The comma cut to the quadriceps begins with an arcing forehand thrust. Once penetration through the pant leg is achieved, drop your elbow to your ribs, turning your hand palm up. After turning your hand and the blade, continue your motion, cutting out of the wound channel.
Good self-defense technique uses natural, easy-to-learn body mechanics to produce devastating physical damage. Great self-defense technique does this in a way that is immediately incapacitating, taking your attacker out of the fight efficiently and keeping you safe. Truly superior technique does all of the above, while providing multiple offensive and defensive functions that enable you to instinctively adapt to the dynamics of a critical incident. The comma cut is an example of the latter.
Like most things in the martial arts, the comma cut exists in many different systems under a variety of names. Our late friend Bob Kasper taught a version of it called the “crowbar” that shared most of the same qualities. If you call it something different, that’s fine. Focus on understanding the technique, not martial politics.
Placing A Comma
The basic movement of the comma cut is a thrust-then-cut motion. My favorite target for it is the quadriceps muscle group at the front of the thigh. Applied properly, even a folding knife with a 3-inch blade will sever the muscle completely, destroying the attacker’s mobility and allowing you to escape safely—the real goal of all self-defense.