An advanced Tai Chi practitioner will also practice push hands. This is an exercise done by two people in which one tries to unbalance or uproot the other with as little force as possible - only four ounces, according to the Tai Chi Classics. The practice helps develop the qualities of rootedness and yielding as well as listening, which is the ability to react with lightning quickness to the opponent's movements.
Pushing Hands / Hand Pulls - Teui Sau / Tui Shou
Pushing hands is an advanced form used for developing an understanding of the essential meaning of tai chi - "Subtle Energy Response." After one has memorised the basic Tai Chi form, and is beginning to refine the details of the form, one may begin to learn the art of "sparring," or pushing hands. Pushing hands is an exercise involving two people, where the thirteen principle movements are applied in graceful succession, until one feels an opening in his opponent's energy flow, which he attempts to take advantage of in order to unbalance his opponent, and therefore defeat him.
Pushing hands goes hand in hand with the form. Each method helps to refine the other. After much patience and practise one may begin to truly excel in controlling one's chi, properly strengthening the body, improving balance (physically, mentally, and metaphysically), improving internal healthiness, relaxing the mind and body, and understanding how to defend one's self.
In class, pushing hands is normally taught using three basic methods: a stationary form of pushing hands called fixed step; and two moving forms of pushing hands called three step and four corners.
Sticky Hands - Nim Sau / Nian Shou
Sticky Hands is an essential first step in learning how to feel one's opponent's energy flows. The idea is to keep the hands/arms of each person in contact, following or yielding to each other's movements, attempting to maintain control. One learns how to use one's own energy flow to gain more power when striking, and to gain more emptiness when being struck. This is where the true understanding of, "a force of four ounces deflects a thousand pounds," is first obtained.
Fixed Step - Ding Bou / Ding Bu
In fixed step pusing hands, one learns how to apply the 4 primary hands of the 13 principle postures: ward-off slanting upwards, pull back, press forward, and push forward. In this form the feet should remain flat on the floor at all times, forcing you to learn how to sink the chi in order to root yourself into the ground, and also how to use internal strength to uproot your opponent.
Three Step - Saam Bou / San Bu
Three step is a moving form of fixed step. It teaches you how to apply the four primary hands of the thirteen principle postures, and to cultivate the coordination of the legs, waist, and hands while in motion. You must learn how to root yourself and apply internal strength when needed but be able to keep light on your feet while following or yielding when your opponent is in motion.
Four Corners - Daai Lei / Da Lu
Four corners is also a form of moving pushing hands. Again, the goal is to improve one's ability to respond to the energy flows of one's opponent, and to coordinate the feet, waist, and hands. In this exercise, the four primary hands of the thirteen principle postures are performed, as in three step, but this time the defender and aggressor tend to use the four corner hands to unbalance his opponent.