There are several curves in the human back, and the location of each denotes a region of the spinal column. This includes the cervical, lumbar, sacral and thoracic areas. Individual spinal bones, or vertebrae, comprise each region. As such, the fifth lumbar spine vertebrae (L5) is part of the greater lumbar region, just above the sacral. To the human eye, this is the curve just above the buttocks, which is also commonly referred to as the small of the back. The fifth lumbar spine vertebrae (L5) is larger than its counterparts with the thoracic and cervical regions. The L5 is the lowest with the lumbar region, as it is the closest to the sacrum and the pelvis. Like other vertebrae, the L5's primarily protects the spinal column. This is the case for most individuals; however, there has been some anatomical variation that has occurred. Some people have been born without a L5, while others have been born with a sixth additional lumbar vertebrae. Common conditions affecting the L5 include spondylolysis.
Written and medically reviewed by the Healthline Editorial Team
In Depth: L5