The medial branch block is used to identify where pain is coming from. You will receive a local anesthetic into your back, and then the doctor will watch a video x-ray as they guide the needle into the medial branch nerves in your back. They may give an injection in one place or in multiple places in your back. If your pain goes away, then the pain was correctly identified as coming from those nerves.
While a medial branch block may provide temporary pain relief, it is used to diagnose the pain. Your doctor will develop a plan for treating the pain with you.