Therefore, as a Taekwondo student, you should be as elastic as possible as protection against damage. Proper focus unites the bones, muscles, tendons, and ligaments into a structure that is better able to distribute forces elastically (non-destructively), such as pre-stressed concrete does in buildings. It also means that an onrushing opponent who is impaled on a well-rooted reverse punch will sustain more damage than a stationary opponent. The effect of having a firm stance is most important when the opponent is stepping toward you, therefore, your best strategy for causing damage is to wait for the opponent to step toward you with an attack, deflect the attack, and then use a well-rooted reverse counter punch. Colliding elastically does not transfer any kinetic energy, so it should be avoided. An inelastic collision with the target transfers kinetic energy that damages the target rather than your striking limb. You want your victim to be damaged, not pushed backward. To cause maximum damage to an opponent, targets should be chosen for their inability to respond elastically. The ability of a target to respond elastically depends on its structure, the speed of the impact, and the area of impact pressure.
All tissues have a range of pressures over which they are capable of responding elastically. The transition from elastic response to inelastic response is called "yielding." As pressure builds in a collision between two objects, both objects are initially elastic. A striker strives to have a larger elastic domain than the target. Once the target yields, the pressure between the two objects stops increasing and starts decreasing. When we consider momentum rather than pressure, the speed at which your technique travels has a greater effect upon the collision than the mass of the technique. Therefore, maximize speed to maximize damage. If purpose of a technique is to break bone, then use a high velocity impact with a small target area. If purpose of a technique is to cause internal damage, then use a technique that will transfer momentum.