The body’s Center of Gravity is low belly, in Western terms the pit of the stomach. This is where you feel the misgivings when a minor chord is struck in life. Where you feel the satisfaction (“Yes!”) at life’s little victories, when you have really aced something. In Chinese, this Center of Gravity is called Tan T’ien (or Dantien in Pinyin, Tanden in Japanese.) This Center of gravity is also the center of being, the energetic reservoir, the origin of movement & realization. Think with your gut.
Posture and postural alignment allow room for the physical as well as the energetic anatomy. These exercises will start with and return to the Wu Chi posture – simple standing alignment. One might use the outside edge of a corner, perhaps the edge of a door. The alignment cue is three contact points: sacrum, between shoulder blades, base of the skull. The heels are slightly behind the edge so that you are not leaning back. Feet are parallel, toes pointing forward; weight is on Yong Ch’uan (K3) sole of the foot. Now relax, allow the weight to settle, allow the cervical and lumbar curves to open and straighten a bit, the knees unlocked. (A mild “Chin Tuck/Posterior Pelvic Tilt.”) The hands are alive, backs of the hands turned slightly forward.
“The ch’i follows the Yi” is a common sense expression; it means that where you put your attention is where you are.
Regard the Tai Chi diagram: the Yin area might be seen as the receptive listening, the Yang as the creative treating. Notice that they are balanced.