Can you find another video where they don't rip the head off?I use a broom with an angled wooden head, so that keeps the broom shank off the ground at one end to stop asphyxiation rather than a divot in the ground. I have to say though, I thought the woman in the video was rather slow and I felt the chicken was stressed, so I personally didn't feel it was a very good example of how to do it, but you get the gist of what's required.
At least it was clear.
When I employed the technique there wasn't much distress.