Reaction Force

Discussion in 'Tae Kwon Do' started by Alexander, Nov 20, 2005.

  1. Alexander

    Alexander Possibly insane.

    O.k. This is one of those areas I'd utterly ignored (I don't tend to fight traditionally) but never bothered questioning until recently.

    I've kind of taken it for granted that the reason one hand is pulled back to the hip during the traditional punch is due to the reaction force generated in order to get more power. (Note: I'm not questionning the virtues of starting punches from the hip or a guard position - this is purely about the 'reaction hand').

    However recently I was alking to a very well respected Karate Master who said that generating more force from pulling the hand back is not possible. Apparantly the human body is not structured in a way where this could work.

    What are your views on this?

  2. Slindsay

    Slindsay All violence is necessary

    I don't know about it, I always just kinda assumed that reaction force was the same thing as getting your shoulders into a punch. Thinking about it reaction force doesnt actually make much sense as a name. It produces extra power but I suspect that is from the extra torquing of the shoulders and hips.
  3. Artikon

    Artikon Advertise here ask me how

    Pulling the opposite hand back is simply a teaching tool. When students are learning then yes it can help develop more power, but when an experienced MA throws a punch they should understand the principle enough to know how to develop that tourque without sacrificing a guard.
  4. Alexander

    Alexander Possibly insane.

    I thought it might be a tool used to get the hips into it.

    The Karate Master said it evolved as a metaphor for grabbing someone and pulling them onto a punch (hence also in Karate there are no 'blocks'; only 'recieves'). Since TKD is mainly derived from Karate I found talking to him fascinating.
  5. Kwajman

    Kwajman Penguin in paradise....

    Plus its a tool so someone can't grab your arm when you hit them.
  6. Plato

    Plato New Member


    You're on the right track my man: reaction force does generate more power, but many other factors come into play.

    (1) Both hands have to be moving at the same speed.
    (2) You have to have the hip/torque movement going on.
    (3) At the point of impact, you have to settle, or lock, into your stance firmly. This creates the downward motion of the sine wave.

    Ever notice how boxers punch? They step into their punch while the opposite shoulder shifts back? Same principle. They also stand in a pigeon stance (karate name?) which gives them fluid movements on their feet. Once they strike, they lock their stance transferring weight to the striking arm.

    When we do punching drills in Taekwon-Do, we practice keeping our shoulders straight and try not to lean into our punch. We try to focus on reaction force, hip jerk/torque movement and lock the stance on the downward movement when we punch. All of this is very, very, restrictive in self-defense and of course sounds useless to those who don't know the real purpose of this exercise. Well . . . the purpose is this:

    If you learn how to punch hard in such a restrictive way, how much harder will your punch when you're moving and not restricted?

    Good question. Thanks.

  7. Alexander

    Alexander Possibly insane.

  8. Mitch

    Mitch Lord Mitch of MAP Admin

    From the condensed encyclopaedia:

    Reaction Force
    According to Newton's Law, every force has an equal and opposite force. When an automobile crashes into a wall with the force of 2000lbs, the wall will return a force of 2000lbs; or forcing the end of a seesaw down with a ton of weight will provide an upward force of the same weight; if your opponent is rushing towards you at high speed, by the slightest blow at his head, the force with which you strike his head would be that of his own onslaught plus that of your blow.

    The two forces combined; his, which is large, and yours, which is small are quite impressive. This then is the reaction force from the opponent. Another reaction force is your own. A punch with the right fist is aided by pulling the left back to the hip.

    So, the first thing to notice is what a small part of the definition is given over to the idea of the reaction arm generating power. Secondly, I think the two parts of the definition are often confused, giving rise to the idea that pulling one arm back somehow adds more power in and of itself.

    Personally, and as I've been taught, I don't think this in itself generates power, but it does help the beginner in developing hip movement. In addidion, I think the pull back works the non-punching side of the torso. My understanding is that having the abdomen and chest tense at the point of impact poduces a more powerful technique, not because those muscles directly power the punch, but because they are the base from which it is working.

    As a TAGB practicioner I don't subscribe to the (IMHO) over-emphasised sine-wave used in some ITF schools. See the sine wave thread from recently where this was discussed in some detail.

    Theses are only my thoughts, I'm sure others may have different ideas!

  9. G50

    G50 Night Owl

    It's also to make the punch look better and stronger in front of a judge, for tournaments and gradings and things like that (my masters always told me that). You also gain more confidence while doing the punch, if your hand is brought back.

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