What is the primary purpose of performing a straight-leg raise test in the context of back pain?

• A. To assess for herniated disk on imaging
• B. To assess for radiculopathy due to lumbar nerve root irritation
• C. To measure hamstring flexibility
• D. To diagnose spinal stenosis

Answer: (B)

The straight-leg raise mainly checks for radiculopathy from lumbar nerve root irritation, often due to a disc herniation compressing a nerve root. By raising the leg in a person lying on their back, you tension the sciatic nerve and the traversing lumbar nerve roots; if radicular pain is reproduced and radiates below the knee—typically beginning around 30 to 70 degrees of hip flexion—that pattern supports nerve-root irritation rather than a simple muscle strain. This helps distinguish neural (nerve) pain from non-neural backache or hamstring tightness and guides further evaluation or imaging for disc herniation. It’s not an imaging test, and it’s not a direct measure of hamstring flexibility; nor is it specific for spinal stenosis, which classically presents with neurogenic claudication and relief with flexion rather than a straightforward radicular pain pattern.