It was so nice to read your acknowledgement. My chiropractor advised the ball to sit on. Dynamic sitting she called it. Because the ball can be rolled around ever so slightly while sitting on it your joints and muscles are being moved instead of freezing. I sincerely hope that it is of some benefit for you.
The only other advice I have found over the years is that with this condition you MUST pamper yourself. Maintaining this condition means you have to look after your level of comfort, because it's not going to go away without input from yourself. You must have that massage or therapy (and I can't recommend Feldenkrais enough), because it is the only way to stay on top of it. I was concerned about the costs but found it better to invest in self help than more doctors' bills and pills that didn't help.
Good luck Lorraine


