For the last four weeks, the day after shoulder day my left posterior delt hurts. It doesnt feel like a strained muscle but a bruise. I have full range of motion with no pain but like I said it feels like a deep tissue/bone bruise. The thing is there is no black and blue mark or sign of bruise on my shoulder.
It starting to mess me up because when I try to squat and I have all the weight resting on my upper back its like 300 lbs pushing down a bruise. I cant focus.
What could it be?!?!?