Yep, tennis balls can work wonders. They were recommended to me by a physical therapist to massage the bottoms of my feet for pain related to achilles tendonitis.

I also have lower back pain.  I take percocet 10-325 twice a day. I have Flector patch that I apply on really bad days. Recomended to me at the Mayo Clinic here in Florida. It takes care of the pain. Mine is L4 and 5 with deteriation or stenoisis, bulging also. I also use two tennis balls put in a sock and tied to keep them close together.  I stand against a wall and roll the balls over the pain area and around my hips and I have to tell ya this is the best thing going for pain. A massage therapist that I use to work with, turned me on to the balls and you have to try it you won't believe the relief that you will get. Feel Better