Guys, as I have mentioned before I have bad shoulder (and bad strength in them), and have been told by a friend that I should incorporate shoulder shrugs into my routine.

I have always done them straight up and down, but my friend says I should rotate my shoulder while I lift. I have seen others do this but I have heard from some guys that is unsafe.

Is it okay and does it help build or is it actually more harmful?

Thansk for the replys in advance.