Lumbar Spine

Have you ever asked, "Why do so many people suffer from low back pain?" The answer involves a brief overview of the lumbar spine. Although the entire spine is involved in everyday activities of rest and movement, the low back can be vulnerable to many pain-provoking disorders. Simple sprains and strains from overexertion, a herniated disc from a slip and fall, degenerative disc disease or spinal stenosis from normal aging, and other disorders can cause low back pain. To help you understand back pain, the following brief and illustrated anatomy lesson is provided.

What is the Lumbar Spine?
The lumbar spine - or low back - is the third major region of the spine (Figure 1). Most people have five bones or vertebrae in the lumbar spine, although it is not unusual to have six. Each vertebra is stacked on top of the other and between each vertebra is a gel-like cushion called a disc (intervertebral disc). The discs help to absorb pressure, distribute stress, and keep the vertebrae from grinding against each other.

Figure 1. Spinal Column

Ligaments, Tendons
The vertebrae and discs are held together by groups of ligaments (Figure 2). Ligaments connect bone to bone, where as tendons connect muscle to bone. In the spine, tendons connect muscles to the vertebrae. The ligaments and tendons help to stabilize the spine and guard against excessive movement in any one direction.

Figure 2. Spinal Ligaments

Spinal Joints
The spine also has joints - similar to knees, elbows, and other joints. The spinal joints are called facet joints (Figure 3). The facet joints have been described as finger-like and link the vertebrae together. The facet joints are located at the posterior area of the spinal column. In addition, the facet joints help to make the spine flexible.

Figure 3. Spinal Facet Joints

Nerve Center
In the center of the spinal column is a vertical hole called the spinal canal; it contains the spinal cord. The bones that create the spinal canal serve as armor to help protect the spinal cord from injury. Small nerve roots branch off from the spinal cord through spaces on between each vertebra and extend out into the entire body (Figure 4). The spinal cord and the nerves are part of the central nervous system that includes the brain. The nerves are the body's neural message system.

Figure 4. Spinal Nerve Structures

To learn more about disorders that affect the lumbar spine, you are invited to click on any of the links below.