T’ai Chi Ch’uan (or Taijiquan) is a martial art, which the character “Ch’uan” (or “quan”) means. Thus it’s shenfa or “body method” should have a clear martial purpose. The purpose of balance is to withstand force and to support the structure on the impact from issuing a strike.
The purpose of body connection and whole body movement is to develop whole body power. When striking, throwing or any martial application, the whole body should be used. The power of Tai Chi does not come from use of an isolated movement of a limb. Instead, the power comes from clever use of the whole body, from the sole of the foot to the palm of the hand.
The Tai Chi Classics says:
rooted in the feet,
generated from the legs,
controlled by the waist, and
manifested through the fingers.
The movement is not sequential. Some pactitioners mistake this for a whip like movement. But the classics clearly says that the whole body must work as a whole:
The feet, legs, and waist should act together
as an integrated whole,
If correct timing and position are not achieved,
the body will become disordered
and will not move as an integrated whole
Compare with the sayings from Xingyiquan: “When one part of the body moves, the whole body moves [together]. When one part of the body stops, the whole body stops [together].” The same mechanics and the same feeling should be there in Tai Chi. There must be a direct connection from the foot through the hand. In every transition, when you step down or move your weight into a foot, the sole of the foot must be felt directly and instantaneously in the palm of the hand.
This direct connection is only accomplished by a careful coordination of the body as a whole. It must move together. The Tai Chi shenfa is compact even if it appears large and bold.
When the hand strikes, it is the body that should strike, not the limb. In other arts, the body is just to throw out the arm and support it upon impact. But in Tai Chi, when the hand reaches the goal, the whole body moves into the target. Upon impact, there is a sudden, explosive movement. It’s very sudden and very fast. This is what is called fajing. The fajing of the body center should be used to strike with, not only the fajing of the arms. There is a great difference between striking your enemy with the middle of you body through your hand, or using the body movement to strike with your hand. The difference is about using your body as a whole upon impact. Only through experience and practice, and by feeling the difference yourself, you will understand how superior one method is over the other.
The power issued in Tai Chi, regardless if it’s about a take down, qinna, a throw or a fist or a palm strike (or by hitting your opponent with any of the “seven stars”), should be tremendous. But if you can not learn whole body movement and how to trust in softness and relaxation, so that your body will work for you, you will not learn what the power in Tai Chi is all about.