Strange "Hitch" or Stall-Out during Squat

[brittf]

Hi Mark.

After your prior comments about my squat form (along with some good insight from other posters), I have been focusing on my squat form (and not using box squats to gauge depth). I also received MOMG and the SS DVD and have been reviewing them to see what hints I can get.

1) Neck neutral, eyes on ground 4' ahead - done...
2) Focus on pushing knees apart - done...
3) Dropping the box squat and relying on hamstring tension to find the bottom - done...
4) Finding the "optimal" foot/stance width for max hip drive WHILE hitting legal depth - NOT SO EASY...

I have clearly "trained myself" to prefer the wide powerlifting stance over the past year. However, as you said, wide stances make it harder to reach depth, and I was cutting my squats an inch or so short before. When I use a "slightly wider than hip width" stance, I go well below parallel (first two reps in video). However, it "feels" like weaker hip drive to me and I see a "temporary stall out" when I am about 1/3 of the way up on the squat. I have a shareware video tracing program called Kinovea that will trace the bar path, and there is clearly a hitch in bar path when I stand up. When I widen my stance a bit (second two reps - with the bonus that you get to listen to some great METAL in-between the sets :)), I just barely reach parallel but the "temporary stall out" seems to diminish.

Yes, yes, I know - self experimentation is necessary and I don't need your permission to try it :)...

However, I am curious - what is the bio-mechanical nature of the "temporary stall out"? Is it where the hamstrings peter out and the back takes over?

I am interested in learning more since 85 kg is quite light for me (identical weight as in the prior video to keep conditions constant) and I would have thought I could just stand up without any issues. The stall is also in a strange (at first glance) place since it is NOT in the bottom which "should be" the hardest portion of the lift, but rather in a 3/4 squat position which "should be" much easier...

http://www.youtube.com/watch?v=1fhApK5yXOw

Thanks again for all of your help...

Regards,
brittf

[Mark Rippetoe]

The stall-out happens when you lift your chest, thus pulling your hips forward, even a little, and therefore closing your knee angle. This shortens the hamstrings distally and thus takes the tension off the proximal ends where you are attempting to use them to extend the hips. I'm pretty sure the long version of this made it into MOMG. Even if the chest comes up and the knees manage to not move forward much like you show here, the hamstrings have shortened since the hip angle opened and tension is lost that would otherwise contribute to moving the load up. If the chest is lifted too much, the bar also moves behind balance over the mid-foot, screwing up things this way as well.