I also had back pain, and I just knew it was from the rsd. My pm dr, who is also a spine spec. insisted that it couldn't be rsd spreading, and ordered an MRI. It came back clean for lower back. So he said that he agreed, that it was the rsd. Now I'm on Opana ER, and my pain is almost totally gone, back, legs, feet, shoulder, Actually, I guess the pain is still there, I just don't feel it anymore.
I'm sure if I went off the meds that I would feel it.

Hugs
Mary