your ass is curling in at the bottom dude you will defo have to stretch or thats an injury waiting to happen once you start upping your weight, ive just had part of my disc cut off in nov 2011 because of that, wont be squating or deadlifting agin,
your ass curling in is a serious problem and its down to not being flexable enough, other than that you do look better, another thing to think about is to keep the bar directly above the balls of your feet, too far forward and you will feel your weight shift onto your tows and too far back you will get pulled back, the most common problem if shifting weight to your toes,
aslong as your driving through the balls of your feet and cant feel the weight going to your toes and having to tense your toes to push you back your on the right track, but you need your aas curling sorted asap.
you will see on your vid just before you touch the box your ass curl in then on the way up it will flick out and go back into the arch, it needs to stay in the arch for the whole movement, your ass shouldnt curl under like that, its only a small change in position but when the weight gets heavier you can fuk your discs.
you will notice it most on 2,4,5th rep
<message edited by stone14 on 24 February 2012 19:10>