This 23-year-old woman was asymptomatic until several weeks before this examination. She complained of slight stiffness in the neck and even lesser stiffness in the thoracic region. As a child she fell from a horse, was sore for a few days and was not radiographed. There is no other history of any significance. A lateral film of the cervical region is shown. Another lateral film in flexion showed a good range of movement. Lateral films of the thoracic and lumbar areas showed slight smooth concavity of the anterior borders of many of the vertebral bodies but no other abnormality was identified. Films of the sacroiliac joints were not available but the patient was able to bend normally in the lumbar and hip areas clinically. There are no stigmata of developmental generalized disease. The following tests were normal/negative: full blood count, ESR, "biochemical profile" and rheumatoid agglutination tests.