This is an introduction in to the Chu Sau Lei body structure method. Body structure or Force Flow is a vast subject and integral to everything we practice in our Wing Chun.
It is such powerful concept that by just applying the basics we discuss here you can make a big difference to your Wing Chun training.
What is Body Structure?
The term Body structure was coined by our GM Robert Chu is his 1999 classical essay: “The Root of Wing Chun Kuen Power” In this famous article he explained what is “body structure” , a method to receive, re-direct and expel force through proper body alignments and power vectors.
Hendrik Santo, a good friend GM Robert Chu, developed “6 Core Elements, 13 States and 3 Keys” model (also called 6-13-3) or template for learning and analyzing Chinese Internal Martial Arts. In recent years the 6-13-3 model has been fully integrated into Chu Sau Lei Wing Chun’s body structure method.
Now 15 years on, the body structure method developed into what is today: a comprehensive model, a skill (not a technique) with many layers of understanding, concepts and strategies to handle yourself and your opponent’s physical structure (balance, form) and energy (Jin).
We will discuss some fundamental concepts of the system, rooting ,strength and applications of Jin (劲)
First we will discuss rooting, a very important concept, it is the “ability to to lead incoming force into the ground”. Image your opponent pushes you and you lose balance? You lost your defensive and attacking options and you are in deep trouble. That’s why it is important to maintain your physical structure or form.
It is important to test your physical structure it provides you with a feed-back (expected or undesirable). We called this structure testing and we practice testing various positions in our forms and Chi Sao.
For example, testing bong sao position. One student presses in to the other student’s Bong Sao, he then must maintain his position and structure. It is basically done just like the “push wall” drill mentioned before. Use your physical structure (sink-press-rise) and relax your mind, body and breath.
Check out the video where we show you structure tests from YKYM, Lan Sao, Tan Sao and Bong Sao position.
Li (力) and Jin (劲)
In Chinese martial arts we distinguish two types of strength: Li (力) and Jin (劲) 
- Li is strength or force. It is local, stationary and muscular. For example, clench your fist, that is Li.
- The handling of Li depends mainly on tensing and loosening the physical body.
- Jin is the lively use of Li (strength, force).
- This lively use of strength “flows” from one end to the other through the physical body.
- This “flow” or “force flow” is time depend and can be linear or spiral flow.
- Thus the handling of Jin (or Force flow) relies on timely activation and sequencing of the physical body’s tendons and joints.
Jin is what is commonly used in Chinese Internal Martial Arts. To experience what Jin actually is you can do the following exercise:
- Push into a wall
- Don’t use strength (Li) use your body to press (sink, press, rise).
- Your body is relaxed and loose (song). Your mind is quite and use lower abdomen breathing
If you follow these steps you will feel the Force Flow (Jin) from your palms into your feet. Watch the accompanying video for further clarification.
Here are some applications of using Jin.
Float, Sink, Spread and Spit 
These are common concepts of power or strength used in most Southern Chinese Martial Arts and part of the 19 Mental Methods of the Chu Sau Lei system.
Here are some examples of how you can apply these concepts in Chi Sao. (See the accompany video for more details).
Fu (浮) Methods of floating, unbalancing and uprooting.
- Use pressing bong (Bik Bong) to uproot your opponent.
- Relate technique Poh Pai (butterfly palm).
Chen(沉) Methods of sinking or collapsing your opponent’s structure.
- From my Fook Sao hand in Chi Sao, I enter with a spring punch. Gladdy defends with Tan Sao and I immediately counter with Wu Sao that collapses his structure. Followed by Biu Sao and inside Pak and palm strike.
- Relate technique Jum Sao or Lap Sao.
Tun (吞) Methods of folding, swallow and dissolve an opponents force.
- From my Bong Sao hand in Chi Sao, I enter with a spring palm. Gladdy defends with Jum Sao and I dissolve his defense with Tan Sao. Followed by Lan Sao and inside palm strike.
- Relate technique Wu Sao or Bong Sao.
Tu (吐) Spit Methods of expelling and extending force.
- From my Bong Sao hand in Chi Sao, I enter with a spring palm. Gladdy defends with Jum Sao and I collapse his structure with Fook Sao (sink), followed by a spring punch (spit)
- Relate technique Biu Sao.
In this introduction to body structure, we discussed Jin, rooting or bracing and some applications in Chi Sao (Float, Sink, Spread and Sink). These are the basics covered in our Level 1 Wing Chun Syllabus. The body structure method is a very powerful concept that will greatly enhance you understanding and application of your Wing Chun techniques.
As always feel free to comment and share this post. Contact me if you have any questions.
All the best,
Chu Sau Lei Wing Chun Singapore
 Hendrik Santo, edited by Robert Chu: “Basic Wing Chun Kuen Art and Science” (2015), chapter 6, page 58 – 70.
 Alan Orr, “The Structure of Wing Chun Kuen” (2015) page 128