Effect of the Severity and the Treatment (Orthosis Versus Surgery)of the Idiopathic Scoliosis on the Locomotor Mechanism of the Gait.

Introduction X-ray studies and three-dimensional analysis in standing showed that this Adolescent Idiopathic Scoliosis was characterised by stiffness of the affected vertebral levels [3, 7, 10] with decreased segmental mobilities. The impact of this stiffness was studied during functional activity such as walking to quantify the functional dynamic consequences. During gait, thoracic AIS provided an asymmetrical trunk rotation with a lack of rotation on the convex side [8] and an excessive paravertebral muscular bilateral activity [11]. These studies included only moderate scoliosis. There were no studies approaching the effects of the severity of the scoliosis curves on gait parameters.

We hypothesize first that, the spinal deformations in AIS, producing a stiffness of the trunk, pelvic and hip motions, will deteriorate the gait by reducing the segmental mobilities, increasing the mechanical work and the energy cost and second that the severity of the frontal curves will be more damaging on this parameters. To this end, we hope to gain valuable insight as to the functional effects of the scoliosis aggravation from a more dynamic perspective.

Material Fifty-four female adolescents will be included in the study. This sample consists in two groups: healthy girls and girls with adolescent idiopathic scoliosis (divided in 3 subgroups according to the Cobb angle range) [9].

A standard full spine XRay assessment will be performed to measure the Cobb angle curve, the frontal body balance, the apical vertebral rotation [13].

Gait will be assessed by a three-dimensional analysis, including synchronous kinematic [4], electromyographic (EMG) [14], mechanic [5, 6, 15] and energetic measurements [1, 2, 12].