Assessment of the Evolution of Lumbar Spine Movement Fluidity Using Xsens Inertial Sensors in Subjects With Chronic Low Back Pain Before and After Rehabilitation

Low back pain, defined as pain located between the thoracolumbar junction and the lower gluteal fold, becomes chronic in 8% of patients. As the leading cause of disability worldwide, it has major individual and medico-economic consequences. Three-dimensional biomechanical analysis allows exploration of movement alterations related to low back pain. Although several parameters have already been studied (maximum joint range of motion (ROM), lumbopelvic rhythm, movement variability, gait), no consistent kinematic profile has emerged. Movement fluidity, assessed by the presence of jerks (brief movement disturbances), remains under-described despite its relevance in evaluating movement quality. Invistigators hypothesize that lumbar spine movement fluidity during flexion improves after a rehabilitation program and correlates with clinical response. This project stands out by exploring a rarely studied parameter (movement fluidity) and integrating it as a potential indicator for rehabilitation monitoring.