Acute Lower Back Problems in Adults - Medical History

Evidence on Efficacy of Assessment Methods
Medical History

A few key questions on the medical history can help ensure that a serious underlying condition, such as cancer [26] <http://text.nlm.nih.gov> or spinal infection, will not be missed. These questions include: age, history of cancer, unexplained weight loss, immunosuppression, duration of symptoms, responsiveness to previous therapy, pain that is worse at rest, history of intravenous drug use, and urinary or other infection.

Symptoms of sciatica (leg pain) or neurogenic claudication (walking limitations due to leg pain) suggest possible neurologic involvement. Pain radiating below the knee is more likely to indicate a true radiculopathy than pain radiating only to the posterior thigh. A history of persistent numbness or weakness in the leg(s) further increases the likelihood of neurologic involvement. The articles indicate that cauda equina syndrome can be ruled out with a medical history that ascertains the absence of bladder dysfunction (usually urinary retention or overflow incontinence), saddle anesthesia, and unilateral or bilateral leg pain and weakness.

Patients' reports of symptoms and treatment outcomes may be influenced by psychological or socioeconomic factors. Several studies have reported a variety of such factors for patients with low back problems. These factors include work status, typical job tasks, educational level, pending litigation, worker's compensation or disability issues, failed previous treatments, substance abuse, and depression. [23] <http://text.nlm.nih.gov>, [38] <http://text.nlm.nih.gov>, [39] <http://text.nlm.nih.gov>, [41] <http://text.nlm.nih.gov>, [43] <http://text.nlm.nih.gov>, [50] <http://text.nlm.nih.gov>, [58] <http://text.nlm.nih.gov>

Clinicians are urged by some authors to augment the medical history with pain drawings and visual analog pain rating scales to document the distribution of pain and intensity of symptoms (Attachment B) <http://text.nlm.nih.gov>. [40] <http://text.nlm.nih.gov>, [45] <http://text.nlm.nih.gov>, [46] <http://text.nlm.nih.gov>, [52] <http://text.nlm.nih.gov>, [53] <http://text.nlm.nih.gov>

Physical Examination

The physical examination supplements the information obtained in the medical history in seeking an underlying serious condition or possible neurologic compromise. The basic elements of a physical examination are inspection, palpation, observation including range of motion testing, and a specialized neuromuscular evaluation. This evaluation emphasizes ankle and knee reflexes, ankle and great toe dorsiflexion strength, and distribution of sensory complaints. For patients presenting with acute low back problems and no limb complaints, a more elaborate neurologic evaluation is usually not necessary.

The physical examination is less useful than the history in searching for underlying serious conditions such as cancer, but may be helpful in detecting spinal infections. Fever, vertebral tenderness, and very limited spinal range of motion suggest the possibility of spinal infections, but these are also common findings in patients without infection. Otherwise, evaluation of spinal range of motion has been found to be of limited diagnostic value, [62] <http://text.nlm.nih.gov> although some clinicians consider it helpful in planning and monitoring treatment.

Findings from both the history and physical examination provide useful information in the search for possible neurologic compromise. For example, sciatica has such a high true–positive rate for lumbar nerve root compression that its absence makes a clinically important lumbar disc herniation related to neural compression unlikely. In addition, leg pain usually overshadows back pain when such a clinically significant radiculopathy is present. Finally, crossed straight leg raising is such a highly specific test that a positive finding makes neurologic compromise due to herniated lumbar disc very likely, but this is not a sensitive test since discomfort upon crossed straight leg raising may be absent in many patients with neurologic compression. [31] <http://text.nlm.nih.gov>, [34] <http://text.nlm.nih.gov>, [61] <http://text.nlm.nih.gov>, [63] <http://text.nlm.nih.gov>

Deyo, Rainville, and Kent's summary [54] <http://text.nlm.nih.gov> of available data suggests that in the primary care setting for patients with leg symptoms, the neurologic examination can safely be limited to a few tests. These are: (1) testing of dorsiflexion strength of the ankle and the great toe, with weakness suggesting L5 and some L4 root dysfunction; (2) testing of ankle reflexes to evaluate S1 root dysfunction; (3) testing of light touch sensation in the medial (L4), dorsal (L5), and lateral (S1) aspects of the foot; and (4) the straight leg raising (SLR) test.

This abbreviated neurologic examination of the lower extremities will allow detection of most clinically significant nerve root compromise due to L4–L5 or L5–S1 disc herniations, which together make up over 90 percent of all clinically significant radiculopathy due to lumbar disc herniations. [35] <http://text.nlm.nih.gov>, [37] <http://text.nlm.nih.gov>, [56] <http://text.nlm.nih.gov>, [61] <http://text.nlm.nih.gov>, [63] <http://text.nlm.nih.gov> Although this limited examination might miss the much less common L2–L3 or L3–L4 disc herniations, these conditions are more difficult to diagnose on physical examination. Moreover, if such patients have not improved by 1 month, this guideline suggests a further diagnostic workup or consultation (Chapter 4), <http://text.nlm.nih.gov> which may clarify the diagnosis. For over 95 percent of patients with acute low back problems, no special interventions or diagnostic tests would be required within the first month of symptoms.

Potential Harms and Costs of Assessment Methods

Potential harms and costs are considered low for both the medical history and the physical examination.


Bigos S, Bowyer O, Braen G, et al. Acute Low Back Problems in Adults.
Clinical Practice Guideline No. 14. AHCPR Publication No. 95–0642.
Rockville, MD: Agency for Health Care Policy and Research, Public Health
Service, U.S. Department of Health and Human Services. December 1994.