Erick Mead

In torque one stress spiral is compressing, "flowing down" while the other spiral is extending, in tension, "flowing up." They act simultaneously at right angles to one another. Because of the junctions in our "upper cross" dantian and at the hara we can split these simultaneous flows into their components (tenchi) and back again in our arms and legs, respectively.

Understand the spiral lines that I use to illustrate the simultaneous stresses in the body as connecting from the hand and opposite foot. But they do it in two ways one through the upper cross between the shoulder blades around the torso and down through the opposing leg. The other one runs down the front of the torso through the hara and down the opposing leg. The right angle, complementary relationship of these stresses is critical to understand.

Even when acting bilaterally (some forms of agete and sagete) the complementary stress relatisnship is preserved. When the hara closes (front vertical compression) -- like an abdominal crunch -- the hip girdle rotation causes the gua (thigh groin crease) down the leg to close tending to rotate the heel outward/toe inward The upper cross dantian extends creating posterior horizontal tension across the shoulder girdle and extension down the arms, turning thumb inward.

In the reverse stress profile, when the hara opens (front vertical expansion or extension) -- bowing out the chest and belly, the hip girdle rotating causes the gua to the leg to open, tending to rotate the leg toe outward/heel inward. The stress profile in the upper cross reverses,causing horizontal compression in the shoulder girdle and retraction of the arms, splaying thumb outward (asagao).

So you can seen that the expression of spiral torques in the body and limbs and the traditional CMA vertical plane up/down open/close front/back dantian or equivalent six-harmonies models are, in fact directly and mechanically related observations.

Let's take katate dori nikkyo for a more concrete example.

A lot of this following description depends on where uke actually weights his attack, and how he uses the grab, but the principle is the same regardless how he is weighted, It is just that the sense of direction of stresses may be reversed. Let's say he weights the forward foot more, holding me in place so as to strike me to the face with the free hand, a very natural attack. He might also draw me or drive me with that grab, but we will leave it as solidly neutral, intended to fix me in place for the beating he means to deliver.

I do not block his strike directly. Instead, I do one of two things to initiate the nikkyo. I can either open the connection or close the connection between us.

In opening, the rear leg is stressed as I torque from the hara down into the ground, which shortens the connected arms slightly at the same time ass the distance between us enlarges slightly, drawing stabilization weight off his back foot. I then allow that "compressed" torque to be unwound back through my body into the connection to turn it over and extend it again, while decreasing the distance between us, which causes it to buckle if done correctly. My free hand then stabilizes the connection from fully buckling by holding his fingers to my wrist --in fact, when done ki-no-nagare the buckle is not lost but progressively driven into and through his structure as that occurs. And this progressive collapse is what we call nikkyo.

The initial response is opens the front as the chest and belly naturally expand forward and the shoulders close and the arms splay out. The followup closes it again.

Static "cranking" forms of nikkyo only roughly mimic the proper dynamic state of the stresses.

If I begin by closing the connection, I torque from the hara down into the ground on the front foot, uncoiling from the hara off the back foot and thus through the opposite arm he is holding, causing it to turn over and buckle as the distance shortens while the connection extends. And then I stabilize the connection with the free hand to ensure that I can continue drive the buckle I began through his whole structure, collapsing him.

This begins by closing the front initially and immediately.

The effect on his strike in either case is profound. In opening, his holding arm is drawn like a snatched cable put in tension, and his extending strike, on the complementary spiral is suddenly compressing itself or pulling back, when it meant to be extending to hit. The unbalanced forces he is now trying to reconcile cause his whole torso to turn over his front foot, now fully weighted, turning toward his striking side, and carrying the continually diminishing strike slightly off-line on his striking side.

You could look at is as though he intended to fix his nonstriking side as the center to swing his striking side around. Effectively, I fixed his striking side in place indirectly and thus making his nonstriking side have to swing instead.

In closing, the initial buckle is driving into his holding side, and the same kind of dynamic imbalance is created in him causing his torso to run toward the non-striking side and wildly over-rotating to carry the strike off line to his non-striking side.

You could look at this as as though, again he intended to fix his nonstriking side as the center to swing his striking side around. This time I effectively fixed his center in place indirectly and made his nonstriking side add to his striking rotation, carrying him too far around and off his base.