This post is a continuation of the post Kneeing Elbow in Biu Jee – Tangential Force and Sucking in Whirlpool Analogy, which ends with the pending question: What is still lacking for creating the whirlpool effect?
Recall the 5-gear analogy put forward in The Book of Wing Chun (Vol. 1, pp. 225-229; also refer to the post, 5-gear Analogy in The Book of Wing Chun, for an explanation). The lacking piece is exactly the 3rd gear, Propelling and Drawing Power of the Shoulder. It is in fact the first ability to open up in training Biu Jee, and is also the key for enabling the whirlpool effect. The “propelling” and “drawing” don’t mean head-on pushing and pulling by the shoulder respectively. Instead, They refer to the shoulder being able to move a full 360 degrees (for convenience, regarded as a circle), though small, both clockwise and anti-clockwise. To be specific, it is the shoulder joint socket (not the joint inside) moves a full circle; and to be precise, it is the shoulder joint socket being moved a full circle by the rib cage. It is this all-round circling ability that bridges the body trunk (body momentum the 1st gear and Chum Kiu pivoting the 2nd gear) and the arm (shoulder joint rotating the 4th gear and forearm movement the 5th gear) without disruptions throughout the swirling by navigating the shoulder joint (in the socket) to positions and directions originally not possible, and hence diligently draw out the trajectory of the elbow to give out sucking power.
The rib cage has to be free from restrictions caused by muscular contraction in the chest and the upper back. The muscles there have to be sufficiently soften-melted into the rib cage bones and joints, so to speak. This allows the rib cage to be moved by the spine via the direct connections in-between, instead of by muscles. Thus, the spine empowers the rib cage in the way that the rib cage can move the shoulder joint socket a full circle, both clockwise and anti-clockwise. Take the right shoulder as an example, when viewed from the right side, in Biu Jee elbowing, the shoulder socket is being moved clockwise by the rib cage, while the shoulder joint (inside the socket) spins the elbow as usual as in a Tarn-to-Bong or Bong-to-Tarn cycle. Note that the distinct effect seen in whirlpool elbowing is basically brought out by the activity of the shoulder joint socket governed by the rib cage.
That the shoulder joint socket can be moved a full circle has significant implications. That means when the body momentum is transmitted to the upper arm, there will have no pressing at any moment, because the shoulder joint socket is ever progressing along its prescribed circular path, however small, and will never pause to exert a strictly linear force, which is prone to be caught up and then blocked. Such non-stop progression ensures a good pass-through of the body power into the upper arm to reach the elbow, ever navigating the elbow to travel along its trajectory in the sucking whirlpool – that is, the swirling property is a direct result of the 3rd gear, which is the non-stop circling, big or small, of the shoulder joint socket both clockwise and anti-clockwise.