Nerve roots exit the spinal cord and form nerves that travel into the arms or legs.
These nerves allow movement of the arms, chest wall, and legs. These nerve roots may become inflamed and painful due to irritation, for example, from a damaged disc or a bony spur. A selective nerve root block provides important information to physicians but is not a primary treatment. It serves to prove which nerve is causing pain by placing temporary numbing medicine over the nerve root of concern. If a patients usual pain improves after the injection, that nerve is most likely causing the pain.