You are in the same fix I am...bone on bone shoulder, PT 2x a week, rail thin, older than dirt and in pain......My usual routine of zumba 5x a week not good as I can't help but go with the music so I am (reluctantly, hating it) doing the recombent bike and slow treadmill in our gym, just to keep body moving.....watching mindless TV while pumping away. It is the only thing I can think of to keep up cardio..I do PT 2x a week and will be paying out of pocket after next week as medicare stops covering rehab after 6 weeks...