About the lumbar spine
The lumbar spine is the lower back. It is made up of five or six vertebrae, depending on the individual. (The extra bone does not make a difference to one's health.) The vertebrae in the lumbar spine area are the largest of the entire spine.
Approximately half of the ability to bend forward comes from the hips, while the rest comes from the lower back.
Because the lower back has a more motion than the thoracic spine and carries all the weight of the upper body, it is more commonly affected by degenerative disc disease or injuries.
The lower back is divided among five motion segments. These are the segments most likely to break down from wear and tear. They are prone to developing conditions, such as osteoarthritis and degenerative disc disease.
The lowest discs (L4-L5 and L5-S1) take a great deal of strain because of their location and the greater weight they support. They more commonly develop herniated, bulging or ruptured discs.