Sciatic Nerve

About the Sciatic Nerve

The sciatic nerve is the largest and longest nerve in the human body, roughly as thick as a finger where it begins. It forms from nerve roots of the lower lumbar and upper sacral spinal cord, leaves the pelvis through the greater sciatic foramen, usually passing below the piriformis muscle, and descends through the buttock and the back of the thigh. Above the knee it typically divides into the tibial nerve and the common fibular, or peroneal, nerve, which together supply the muscles of the back of the thigh, the lower leg, and the foot, and sensation to much of the lower leg and foot. The term sciatica describes pain radiating along the course of the nerve, most commonly caused by a herniated lumbar disc or spinal stenosis compressing one of its nerve roots rather than the nerve itself. Injury to the nerve can result from hip fractures, hip surgery, or poorly placed injections in the buttock.