Correct me if I'm wrong, but it looks as if you are breathing altheway OUT, then holding your breath then doing the rep? You should be doing the opposite. Breathe in nice and big, filling your lungs with air, chest big and tight, and then hold it in, and SQUEEZZZZEEE and squat, you don't see to be bracing properly, if at all. But your form looks decent, and better than your other post, good job!