I'm a college pitcher who's been throwing in my summer league. Over the past three weeks I've been having some pain in the lower left part of my back. I honestly don't feel it much until I'm doing physical activity ie. squatting, throwing, sometimes running hurts. I always make sure to get a good stretch before I do anything, and I've been talking to some of the trainers about it who don't seem to see anything terribly wrong. All I know is that when I threw last night each time I tried to follow through, I got a shooting pain in the lower left part of my back. It's slightly about my left butt muscle, not quite on the side of my body but definitely not in the middle of my back. Im a 6'4'' RHP if that makes a difference. I was just wondering if anyone else has had that problem. I'm thinking maybe a pinched nerve? Strained muscle? Please help I don't want to hurt it further for my season.