Yeah, but my point being that you can get the same from the Karate roundhouse knee strike, with (worst case) the same power or much more, seeing as the Karate technique is powered by bigger, stronger muscles. So why do it as seen in the vid.?
Karate as we know it today is not as it was in Okinawa or the likes. It has become a melting pot of Techniques from various influxes of different martial arts from different countries. Originally there were no kicks higher than the waist in Okinawa Te.
Now I agree to a point that the round knee is a good technique but this is for the ring and a round knee in this instance puts you off balance and more prone to a foot sweep that are commonly used in the ring with Muay Thai matches etc