Leg Pain
Common reasons for radiating leg pain, known as sciatica, would be diseases of the lumbar spine that can irritate or compress the lumbar nerves as they travel through the spinal canal.
Examples would be a herniated disc where a piece of the interverbal disc compresses nerves or sometimes bone spurs from the disc or from overgrown arthritic facet joints can compress nerves and cause leg pain. Generalized narrowing of the spinal canal, called spinal stenosis, which results from thickened ligament disc bulging and overgrown arthritic joints is also a common cause of leg pain emanating from the spine.
Rarely do these cause paralysis; however, you should seek medical attention if you are experiencing numbness, having difficulty with weakness, bowel or bladder disturbances, fevers or chills, or if your acute symptoms have not gotten better after three days of nonoperative care or chronic symptoms last longer than six weeks.