I had been seeing doctors for years about my back pain. I ended up spending about $500 to have a podiatrist make a cast of my foot and create custom fit insoles for me. They worked wonders and over about 6 months my back gradually got much better.
Recently I stumbled across a cheaper solution in Esquire. Apparently, there is a product called Zapz that you can mold to your foot at home. They cost about $50 and are a much more economical.