My last two workouts I have been getting pain in my left shoulder/upper back area, it doesn't bother me until I start working up in weight, around 350 it starts to ache a bit and around 400 it hurts like hell, my left arm feels weak and the whole upper left part of my body hurts. By the way, this only happens AFTER I rack the bar, no issues while actually squatting. I had some tightness in my upper back so I did a bunch of myofascial release stuff and hoped for the best, but the next day I (stubbornly) tried low bar squatting again and the same thing happened.
I have searched online for a solution and there doesn't seem to be any good advice available. And in case you are wondering, no, this is not a shoulder mobility issue. It seems like the bar is pressing on a nerve, but this has never been an issue before. I have no pain or discomfort throughout the day, only when squatting. Looks like it's high bar or SSB squats for now.
Has anyone else had similar issues? Any advice would be appreciated.