" Two extremities leading strength, two poles coiled on themselves" theory

According
to Zhang Zhijun, the most important theory to apply in Tai Chi Chuan is
called " Two extremities leading strength; two poles coiled on
themselves" (shao jie ling jin, liang tou juan qu), which can be
defined according to these three following aspects:
1) Tai Chi
Chuan generates three-dimensional diverging and converging rounded
movements. Diverging movements come from the centrifugal force
generated by an "internal opening" called -nei kai- while converging
movements come from the centripetal force generated by an "external
closing" called -wai he-.
"Two extremities leading strength" is the
centrifugal force starting from the very internal part of the body
(according to ancient Chinese) which is the "dantian", then
continuously expanding up to the extremities of the body.
"Two poles
coiled on themselves" is related to the centripetal force generated by
the "external body" with all transformations induced.
2) To
achieve a separating force up to hands you need to use your waist in
your steps. "Two extremities leading strength" induces a stretching
reaching hands. Three subtle aspects of transformations are expected:
"strength transformation," "form transformation" and "speed
transformation"."Two poles coiled on themselves" requests the waist to
"relax " entirely, that means not in multiple phases, but at once as a
single entity. Arc down contraction of the scrotum is the prime request
in Tai Chi Chuan steps if one's needs to achieve a successful change
between insubtantial/substantial (also translated empty/full) called
-xu/shi- .
3) To achieve a closing force from your hands you
need to use a (proper) technique of spine strength. Withdraw your chest
and stick the "Qi" on your chest. Bend arms and forearms. Full
coordination of legs and feet requests a (proper) technique of thighs.
Two knees are like embracing a large tree without embracing it. This
should give you the sensation you should have in your legs and feet.
Add belly and chest sucking in/out, spine and waist sticking than you
have a whole body arc. The whole body can breathe in/out with full
elasticity only if you have these three arcs.
" Two extremities
leading strength, two poles coiled on themselves" theory explains, in
fact, Tai Chi's method of three-dimensional opening/closing movements.
However, " Two extremities leading strength" expresses also the heart
of Tai Chi combat strategy.