Another squat form check, question about hip position

[paul1204]

New squat rack, here’s a video that’s at hip height at around 45 degree

In Rips video with Art of Manliness, The trainee looks like he doesn’t lock his hips when he’s done with the rep. When he does lock out the hips Rip says not to move the hips forward. Bret looks like his in an anterior pelvic tilt, and when he locks it out, it looks like a posterior pelvic tilt.

In Alan Thralls videos on low bar, he talks about locking out the hips at every rep. When he lock his hips out, it looks the same when Bret does it and Rip says not to do that.

What’s the proper hip and spinal position to ensure proper form and safety for low back. Because of the conflicting directions, I have trouble finding good position.

I have a tendency to over look things so this maybe irrelevant

I also from time to time feel discomfort on my right low back, either it’s on the right side of the SI or near the right side of the periformis

YouTube

The YMCA is playing that music for those that are wondering
Thanks for looking at this. Santa will be proud

[Jeff Illingworth]

Paul, don't look in the mirror, look more down. The hips will "lock", but because they're a ball joint and not a hinge joint, the lock is different than for the knees. The main thing is that you want to keep your back in extension at the top of the squat without pulling your hips forward.

You would also benefit from reviewing the thoracic extension article and re-watching the squat grip clarification video.

[paul1204]

Paul, don't look in the mirror, look more down. The hips will "lock", but because they're a ball joint and not a hinge joint, the lock is different than for the knees. The main thing is that you want to keep your back in extension at the top of the squat without pulling your hips forward.

You would also benefit from reviewing the thoracic extension article and re-watching the squat grip clarification video.

I took a look at this article pertaining to thoracic extension, RIP's video on youtube call "Lower Back Positioning" and when I apply the extension, I look like person in Photo number one. I also squatted this morning and when I tried being in extension, I could feel some discomfort in my low back to the right of the sacrum. When I 'tuck my hips under to be in a neutral position by squeezing the glutes" and think about externally rotating legs so that the knee can track over the middle toes (to help prevent back pain) I look like the individual in photo number two.
So if your stating that I need to be in extension, how will I know if I have properly extended.
Identifying and Correcting Thoracic Spinal Flexion in the Squat | Bill Hannon

Just in case the photo did not attach, here is the youtube video. Picture one would be at exactly 5:44(before the green check) and picture two would be at exactly 5:45 (green check)
YouTube

I do have a sense of thoracic extension, I am finally able to set my back properly using the 5 step deadlift, before I would round my lumbar and have to resort to sumo.

I've had many small and 2 large injuries and because of that from high and front squats, I have been out of the gym (before I learn to do what I can in the gym instead of sitting at home doing a bunch of mobility work) to many times to make any real progress.
I truly appreciate you taking your time to help me.