I have 2.5# weights in my office that I do "cans" with on a pretty regular basis (an exercise a lot of pitchers use in baseball to strengthen their small shoulder muscles).
I have terrible shoulders. I had the bow arm shoulder scoped in '99 after a slap lesion and a 50% tear of my super spinatus tendon. It's a LOT better than the right one, though
. They removed a type III bone spur in the left, also.....and I'm sure I have the same condition in my right.
I would NEVER suggest anyone lift anything over 5lbs. with their small shoulder muscles, though. If that bar is less than that.....I'd say you were spot on. It's also notable that any exercise done with one shoulder should be duplicated with the other.