That makes sense but are we on the same page. I'm not talking about the last half of the lift which is a definite GM. I'm talking about the segment consisting of moving out of the hole up to 1/4 squat position, which then finishes with the GM in the next segment. To get to the 1/4 squat position what musculature is responsible for the movement out of the hole. That's not the lower back is it. The last segment (GM) definitely is all back without doubt
RIght, thats what I mean when I say, the body is getting into a position to use the musculature it wants to.
If you allow it, you will press straight out in front of you during an overhead press too, its easier that way,
for a while. The GLUTES are what I think youre looking for in the position you described, the hamstrings will get more activity the greater the torso lean. When you weak glutes and weak quads, youre going to naturally want to lean and drive your hips up first to get more leverage from different muscles.
In my video, at the 1/4 squat position after coming out of the hole, my back is fully horizontal. No doubt whatsover that the rest of the lift is all good morning. and if thats my body getting itself in a position to lift the weight then that's happening because the bar went fwd and i lost the back angle
or simply having not placed a priority on staying upright long enough for it to become habit yet, and having learned "drive your hips up" vs staying tall and driving the body up as a unit, chest and shoulders up first, in the way you do in any athletic movement in history.
its titled "Powerlifting, Year One" - by gary gibson if you're interested
When ppl do 1/4 squats, their back isn't horizontal obviously, but if it was, then the lift wud not be a quad dominant movement. but in my case with a horizontal back, it was all GM, no quad. I think Gary is wrong anyway, quads dont move the bar out of the bottom of a LBBS. And in later years he changed his mind on the LBBS and he thinks HBBS is better become its more leg dominant than is LBBS
yea I am not sure what he is getting at there, a certain degree of isometric strength is required from the hamstrings at the position you are describing, but it is so miniscule compared to the strength required of the glutes and quads to actually drive the body up, in an upright position. Its simply not an issue in most cases, in fact I would say in my experience most quad dominant guys will stay upright naturally, while guys who have more hamstring strength and weak quads will tend to have to be cued to do so.