The skillful karate fighter is not only strong, but in order to initiate a punch or a kick, they must contract muscles with great velocity and also relax rapidly. The rate of relaxation is very fast. In karate classes for adults, experts learn to start power generation in the legs through the hips, and as the hips explode, the core contracts quickly to transmit the force to the upper body. The initial pulse starts with a quick contraction, then the core relaxes as the punch or kick increases in velocity until impact, followed by a second contraction to avoid energy leak.
In adult karate classes, students focus on initiating with very quick muscle contractions and rapid relaxation to increase speed, and a second sharp pulse ensures full power delivery.
One must engage the big muscles from the hips through the shoulders for power generation, while keeping the spine stable to allow full transmission of force. Power is not generated at the spine itself, which acts as an anchor for the bigger muscles to be fully utilized, reducing stress on the spine.
Therefore, the sequence of contraction is just as important as the rate of contraction. Smaller, inner stabilizer muscles contract first, followed by the bigger force-producing muscles. Mastering this sequence is a key aspect taught in karate classes for adults and adult karate classes, ensuring efficient, safe, and powerful techniques.