It's in the youtube link I posted.
Watching you're video I can understand that you have hip problems. First thing to notice is you're a good 12" high of depth, like you pointed out.. Even at that height your lumbar spine (lower back) is immediately rounding, it hurts more to go lower because those tight hip flexors are pulled tighter by your lumbar spine. The hips and lower spine are all related, all those external and internal rotators connect to it. My guess is you have really tight hip flexors that are also weak along with bad bracing mechanics. You really need to understand what lumbar extension and lumbar flexion feels like, so you can stay in extension and avoid flexion. I'd practice lying supermans to sort of build a minds eye to what proper extension feels like:
As for the tight hips I'd continue to sit on a lacross ball and release the hips. You're main goal should be to squat lower and lower each week while staying in lumbar extension, this will increase your hip mobility too as the weight pushes you under.
I know I get pegged for being crazy with this stuff, but it should be an easy fix if you stay on top of it and it's better than not squatting.
You might want to take a look at your lower back on deadlifts too.
Ok, so I should be mimicking the feeling that I get while doing supermans when I do squats? Like that sensation is the cue that my back is in extension and all is well?
Also, I tried doing couch stretches, could barely keep my one leg straight against the wall. I suppose that's a definite indicator of tight hips.
Mark, those squats are sky high, but I believe you're aware of that.
If you're trying to do low bar, your knees are travelling too far forward. I think you need to open up your hips and push the knees out to the sides.
IIRC you own Kelly Starretts book. He explains the squat very well apart from the feet angle thing. Try to initiate the movement by pushing the knees out, rather than forward and sit your hamstrings back and then down to hit depth.
Your upper back seems to round at the bottom. This is probably caused by the upper back not being tight enough an your elbows pointing backward. They should be under the bar. Work on shoudler mobility with shoulder dislocations, stretching out the pecs and working out tight spots in the pecs, front and side delts and triceps. Take wider grip and push the elbows forward, especially at the bottom of the squat. That'll drive the chest up when you come out of the hole and keep you from rounding over. Arch your upper back hard already when you unrack the weight. As your shoulder mob gets better, narrow your grip to tighten the upper back even more.
Also, you're not built to not squat. Everyone can fix themselves unless their coming from a serious injury. It's just a matter of working on it enough. This might sound a bit weird / braggy / whatever but I just wanna give you an example where I've come from:
A year ago, I couldn't reach further down than halfway down my shins and had to stop back squatting for 6 months. I've also broken my left arm up by the shoulder joint where all the ligaments and muscles attach to the shoulder. It fucked up my strength and mobility so bad I couldn't even hold the arm at 45 degrees or even raise it. Then I started lifting, did 50-100 shoulder dislocations a day and now I can do them with a shoulder grip width holding a broomstick.
When I was doing the most mobility work to fix myself for getting back to squats, I did approx 1-2 hours mobility work every single day. Something like this:
Foam roll and work out trigger points, couch stretch 3x a day, Defrancos agile 8 twice, chinese splits, and sitting in the bottom posiition of the squat for sets of 2-3 minutes. Boring as hell and it hurt a lot but I got better.
Also did this for every lower body session
You're a monster with all the work you put in fixing your mobility and overcoming your injury, props man. Does not come off as braggish in any way.
As for my elbows, I always thought they SHOULD be behind you? Is it better to keep them pointed down towards the ground and closer to your sides?