Sharp back pain (form videos included)

[BreadedChicken]

I have been lifting since April 12th, and I have made all kinds of gains, but in the last few months my back has had sharp pains in the lower spine after every set of squats, and recently I have felt the same pain after deadlifting. I have tried multiple times to tighten up my form but I still live with back pain. Usually my back will hurt after a workout and the next day it feels better so I go back and deadlift and squat heavy all over again, but this time I am being responsible. My back was in a lot of pain when I woke up on monday (3 days after my last workout with no pain in between) and doing anything other than standing or laying with my legs curled up was very uncomfortable. It resolved itself quickly and my back is now feeling better, but it always seems like that after a deadlift/squat day. As much as it pains me to skip a workout voluntarily, I have decided that this last week I would not deadlift or squat. I think that my problem with squats is that I "good morning" the weight up as a lot of low bar squatters do, and I am just wondering why it injures me but not others. I am 16 and have only been lifting for 5 months and I don't want to live with a ****ty back.I am going to make the switch to high bar as soon as possible. Two weeks ago was my last of starting strength.

http://www.youtube.com/watch?v=kCvspJFRYsE
My third set of squats, the video doesn't really show my back too much.

http://www.youtube.com/watch?v=dFa5ZP4GT0Q
This was taken 2 weeks before the other squat video, this was before I tightened up my form, mostly here just to show you what my back looks like.

http://www.youtube.com/watch?v=cxvmdGqZzW8
My back hurt a bit after each rep, but it went away after 5-10 seconds each time. I apologize for it being so long, my handwraps were tangled. I usually don't take so long in between reps. My friends were dicking around a bit so you may have to bear with a little bit of unprofessional camera-work and laughing and ****. These were the deadlifts that put me in intense pain.

Tl;dr:
My back has been hurting after squats and deadlifts, I want to know what is up, form check videos included; I usually don't take so in between deadlift reps.

[rasse226]

First off i need to tell you to go to YT look at "do you think you can squat". PUSH YOUR KNEES OUT when you squat!

And this is for your deadlift

[BreadedChicken]

I may be wrong, but I think that my deadlift form is pretty accurate. My squat on the other hand, that needs some work. I am just confused as to why I am inflicted with so much back pain since my form isn't awful.