5.a.xxiii.dang_jin Section

Dang Jin

A Bridge to Optimising Balance and Power

 (last updated August 2012)

This article is not for beginners. It assumes a considerable amount of practice has already been completed, a variety of skills achieved, a significant understanding of the body has been reached along with a considerable strengthening of the legs. The ideas of loosening (song), peng jin, opening and closing etc are all assumed. If these have not been achieved while it is likely the reader will think they understand what is written, it is almost certain that they will misunderstand and consequently train inappropriately. As in all things taijiquan, there are various paths or routes to understanding. However there is a rough order to the acquisition of skills e.g. standing, walking, running, hurdling. The improvement in a more fundamental skill will change the understanding and use of subsequent skills.

There were various stages to my understanding of the concept and construct of the dang. When Wang Hai Jun first commented to me that I “now had dang jin” I had no idea what he was talking about. ‘Dang’ was not a term I was familiar with. So I managed to gain some skill in this area without understanding or even knowing what it was. This bears thinking about. Since then I have researched and read about the idea of the dang in taijiquan for 6 years. There is very little written about it, hence this article.

What is the dang and dang jin?

In taijiquan, dang is the Chinese term used to describe the structure of the legs and pelvis. It refers in this context to the arch of a bridge (e.g. the underside of a hump-backed bridge.) The inner shape of the legs and crotch must be rounded like an upside down U shape and not be angular like an upside down V shape. This shape is three dimensional, from the tips of the toes to the back of the pelvis, like the shape of the legs of some one riding. When the legs, hips and pelvis all work in the correct manner to form this shape and it is maintained in motion, then the practitioner is said to have dang jin. Dang jin is an essential element to higher-level taijiquan skills.

How does the dang work? What does it do?

The dang has a supportive / pressure absorbing function, a protective peng jin function and a powering function. These are described below. They are not separate but all function simultaneously as a consequence of functional dang jin.

The dang acts like the springs on a car as a shock absorber, allow a practitioner to maintain balance while converting linear pressure to the body into rotational pressure (torque - stored across the body but particularly in the dang and waist,) and pressure through the feet into the ground. However, we only have two legs, so while a more appropriate simile might be the shock absorbers on a motor bike, a correctly formed and used dang provides this shock absorber capability from pressure in all directions.

The dang also has a protective, listening function is the same way the whole body has in its maintenance of peng jing and through peng jing its ability to listen and respond to contact to the lower body.

Finally the dang acts like a spring to store and release a considerable proportion of the power used in action. All the body parts of the dang (feet, shins, ankle, knees, thighs, hips and pelvis,) contribute to this power providing function though most is derived in the thighs and hips.

In the beginning the hips need to be loosened (song kua.) (See my article ‘Song Kua’ for more details.) This loosening is a long and demanding process. As the hips loosen, then the knees must be maintained in the correct alignment, with the feet placement and toe direction appropriate. The knees must be opened while the feet remain flat on the floor. The feet grip the floor slightly. The buttocks feel like they are spread open (fan tun.) In motion the ankles, knees and hips must rotate freely, conserving rotational moment to maintain balance while maximizing the release of power through the winding of the legs and rotation of the waist.

Generally speaking the feet are placed so the direction of the toes are not more than 90o apart. Three parts of the feet must remain flat on the floor, the heel, the outside ball and the inside ball, so pressure is transferred directly to the ground. If it does not and instead transfers across the foot, this will cause the foot to curl onto its outside edge and the inside edge of the foot to lift off the floor, breaking the dang. The toes grip the ground lightly, The arch of the foot is maintained as a slight hollow. This is all usually done without conscious thought. (If you need to think about it you are getting ahead of yourself reading this.)

The ankle must be loose and free to rotate.

The knees must also rotate freely. The knee initially makes a larger circle but, as understanding arrives through considerable practise, the knee circle becomes smaller and the knee stays more over the ankle when the weight is on that leg, with the shin mostly vertical. If the knee goes too far forward, too far in or too far out, the dang becomes broken and peng is lost.

