Sometimes my back hurts, a lot. This is what I have used to help with pain relief:
Needed - 1 old sock (or you can make these for Christmas gifts, in that case 1 new sock)
Cheap white rice
Fill sock with rice, tie the end. Stick in microwave for a minute or so - till warm.
Apply to sore spot.
You can use this over and over and over again. I know people use oatmeal (but heat in an oven according to the directions). Beans would work also.
When my back aches this Works for Me!