Ray
Master Black Belt
I have never cracked a whip and used to assume that the cracking of the whip was akin to "snapping a towel." I have since heard that the crack of a whip is not created like snapping a towel (i.e. that there is no sudden reversal of motion in a whip). Rather, it appears that the construction of a whip, larger diameer at the handle and small at the end creates a loop in the whip which accelerates (like a wave in water under certain circumstances) until the end goes faster than the speed of sound.just like an actual whip, gets its power from the snap incurred when its direction is changed... therefore, the motion will be traveling away from the attacker at the point of contact.
http://www.bullwhip.org/faq/forward.mov
I have to believe that the force in finger whips is because of the acceleration of the fingers in the final turning of the hand as the arm reaches extension...that it propels the tips quickly and that the small surface of the finger tips concentrates the force into a small area; which is why finger whips can cut flesh (like the flesh on a cheek).
As for the finger whips not "standing on their own" : In many cases other strikes don't stand on their own. Take the handsword in Delayed Sword - it is prefaced by an inward block and therefore doesn't stand on its own either. You could (you could, not necessarily would) execute an outward extended block with your hand in the shape of a crane and be cocked to execute a finger whip (kind of like shielding hammer or Sword of Destruction). You could execute a hooking crane to pull down an opponents arm and return your own hand as a finger whip. I'm kind of thinking that you could almost pull one of in Triggered Salute after craning the attacker's right arm, but your hand isn't quite facing the right way.