Many studies are in favour of the importance of the rachis on the postural balance of the body.It is possible to study the upright posture by determining the center of pressure using a platform of strength.The spinal surgery have two objectives ,mechanic and neurologic .By deformation correction and stabilizing vertebral stages via arthrodesis, it seems to hypothesize that surgery can modify postural balance.

This study aim to evaluate spinal surgery effect on posture using that plaftorm .

At the inclusion, Day 1 and day 2 after surgery, the patient will stand on the stabilometric platform, with arms extended along the body, barefoot at 30 ° with a 2 cm gap at the heels.

He will fix a target located 1 meter away from him, in silence and will be instructed to "stand as still as possible, with his arms along his body, look in the direction of the visual target, do not think about anything. ". Then there will be a collection of data in 3 shots of 90 seconds, with a rest period between each shot, using the Winposture® software. The patient will answer health related quality of life questionnaires.

6 months after inclusion, patients will answer health related quality of life questionnaires.

Inclusion Criteria:

• Age> 18 years old
• Patient programmed for spinal surgery
• Patient accepting participation

Exclusion Criteria:

• Refusal of participation
• All patient with vestibular disease
• All patient with neurologic disease
• Patient with pathologies not allowing to maintain the prolonged standing.