Take the stand hand as an example to build a model (see the figure below):
1. Geometrically stable triangular frame model: the lower left batten connecting the wall is fixed with the wall, and the other two battens are hinged. Theoretically (if there are no three sides restraining each other), the hinge can rotate at any angle, the hinge is smooth enough, and the friction can be ignored.
2. Simplified model of spreading hand structure: the position where the left lower batten connects with the wall is fixed with the wall (here, for simplification, the structure of the default shoulder is good enough), and the position where it connects with another batten is hinged, and the hinge is rough enough that it will not rotate even if extrapolated.
Both models ignore the gravity of the battens.
Now add the horizontal thrust on the left to the two pictures respectively.
Then the force on the left side is particularly easy to analyze, and the horizontal side can directly provide the reaction force.
The analysis on the right is slightly more complicated, as shown below:
Because the hinge (elbow) is rough enough (that is, the so-called "good hand-spreading structure"), the hinge can provide horizontally distributed force to balance the force on the right wooden bar (forearm). Moment balance. The reaction force of this distributed force makes the wall (that is, the shoulder) produce horizontal supporting force.
Although the force generated by the shoulder is the same as that of a stable triangular structure, the premise of the stability of this structure is that "the hinge is rough enough", that is, the structure should be well trained; Without using a real triangle, even if the hinge has no friction, the triangle is still stable.
Therefore, to sum up, if the stability of the hand stand structure is due to the stability of the triangle (born), then unless the elbow is relaxed when doing the hand stand, there is still a structure (which is obviously impossible), otherwise it is a mistake.
It is often seen that people explain that the triangle structure of Wing Chun is the stability of the triangle, and there are many such explanations about the official account push of Wing Chun's WeChat. Even in order to "clarify" this truth, I drew a simple sketch of the technique, with the big arm on one side and the small arm on the other, and then "connected" the handle and shoulder with a pen as the third side ...
I don't deny that the shape of the control structure is a triangle, but what does this triangle have to do with the stability of the structure …
There is no intention to target anyone. People who know this are actually unintentional. They just watch too much and can't watch any more. They pretended to write this article. This explanation is really a big mistake for scientists and engineers.
Wing Chun Boxing is a very scientific boxing method, but what we need to do is to analyze it with rigorous science, instead of arbitrarily imposing so-called science on it. Before we make a scientific explanation of boxing theory, we need to think carefully, not only in boxing, but also in physics and physiology to ensure that our explanation conforms to scientific truth. This is the scientific Wing Chun.
If you don't understand science, you can only use science by your own imagination, just like you can't box without boxing with boxers in the street. You often make mistakes that other professionals think are wrong but you don't realize.
? Yongchun Xiaobai 17.03. 18