Chroma,
I have been ordered regular shoulder shrugs and extended shrugs...where you go up forward and then roll back. Initially it was 30 @ 3xday. I never felt like it made a positive difference at those numbers.

Now it is different. I agree with Coop...doing more than a few at a time will bite me later. I do 10 or so several times a day. I find it helps to relax my shoulder and resets my arm to a better position. I am learning that if it hurts I don't do it. Finding the right number is very personal and changes without warning. Some days I cant do one without an immediate negative response.

Only my left shoulder is involved but I do both sides anyhow. My left wants to drop forward. It hurts less in that position so I fight all day.
Hope this helps,
Daesin