I’ve posted here before about my recovery from my partially torn pec using ART. Have gotten back in the gym, and am having no problems with benches (given, doing them light). However, today I went in to do squats, and i feel like i slightly pulled the area again. Have been icing it and such. My question is, why would my pec hurt when i’m doing squats?
I had a strain, less severe than your injury and had the same issue. I think when you hold the bar, the pecs are stretched significantly for your set - 30 sec? - therefore it still hurts because its not completely healed.
Additionally to what the other guys said, it sounds like you may have some flexibility issues in the pec and ant. delts. Try stretching 'em out prior to squatting and see if that makes the symptoms less severe. Some dynamic stretches or PNF would fit the bill nicely - last the last two issues for some excellent stretching advice.
It really amazes me how many people fail to stretch their upper body muscles prior to a lower body workout…think about the ROM at the shoulder joint that is necessary to have a decent low bar placement in squatting!