Dear Kathy, Sorry my response is so late but have not been available to enjoy the list for the last week......... Your mother's arm pain could certainly be PD related. I definitely have shoulder and arm pain, at times quite severe and other time not so bad. It also could have other origins and checking with her family physician or neurologist might be wise, as other help might be available if it is not PD related. Before my PD was officially diagnosed, I had spent the previous two and a half years bouncing back from a shoulder injury and surgery...in retrospect both my neurologist and I know that some of that pain etc. was PD related. However, there are several other things that should be ruled out, rotator cuff tear, degenerative "wear and tear"- there could be bone on bone from osteoarthritis, pinched nerve, carpal tunnel from repetitive motions, etc. Some of these conditions may be helped by treatment...so from my way of thinking make sure it isn't something that could be helped and improved. I don't know if what I do would be helpful for your mother, but one of the simplest things is one of those packs that can be heated in the microwave and then laid on you arm or shoulder for warmth. Or a pack which I keep in the freezer all the time, and then put on the arm or shoulder and it helps with the pain. Even though simple, both these packs should be used with caution. The warmth loosens me when I'm stiff and the cold helps with the pain and inflammation. I make myself do certain things throughout the day with my left hand and arm "only" so that it gets stretched, which is very important as you DO NOT want a "frozen" shoulder...that is very painful and a challenge to work back from. Any one of the most important things that has been beneficial for me is seeing a good physical therapist. Even if the pain is PD related seeing a physical therapist would be good and your mother could learn some exercises that would help. Sorry I'm so "wordie" but hope it helps....Good Luck! Best, Sharon E.