A consequence of a novel slip perturbation on spinal kinematics and reaction time in subjects with and without chronic low back pain.

Trunk reaction time and three-dimensional trunk-hip motions were compared between subjects with and without chronic low back pain (LBP). The control group demonstrated greater trunk flexion; however, the LBP group reduced trunk flexion to protect against further injuries following the novelty of the slip perturbation. Although trunk reaction time was not significantly different between groups, the hip flexion changes were significantly different following the perturbation. The negative correlation between reaction time and trunk flexion in the chronic LBP group was related to a compensatory pattern. A compensatory strategy to improve trunk flexibility might be necessary to enhance postural control in individuals with LBP.