moish, I’ve been doing various martial arts for a very long time. The edge of the hand is only one blow, and it’s really not that common. The body has many natural weapons. Among the best are the knee, the elbow, the shin and the forehead. Hitting someone in the skull with your ungloved, unwrapped, untaped fist is a good way to break the delicate bones of the hand. There’s even a condition called “boxer’s fracture”.
Self defense is a whole separate world far, far removed from the yeshiva…