The results of a morphometric study of selected human vertebrae undertaken to provide data for implant design are presented in this report. Twenty-seven dimensions were measured from thoracic (T2, T7, T12) and lumbar (L1-L5) vertebrae using prepared spinal columns from 30 skeletons belonging to the Hamann-Todd Osteological Collection. Maximum and minimum pedicle dimensions indicated that the pedicles are less symmetric cephalad than they are caudal. Vertebral body height increases caudally except posteriorly where, after an initial increase, it decreases in the lower lumbar region. Major and minor body diameters and the major spinal canal diameter slightly increase caudally, whereas minor spinal canal diameter exhibits little or no change.
If foraminal stenosis creates pressure on the spinal cord or a spinal nerve root, a variety of symptoms can develop, including pain, numbness, tingling, muscle weakness and spasms. The nature and location of the symptoms vary based on the site of the affected foramen. More specifically, the symptoms can be localized or they may travel through the peripheral nervous system and radiate along the path of an affected nerve root. For instance, foraminal stenosis in the cervical spine can lead to symptoms in the neck, shoulders, arms and hands; nerve compression in the lumbar spine can cause symptoms in the lower back, hips, buttocks, legs and feet.
African apes have three and four lumbar vertebrae, ( bonobos have longer spines with an additional vertebra) and humans normally five. This difference, and because the lumbar spines of the extinct Nacholapithecus (a Miocene hominoid with six lumbar vertebrae and no tail) are similar to those of early Australopithecus and early Homo , it is assumed that the Chimpanzee-human last common ancestor also had a long vertebral column with a long lumbar region and that the reduction in the number of lumbar vertebrae evolved independently in each ape clade .  The limited number of lumbar vertebrae in chimpanzees and gorillas result in an inability to lordose (curve) their lumbar spines, in contrast to the spines of Old World monkeys and Nacholapithecus and Proconsul , which suggests that the last common ancestor was not "short-backed" as previously believed.