Squat problems
 

For as long as I can remember I have had the problem of my butt tucking under once i reach parallel in my squat -- either my lower back rounds and I cannot stay vertical, or I stay vertical and fall over backwards. It improves significantly under heavy weights, but the tuck is still there to some extent. As far as I know my hips and thoracic spine have no serious mobility issues. Here is a video of an air squat with the tuck under:
http://www.youtube.com/watch?v=HxDT0F5CEY4

I have read in some places that some people have levers such that they won't be able to squat below parallel correctly, but I would like to think that I can improve with some flexibility work. Any ideas?

Butt winking is almost always hamstring flexibility

Hit it up with some PNF or AIS

I don't see the issue unless you back does that with maximal loads which I've seen happen maybe once...ever. I see guys who squat well over 700 raw have the same issue without weight and no issue once they are under the bar.


Hamstring tightness and associated hip flexor tightness is rarely fixed by stretching alone (if at all). The fix? Squat more...this will usually correct IF you are patient and progress slowly and appropriately.

If you can't squat with weight without it tucking excessively, squat high-gradually working your way down. Squatting to a box can work, pause squats are even better if you can handle them.