Fa Jin (fā jìn, 發勁)
Wikipedia: It means to issue or discharge power explosively or refining the explosive power, and is not specific to any particular striking method. Jìn (勁), or "power", is often confused by Westerners with the related concept of jīng (精), which literally means "essence." To generate the fa jin it is necessary to create a spiral from Dantian towards the limb or body part (e.g. shoulder, head, hip) that will perform the technique with explosive force (Bàofālì 爆發力).
Yes it has a great mysterious sound that attracts too many Kyusho Practitioners... many erroneously using the term "Fa Jing". The training includes a rapid shift and compression of the body, which in all honesty will issue great power, but it is not exclusive to this action. It also is not what many choose to equate with Chi, Ki or other energy related terms.
It is simply "Velocity" folks... Do not get so carried away in mystery, concern yourself with physiology and reality.
Now of course this Fa Jin method will generate great power as it contracts the body on impact as well as rotates into the action... and yes it is an efficient release of energy, but in the form of kinetic energy, or motion or velocity. However there is a huge caution that should be stated, in that this type of action is impractical for real combatives.
It will definitely work one on one with a stationary or compliant individual as we see time after time on the internet or YouTube. But it can not be as easily accessed on a moving target, significantly less to none on a fast aggressive attacking target and completely forget about multiple opponents. You would be much better advised to use the 6-Ji Hands for the energy transfer.
Lets take a closer look at this better method... 6-Ji Hands, they have the rotational power (see "Torque" blog), the compression factor and the combined velocity that the full body "Fa Jin" method incorporates, but without the limitations. Using the hands of the Bubishi, you gain greater spontaneity, adaptability, multi-directional application, tighter fighting range up to and including body to body grappling and ground fighting. As an example of ground fighting if you are in mounted position, there is no way to use the hips and full body actions demanded with the Fa Jin method, but the energetic transference will still be in the hands. So to spend valuable time on a process that is far too limited, removes time in more productive practices.
In the Martial Arts people tend to reach for myth, mystery and just plain cool sounding stuff that others have not yet heard of. Many profess to have magical powers or the secrets to releasing a magical energy. While energy is real (nerve energy is bio-electrical and essential for life to exist), what people conceive energy to be is perhaps a bit overstated, or mis-stated or just not understood. Some even misunderstand or morph it into their own needs instead of reality, case in point:
From Vince Morris' book:
"In Evan Pantazi's modern book about pressure point fighting, the author propagates the erroneous information that striking points will "stop most of the energy from reaching the organs and thus cause their failure". Although I do believe that (to quote Hamlet) “there are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy," to perpetuate the myth that there is a mysterious energy which acts upon individual organs of the body and can be used in combat is, frankly unacceptable in light of modern medical knowledge."
He did not or could not conceive that I was discussing the neurological messaging or transmission from the brain through the nerve system for the function of the organs... he read it as a function of Chi/Ki as opposed to actual physiology. Boy he either did not read it well, or he just used a portion of the statement to twist into an agenda and swing at me (sorry Vince, ya missed the point). - Sent to me by a concerned citizen.
In conclusion, do not be like a moth attracted to a flame, experience each concept fully and realistically, you will gain more from it as you unfold the core concepts (or vital point) of all presented.
-ep