A NOVEL APPROACH TO THE ASSESSMENT OF ADOLESCENT IDIOPATHIC SCOLIOSIS

Abstract

Objective: To establish a relationship between the scoliotic curve and the centre of gravity during level walking in patients diagnosed with adolescent idiopathic scoliosis.

Background data: There is no established aetiology for adolescent idiopathic scoliosis and the reasons for the progression of the curve are still unknown. But there is an agreement regarding multifactorial nature of the aetiology among many authors. One of the interesting factors suggested is asymmetry in the ground reaction forces during walking and their relation to the deformity, indicated by gait analysis studies. Studies have also indicated that the cause and progression of the deformity in idiopathic scoliosis may be due to kinematic differences in the spine, pelvis and lower limb. If a relation could be established between the scoliotic curve and the centre of gravity, it is possible to draw some conclusions regarding the aetiology. There is no method or study till date which looked at the relation of scoliotic curve with the centre of gravity.

Materials and Methods: Patients who were diagnosed with adolescent idiopathic scoliosis were selected. Informed consent was taken for gait analysis. 16 Markers were placed over the lower limb and force plate, using modified Helen Hays set. 5 markers were placed over the surface landmarks of selected spinous processes (C7, T6, T12, L3 and S2). Ground reaction forces and motion data were analysed, using APAS gait system and the lines of vectors were developed and correlated with the marker over the second sacral spinous process.

Results: With the help of this method we were able to establish a relationship between the scoliotic curve and centre of gravity line. These in turn were expressed in terms of changes in the moment in relation to the midline of the coronal plane. The results indicated that the changes were proportional to the severity of the scoliotic curve.

Conclusion: We present a new method of establishing the relation of scoliotic curve with the ground reaction force and the centre of gravity. Initial results obtained from this method indicate the asymmetries in the deviation of the centre of gravity line in relation to the curve, during walking. Ongoing studies based on this method, will help to understand the pathogenesis and aetiology of scoliosis on a biomechanical basis which can help in developing new treatment modalities and efficient management of these patients.