Hi Ada,
I hate to say yes it is part of RSD but I have problems with my hands curling up and my wrists wanting to curl in too so it very well be part of it or it could be something else. You should mention it to your doc to see what he thinks as he knows your history. I think you are doing the best thing by straightening them out. We have to keep our bodies moving or else atrophy sets in and it gets worse. Best of luck,
kathy d