Mike Sigman on Zhan Zhuang

Movement 2

The saying is that there are many jins, but there is only one jin. Jin-force (basically up-force from the ground and down-force from gravity/contraction) is the basis for short-power, long-power, inch-power, cold-power, spiraling power, "aiki", and so on. But jin has to be trained in application and in the conditioning that is needed to apply it well and correctly.

In standing-post (Zhan Zhuang), jin is practiced in six-directions. It's easy to confuse muscular tension with jin, but they're different things and jin is
done with the body relaxed except for the slight extension of the body, the sinking, and the perineum being held up (there's a pressure aspect, but that's beyond the scope of where I'm trying to go).

The first two jins to practice are (1.) the jin up through the body that holds the head up, which in turn gives the slight stretch to the torso that helps
propagate power through the body and (2.) the jin of weight/downward force that goes along the undersides of the body and limbs; it originates with the dantian sinking/pulling downward. These two jins are "contradictory" or "antagonistic", which over time helps condition the body.

The second two jins, which are added to the first two jins as progress develops, are the jins of forward to the hands and backward [or pulling (Lu)].
If someone is in a balanced stance with one foot forward and one foot backward, the jin to the front normally originates from the back foot and the jin to the back originates from the front foot. These two jins set up a contradiction in the front-to-back direction.

The third two jins, which are gradually added to the prior four jins, are the expansion to the sides coupled with a contraction toward the middle. The
expansion to the sides rises up from the feet (using the expansion of the muscle-tendon channels of the back of the body and outsides of limbs) and the contraction comes downward from weight and inward from contraction of the front of the body and insides/undersides of limbs.

All of these jins are derived from (A.) the solidity of the ground and (B.) the gravity force downward.

Sometimes you hear a saying that basic jin usage is "Float, Sink, Swallow and Spit". These are fairly rudimentary usages (there are more sophisticated usages) in which an opponent can be slyly "floated" by up-rising jin, or weighted into an off-balance direction by downward ("sinking") jin, or tossed
away by sinking to an incoming force, getting under the opponent's incoming force, and then rising up under the force to toss ("spit") the opponent away.

The dantian's movement is always derived from the manipulation of the jin forces, so when you talk about movement in 6H, you always have to consider the jin forces which are being manipulated by the dantian and the way the connection or "suit" is being pulled and twisted and tensed by the dantian and intent.

(Note) In the two diagrams below, look at the side-view. Notice the purple lines indicating forces coming up at a steep angle to the hands and to the point in the back between the shoulder blades. I'll have to clarify how that really works with a side article that I'll post shortly about plain jin and unity jin.