What is the function of exchange block, taught in Toigye form in taekwon do? Also called outward backfist strike.
The official explanation is that you are backfisting someone in the face for great justice while simultaneously blocking a mid-section kick. Another explanation is that you're tearing someone's junk off. This is supported by the idea that the movement preceding it is a spearthrust to the genitals (it's not an inward knifehand block like many think). The latter explanation comes from 9th Dan grandmaster Goy Janzen of the TAGB and TKD South Africa. Whether that makes it true or not is up for debate, but he holds a bit of authority.
To me it seems more likely that you are simply performing a stylised pose to help you get into position for the next technique. The reason I say this is because you are creating the pattern of the scholar/student idiogram with your footwork and without a technique that brings your feet together with you facing forward, the pattern will be broken and/or sloppy.
Well, a late answer to a good question. I am a bit confused about the block/strike mentioned; I have in front of me a copy of the Encyclopedia compendium. In vol 3, there is no mention of exchange-anything, and the outward backfist strike in the TOC refers to p134, which describes a back stance horizontal knifehand.
But judging by other answer and commentary, I conclude you might be asking about the 3rd movement, which has the right hand at 90 degrees "backfist" to the rear, while the left hand is in a sort of low block to the front.
I read Choi's description, and I flatly disagree with the application shown in Vol X, p39.
It states that the strike is a fingertip strike to the pubic region - all the while the left hand is neatly tucked into the chest. It is most absurd to perform a technique whilst facing an opponent in this manner. Further, that the next movement is a groin grab which has you turning 90 degrees and raising the right arm (junk in hand) while striking the groin via the "low block" is also inconsistent with the movements.
Here's why: you've exposed your center to your opponent - who, by the way, has free use of both hands, both feet, and head, while you are uber-focused on grabbing the groin and tucking your left hand into your chest - and now you've managed to secure the groin and, I guess, the thinking is to pull it such that you turn away from your opponent and raise the right hand in a most strenuous way...
Just look at the ridiculous photo of the protagonist grabbing toward the groin with his right hand, and with his left hand neatly tucked into his chest, while the opponent has BOTH hands down and away. This is reminiscent of a rated X film just about to get busy with the action. Who allows their groin to be so grabbed and then throws his hands to the rear???
No way. Choi was wrong.
Go back to first movement: your hands cupped suggest you are grabbed from the front, and antagonist has your right hand, since that is how you are facing.
First movement: turn left, outside block
First movement, you issue a left outside "block". This is not a block; it's a throw by way of a come-along arm-bar. Your left hand reaches under antagonist's LEFT elbow (or, as suggested by the fist technique, you grab your opponent's elbow clothing) and pull to the left, thus throwing the opponent to the left. This makes sense given the stance (right back stance to the left) and the hand (outward block to left). Since he has grabbed your right hand, and your right hand is chambered to your right hip/chest (depending on your instruction), his arm is firmly locked and cannot easily escape.
Antagonist is now facing your rear-ward direction by way of standing and being bent over on your left. His free hand is away from you while you've got his close hand in control by way of the come-along.
So far, all principles of defense are properly observed.
Second movement: turn into front stance, spearhand to groin
Next movement is the strange groin strike with the left arm tucked.
No, not a groin strike at all. Nor is it a pull. In fact, it's nothing to do with the groin at all; thus we don't have to assume a male antagonist. ;-)
Antagonist is still grabbing our right hand with his left, so, his elbow is bent during the come-along. His hand is also in our chamber.
As we turn (into front stance), we are reaching toward the opponent with a right spearhand palm up; remember, he's got that hand. And, we've got him in an elbow lock with our backfist. As we turn toward him, we pull his elbow to our chest, preventing any hope of escape for him. We reach low to break his grip on our right wrist. The spearhand is an open hand technique: that suggests we aren't grabbing anything, we just want to break out of his grip.
Third movement: exchange block
Next movement, we turn 90 degrees back to the front and issue a right handed backfist and left-handed low block.
The "backfist" is a fist, which means, we grab something. (no, there's no one behind us receiving a backfist; this presupposes a multiple attacker scenario, and that's not allowed in form analysis; especially as we haven't even dispatched our antagonist yet.)
