Junior Olympic knees in

[OITW]

Looking at the junior world championships just held in the linked vids,

http://www.youtube.com/profile?user=...AS&view=videos

I noticed many 98kg and 105kg lifters have a tendency to "knee in" at the bottom of the squat, but as they start up it's almost as if a coach yelled their cue and they jam their knees out. I don't know olympic lifting, is there a reason for this?

[Mark Rippetoe]

In the front squat you hamstrings are not available to help extend the hips, discussed at length, ad nauseum, ad infinitum, elsewhere. This leaves the adductors and the quads. I think the knee flutter you see is an attempt the re-recruit the adductors several times during the drive up.