The following exclusion criteria were used: developmental abnormalities, including cretinism, dwarfism, and gigantism; vertebral abnormalities, including lumbar sacralization, sacral lumbarization, hemivertebrae, wedged vertebrae, butterfly vertebrae, vertebral fusion, scoliosis, lordosis, kyphosis, and spinal bifida; and a history of lumbar surgery.
Source: wiktionary