Although injuries to the lumbar spine, including L4 and L5, are severe, they alone are not typically life-threatening, however other injuries or complications caused by the traumatic event certainly can be. The lumbar spine, which is located below the cervical and thoracic sections, consists of five vertebrae that control areas that include the hips and groin, and sometimes also the lower abdominal muscles and thigh flexion as well. As with other spinal cord injuries, the completeness of the injury — whether the spinal cord is partially severed (incomplete) or completely severed (complete) — will determine the true severity of the injury and its resulting symptoms.