Spinal anesthesia involves the injection of a medicine into the canal around the spinal cord. It is used to numb the body below the chest, usually before a surgical procedure.
The area where the needle will be inserted is first numbed with a local anesthetic, then the needle is guided into the spinal canal and the anesthetic is injected. The person may not be able to move his or her legs until the anesthetic wears off.
WebMD Medical Reference from Healthwise