I'll ask again, Chris. Explain how the arm does what you say it does. How does him having his arm there redirects the force of the push back to the big guy. How does it work?
Jason, grab your wife and do it, you'll see instantly. If it doesn't work, watch the video link I supplied. If that still doesn't work, look at the diagram that I supplied. If still after trying it you don't understand, let me know, and when I get a moment, and some people to film and demo on I'll make you a step by step how to.