What is resonant frequency and what can it be used to accomplish?
http://www.answerbag.com/q_view/281691 This is a Ninjitsu hand exercise set that is part of the “flutter stroke” or “quivering palm” substyle lessons. You will need some sort of container for fine sand with no rocks, gravel, or lumps (a pail that is 20 litres or 5 gallons will be enough … or a deep firm box) and you will need a whole lot of small balloons. The sand container will need to be placed so it is elbow high at the upper edge, and it will need to be deep enough so when your finger tips touch the inside bottom, your elbow is just below the upper edge. The balloons will need to be SMALL / LARGE enough to be used to represent internal organs, from spleen size to liver size but no smaller or larger. For the sand – stand close to the sand container, make a firm “Knife hand” and strike vertically down into the sand. If you strike with a constant power and a constant firmness to your hand & arm, then the sand will stop your hand fairly soon and the depth of penetration will be mini
