVp), and offset variability (CVo) were also examined. Statistical analysis revealed a significant difference in (1) the trunk muscle endurance and (2) sagittal, frontal, and transverse planes CVp between groups (P < .05). A significant moderate correlation was found between supine double straight-leg raise and frontal CVp (r = .521, P = .03) and transverse planes CVp (r = .442, P = .05). However, a significant moderate correlation was observed between prone double straight-leg raise and sagittal plane CVp (r = .528, P = .03) and transverse plane CVp (r = .678, P = .001). The relationship between (1) lower trunk extensor endurance with transverse and sagittal planes CVp and (2) lower abdominal muscle endurance with transverse and frontal planes CVp suggests that gait variability in these planes may result because of trunk muscle deconditioning accompanying NCLBP. © 2020 Human Kinetics, Inc