Hi jryan15,
Can I make a suggestion that you re-consider the above collage as a guide for maximizing leg drive? I hope that I'm understanding your post correctly.
Ken posted an ideal hypothetical above, which involved swinging a hammer. That's perfect for at least two reasons. First, it eliminates the dead start. Second, it promotes a negative movement prior to a positive drive.
Should I be this young lady's coach, I would suggest a few simple changes to help promote more drive prowess. First, re-position the drive foot. Second, incorporate a negative full body lean in the pre-motion. Third, get those hands together up in the bread basket, close to the core for maximum drive explosion. Finally, let those knee hinges work. The big muscles in the lower body can only load explosively when the knee joints are allowed to bend naturally. Think sprinter's drive.
Can you remember a Jordan dunk, or a Chelios break-away without any explosive closed-chain kinetic energy utilizing the knee joints?
Rick mentioned his stance of the IR 90/10 speed ratio. So, staying true to his example, it's important to utilize as much of the closed-chain kinetic energy as possible. In this scenario, there is a minimum of 10% energy available beginning at the feet, that can equate to additional mph. In my opinion, that would be difficult to maximize by utilizing the images in your post above.
Chris