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.