2. One back straight, one leg bent, calf perpendicular to the ground.
3. Land on the ground with your legs together.
The main points of the action: the abdomen is tightened, the quadriceps muscle is contracted, one leg is kicked, one leg is sucked in, the two knee joints are together, and the upper body is slightly leaning forward.
Assisted exercises: 1. jump from the body, 2. jump from a little height of the table down to feel the control of the air posture.