Tai Chi Basics (2) - Empty Stance
While the Bow Stance is the stable "mountain" of Tai Chi, the Empty Stance (Xu Bu)—also known as the Cat Stance—is its agile counterpart. It is a posture designed for fluidity, evasion, and quick transitions.
1. The Geometry
In an Empty Stance, the weight is almost entirely on the back leg, leaving the front leg "empty" and ready to move instantly.
Weight Distribution: Typically 80%–90% on the back leg and 10%–20% on the front leg.
The Feet: * Back Foot: Angled outward at 45°, with the knee aligned directly over the foot.
Front Foot: The foot rests lightly on the ground. Depending on the specific move, you either touch with the ball of the foot (indicating a potential kick) or the heel (often used for hooking or stepping).
Width: The heels are generally closer together than in a Bow Stance. Depending on your body facing, it can range from one-fist width to hip-width
2. Structural Checkpoints
The "Kua" (Hip Joint): You must "sit" into the back hip. The secret to stability here is keeping the Kua open and relaxed so your weight can sink into the ground.
The Spine: Keep your torso upright and your crown pulled up as if suspended by a string. Avoid leaning too far back or arching your lower spine.
The Test: A true empty stance means you can lift your front foot off the ground without having to shift your body weight at all.
3. Martial & Health Applications
Agility & Defense: Because the front leg carries no weight, it can be used for fast kicks or to quickly retreat if an opponent tries to sweep your leg.
Leg Strength: This is essentially a one-legged squat. Practicing it builds immense strength in the quadriceps and stabilizes the knee and ankle of the weighted leg.
Balance: It is the "final exam" for balance. It forces you to find your center of gravity on a single point of support.
Common Examples in the Form
You will see the Empty Stance in iconic moves such as:
White Crane Spreads Wings (Front ball of the foot). Body square-faces the front toe direction.
Play Guitar / Lift Hands (front heel of the foot). Body faces the rear toe direction.
Step Back and Repulse Monkey. (front heel of the foot). Body faces the rear toe direction.
Pro Tip: If you feel strain in your back knee, check that your knee isn't "collapsing" inward. It should point in the exact same direction as your back toes.