I just filmed this today at The 2016 World Handmadang at the Kukkiwon. This shows you that sky high flying board breaking may look cool but it really is not practical for martial arts. Also, they have to know they are on a regular Taekwondo mat floor, not an air matress. They got to know the floor can only give so much if they land from so high. This kid most likely has to get knee surgery now. Poor guy I feel bad. But he was doing really acrobatic and cool stuff.
Taekwondo performance is for acrobatics and show, not actual practical martial arts.