Leg-length inequality has poor correlation with lumbar scoliosis. A radiological study of 100 patients with chronic low-back pain.

Leg-length inequality and its hypothetical consequences, pelvic tilt and lumbar scoliosis, were measured in 100 young or middle-aged adults suffering from chronic low-back pain. Leg-length inequality had a good correlation with the pelvic tilt assessed from the iliac crests, a moderate correlation with the sacral tilt, but a poor correlation with the lumbar scoliosis. The sacral tilt correlated well with the lumbar scoliosis when the tilt was more than 3 degrees but poorly when it was smaller. Thus, there is a gradually decreasing correlation between the posture parameters when moving from the hips up to the lumbar spine. We conclude that before a radiologically observed leg-length inequality be considered as the cause of low-back pain, an erect-posture radiograph of the whole pelvis and lumbar spine is essential, in order to assess an existing pelvic tilt and scoliosis.