The latest blog entry “Transmissions in daily life, Part 1” presented a simple transmission for a straight punch. But, what happens when a transmission hits another transmission? Imagining this with punches and blocks is a bit too much for the start. It is much easier to look at transmissions that affect everyone in his daily life. A variety of things can happen when transmissions hit each other. A transmission that does not contact something else is just performing its intended movement. When two transmissions affect each other, the transmission with the more rigid structure will “overwrite” the other transmission´s movement. When both have roughly the same rigid structure, things get complicated. The following example will therefore concentrate on the first case.
Every time you open a door, your intended movement is “adjusted” by that door. Think for a second about the movement of opening a door. You grab the handle, push it down and push the door forward. The straight forward movement looks like the already discussed straight punch. Well, at least you think about pushing forward, don´t you? The door is fixed in the doorframe and can only rotate around its joint. So, you try to perform a straight push forward while the door can only rotate. The door certainly has a much more rigid structure then your arm. You still execute the push, but the rotation of the door is superimposed on your arm.
You are used to this. Your body doesn’t detect anything unusual. Hence, your movement is executed without any complaints. Things get more interesting when your body detects a disturbance. Your body is using a so called efference copy to model and store its own movement. Nothing happens when this internal copy matches the sensed and expected movement. If it doesn’t match the sensed movement, your body will start to adapt and tries to match it using automatism. If this fails, you have to consciously correct the errors.
Both effects, match and mismatch, are used in martial arts. You can give your opponent the impression that everything works fine for him. This way, he will go on and execute his movements. It is like the saying “Never touch a running system”. If you know what follows, it is better not to interfere so you can use this knowledge. Your body executes the push against the door without any adjustments, since the efference copy already includes the modification by the door as known and “allowed”.
On the other hand, modifying an opponent’s movement can trigger his automatism since his efference copy is different from the modification. Again, you can use this information if you know what follows. Triggering a known automatism opens the possibility to construct a dedicated counter against it. The opponent will not be able to stop these automated movements if the modification and the following counter are performed fast enough. The responsible internal feedback loops for information have certain time limitations. These limitations don’t allow for very fast adjustments.
Please be careful with argumentations based on efference copies. There are other internal feedback systems that come into play in the discussed situations (reflexes, etc.). The feedback system of the efference copy is just one among many others. Sometimes, the combination of these feedback systems will complicate a successful usage.