Acute low back pain.(WOMEN'S HEALTH ADVISER)

Acute low back pain is one of the most common disorders in the general population, with a life-time prevalence of about 80%. At least 90% of cases are due to soft tissue strain or injury and heal within 4-6 weeks.

Still, the impact of back pain is quite large. Each year, it temporarily disables about 4% of the U.S. population. Back pain also is likely to recur, and factors influencing the transition from acute to chronic conditions are unclear. Good nutrition and regular exercise, with a focus on abdominal strengthening, can help prevent back problems by keeping bones and muscles strong.

Diagnosis

Back strain usually is biomechanical, resulting from activities such as moving furniture, repetitive motions, or even traveling (hefting suitcases and sitting for long periods). Most patients with back strain (about 90%) will complain of an ache or spasm in the low back, posterior thigh, or buttocks. The pain will ease with inactivity or when lying down, and will increase with activity or bending. There will be local tenderness and limited spinal motion. This disorder is most often seen in patients aged 20-60 years. Pain that radiates down the leg is usually not associated with back strain but radiculopathy.

The remaining 10% of back pain complaints will vary according to etiology. These symptoms should be red flags that prompt quick imaging studies, as should any exam that shows pathologic reflexes.

Acute disk herniation presents as a sharp, shooting, or burning pain in the leg, sometimes with paresthesia. Osteoarthritis and spinal stenosis will cause an ache with a "pins and needles" sensation. Ankylosing spondylitis may present as an ache, especially noticeable in the morning. Infection may be a sharp pain or ache with point tenderness on palpation, perhaps accompanied by neuralgic abnormalities or fever. Malignancy is most often a dull throbbing ache that increases with recumbency and interferes with sleep.

Treatment