Trapping is one of the things that sets Wing Chun apart. It’s the skill of controlling a partner’s arms so they can’t be used to defend or attack, creating an opening for your own technique. At the heart of much Wing Chun trapping is a simple but clever movement called lap sau. This article explains what lap sau is, how trapping works and why, at our school, we build it on a solid foundation of structure first.
What is lap sau?
Lap sau means “pulling hand” or “grabbing hand”. In its basic form, one hand grips or hooks a partner’s wrist or forearm and draws it downwards and across, while the other hand strikes. It’s a short, sharp movement, not a big tug. Done well, it disrupts a partner’s balance and structure, and clears a path for your strike.
Lap sau is also the basis of a classic partner drill, sometimes called the lap sau drill, in which two partners cycle through bong sau, lap sau and a punch in a continuous flow. It’s one of the best drills for developing timing, coordination and the feel of changing between techniques.
What is trapping?
Trapping is the broader skill of controlling one or both of a partner’s arms. The aim isn’t to hold on. It’s to pin, jam or redirect an arm for a moment, just long enough to strike or change position. In Wing Chun, trapping happens at the “bridge”: the point where your arms and your partner’s arms meet.
Techniques commonly used in trapping include:
- Lap sau: pulling an arm down and across.
- Pak sau: slapping an arm aside.
- Jut sau: a short, sharp jerking movement downwards.
- Pinning: using one arm to trap both of a partner’s arms momentarily.
Controlling the bridge
The bridge is a key concept in Wing Chun. When you make contact with a partner’s arm, you gain information: you can feel their pressure, direction and intention. Controlling the bridge means using that contact to stay safe while creating opportunities. Trapping is one of the main ways Wing Chun uses the bridge.
This is where chi sau, the sticking hands drill, becomes so valuable. It develops the sensitivity to feel when an arm can be trapped and when it’s time to change.
Why trapping comes after structure
Without structure, trapping fails
If your stance is weak or your elbows are out of position, you’ll struggle to trap effectively. A strong partner will simply pull their arm free or push through. Trapping relies on good body mechanics, not arm strength.
Without sensitivity, timing is wrong
Trapping is all about timing. Grab too early or too late and it won’t work. That timing comes from sensitivity, which comes from drills like chi sau.
Without the basic hand shapes, you have nothing to trap with
Lap sau, pak sau and the punch all come from the forms. Students need to know them well before they can combine them smoothly.
That’s why, at our school, trapping is introduced once students have a good foundation in Siu Nim Tao, the basic hand shapes and simple partner drills.
How we train trapping
- Single techniques: learning lap sau and pak sau on their own, with a partner feeding a steady arm.
- The lap sau drill: building a continuous, flowing exchange between partners.
- Applications: for adults, applying trapping with a partner in a controlled way, gradually increasing realism and pressure.
- Chi sau: developing the sensitivity to trap when the opportunity arises, rather than forcing it.
Common beginner mistakes
- Pulling with the arm alone instead of using the body.
- Holding on too long instead of releasing and striking.
- Leaning forward and losing balance.
- Forgetting to protect the centreline with the free hand.
- Using too much force, which tells your partner what’s coming.
A skill that grows with you
Trapping is one of those skills that keeps developing for years. Early on, it feels mechanical. With practice, it becomes fluid and almost instinctive. It’s a big part of what makes Wing Chun so fascinating to train.
Learn trapping the right way
If you’d like to learn lap sau and trapping on a proper foundation, adult classes run Monday to Thursday, 7:15 pm to 8:15 pm, and Friday, 7:05 pm to 8:05 pm. Read more on the adult Wing Chun classes page, then book your free trial class. You’ll find our full timetable on the Wing Chun classes in Halesowen page.
Sifu Alan Bagley, Wing Chun Halesowen