Comparison of spinal range of motion during flexion-extension using a three-dimensional opto-electronic system in healthy volunteers and patients with chronic low back pain

Spinal flexion-extension was kinematically analyzed by a motion analysis system (ELITE). 21 asymptomatic subjects (10 women and 11 men), and 17 patients with chronic low back pain (9 women and 8 men) were evaluated. None of them had pain on the day of the examination. The ELITE system on-line computed the trajectories of 5 reflective spinal markers. We evaluated the variations of the dorsal and lumbar angles in the sagittal plane. Patients with chronic low back pain were found to have dorsal rigidity, and to lack lumbar spine convexity at the end of flexion.