How does AS affect the spine?
AS is mainly associated with the spine. The spine is made up of 33 bones known as vertebrae and can be divided into three sections; the cervical, thoracic and lumbar regions.
When someone develops AS, ligaments or tendons which are connected to bones become inflamed (swollen). This inflammation usually begins at the base of the spine in the sacroiliac joint (found between the sides of the sacrum and the rest of the pelvis), and is known as sacroiliitis.
This inflammation of the ligaments or tendons can begin to wear away the nearby bone. Once the inflammation goes down, abnormal new bone can develop where the original bone was worn away. This means joints can become fused together and become less flexible.
Further information
For further information about AS, please visit the National Ankylosing Spondylitis Society (NASS)