Is the pain in your spine or in your back muscles? If it is in your back muscles then you should try adding magnesium, or more magnesium, into your diet. Read this info: "Magnesium's role in relaxing muscles. Another primary role of magnesium is to work with calcium to help regulate the body's nerve and muscle tone. In many nerve cells, magnesium serves as a chemical gate blocker - as long as there is enough magnesium around, calcium can't rush into the nerve cell and activate the nerve. This gate blocking by magnesium helps keep the nerve relaxed. If our diet provides us with too little magnesium, this gate blocking can fail and the nerve cell can become overactivated. When some nerve cells are overactivated, they can send too many messages to the muscles and cause the muscles to overcontract. This chain of events helps explain how magnesium deficiency can trigger muscle tension, muscle soreness, muscle spasms, muscle cramps, and muscle fatigue especially in the back and legs where some of the body's largest muscles live."
http://www.jigsawhealth.com/products/magnesium_supplement.html
sounds like a disc problem