There isn't much we can tell from watching you squat an empty bar. It doesn't give us a very accurate idea of what you look like when squatting real weight.
What I can tell, though:
1) Bar position is wrong. You are not supposed to support the weight on your wrists.
2) Don't do that with your head. Look down.
3) Toes are probably turned out a bit too far.
Please read the stickies on how to film form checks here: http://startingstrength.com/resource...play.php?f=155
And you do have the book and have read it, correct?
Uless the pain is very bad, it's probably something you should train through, and you probably should be taking ibuprofen 4x a day, if your stomach can handle it.