Many people would like me to describe the fine details of Chinese Internal Martial Arts using vocabulary from sports or physical therapy. This is always problematic for two reasons. First, one can only go so far describing kinesthetic experiences before one starts sacrificing subtlety--language is an imperfect tool. Second, by discarding Chinese concepts, one loses the primary organizing metaphors of Chinese culture, and what might be simple suddenly becomes complex.
Still, sometimes we give in to the pressure. Today is one of those days.
There are three big muscles on our backs which are extremely powerful and efficient. Unfortunately, the problem with humans is; we don’t use these big muscles very well. Our arms are just too smart. We habitually use our many smaller arm muscles to do complex and repetitive tasks. This is the cause of a lot of stress and tends to shorten our lives. For this reason advanced internal martial artists have developed ways to make use of the three big muscles.
We evolved these three big muscles as four legged creatures with our torsos parallel to the ground. This is important because on a horizontal torso the three big muscles hang in a relaxed way towards the front of the body (originally the underside).
- The diamond shaped Trapezius muscle hangs from the spine wrapping the ribcage towards the arms.
- The Latissimus dorsi muscle hangs from the spine around towards the belly and reaches around to the inside of the arms.
- The Gluteal Fascial muscle complex hangs off of the lower spine and pelvis onto the outsides of the legs.
If you naturally move from just these three muscles, you are probably a very strong and efficient cave man--because this is not how humans normally move.
To activate these three muscles is a fairly complex process. Normal sports training doesn't do it.
First we have to get them to hang loosely. Most of the time when we are moving around or working, the three big muscles are being used for stabilizing. They stabilize the pelvis, the spine and the arms. (This is an important function in the event that we get hit by a car or a buffalo, but it isn't necessary to walk around all the time using these muscles as stabilizers.)
Basic structure training in Internal Martial Arts gets us to stop using these three big muscles for stabilization by getting us to put our weight directly on our bones. The other 400 or so smaller muscles in our bodies are then used to focus force along our bones through twisting, spiraling and wrapping. In that sense, the early years of internal martial arts training teaches us to use our muscles like ligaments; or put another way, the primary function of the smaller muscles becomes ligament support. (To develop this capacity in ones legs requires many years of training.)
Once the three big muscles are relaxed and loose and the rest of the muscles are being used for ligament support, a transition begins.
The transition is difficult because it requires turning off the active quality of the smaller muscles. The main function of the smaller muscles then becomes simply to transfer force or weight from outside the body (like from an opponent or gravity) to the three big muscles of the back. The smaller muscles also have a minor secondary function of changing the direction of force coming out of the three big muscles.
This minor secondary function is not to be confused with active control. To make this transition means practicing doing nothing with your arms for hours everyday and connecting the unengaged emptiness of your arms to an equivalent lack of active muscle engagement in your legs. (In practice, this usually looks like loose flailing or slow spongy movement.)
The three big muscles are already so big they don’t need to be strengthened but they do need to be enlivened. All three muscles should be like tiger skin or octopi, able to expand and condense and move in any direction. They then can take over control of the four limbs in such a way that movement becomes effortless--even against a strongly resistant partner. If you accomplish this all of your smaller muscles will be doing the task of transferring force to the three big muscles---preventing an opponent from being able to effect your body through your limbs. Yet whenever your limbs make contact with your opponent, he will be vulnerable to the force of your three big muscles.
In the Taijiquan Classics they call this, "I know my opponent, but my opponent does not know me!"
(Note: weightlifting/surgical ideas about anatomy are so dominant that the gluteal muscle fascial complex doesn't actually exist as a picture on the internet.)