Conventional martial arts wisdom says that a forearm risking block is used to block and deflect a downward attack. In the Encyclopedia of Taekwon-Do, General Choi says that it can also be used to block a weapon, or even a punch or side piercing kick aimed at the nose or higher.
In reality, blocking a downward attack like this would usually be silly, especially against a weapon. It’s a good way to get your arm broken. General Choi even wrote that this block could be used against a club. Bad idea.
Silly or not, we still have to perform this block in our patterns as if we’re blocking a downward attack. So we might as well make it look good.
The outer forearm is the blocking tool. Or instead of a forearm rising block, you can perform a knife-hand risking block with only a very small modification.
You’ll typically see these rising blocks done in a walking stance, but other stances can be used as well. No matter what stance you’re using, always block with the front arm—unless you’re doing a twin block. For example, if your right foot is in front, you would block with your right arm.
Prepare by crossing the backs of your wrists together, just a little higher than your waist. Your blocking arm sits on top, with the back of the fist facing the floor. The blocking arm reaches across your body with the elbow bent so that the arm can simply move straight up as it rotates to reach the finishing position.
Make sure to finish full facing toward your target, with the blocking tool on your centreline (directly above your nose). Your hand will finish a little higher than your elbow, and your elbow is bent at a 45-degree angle.
When doing the forearm rising block, your inner forearm should finish about 7 cm away from the front of your forehead. Your inner forearm should also be level with the top of your forehead.
Here’s another way to think about that: 7 cm is about the width of your fist. Place the thumb side of your opposite fist against the top of your forehead. Now place your block against the other side of your fist. That’s about where you want your forearm to be.
When doing the knife-hand rising block, there should be about 7 cm between your thumb and forehead. Remember: because you’re now doing a knife-hand block instead of a forearm block you’ll need to shift your arm slightly to get your knife-hand on the centreline of your body.
And there you have it. As always, if you have any questions, or any details to add, feel free to let me know.