Yang Jun Laoshi stated that Tai Chi Chuan is a study and practice of cultivating energy. It is not postural; creating and holding one body shape after another. Each movement in the Hand Form is a martial art fighting technique, that issues energy in a linear fashion out of the body in a specific direction. 

Before this energy can be expressed out, first via the arms along a curve, energy from the opponent is absorbed and stored inside the body, to be returned back out along a straight path*. This is the meaning behind using the enemy’s power against them. Instead of resisting with hard force to stop their attack, using clear intent, a strategy of using softness to overcome hardness is employed by yielding. Basically, a trap is being set by, “Let the thief in the door”. Although some techniques are more complex, the majority have two parts; energy storage and energy release.

The relationship between body position and energy storage is through analyzing their Yinyang locations and potentials. It is important to be clear about the topic. 

In the technique of Push, when the arms are flexed bringing them closer to the torso, this is a yin position called Close. When the arms are extended out, this is a yang position called Open. Energetically, the close position has stored energy potential, so it is yang. When the arms are in the final open position away from the torso, and the energy has been fully expressed out, this is yin.

Compare this to the technique of “Raise Palms and Step Up”. When the arms are wide open (yang) the energy potential is also stored (yang). When the arms are positioned close (yin), the Split energy has been fully expressed out and this position is also yin.

The point is, energy can be stored either way; when the arms are open or close. It all depends on the technique. In Push (a square energy), both hands are expressing the energy together, either upward or downward. In Split (a diagonal energy), the right hand is expressing energy toward the left forward corner, while simultaneously, the left hand is expressing energy toward the right forward corner. Split energy is expressed out of both hands intersecting like an X breaking the opponent’s arm in between.  Don’t practice Form. Practice Kung; Skill. Fa Jin; Issuing Energy is a Skill. “The Energy starts in the root, is developed by both legs, directed and controlled by the waist, and expressed by the arms and hands.”                               

*Force tends to move in a straight line, unless it is redirected off course, by a counter force like gravity or resistance.