A positive straight-leg raise test most specifically suggests radiculopathy due to irritation of which structure?

• A. Spinal cord compression
• B. Lumbar nerve root irritation
• C. Hip joint pathology
• D. Sacroiliac joint dysfunction

Answer: (B)

The main idea is that a positive straight-leg raise test tension-distributes force along the sciatic nerve and the exiting lumbar nerve roots. When a disc herniation or other pathology irritates these nerve roots—most often the L5–S1 roots—the neural tissue is stretched, producing sharp, radicular pain that radiates down the leg below the knee. This pattern points to nerve root irritation rather than a problem in the hip joint or the spine itself at the cord level. Spinal cord compression tends to cause more widespread signs and upper motor neuron findings rather than a clean radicular distribution. Hip joint pathology usually causes groin or anterior hip pain focused in the joint rather than leg-radiating pain along a dermatomal path. Sacroiliac joint dysfunction can cause low back or buttock pain but not the classic nerve-root–driven leg radiation seen with a positive straight-leg raise. So the structure most specifically irritated is the lumbar nerve roots.