The Thirteen Energies or Postures
Taichiquan (Tai Chi Chuan), was not a single entity from its origins, but rather it evolved, through the monks' observations, discussions, ponderings and experimentations with movements and energy flow. The thirteen postures (consisting of Eight Energies or Gates and Five Steps) were the original movements of the first attempts to put together a single set in H'ao Ch'uan (loose boxing) which later became known as Taijiquan. There are many interpretations of the meaning of 'Taichiquan' the most common being 'Supreme Ultimate Fist'. However, Taijiquan means more than that. Master Jou Tsung Hwa explain it thus:
"Now, in the case of “tai chi chuan,” it means the martial practice of the state of “tai chi” (the change from no polarity to great polarity). That is why tai chi chuan delves into a serious study of the balance of yin and yang – physically, mentally and spiritually. The goal is to understand this balance in yourself and to be able to manifest a change in your balance of yin and yang. Then, if desired, you can extend that study out to martially affect an opponent. Yet, the martial arts need not always be expressed as outright sparring. The same principles can be used to affect the balance of yin and yang in anything outside of your body – this includes: your lifestyle, your working environment, your opportunities, manifestations, and so on." (www.internalgardens.com)
The Thirteen Postures are grouped into 2 categories: The first being the eight ways of directing energy with the arms. These are known as the Eight Gates which are said to be associated with the eight trigrams (Bagua) of the I Ching. The second category is based on stepping and there are five ways of stepping, named the Five Steps. These movements are associated with the Five Elements: metal, water, wood, fire, and earth.
The Thirteen Postures is also known as Bafa Wubu. Ba means ‘8’ and Fa means ‘method’. So, Bafa are the 8 hand skills. Wu means ‘5’ and Bu means ‘step’. So, Wubu refers to the 5 footwork skills.
The Eight Gates
The first four energies can be found in the Grasp Peacock's Tail posture and are known as the Four Primary Hands:
1. Peng (ward off)
(The first part of Grasp Peacock's Tail)
Peng is the primary energy and can be seen in all other energies. Peng is 'moving' energy and has an expanding, opening quality, likened to filling a balloon, or how wood can float on water. It is like a buffer zone. Rather than exercising raw physical strength Peng trains a connection from the ground, through the body with the mental intent of opening and expanding through the arms ultimately uprooting the opponent. Using yang jin (jin meaning energy), we ward off any kind of attack. When moving, receiving, collecting, and striking, Peng energy is always used.
2. Lu (roll back)
(The second part of Grasp Peacocks' Tail - drawing both arms to the side and down slightly)
If Peng is 'moving' energy, then Lu is 'collecting' energy. It has a yielding absorbing quality where one is connecting to the opponent’s oncoming force, and moving in the direction of the force whilst ‘sticking’ or ‘adhering’ and ultimately leading that force into emptiness. Lu energy is receiving and collecting energy, or inward receiving energy. The greater the force of the opponent’s attack, the greater his loss of balance.
3. Ji (squeeze or press, depending on interpretation)
(The third part of Grasp Peacock's Tail, where we centre first, the the hand on the wrist)
If Peng is moving energy and Lu is 'collecting' energy, then Ji is 'receiving' energy. Ji is a yang attacking movement and means to 'press', although the Chinese character means to squeeze. Again, the power comes from the centre at lower dantian. The elbows are squeezed inward as the lower dantian also squeezes. One hand is placed inside the wrist. This hand is yin, while the outside hand is yang. This is a whole body movement and not only an arm movement and is designed to disturb the opponents equilibrium. Ji energy is to ‘advance to receive and adhering to the opponent. It is not a push, but rather like a coin bouncing or rebounding on a drum.
4. An (push)
(The final part of Grasp Peacock's Tail, where the energy is pushed forward onto the attacker)
If Peng is moving energy, Lu is 'collecting' energy and Ji is 'receiving' energy, then An is 'striking' energy. This is a yang attacking movement coming from the whole body issuing yin and yang Qi into the attacker's vital points on his chest. The push comes from connecting to the ground, through the feet, pushing from the feet, into the palms and uprooting the opponent. Never in Taijiquan is there a two-handed strike or attack using the same power in each hand at the same time. Experienced tai chi players will use a 'fa-jing' in the waist causing one hand to strike just before the other. The hands are firstly yin, then yang thus releasing yang Qi into the attacker.
The following four energies are said to make up the Four Corner Hands
5. Tsai (or Cai) (grasp or pluck)
This energy has a 'pull down' movement, and in martial applications is a snap, with a violent jerking fa-jing application. As always, the power comes from the centre and not only from the arms and hands. It can be likened to picking, or plucking fruit from a tree with a snap of the wrist. Often one hand will be placed right on top of the other wrist to assist in the power of this jerking motion.
6. Lie (or Lieh) (split)
Lie is an opening, splitting or striking movement which separates parts of the opponent’s body in two directions. In a martial application scenario, place the leg behind the opponent’s whilst connecting their own arm across their chest and turning from the centre causing the opponent to fall backwards with the opposing forces being applied to the upper and lower parts of their body. Postures with Lie energy are Part Wild Horse's Mane, Slanted Flying and White Crane Spreads its Wings.
7. Chou (or Zhou) (elbow strike)
Known as an elbow strike, it is another method of attack used when the opponent is in close proximity. It is often a secondary strike. And, of course, the force is coming from the centre, and propelled from the feet.
8. Kao (lean or shoulder stroke)
Often called a shoulder strike, it is not a primary attack, but rather a line of defence. The power comes from the centre using the legs and waist together. It is a full body strike energy. The Peng energy is mobilized throughout the entire body, and then the entire body is used as one unit and the force is delivered with the shoulder or back.
The Five Steps
The five movements that make up the rest of the thirteen postures are steps, or directions:
1. Move forward - advance
2. Move backward - retreat
3. Stepping to the right
4. Stepping to the left
5. Balance, settling and centring
These movements are used for attack, retreat, to readjust, to remain centred and balanced. Movement is continuous, smooth and with purpose. These five steps are also associated with the Five Element Theory, and the Eight Trigrams (Bagua)
For more information, Tai Chi World and Tai Chi Forum have detailed descriptions of martial applications and use of of the Thirteen Postures. Egreenway is also an excellent reference.