Low Back Pain

The low back is the region of the body situated above the pelvis and the hips. This part of the body is also known as the lumbar region. The skeletal support for the low back is provided by the lumbar spine, the assembly of five vertebrae that are connected to the pelvis by the bony structure known as the sacrum. The lumbar vertebrae are each separated by intravertebral disks, which are composed of a fibrous material, in which a thick gel material is enclosed. The disks act to absorb the forces received by the vertebrae, as well as working to stabilize the lumbar spinal column.

The lumbar spinal column encloses the spinal cord, the transmission route for all signals generated by the brain; it also provides openings in the bony surface of the vertebrae for nerve endings to extend into the tissues of the body from the spinal cord. The lumbar spine is made flexible due to the facet joints, the ligaments that connect the vertebrae one to

X-ray showing site of chronic lower back pain.
another. The spinal column is connected to the larger muscle and tendon groups that both support the spine and power the bending, twisting, and turning mechanisms of the low back; the abdominal, gluteal (buttocks), lateral, and oblique muscle groups work in concert to facilitate low back movement.

As the lumbar vertebrae are both the weight-bearing segment of the spine as well as essential to flexion and extension motions, the low back is subject to significant stresses in both sport as well as everyday human activity that often lead to injury and consequent pain. Low back pain is not restricted to one cause; the condition may be attributed to a number of circumstances, some of which are cumulative and others which are the result of a single physical occurrence.

There are a number of common causes of lower back pain. For example, pain can occur if the low back is subjected to the stresses caused by a slumped posture, or by excessive periods of being seated in a position in which excess body weight rests on the low back where it is not adequately supported, such as in computer use, the lumbar vertebrae and their disks may become damaged. Also, the low back will be more susceptible to strain if it is required to bear additional or excessive body weight for extended periods. Sudden twisting or turning movement is often the cause of low back pain where the low back is already significantly stressed or damaged.

Lifting heavy objects can result in low back pain. If the low back is not in an optimal position at the point when the force is exerted to lift the item, both the muscles and the spine are susceptible to damage. Such injuries occur in athletic and non-athletic circumstances, particularly where the movement is attempted without the benefit of a proper warm up and stretching of the low back structure. In addition, if someone is struck in the lower back area, the force associated with the blow, such as an ice hockey body check, or a tackle in other sports, can damage the low back. In extreme cases, the force can produce a fracture of one of the vertebrae. And finally, when a blow is given to either the top of the spine that radiates down the spinal column to the low back, or a similar radiation of force from a blow delivered at the buttocks and pelvis that radiates upward.

In rare circumstances, low back pain may be triggered through no physical cause; such cases often involve a problem with a nerve in the vicinity.

The most common cause of low back pain is a strain in the muscles adjacent to the lumbar spine. In many cases, such pain will resolve itself through rest. In some cases, nonsteroidal anti-inflammatory drugs (NSAID) are used to assist in the management of the condition. The follow-up to ensure the prevention of this type of injury will include an emphasis on proper stretching of the low back muscle groups, as well as the technique employed in all manner of twisting, turning, and lifting. A back brace, a flexible assistive device worn around the midsection, may also be used in the rehabilitation of this type of injury.

A medical examination may reveal the existence of a degenerative disk disease (DDD); the presence of DDD is not itself evidence of the cause of back pain, as many people have the condition without limitation of movement. In many cases, DDD, which includes a narrowing of the disk space, precipitates back pain.

A failure to properly warm up and stretch the muscles and the structure of the lower back is the leading cause of injury to this part of the anatomy. Stretched and properly stimulated muscles, along with elevated heart rate and respiration that accompanies a proper warm up, will prepare the low back, especially where it will be the subject of explosive lifting movements or twisting motions.

SEE ALSO Back injuries; Hip and pelvis anatomy and physiology; Neck injuries.