Not helpful.
The heel strike is a great move for weaker people. I didn't watch the vid, since I was just looking for a demo. If the language was bad, be advised that people that fight use rough language. As for the move itself, taught it to a former girlfriend of mine for self-defense when she was unsure of her ability to gun an assailant. She had to use it on a would be rapist, broke his nose and then shredded him with her claws. She said when he grabbed her, that it was her first response and I was very proud. She is now over the shooting thing. Next time he'll get 158 gr instead of the punch. It is very effective move for a weaker person.