Back Pain

August 1, 2011

Back pain is the second most common reason for medical office visits. About 60-90% of people will have at least one significant episode of low back pain during their lifetime. Low back pain is the most common and the most expensive cause of work-related disability in the United States. Workers’ compensation costs as well as medical expenses run as high as $100 billion per year. At any given time, at least 1% of the workforce is either permanently or temporarily disabled by back pain.

There are many risk factors for low back pain including increasing age, heavy physical work, obesity, smoking, drug abuse, and history of headache, job dissatisfaction, and monotonous work. Rarely, severe scoliosis (sideways curvature of the spine) can place a person at risk for low back pain. Minor postural problems including mild spinal curvatures, leg length differences, and physical fitness do seem to affect the development of low back pain. Most important, abnormalities on x-rays including lumbar spine films that are commonly taken by chiropractors as well as abnormalities seen with computerized tomography (CT) scans and magnetic resonance imaging (MRI) scans, do not match up with the existence of low back pain. In fact, abnormalities on spine films are found in the majority of adults, most of whom have no back pain at the time.

There are many causes for low back pain, and the more serious causes need to be excluded by an accurate history and physical examination. However, in acute low back pain, a definite source of pain cannot be found in about 85% of people.

Low back pain that does not send pain into a leg is rarely if ever caused by a ruptured disk in the low back. Usually, this kind of low back pain is related to muscle strain, spasm, or trigger points. Trigger points are areas in the muscle that are tender, feel like a taut band, and reproduce a patient’s pain when pressed on. A lot of pressure on these trigger points can sometimes cause shooting pain, which may mimic a herniated disk. Another cause for acute low back pain is inflammation in the sacroiliac joint, where the base of the spine rests on the pelvis. This can cause pain that increases with walking, sitting, or standing, and improves with position change. Other symptoms include pain that travels to the groin, and pain that travels down the back of the leg or the side of the thigh. This can also mimic a herniated disk in the spine. However, pain from a trigger point or the sacroiliac joint usually stops near the knee, while the pain of a herniated disk more often travels all the way to the foot.

There are many causes of low back pain, including abnormalities of the spinal column, the joints between vertebrae, the disks between the vertebrae, and the ligaments and muscles that support the lower back. All of these problems can cause low back pain with or without pain going into a leg. In addition, acute and chronic low back pain may be caused by infections, either infection elsewhere in the body or localized to the spine and its surrounding structures. Other causes include autoimmune and inflammatory diseases such as ankylosing spondylitis, psoriatic arthritis, and reactive arthritis. Endocrine abnormalities and certain toxins can produce low back pain. Cancers beginning in the spine
or metastasizing from other parts of the body, especially from the lung, bone, kidney, prostate, or thyroid gland, are also important causes of acute low back pain. Blood vessel problems such as strokes in the spinal cord and abdominal aortic aneurysms can produce pain localized to a particular region of the lumbar spine.

If the history and physical examination raise the suspicion of a serious cause for the pain, then more testing needs to be done. However, it is important to remember that even when abnormalities are seen on imaging studies such as CT scans and MRI scans, the abnormality often has nothing to do with the pain. Eight-five percent of patients with acute low back pain and approximately 65% of patients with chronic low back pain cannot be given a specific diagnosis.

The treatment of low back pain is usually nonsurgical. Ninety percent of patients with an initial acute episode of low back pain will recover with simple treatments. In large studies, elaborate treatments for acute, nonspecific, nonradiating low back pain have not been proven to be particularly effective. Bed rest in particular should be avoided after 1-2 days. During the first week or so of low back pain, physical therapy should be avoided, but after about 7-10 days gradual stretching and strengthening exercises of the spine and abdomen can help relieve the pain. Careful use of narcotic pain relievers and muscle relaxants can be helpful in severe, acute pain. However, over the long term, nonsteroidal anti-inflammatory drugs such as ibuprofen, naproxen, and similar prescription drugs are more effective. Surgery should only be considered if there is progressive weakness, bowel or bladder incontinence, or a significant structural deformity.

Back braces, except in rare instances, are not helpful, especially in someone who has chronic low back pain, since braces can lead to weakening of the muscles. Heat and cold can provide comfort. Epidural steroid injections have not been proven to be an effective therapy for back pain or radiating symptoms, according to researchers who reviewed lots of studies of back pain. In fact, some of the additives in steroid preparations, when injected in and around the spinal canal, can be toxic to the nerves. This can cause increased pain due to scarring and infection. Other treatments, such as spinal manipulations, acupuncture, and transcutaneous electrical nerve stimulation, are not very useful in acute back pain but may be helpful in chronic back pain.

Chronic low back pain should be treated with an aggressive regular exercise program and nonsteroidal anti-inflammatory drugs. A variety of other medications that are used for all kinds of chronic pain are also helpful in chronic low back pain. These medications include antidepressant medications and antiseizure and antispasticity drugs. Special programs that teach about pain and stress management and include physical reconditioning and an ergonomic evaluation can also be extremely helpful for people with chronic low back pain.

SEE ALSO: Arthritis, Autoimmune disorders, Chronic pain, Exercise, Physical examination

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