Flexion and extension of the vertebral column measured using MRI

The degree of mobility and flexibility of the vertebral column on a small s ample of normal subjects in different positions of the head and lower limbs has been investigated using an MRI protocol. The results have demonstrated that flexion and extension had little effect on the normal curvatures of t he spine, such as the kyphosis or lordosis, but did alter the relative posi tions of flexion or extension of adjacent vertebrae. Additionally, a pivot point along the vertebral column was demonstrated, centred on thoracic vert ebral T6. This pivot point reflects the degrees of freedom of movement by t he vertebrae within the vertebral column and might explain why scoliotic cu rves high in the thoracic region are uncommon.