In a karate step, the force comes from the back foot (ground force): The heel is pressed to the ground, transferring the force to the center of the body. Then the hip is turned forward on the side of the executing arm. Through this, the generated force is transferred through the torso by the arm to the target. Of course, the same principle applies to the kick. The use of the hip varies depending on the technique. This type of power transmission results from rapid successive movements, so-called chain movements. Due to the speed of execution, they are hardly perceptible with the eyes, but crucial!
Here you will find all information about the techniques in the video