Imagine a stone falling into a still pond of water, at the point where 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 increases 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 mostly responsible for stability and providing a base for the outer, bigger muscles to move from effectively. Latest research shows that inner muscles are also important for movement, especially at high intensities. 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. The outer core muscles are more powerful, but the arms and legs have a higher percentage of fast-twitch muscle fibers, making them faster than the core.
Therefore, effective movement in martial arts classes for adults and adult karate classes starts from the center, increasing energy in a ripple effect with maximum power being accumulated at impact. Like the pond example, the further away from the center, the weaker the ripples are; in the body, the strongest muscles are around the center, and the energy increases as it travels to extremities.
Understanding these principles is crucial to making training effective, but knowledge alone will not internalize them. Specific drills in adult karate classes and childrens karate classes give feedback to students and help them embody these principles naturally.