44. Keumgang opening

Let's do one from a WT poomsae.

Keumgang utilizes a palm striking technique. This technique differs from the ITF palm strike in that the hand is bent 45-degrees. The ITF palm strike (as found in Choong-Jang) is vertical.

ITF (left) vs WT (right) palm strike

While the purpose of this 45-degree bend could be to alter the striking surface, it also reminds me of an open-handed strike a Kempo instructor once showed me. The strike is aimed at an unusual target: the angle of the mandible.

Why strike here? For one, it's very disorienting to the opponent. Both the jaw and neck are sensitive areas. Two, because you hook the opponent's jaw with the meat of your thumb, this is effective at pushing the opponent away from you. Three, according to the Kenpo instructor, striking hard enough will damage the opponent's temporomandibular joint (TMJ).

But how do we get the opponent into a position where striking here is feasible? With the opening movement of Keumgang, of course. One application of this, what we call an "inner-forearm wedging block" in ITF, is a shoulder lock against a right hand grab.

Source: One Minute Bunkai

1. Opponent grabs your shirt with their right fist
2. Grab their elbow sleeve with your right fist and their wrist with your left fist. 
3. Step forward with your left foot, away from the opponent's free arm, while executing the inner-forearm wedging block. This pulls the opponent's elbow and wrist in opposing directions, locking their shoulder
4. Step forward and strike under their jaw bone (angle of the mandible) with the right hand palm strike
   

Additional strikes

Could you not also use the palm strike as a strike to the chin? Of course! Keumgang contains two more palm strikes moving forwards. Since the poomsae is symmetric, the intended set is two palm strikes.

The poomsae is telling us that if the opponent blocks our first palm strike with their left arm, we may pull that arm out of the way as we step forward and strike their chin with our left palm.

You may repeat this as often as necessary: moving forwards while striking with the palm or moving backwards while striking with the inward knifehand (steps 5-7 of Keumgang).