Most traditional martial arts teach the use of the Ridge Hand Strike (also known as Reverse Knife Hand Strike) as striking with the base of the forefinger (where the finger joins the hand) or even with the thumb. No disrespect to anybody who practices or teaches that way, but it does leave a small joint vulnerable to damage. When we strike with the forearm instead, it is much more powerful and more versatile. In this video, I demonstrate the difference between striking with the hand and striking with the forearm and the forearm is clearly significantly more powerful. If you have any doubts, then please try it yourself on a bag or with somebody holding a substantial pad.