The goal of this interventionnal study is to learn if teenagers who have severe scoliosis (a curvature of the spine) have trouble sensing their body's position in space (this sense is called proprioception), which are directly linked to abnormalities in the part of the brain that controls movement and/or caused by the muscles on each side of the spine not being the same size or not developing in the same way.
The main question the investigators aim to answer are :
* Do adolescents with severe scoliosis have problems with their sense of body position (proprioception)?
* If so, are these proprioceptive issues linked to specific problems in the part of the brain that controls movement?
* Are these proprioceptive issues also possibly linked to an uneven muscle structure on either side of the spinal curve?
Researchers will compare the part of the brain that controls movement (ensorimotor brain network) of healthy subjects to that of the participants that will enroll in this study.
Participants will only have to do one more MRI that is not included in the routine of clinical management of scoliosis before surgery.
Data will also be retrieved from clinical practice Participants will answer questionnaires after the day of the surgery