Which finding is a red flag for back pain indicating possible nerve root involvement?

Which finding is a red flag for back pain indicating possible nerve root involvement?

• A. Positive Straight-Leg Raise
• B. Fever
• C. Sphincter Tone
• D. Point Tenderness

Answer: (A)

The key concept is recognizing signs of lumbar nerve root irritation (radiculopathy). A positive straight-leg raise test reproduces sciatic-type pain when the leg is lifted with the knee straight, stretching the lumbar nerve roots. If a patient has nerve root compression from a disc herniation, this maneuver often provokes pain radiating below the knee, sometimes with sensory or weakness changes in a dermatomal pattern. This finding is specific for nerve root involvement more than local back tenderness or systemic illness. Fever points to infection or inflammatory processes rather than nerve root irritation. Abnormal sphincter tone raises concern for cauda equina syndrome, a different and more urgent pattern involving multiple nerve roots. Point tenderness indicates localized musculoskeletal strain rather than nerve conduction along a root.

The key concept is recognizing signs of lumbar nerve root irritation (radiculopathy). A positive straight-leg raise test reproduces sciatic-type pain when the leg is lifted with the knee straight, stretching the lumbar nerve roots. If a patient has nerve root compression from a disc herniation, this maneuver often provokes pain radiating below the knee, sometimes with sensory or weakness changes in a dermatomal pattern. This finding is specific for nerve root involvement more than local back tenderness or systemic illness.

Fever points to infection or inflammatory processes rather than nerve root irritation. Abnormal sphincter tone raises concern for cauda equina syndrome, a different and more urgent pattern involving multiple nerve roots. Point tenderness indicates localized musculoskeletal strain rather than nerve conduction along a root.