Sciatica: A Pain in the Butt, Literally.
Sciatica is characterized by pain in the lower back and buttock, which travels down the leg, usually to the knee. This is caused by pressure placed on the Sciatic nerve, which branches out from the spinal column at the base of the spine and travels down the back of each leg. Sometimes this pressure is applied by a disk herniation or vertebral displacement, but more often is the result of hypertension in the Gluteus muscles, or the Piriformis. As the Gluteus muscles are essential for pulling the leg back, and the Piriformis for rotating the leg so the foot travels inward and the knee outward, both can be weakened and stretched through extended periods of sitting, particularly with bad posture or on uncomfortable chairs.