As we turn to the front, we also grab his wrist (that's the right-handed backfist) and pull upwards to the right.
This forces his elbow (pointing up, because we've cupped it to our chest) to flatten out, easily allowing us to pull, dragging his head to our front. That's where the left-hand "low block" comes in: a strike to the temple or neck.
Some myths about our forms
We never grab the groin. It's not that it's an unfair technique; rather, it's ineffective. To pull at the groin means to also pull along the clothing. This in of itself just doesn't make sense. And then, we're raising our grabbing hand to our ear. Really? You're grabbing someone's groin to the height of your ear? Good luck with that. This might work if your antagonist is an 8 year old boy. So I think: no, we're not grabbing the groin at all. We might be pointing towards it, and such is a good visual. But that is far from what we're really doing. It limits the technique to a small male only. I can think of a better explanation that applies to any size opponent, no matter the gender.
Next, the backfist to someone behind us. This is rarely the case it applies. In this form, that would presuppose another opponent. While we always assume a second attacker is around, our forms don't consider the quantum mechanics of a secondary or tertiary opponent - the calculations of what-if's are just too complex to deal with. We only fight one person at a time anyway, no matter how many the enemy throws at us. We might timeslice between the antagonists, but we only fight one at a time.
Next, our junbe position. No, this is not ever a greeting. It is the initial attack. Because of one closed fist and the other covering, we assume we are grabbing, or that we are grabbed. In my bunhae (analysis), I assume I am being grabbed. Were I to assume the other way around, I then become the attacker.
For a beginner, there is an alternative and simpler interpretation of the exchange block. Everything is the same as I mentioned. However, as you turn 90 degrees to the front, you are lifting the antagonist's hand with your right, while your left hand (a fist, representing a grab - not a strike/block) is grabbing the antagonist's elbow - a classic straight armbar. The 4th movement presupposes we can dispatch our attacker in some way; a beginner need only demonstrate an armbar, not necessarily following up with a strike as I had originally suggested. There are many possible interpretations, I gave only two.
At it's most basic it is a strike to the groin, but, probably not with the fingers. It's probably a slap to the groin whilst protecting your face/ body with the other hand. Imagine someone has thrown a straight punch at you (R Hand) or has tried to grab you. You might step forward with your left foot, whilst slipping the punch or grab. So your left hand is guiding their right hand away from you whilst you are moving into them. Almost, simultaneously, you are striking upward from below, to their groin. In my view, you use a hard, sharp, slap and not a fingertip thrust which is very likely to miss. So you are parrying with the left hand whilst slipping and striking the groin with the right. Then, you grab the clothing or hair, tie or face and pull downward while tripping your enemy by moving their leg out from under them.
That in my view is why you are dragging your leg in slow motion. It's a trip. That's why you extend your hand downward.
You are pulling someone down by grabbing some part of them. The hand that's held high is either protecting your face or is actively pulling your opponent's hand (this may be the striking hand or the other hand) to aid the trip.
It's like the trips boys do to each other in school. That's why your body is turning. You've got to do the turn to unbalance them while you kick their leg out from under them and are pulling them down.
It's the groin strike and the resulting shock and disorientation that follows it, that allows you to do the throw.
It's a bit of rough and tumble there, in my opinion.
So it's a slip, parry and slap to the groin, followed, by a schoolboy trip/throw, in the event of a straight punch. In the event of a hook, it's a block, or cover, protecting the head, followed by a straight attack up the center. I think a cross would be best, in that case. I do not think you'd be able to do the follow up throw in that situation. You've got to the adapt the idea of the pattern to real world self defense.
Update: I've been wondering why we do a back fist to something behind us in that technique? In my opinion it's a modification of a similar technique that's part of Southern Shaolin.
NOTE: In this update I describe a Chinese martial arts stance that I call the 'Empty Stance'. I think that is NOT it's true name. But I've NO idea what it's really called. So, I created a description of it and left a link to a video of someone performing it.
I thought the stance in the video, below, was called 'EMPTY STANCE'. https://youtu.be/LBi4VWwx5EM?t=22
I thought I heard it called "The empty stance" and I thought that was the correct name for it. Anyway I created a description so you can know what I'm talking about when I use the term 'empty stance'.
