Hey Alan, only just saw this. Three things which immediately pop out:
1) On the way down you're leaning into your right hand side. This is why I requested a vid from the front, each of those reps you can visibly see veers off to the right and then as you come back up you correct that. You need to concentrate on descending centrally, or even slightly to the left and do that until it looks better.
2) From the side view, each of the final reps shows a clear inclination to come up on your toes. Now, I don't necessarily agree with Bev/Soldier's viewpoint that you should start with your butt back. I think that will limit your depth and is more of a geared thing. I think you should carry on breaking at the knee, but if you're going to do that you MUST concentrate on pushing up from the bottom with your heels.
What might help you here is a slight raised heel. This will allow your knee to track forward more freely and might help you to sit back more. Possibly.
3) As MikeM said your knees can track forward and out. At the moment you're buckling somewhat and this could possibly be caused by knees not being pushed outwards. Push them out strongly and this should allow your hips to come inline with your torso and prevent you from tipping forward.
If you can't push your knees out, then take your stance IN a little. This will allow you more room to move your knees out as you need to on the descent.
Last edited by Fazc; 01-07-2013 at 03:42 AM.