I love the responses on here arguing what someone like Nick Faldo's saying....Has anyone on here won 6 majors and 40 tour events? NO... If you follow TPI and biomechanics, the right knee must remain flexed no different than any other sport in order to fire off of. Do you throw a baseball or foot ball from a straight right leg? Do you shoot a basketball that way? If you look at those pics, its hard to see flex because of the way the pants fall....
Here's the thing, you do not fire off the right foot. Impact has 80 plus percent weight on the front foot, so you fire off the front foot. How can you fire off a foot that has such lack of contact with the ground. Most pros bank there back foot in, you don't push off a banked foot, there's no support there.
If you actually read what was posted you'd realize Faldo says one thing and does another. Feel isn't real, it's been proven by video analysis. How about you educate yourself and read the entire thread first.
This Dominic guy doesn't know what he's talking about re: the right knee flex, but you do actually fire off the back foot to start the downswing. Check the pressure testing swing thoughts thread. Good players fire off the right foot. That's how the trail knee regains its flex in the early downswing after having "straightened" on the backswing.