I too have severe discomfort and pain in my rib cage, which I believe to be caused by muscle contractions, and which seems to be primarily associated with the "off" period. They are severe enough at times to hamper my breathing and can be alarming. I have found no cure for it, but get relief if someone else gently massages,(rubs) my rib cage. I have found some relief from a hot bath, but have not tried a hot pad across the ribs, which may help. I believe that the secret of relief is relaxation, which is not easy to attain when you are scared, so it helps if you can tell yourself that this too shall pass, and its not life threatning. It does not seem to be a very common symptom of PD, but certainly it's been mentioned on this list before, and I hope that others who have this symptom will contact you, so that you in turn, can reassure your father. He's lucky to have your concern for him. Heather Hewitt.