
Originally Posted by
nmarman
Might be a ligament tear I have seen significant tears in gym goers that. Lift heavy weights and normally because their strength is very good they don't notice pain for a while and in the movements they do get pain they just avoid.
Ac joint is most common.
Try scratching the ban with effected arm see if it gives any pain sensation and try the same with a heavy draw opening and closing.
It did sound like a nerve or nerve root lesion (c5) but without tingling or numbness it would be rare.