background: this was my first heavy pull session in about two months. I had previously pulled my right hip flexor squatting, then pulled my left erector(s) about mid-back chasing a rep record while jackhammering my DL's.
I've self-diagnosed as much as I can. SSC mentioned that it looks like I'm not pulling through my heels enough. I also think that maybe my hips are too low at the start of the pull. if that is the case, then should I lower my hips only up to the point that my shoulders just clear the bar (looking down from my point of view), because iirc my shoulders are behind the bar completely.
also, about the upper back. i think Dave Tate said allow your upper back to round, Tony gentilcore and others say to lock your shoulder blades and put them in your back pocket. others say to flex your armpits. after I get my air and get set, I try to keep my chest out as much as possible. is some upper back rounding acceptable?