An intervertebral disc prolapse occurs when a tear in the annulus fibrosus allows the nucleus pulposus to bulge out. This most commonly affects the lumbar region, specifically the L4-L5 and L5-S1 discs. Symptoms include back pain radiating into the buttocks and legs. A physical exam reveals limited back movement, muscle spasms, and tenderness over the affected disc. Straight leg raises can reproduce the pain. Diagnosis is confirmed with imaging studies.