I'm a personal trainer, and I've noticed with a few of my clients, when squatting, their hips tend to sway to one side at the bottom portion of the lift. And were not necesarily going below parallel either.
Usually doesn't show up till heavier weight.
After taking notice, I've come to see that I do it as well.
I know I've seen it plenty more on the smith machine than free weight, and can't readily recall seeing it on free weight squats at all.
Can some1 explain this, and maybe how to correct it?