An 11-year-old high-level competitive female gymnast presented with back pain. Approximately 10 months earlier, she experienced acute pain in the (thoracic-lumbar) mid-spine during a training camp, on the uneven bar. She reported no acute trauma. The pain was located at the paravertebral right side and was provoked by rotation movements to the right. Night-time pain existed. She went to a physiotherapist, who at physical examination found a movement with typical local fixation in the spine (paradox movement). There were no neurological symptoms. The pain was mainly felt when her posture changed from anterior flexion to extension of the spine and with rotation to the right. At this first presentation of symptoms, she trained 20 h a week. Although physiotherapy, manual therapy and a period of rest slightly improved the situation, a setback occurred after another intensive training camp, now with continuous pain, increasing during jumping (like dismounts from the gymnastics apparatus) and running. On examination, there was a painful right straight leg raise without neurological symptoms. There was painful limited range of motion during extension of the spine; anterior flexion was only slightly painful. The pain was again located on the right side (paravertebral) and on palpation of the vertebra in the proximal lumbar spine. The patient was first referred for conventional radiography (figure 1) and 1 month later for MRI of the lumbar spine (figures 2 and 3).