The movement of the hips can be more complicated. See also my article ‘Beyond Song Kua’.) When the hips relax then the rotation of waist can be transmitted to the legs and the coiling of the legs transmitted to the torso. Transmission is not linear. I used to think of it as an anatomical version of a car CV joint. However I now see that the transmission is always three dimensional.

WHJ teaches that there are two ways for the hips to move, horizontally (Dang Zhou Hou Hu) and vertically (Dang Zhou Xa Hu). (Other teachers might refer to these types of motion as ‘first movement principle’ and ‘second movement principle’.) Initially the first mode of motion is described in his training. Initially all the postures are worked using this principle.

Dang Zhou Hou Hu can be translated as the crotch (dang – literally a bridge to the ground made by the two legs and crotch) moves (zhou) in a backwards (hou) arc (hu). When moving the perineum in a figure of eight (shift weight right while turning left and shifting weight left while turning right,) the hips work to move the jin in a backwards direction, commonly used in shoulder with the back (kao.) This type of movement is taught by WHJ during his initial training in reeling silks (see my article on Silk Reeling Motion) and when learning the choreography of the laojia yilu. Until this type of motion is weel grasped it is unproductive to think about an alternative.

Dang Zhou Xa Hu can be translated as the crotch (dang) moves (zhou) in a downwards (xa) arc (hu). It is difficult to grasp because the motion of the driving hip is similar to that of a rotating wheel in that it is important that the wheel stay down. In this case it is important that the hip stays down even as it rotates vertically. The transmission of this information was solely hands on. As my right hip rotates forward, my left hip must rotate back to balance the rotation torque. The teaching of this to me by WHJ was more circumspect, probably because I was slow to understand the first part. To do this effectively considerable leg strength is needed. Sufficient body understand or body mechanics (shen fa) must have been acquired or the subsequent distortions of the body will significantly or totally reduce any addition jin gained.

To summarise, in using dang jing, the dang must be correctly formed with peng to both knees continuously.

    1. As the weight moves onto a leg the knee opens,
    2. The hips open and the knees close helping drive from the ground (see below)
    3. Also the hips close and the knees open (see below)

The winding that occurs in the legs and across the dang is the key element of understanding dang jin. While the structure of the dang must be maintained, it is mostly a conduit for a much more important expression of skill, namely the winding or opening and closing. (This winding is typically learned in silk reeling exercises and a significant familiarity with these ideas is assumed here. See also my article on ‘Opening and Closing – Winding for power.’)

When the dang is maintained correctly, when storing and releasing the winding is directly along the leg and through the hips to the waist and upper body, with each part contributing to the power and not resisting or hindering it in any way. This is very difficult to achieve. The upwards and outwards pressure from the ground with the winding must not cause the dang to break in the hip through the hip rising above the other hip as it rotates. Otherwise much power will be lost. Similarly when neutralising, the downwards and inwards pressure to the ground with the winding must not cause the dang to break in the hip through the hip falling below the other hip as it rotates. (Taijiquan aims at balance and any imbalance must be paid for, usually costing more than the benefit derived from the imbalance.)

When winding or coiling something, the opposite ends of the coiled object must move in opposite directions of rotation. In the process of understanding this winding in the legs it is likely that some exaggeration will aid comprehension. Winding the knees in excessively is quite common in the training process and sometimes seen as a flaw in even very high level practitioners. Those same very high level practitioners also comment that this is not optimum and is better not to do. However a compromise is often the best way forward initially to gain understanding. As the skill becomes clearer and cleaner the joint positions are maintained and the coiling is inside the leg, with the maintained joint positions allow more torque to be stored and released. Considerable strength is required without the body stiffening.


Nick Gudge is a student of Wang Hai Jun and teaches Chen style taijiquan (tai chi) classes in Limerick.