They are the largest segments of the vertebral column and are characterized by the absence of the foramen transversarium within the transverse process (since it is only found in the cervical region) and by the absence of facets on the sides of the body (as found only in the thoracic region).

[1] The spinous process is thick, broad, and somewhat quadrilateral; it projects backward and ends in a rough, uneven border, thickest below where it is occasionally notched.

[1] The superior and inferior articular processes are well-defined, projecting respectively upward and downward from the junctions of pedicles and laminae.

The facets on the superior processes are concave, and look backward and medialward; those on the inferior are convex, and are directed forward and lateralward.

The mammillary is connected in the lumbar region with the back part of the superior articular process.

They include fundus of the gall bladder, celiac trunk, superior mesenteric artery, termination of spinal cord, beginning of filum terminale, renal vessels, middle suprarenal arteries, and hila of kidneys.

Furthermore, flexion and extension in the lumbal spine is the product of a combination of rotation and translation in the sagittal plane between each vertebra.

[4] Ranges of segmental movements in the lumbar spine (White and Punjabi, 1990) are (in degrees): [5] Congenital vertebral anomalies can cause compression of the spinal cord by deforming the vertebral canal or causing instability.

[6] 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.

[7] This article incorporates text in the public domain from page 104 of the 20th edition of Gray's Anatomy (1918)