1, first of all, the two legs alternately do elastic a bend has been the action, which requires the legs must be flexible.
2, and then when the left leg is bent, that is, when the left leg heel is off the ground, the right leg must be straight.
3. And when the right leg is bent, that is, when the heel of the right leg is off the ground, the left leg must be straight.
4. When performing the exercise, we can do the movement in place, we can do the movement when we move forward, we can do the movement when we move backward, and we can do the movement when we walk laterally from side to side.