Characteristic dynamic differences between healthy and low back pain subjects

Study design: Open retrospective study. Objectives: To assess the functional capacity impairment of chronic low back pain (LBP) patients using characteristic dynamic changes. Setting: Orthopaedics and Physiotherapy departments at Tel-Aviv, Israel. Methods: Thirty-eight normal healthy volunteers and 607 chronic LBP patients were tested on a computerized 3-D lumbar dynamometer. The four major parameters measured were the maximal isometric torque (MIT), maximal velocity against 25% MIT and 50% MIT (MV₂₅, MV₅₀, respectively) and maximal torques in secondary axes (MST). All patients parameters were compared to the normal, healthy findings. Results: All four parameters were found to be significantly different between healthy (or non-symptomatic) and symptomatic LBP subjects. Conclusions: The findings support the use of 3-D dynamometry and the four parameters mentioned to objectively classify patients with functional disability.