Is an epidural injection helpful for chronic back pain?

Epidural: Generally no, or for a very limited time, with potential complications, in the neurology literature.

Depends: It depends on cause of back pain. If you have pain from lumbar facet joints, the epidural will have almost no effect on your back pain. If the pain shoots down a leg or two and is from a disk herniation, you have a good chance the pain will go away for a while (a week to a year). If you also do physical therapy, there may be even more chance of improvement. Talk to your doctor and good luck.