Three years ago this past June, I had to have major surgery on my right arm/shoulder (I fell and broke the humorous - (nothing funny about it!!!) clean thru, plus chipped a shard off the back of it and severly dislocated my shoulder - so now have a rod from shoulder to 1/2 way to elbow) :cry:
Anyway, because of having to keep it immoble for so long, I ended up with a "frozen" shoulder which limits me from reaching my arm completely up in the air. I also have limited strength while trying to lift anything with that arm. I try not to let it limit me and can pretty much do what ever I want, just have to be aware of what I am doing.
Do get it checked out though to know for sure that is what you have. You may find improvement with physical therapy.