Leg Press: Hands on Knees?

[quote]Bill Roberts wrote:
I’d credit a lot more to what could be pushed with the hands even if there were no chest involvement, judging from triceps pressdowns, and actually the movement seems to me more in the dip/decline press category, but ORDINARILY it does not seem to me those that use this method apply much force with the hands.

And certainly not, relative to the total weight involved, if their impression, as with the OP, is that they are not pushing at all.[/quote]

its isometric. if im doing a hacksquat how are my arms doing anything? theyre pushing my legs open thus moving the weight up vertically? visualize a hacksquat, visualize the motion of it, visualize how it works, now visualize putting your hands on your knees and even if you pushed as hard as you could from a mechanical point it would do absolutely nothing.