3D EXPERIMENTAL EVALUATION OF GLOBAL POST URE AND MOTION OF THE SPINE

Purpose The aim of his study was to assess 3D global posture and movem ent of body segments, especially for scoliotic subjects. As scoliosis is a three-dimensional deformity, it needs three-dimensional evaluatio n and correction, but there is no mean today to get 3D dynamic examina tion of the whole body. Material and methods Using opto-electronic met hods, an experimental protocol was established to compare the pre-and post-operative results of treatment. Firstly, the reliability of the p rotocol was tested in healthy adult subject. Secondly, a reference gro up of 15 healthy teenagers was analysed Besides, first scoliotic subje ct in pre-and post-operative situations were followed. The markers fix ed on the skin allowed us to calculate the position of the head, the p elvic, the shoulders and the spinal axis, during a static trial and mo tions. Results The reliability of the protocol was satisfactory (stand ard deviation (s)<5.4 degrees in a flexion movement). The intersubject variability was greater for the position of the head than for the pel vis, the shoulders or the spinal axis. The scoliotic patient showed a straightening of the whole body in the three anatomic planes. One mont h after treatment, the range of motion were reduced (+13.8 degrees for the pelvic flexion during a flexion movement), but six months after s urgery they were greater than before (+14.7 degrees). Conclusion - dis cussion Many systems have been proposed to measure the motion of the t runk, but they were not three-dimensional. The opto-electronic method is a non invasive, external and dynamic system.