The second picture shows a woman attacking an opponent who is approaching from behind. She hits the opponent by looking over her shoulder while bringing her knee up and then unfolding it straight backwards to hit the opponent with the heel.
This kick is called turning side kick. It is advantageous because of its powerful force. When an opponent is approaching from the front, you will need to rotate your body so practicing balance is important.
When practicing, put both knees close and then practice kicking a leg straight backwards, making sure that the toes are pointing to the side or to the ground. Practicing balance is extremely important because when you are standing with one leg and kicking with the other, you would not want to lose your footing and be at a disadvantage by falling to the floor.
Turning side kicks are especially useful when hitting an opponent approaching from the front or the back. It is also the most powerful kick among all kicks in taekwondo. Practice this enough to be able to use it in actual situations to keep yourself safe.
By Seo Gyo-sun (email@example.com)
Seo Gyo-sun, an internationally certified Taekwondo Grand Master, judge and coach, holds a B.A. in taekwondo from Kyung Hee University. ― Ed.