Pelvic Tilt, "Butt Wink" and too horizontal of a back angle

So I've just finished reading SS 3rd edition and have been practicing my squat form without load as suggested in the book. I'm no expert but I think it's safe to say that my form is flawed. I can tell by comparing videos of me squatting to the pictures in the book (and videos on the SS youtube) that my back is much too horizontal when I descend into/ascend out of the hole. I've tried shoving my knees out harder, thoracic extension, widening and narrowing my stance and taking a deep breath and holding tension in my abs and lumbar spine region to try and fix my back angle. No matter what I try I can't seem to get the required depth (hip crease parallel to the top of patella) without leaning forward and allowing my lumbar spine to round (butt wink). This is causing a very obvious deviation to the the bar path (which is far from being perfectly vertical).

What am I missing here? Is this an issue with my hip mobility or is there some obvious flaws in my form that I am overlooking?

Form Check for Low-Bar Squat - YouTube

Meaty, you don't practise without a load. You move through the teaching method, then work up in weight the same day.

You're fine except that you're misinterpreting back angle, "butt wink," and what bar path will look like with insignificant weights.

Re-read p27 in the Blue Book starting with "The general plan is to..." and follow those instructions.

Quote:

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Originally Posted by stef

Meaty, you don't practise without a load. You move through the teaching method, then work up in weight the same day.

You're fine except that you're misinterpreting back angle, "butt wink," and what bar path will look like with insignificant weights.

Re-read p27 in the Blue Book starting with "The general plan is to..." and follow those instructions.

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Roger that. I will follow the plan on p27 and see what my form looks like under load. Thanks for the advice.