It seems like the twin forearm block from Do-San is the first pattern technique that many students find completely alien. There’s a lot of weird coordination happening in this move. But it’s really not that difficult with practice. By the time students get to its cousin, the twin knife-hand block from Yul-Gok, they (usually) have it down pat.
According to the Encyclopedia of Taekwon-Do, the twin forearm block and twin knife-hand block are used to block simultaneous attacks from the front and side. But the side block (the lower one) is the primary block.
Each of these blocks is made up of two parts:
- A middle outer forearm block or knife-hand block
- A rising block performed with either the forearm or knife-hand
These blocks are usually performed in L-stance or rear foot stance, but you can use pretty much anything but walking stance or low stance.
Cross your arms in front of your body at shoulder height, crossing at the wrists. Your palms should face toward your body and your hands should be in loose fists.
Make sure to cross at your chestline, not your centreline. Your chestline is basically in a vertical line with where the crests would be on your dobok. The arm that will perform the middle block (your forward arm) goes closest to your body, and the arm doing the rising block (your rear arm) goes on the outside.
Keep your front elbow reasonably close to your body. You don’t want it to flare out so your forearms form an ‘X’. Rather, they should form something between an ‘X’ and a ‘+’.
If you’ve learned rising blocks already, you’ve probably noticed that the rising block portion of the twin forearm block and twin knife-hand block doesn’t come from its regular position. It’s not coming from waist height and on top of the reaction hand. It’s already halfway to its target. This is why General Choi called it the secondary block. The middle block, on the other hand, comes from its usual place.
Your arms should move straight from the preparation position to the final position. There’s no swing or circling involved. Remember to rotate your fists as you move, of course.
The front arm in the twin forearm block finishes with the top of the fist at shoulder height. It’s essentially in the same position as your front arm in the forearm guarding block. And the tips of your fingers finish at shoulder height for the twin knife-hand block, just like the knife-hand guarding block.
For the rising block portion, almost all of the same rules apply as for a regular rising block. Your arm is bent at a 45º angle. General Choi never wrote where your block should line up with the rest of your body, but it looks like the blocking tool should be roughly in line with the eye on the same side of your body. For example, if you’re doing the rising block portion with your right arm, the blocking tool would be over your right eye.
Another way to think about it is if you turned your head back to its regular position between your shoulders, your blocking tool would be in a vertical line above your nose.
And speaking of blocking tools, remember to shift your elbow back slightly when performing the twin knife-hand block. Your knife-hand is on a different part of your arm than the outer forearm blocking tool, but they both need to line up vertically over the same place.
Finally, keep your head upright. I’ve noticed that a lot of people have a tendency to lean their head toward their rear arm. They probably don’t even realize they’re doing it. Use a mirror, a friend, or better yet, your instructor to help ensure your head is where it’s supposed to be.
So there you go. If you have any details to add, let me know!