When we find out that our friend has scoliosis, we can self-judge the angle and severity of the scoliosis before going to the hospital, so how should we measure the angle of scoliosis more accurately? The following is a common measurement method used by spine surgeons: Cobb’s measurement. The severity of scoliosis is most often assessed by measuring the angle of lateral bending, which is most often done using Cobb’s angle measurement. The radiograph used for this measurement is an orthogonal image of the standard full length of the spine. First we identify the end vertebrae of the lateral bend. The superior and inferior end vertebrae are the vertebrae in the scoliosis that are most inclined to the concave side of the scoliosis (T12 is the superior end vertebrae and L4 is the inferior end vertebrae in the figure below). The vertebral space on the convex side of the scoliosis is wider, and the first vertebra on the concave side where the vertebral space begins to widen is not considered to be part of that curve, so its adjacent vertebra is considered to be the terminal vertebra of that curve. Step 2 A horizontal line is drawn at the upper edge of the vertebral body of the upper end vertebra and similarly at the lower edge of the vertebral body of the lower end vertebra. A perpendicular line is made for each of these two lines. Step 3 The angle of intersection of the two perpendicular lines is the Cobb angle. Note: For larger scoliosis, the direct angle of intersection of the two horizontal lines above is also equivalent to the Cobb angle. This is how the angle of the side bend is measured. Full length measurement diagram