uk yan jong (mu ren zhuang, wooden dummy) is perhaps the most famous of the wing chun training aids. It is constructed to match the size of its intended user and is composed of a body post, two high-level arms, a single mid-level arm, and a low-level leg. When originally developed, the dummy was buried quite deeply in the ground and surrounded by loose earth. As apartments grew more common, this arrangement became impractical, if not impossible (especially if one lived above ground level), so the wooden dummy was redesigned to incorporate a solid metal base with heavy-duty springs.

Although a set form is taught at more advanced levels, a wing chun practitioner can use the wooden dummy right from the beginning to train almost any motion. Drilling on the wooden dummy helps to develop the bridges and body structure, build precision and accuracy in movements, and aid in the development of short-range, explosive energy.

Grandmaster Sum Nung is said to have combined elements of Cheung Bo's dummy into the first half of the set. The rest contains movements from the three forms and introduces motions such as butterfly palms, half-dispersing-half-wing, tiger tail kick, and rising knee.

The form itself is also practiced as hong jong (kong zhuang, air dummy). This is simply the dummy form practiced on its own, without the actual physical dummy construct.

When Antony swings at Georgia, she intercepts with a grasping arm and breaks his structure with a wing arm. As he tries to follow up, she quickly levers him around and uses the butterfly palms to seize and control his movement.