Squat Form Check

[David1982]

Just started the program after meaning to 'start next week' for a year or more. I'm fat and weak as hell. I have osteoarthritis in my hips and a painful lower back after a car crash a couple of years ago, so squatting hurts a bit, but hopefully that will ease as I get stronger.

3rd squat session of the program - 44 kg x 5 x 3 - this is the 2nd set -

http://www.youtube.com/watch?v=qkYbWex0XDQ&t=0m26s

What I can see - The bar looks like it's forward of my mid-foot. I don't know if my knees should be coming forward a bit more and if that'll fix it. It looks like I'm not using as much hip drive as I could.

Any help will be much appreciated.

Apologies if the angle isn't great - I especially wanted to see where the bar was in relation to my mid-foot and how far my knees were traveling forward, hence the camera being side-on.