I have RSD in both hands and went to PT to improve function of hands. At that time I was employed, could type 95 words a minute and just was dealing with intense pain and strength decease. The PT helped improve my functionality and strength for a while, but as my RSD worsened over the past year now there is not much to do. I keep my hands active daily (home exercises from my PT therapist) but can barely type, not just because of pain but my right hand is turning into a claw, my middle finger humps higher then all fingers and I can't straighten fingers at all on right hand, left has more function but not much. So to answer your question, PAIN does limit but sometimes the functionality worsens even with exercise, heat, etc. RSD is a strange creature.

Hang in there.