Acute Low Back Pain

Mark S. Rosenthal, M.D.
May 18, 1999

Low back pain (LBP) is a major medical problem. Worldwide, from 60% to 80% of people will have it during their lifetime and 2% to 5% will have it at any given time.

In the United States, LBP is the one of the most common problems for which people visit a doctor [1] and is the most common cause of disability under age 45. The total annual cost in the United States for health care and lost productivity is nearly $100 billion. However, only 10% of the patients account for 90% of the cost. Thus its management and its impact on our workforce are a major drain on the American economy. Our approach to this disease must be changed.

Before discussing the treatment of a disease, it is important to know its natural history — what happens when it is not treated. The natural history is the benchmark against which all proposed treatments must be measured. In order for a treatment to be valid, it must get the person better in less time and with fewer side effects than no treatment. To demonstrate validity, it is necessary to compare groups of people who are treated with similar people who are not treated (control groups) to see whether the outcome with treatment is better than the natural course of the disease.

Acute LBP is pain that has been present for three months or less. The list of treatments for it is very long. Most are claimed to have about a 90% success rate. However, most people with uncomplicated acute LBP get better within one month, and 90 % recover within three months. This is why so many treatments for LBP appear to work so well. Although many have a scientific or authoritative appearance, most have not been substantiated [2].

When to See a Doctor

There is no need to run to a doctor for every little ache and pain; yet significant problems should not be ignored. Any of the following circumstances are reason to see a doctor:

  • Pain that is present for more than a month without improving, or occurs at rest, or is worsening.
  • Advanced age, unexplained weight loss, or past history of cancer.
  • Long-term steroid use, which can weaken the bones and increase susceptibility to fractures.
  • Recent urinary tract infection or unexplained fever.
  • Trauma capable of causing a fracture, such as a high-impact auto accident or a serious fall.
  • In the elderly, minor trauma, especially if the person has osteoporosis.
  • Severe weakness or numbness in a leg, the genital area or the buttocks; or change in the ability to urinate or have a bowel movement. These are signs of possible impairment of spinal nerves.
Uncomplicated Cases

If no signs of fracture, infection, tumor, or neurologic defect are present, spinal x-ray exams, CT scans, MRIs, or EMGs are not necessary. Nor are fancy or expensive treatments. Recovery will take place just as quickly without them.

Since most people with uncomplicated LBP recover spontaneously, is any treatment truly helpful? The answer is yes. Scientific studies show that patients who are educated about LBP and reassured about their problem tend to get better faster and have less discomfort than control groups. Activity is also beneficial. Patients who exercise get better faster and, if they keep exercising, are less likely to have future episodes. Activity that significantly increases pain should be avoided, but a little pain while exercising is OK.

Spinal manipulations, when used during the first month after symptoms appear, can decrease the amount of pain and shorten the episode. Spinal manipulation is the application of force by hand to selected joints of the spine. If manipulation does not bring relief within 2-4 weeks, additional manipulation is unlikely to be beneficial. Once the pain has subsided, additional manipulation is unnecessary and has no proven preventive value.

For severe symptoms, pain-relief medication may be helpful. The amount of pain relief and the speed of return to activities are similar with narcotics and non-narcotics. However, narcotics have a significantly higher incidence of side effects and complications. Therefore, narcotics are rarely useful.

In uncomplicated cases, reassurance and appropriate activities are the best treatment. Remember that 90% of all patients in this category get better, even without treatment. After a few days of taking it easy (avoid lifting, carrying, or bending), a progressive exercise program of isometric strengthening, range-of-motion exercises, stretching, and aerobic conditioning should be started. Often, it is best if a physical therapist provides instruction. Heat, ultrasound, massage, electrical stimulation, and traction may provide a few hours of relief, but they offer no lasting benefit and are expensive. Sleeping on a firm mattress is usually a good idea.

Complicated Cases

If you are among the 10% who do not get better despite an appropriate exercise program, several options are available. Most patients would rather avoid surgery (rightly so). Unfortunately, it is often the best option. Many conservative (non-operative) treatments exist, but most do not work. For patients with a preponderance of leg symptoms whose MRI scan shows a small disc herniation, an epidural block may be helpful. This is an injection into the space around the nerve in the spine, typically with a local anesthetic and a steroid to decrease inflammation. Scientific studies have shown that facet blocks (local anesthetic injections into the small joints in the back of the spine) and rhizotomies (insertion into the spine of a probe that cuts or destroys the nerve that carries the pain) are not effective.

If leg pain, numbness, weakness, or loss of sphincter control occur, an MRI scan should be obtained to look for signs of spinal nerve impingement. This procedure is painless and does not involve needles or even X-rays. If the MRI reveals a large (greater than 6 mm) disc herniation, surgery to remove the part of the disc that is pressing on the nerve is the best treatment, preferably within six months. Removal through a small skin incision (an open discectomy) is still the “gold standard.” The newer techniques of laser surgery, microsurgery, arthroscopy, and percutaneous discectomy (suction of disc material through a tube is placed through the skin) have not been proven superior to open discectomy, and their long-term effects are unknown.

Sometimes the MRI reveals spinal stenosis. This is usually seen in older patients, and is a narrowing of the space for the nerves. It is caused by enlargement of the joints and ligaments due to arthritic change. Epidural blocks usually work, but only for a short time. The only effective treatment for this condition is laminectomy, a surgical procedure in which thickened areas of bone and ligament are trimmed, leaving more room for the nerves.

Chronic back pain is a more complex problem. Some patients may benefit from fusing two vertebral bones together. However, deciding which patient will benefit is extremely difficult and requires more extensive testing and more complex decision-making.

1. Woodwell D. National Ambulatory Medical Care Survey: 1997 Summary. Advance Data #305, May 20, 1999. [
Download report]
2. Bigos SJ et al. Acute Low Back Pain Problems in Adults. Clinical Practice Guideline No. 14. AHCPR Publication No. 95-0642. Rockville, MD: Agency for Health Care Policy & Research, 1994.


Dr. Rosenthal, a Quackwatch advisor, is assistant professor of orthopaedic surgery at the University of Maryland School of Medicine in Baltimore, Maryland.

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This article was revised on 5/18/99.