Your thinking exactly what I was thinking. The question is to make it a minor bend or a bigger bend. I would't want to be standing on a wall and all of a sudden my foot just grips the ledge.
Yeah, i was thinking that the toe part could work like rubber, so when you land, the foot actually bends, and when you move out of the bending position, you'd get a minor speed boost. Just like a sprinter in his starting position.