Functions of The Lower Back
The low back, or lumbar area, serves a number of important functions for the human body. These functions include structural support, movement, and protection of certain body tissues.
When we stand, the lower back is functioning to support the weight of the upper body. When we bend, extend, or rotate at the waist, the lower back is involved in the movement. Therefore, injury to the structures important for weight bearing, such as the bony spine, muscles, tendons, and ligaments, often can be detected when the body is standing erect or used in various movements.
Protecting the soft tissues of the nervous system and spinal cord as well as nearby organs of the pelvis and abdomen is a critical function the lumbar spine and its adjacent muscles.
Lower Back Motion and Back Pain
Fifty percent of flexion (bending forward) occurs at the hips, and fifty percent occurs at the lumbar spine (lower back). The motion is divided between the five motion segments in the lower back, although a disproportionate amount of the motion is at L4-L5 (lumbar segment 4 and 5) and L3-L4 (lumbar segment 3 and 4).
Consequently, these two segments of the lower back are the most likely to break down with degeneration. As these segments break down they can become unstable with an excess of motion creating lower back pain. There are a number of non-surgical treatments available to help manage the low back pain, and a surgical fusion can help alleviate the back pain by stopping the motion.