Article: Rotating Joints and Multi-vector Force

Many years ago I asked Chu Shong Tin what I should focus on in my training in order to progress. His answer was specific to my level at that time rather than a universal maxim. Given that I was in the early stages of training he said that I should focus on rolling my joints. As Chu Shong Tin was not a stoner – what did he mean by this?

In Chu Shong Tin Wing Chun we imagine the joints to be spheres that rotate as we move our limbs. This analogy is useful especially when dealing with the shoulder and hip joints, which of course are the primary connections from our torsos to our arms and legs. For simplicity I will write about the shoulder joints, however these principles also apply to the hip joints. To be clear, this is not to do with anatomical correctness. It is about using metaphor and visualisation to achieve an outcome; primarily relaxed and free movement of the joint in question.

Imagine the bone of your upper arm, (humerus), as a stick with a ball stuck on top connecting the arm to the shoulder. Most people will be aware that it actually looks a little like that. One can easily imagine that rotating the ball in various ways will move the arm in the desired direction. Chu Shong Tin suggested imagining the ball as a small pea because a pea being soft and light concurs with the qualities we desire. To keep it simple however, I will continue to use the word ball.

Imagine a person standing with upright with their arms by their sides. If I insert a screw into the ball/shoulder joint from the side of the shoulder and rotate it; the upper arm will swing up or down. We can call the location of this screw, (X). A screw inserted at the front of the shoulder and into the ball will cause the upper arm to swing to the side, away or towards the body. Call this point ( Y ). A third screw inserted from the top of the shoulder will simply make the upper arm rotate where it is. If the arm was hanging by one’s side the effect would be to turn one’s hand to face forwards or backwards. Call this (Z). In the same way that I can use the coordinates X Y Z to locate any point in space, a combination of rotations of the X, Y and Z screws will move our elbow in any direction.

Locations of X, Z, and Y screws

One can imagine a plane flying along in space. Going up or down in height is equal to the function of the (X) screw. Moving left or right is the function of the ( Y ) screw. Spinning in a barrel-roll would be equivalent to rotating the (Z) screw. Again, the objective here is not anatomical accuracy or geometrical precision; we simply wish to apply a way of thinking that will allow the joint to move in a free and relaxed manner.

Now if we perform a Tarn Sau we can see that the (X) screw is rotating to move the elbow upwards and forwards from the body. Because we started with the palm placed on our centre the (Z) screw is also turning to keep our hand on the centre line rather than continuing across our body in the direction it was originally aimed. One could also imagine the ( Y ) screw rotating to bring the elbow in to the centre, however it is difficult to think of three rotations at once and simply focussing on (X) and (Z) will suffice.

Being aware of different vectors involved in a movement enables one to move in a certain fashion. When one succumbs to using force the tendency is to brace the body and push from the ground. This kind of force can be deflected quite easily. When we move in a relaxed manner we naturally apply multi-vector force.

The difference between the two types of force can be demonstrated quite easily. Take a short stick and hold at it each end about chest height parallel to the ground. Have someone hold the stick in the centre between your hands and ask them to resist you pushing the stick towards their waist. We can now compare two different types of force.

To begin with simply push in a straight line towards the target, (your helper’s waist). Your movement will start at chest height but aim lower to the waist. The line of attack is obvious and if your helper braces in that line they will be difficult to move.

Next, start from the same position but rather than aiming in a straight line, start by aiming parallel to the ground at your helper’s chest and then start to lower the stick while continuing to push forward. The stick will move in the same line as before but now multi-vector force is being applied. If you have managed to follow my directions the difference in the two types of movement will be obvious to you and your helper.

The idea of rolling joints has benefits beyond accessing multi vector force. Here is another very simple experiment. Stand in your stance with your fist at centre around solar plexus height. This is the position prior to executing the first punch in Siu Nim Tau. Have your helper resist your punch by standing in front of you and holding your upper arm at the elbow. Try to do the punch slowly. A more junior practitioner will feel that they are being pushed back. This equal opposite reaction will be felt mostly at the shoulder.

Now do the same movement but this time do not think of moving your fist forward; just focus on raising your elbow straight up by rolling the imaginary ball in your shoulder joint, at location (X), as described above. If this is difficult perform the action without opening the angle on your elbow. This will mean that the fist and elbow both travel straight up.

If you have managed to follow my instructions you will feel the equal opposite reactive force now pushing you down to the ground rather than backwards. Consequently the movement will be much easier. These experiments may be difficult to follow through written instructions, but when done correctly the effect in each type of movement is obvious and even a novice will be able to feel the difference. It is essentially the difference between bracing and pushing off the ground with brute strength as compared to moving in a relaxed manner. I routinely use this demonstration with people visiting my school and in most cases even absolute beginners can make the equal/opposite reactive force travel downwards. This is a fundamental skill in most internal martial arts and a prerequisite for advancement to more expert levels of Wing Chun.

~ Mark Spence