Squat stalling

[wecoyote]

Rip,

Typically when I fail at squats, it is about one third to halfway up during the rep. I loose hip drive, stall out and the barbell comes back down on the safety pins on the power rack. To date, I haven't failed getting out of the hole. Is this a sign of weak quads? Are there any specific assistance exercises to help this condition?

Thanks

[Mark Rippetoe]

It means that you are allowing your knees to go forward at a critical time in the movement when hip drive should be carrying you up. This is because you are looking up or lifting your chest at this point instead of driving the hips on up.