You may be experiencing anterior femoral glide bilaterally. Your form looks pretty good but there looks like there is a slight translation of your weight out to your toes as you descend. Do you feel like you are rock solid on your heels?
Your feet also look to begin turning out when you get to the bottom which leads me to believe you do not have enough internal rotation at your hips (because of the anterior glide?). The only problem with going lighter in the videos is that you may not be adding enough stress to really see your faults. Did this weight cause you pain? I am not saying you need to post a video that does cause you pain but just something to think about.
Typically if you have anterior knee and/or hip pain it is a glute issue of some sort. I would focus on tissue quality of the hips, adductors and glutes. I might also start to work on some positioning while I squat, Goblet squats are awesome for that, bare foot if possible, to really see how you move. It will help you sit into that posterior capsule but being bare foot will show how much ankle mobility you really have or do not have.
Why the belt while we are at it? If you have a weak midsection your pelvis will be all over the place and that will also contribute to hip issues. Just some thoughts. Hope it helps.[/quote]
Yes, if you watch the bar path he definitely slides forward as he descends on all his repetitions. That’s not a great thing.
OP, I would seriously work on tissue quality of your hips, hamstrings, IT band especially, piriformis, and calves. I would stretch your calves, focus on strengthening your glutes and not squatting for a while and focus on hip mobility and internal/external rotation as ATCJM suggested.
It is hard to give advice over the internet on these sorts of things.
What does your warm-up consist of and do you do any soft tissue work?