My understanding is that at this time it is FDA approved for the lower extremity and not yet for the upper extremities...but it can still be used for upper extremity and is effective. The benefit with the lower extremity with the DRG is that it gives better coverage over a larger area...providing pain relief to the whole leg vs a small area. I have RSD is most of my body...but feel it would provide me greater function and mobility with a unit treating my leg. The amount of relief reported in studies...even at the lower end would be life changing for me...which is why I would like to try the treatment. Even though it wouldn't do anything for my upper body pain...being mobile would provide me a better quality of life...which is my goal. My dr said he would want to do a second unit for my upper body later...but we would start with one for the lower extremity.