[video]http://imageshack.com/a/img913/5513/IpOmdM.gif[/video]
This is a pretty good example. You can see Him pulling back with the tops of the legs into to his hips. Most of the guru's here at dfp call it flexion. My DD does it a little different. She does have flexion but She bows her legs out you can't see the bowing because she is resisting it. She is trying to turn the front leg toward pitcher, when she picks it up the front hip gets out of the way causing a sudden move to the ball created by resistance. The resistance also allows her to pick up front foot without moving back toward catcher.
