How do nerve blocks for back pain work?

Nerve blocks are designed to treat back pain when the source of the pain is from arthritic joints in the spine. There are very small nerves that go to each of these joints. The only function of these small nerves is to tell your brain that the joint hurts. A nerve block works by essentially turning off the nerve to the painful joint. As a result, the patient will still have the arthritic joint but will not feel the pain produced by that joint.