Findings and recommendations on the assessment and treatment of adults with acute low back problems-activity limitations due to symptoms in the low back and/or back-related leg symptoms of less than 3 months' duration-are presented in this clinical practice guideline. The following are the principal conclusions of this guideline:

• The initial assessment of patients with acute low back problems focuses on the detection of "red flags" (indicators of potentially serious spinal pathology or other nonspinal pathology).

• In the absence of red flags, imaging studies and further testing of patients are not usually helpful during the first 4 weeks of low back symptoms.

• Relief of discomfort can be accomplished most safely with nonprescription medication and/or spinal manipulation.

• While some activity modification may be necessary during the acute phase, bed rest >4 days is not helpful and may further debilitate the patient.

• Low-stress aerobic activities can be safely started in the first 2 weeks of symptoms to help avoid debilitation; exercises to condition trunk muscles are commonly delayed at least 2 weeks.

• Patients recovering from acute low back problems are encouraged to return to work or their normal daily activities as soon as possible.

• If low back symptoms persist, further evaluation may be indicated.

• Patients with sciatica may recover more slowly, but further evaluation can also be safely delayed.

• Within the first 3 months of low back symptoms, only patients with evidence of serious spinal pathology or severe, debilitating symptoms of sciatica, and physiologic evidence of specific nerve root compromise corroborated on imaging studies can be expected to benefit from surgery.

• With or without surgery, 80 percent of patients with sciatica recover eventually.

• Nonphysical factors (such as psychological or socioeconomic problems) may be addressed in the context of discussing reasonable expectations for recovery.