Imagine a stone falling into a still pond of water, at the point of which the stone enters, there will be an explosive splash, followed by powerful ripples traveling away from this point.
Sensei Nishiyama used to say: “karate technique starts from the center and increase energy in a ripple effect, from the muscles around the spine, to bigger, outer core muscles and to the extremities”.
The outer core muscles, (buttocks, obliques and hips) are the most powerful in our body, the inner core muscles are not as powerful and mostly responsible for stability and providing a base for the outer, bigger muscles to move from effectively(latest research shows that the inner muscles are also important for movement, especially at high intensities of movement). The further away we go from the center the less powerful the muscles are, core to shoulders to arms to hands or hips to upper legs to lower legs to feet. Also while the outer core muscles are more powerful, the arms and legs have higher percentage of fast twitch muscles fibers, and are faster than the more powerful core.
Therefore, effective movement in most sports start from the center, and increases energy in a ripple effect with maximum energy being accumulated at impact. In the case of the water pond the further away from the center the weaker the ripples are, just like in the body, the strongest muscles are around the center and not as strong as we go away from the center. In karate technique the further you go from the center the more energy increases and more power. This and other principles are meant to be understood in order to to be applied and not just as theory.
Understanding is needed in order to make training effective, but by itself will not help in digesting the principles into one’s body, even with hard training.
We have developed specific drills to give one feedback and help internalize this and other principles.