Flexion and extension of the vertebral column measured using MRI

The degree of mobility and flexibility of the vertebral column on a small sample 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 the spine, such as the kyphosis or lordosis, but did alter the relative positions of flexion or extension of adjacent vertebrae. Additionally, a pivot point along the vertebral column was demonstrated, centred on thoracic vertebral T6. This pivot point reflects the degrees of freedom of movement by the vertebrae within the vertebral column and might explain why scoliotic curves high in the thoracic region are uncommon.