DESCRIPTION OF THE 'EMPTY STANCE'.
The feet are pressed together. One foot has only the ball of the foot touching the ground and the other is flat on the ground. The foot that is on the ball is positioned beside the other foot.
The side of the foot that is on the ball will be touching the side of the foot that is flat and it will be touching the ground at a position that is halfway up the length of the other foot. The martial artist then squats down. The martial artist will squat like a weight lifter, glutes first, with a straight back. The martial artist will NOT lean over.
If the right leg is on the ball of the foot then the right arm will be extended down and resting on the right side of the martial artist and vice versa.
The other arm will be bent sharply. The bottom of it's fist will face the martial artist's shoulder and that left arm which is bent sharply upward will be held tightly to the martial artist's left side.
END OF DESCRIPTION OF THE 'EMPTY STANCE'.
NOW back to the update. In the Shaolin technique I'm talking about they also slap to the groin in left walking stance BUT then they reach in with the slapping arm (their right arm here) and wrap it around the right arm of our enemy. Their left arm has pushed their opponent's face or other arm away. They then pull the enemy's arm, whilst stepping out into the empty stance. Whilst keeping the enemy's wrapped arm stretched tight and in close to their body. They pull away while still stretching and twisting the enemy's arm. They then drop their body into the empty stance. The enemy is somewhat compliant in all this because they've just been hit, hard, in the groin.
IMO, this is an attempt to separate the shoulder as well as being an arm break and take-down, in one. IMO, this is the purpose of the exchange motion Toi-Gye, as well.
Some Okinawan or Japanese masters, most likely, changed this movement. They took out the empty stance. They replaced it with closed stance (BTW, The empty stance is used as a vehicle for moving your mass around. In this application it's used to move your mass vertically down to apply pressure to an arm bar).
so, IMO, in Kwang-Gae the empty stance was replaced by walking stance (The upward position of the circular movement in those twin upset punches is a deflection to a strike or grab to your upper body and the stamp motion helps transfer your mass horizontally just as the steeping of say the left leg and then the right leg, into empty stance with twin angle punches, in Shaolin Kung Fu, originally did).
I think the masters changed the stance because they felt it didn't suit their purposes, for reasons. That means the Tkd application that uses the closed stance, instead, requires you to reach in further whilst wrapping the enemy's arm, perhaps almost to the armpit of that arm.
After reaching in, you will push their face (or pull their hair) away, whilst, drawing your left leg away. So you're pulling on their arm, pushing their face whilst tripping them trying to effect a separation of their shoulder. At the same time you angle your body away in closed stance so YOU cannot get struck in the groin. The hair pull/ face push of your left arm protects your own face from being struck.
Then you twist your right wrist so your back fist will face behind you. This is done in order to put even more stress on the stretched arm of the enemy.
We should, IMO, not looking directly at the enemy because that may expose our own vital areas to risk, our eyes, groin, etc. We should be facing parallel to the enemy or even slightly away, in order to protect our own vital spots and in order to properly stress their arm.
That's what I think is happening in Toi-Gye. Who knows maybe the principles of that technique can even be applied to a rear naked choke?
As in, you strike to the groin..maybe hit the face after...curl your right hand around their neck..then put your left hand on their shoulder, then squeeze whilst pushing their head to the left with your left palm. You might turn your body counterclockwise so as to protect your groin from any possible his as they struggle.
Different technique but identical principles perhaps?
Here's the origin of the circular movement in twin upset punch. https://youtu.be/ddqzRD2GnWA?t=1018
See that it's an attempt to protect your head? You ONLY apply it when someone is trying to grab you or attack your head!
(Out of context...but look at this..I'm certain I've seen a black belt pattern with right rear foot stance, left low reverse hand block with the right fist by the left shoulder. Well..here is it's application. https://youtu.be/ddqzRD2GnWA?t=1558)
Also out of context but here's an applcation of knifehand guarding block in rear foot stance as seen in Kwang Gae https://youtu.be/oL7cNpVnM2M?t=760