WING ARM – BONG SAU

Overview
Bong Sau is one of Wing Chun’s most misunderstood shapes. It is never a block. Instead, it behaves like bamboo, flexible, responsive, and able to bend without breaking. Bong Sau appears only when necessary, shaped by the opponent’s force rather than by intention. It redirects downward or cross-body pressure while preparing you to strike the moment the line becomes free.

Purpose of the Technique
The true function of Bong Sau is to respond to force that collapses your attacking line. You punch first. If pressure drives your arm down, across, or into your body, the structure moulds into a Bong Sau to remove the pressure safely. Once the force leaves the line, the shape immediately springs back into attack. Bong Sau is therefore a transitional response, not a defensive technique.

Structure & Rotation
Correct Bong Sau uses rotation through the elbow, not lifting through the shoulder. The arm curves like a wing, soft but structured. The elbow remains slightly forward; the shoulder stays relaxed. This allows incoming pressure to ride up and away rather than collide directly. The stability comes from alignment, not tension.

Different Heights of Bong Sau
Bong Sau is not one height — it adapts:

• Low Bong: used when pressure collapses the lower gate

• Mid Bong: the most common, used when force drives inward or across

Each height serves a unique purpose, all based on receiving the opponent’s force, not pre-emptive movement.

Using Bong Sau Under Pressure
Bong Sau appears because of pressure. You do not choose it first. If the opponent’s force presses down and across your arm while you are striking or controlling the centreline, your structure naturally bends into a Bong Sau to protect your line. Once the pressure is removed, it instantly snaps back into a punch or other attacking shape.

How It Connects to the System
Bong Sau is trained in Siu Nim Tao, refined in Chum Kiu, and constantly fed through Chi Sau. It transitions naturally into Fook Sau, Tan Sau, Pak Sau, or a punch. Bong Sau teaches adaptability, the ability to survive pressure without sacrificing intent or structure.

Common Lessons in Bong Sau

• Never use Bong Sau as a block

• Punch first — Bong Sau appears only from pressure

• Bend like bamboo, never stiffen

• Rotate through the elbow, not the shoulder

• Use the shape momentarily — never freeze it

• Once pressure is gone, spring back into attack