The Chinese internal martial arts technique called " Fa Jin " refers to the release of explosive power by a martial artist. Fa Jin (also known as Fajing, Fa Jing or Fa Chin) has always been known as a mysterious and even legendary strike. If you have watched any martial arts movies, you have probably seen one of the fighters, the hero in the movie, unleash explosive power without any apparent effort. This strike, in which maximum power is generated with minimum effort, is called Fa Jin.
It refers to the explosive delivery or discharge of power or the refinement of explosive power and is not specific to any particular striking method. With this definition in mind, a boxer may also perform fa jin. However, in the context of internal martial arts, the term usually refers to a range of methods for generating and focusing force, resulting in physical feats with much less visual physical expression, such as a one-inch punch.
Jìn (勁), or "power", is often confused by Westerners with the related concept of jīng (精), which literally means "essence". Jin describes the ability to generate power. Jin and qi are intrinsically linked concepts in internal martial arts. To generate fa jin, according to the traditional explanation, it is necessary to transfer qi from the dantian to the limb or body part (e.g. shoulder, head, hip) that will be used to execute the technique with explosive force (bàofālì, 爆發力). If a person is unbalanced and stiff, they have no jin, as their qi cannot enter the muscle to generate power.
Fa means "release" and Jin means "energy" or "power release". Some "experts" claim that Fa Jin is not energy but "the medium through which energy is transmitted". In other words, kinetic energy!!!
Unlike external strength, Internal strength uses the internal body components, the mind, and the martial artist's control over Qi energy. Frankly, this type of strength is very difficult to learn. Fa Jin is not thought out or planned in advance. It is a response to your opponent's actions.
Explosive Power In Fa Jin, Qi flows from the mind to the body through the nervous system. As your Qi becomes stronger, so does your nervous system. This results in a rapid, explosive release of energy when needed. From a biomechanical perspective, Fa Jin depends on both body alignment and coordination to create an efficient kinematic chain.
Although not specific to a particular striking method, Fa Jin releases, disperses, refines, or discharges explosive force. Because it is less physical than external force, it is often associated with the one-inch punch. The one-inch punch was demonstrated by Bruce Lee in 1964 at the Long Beach International Karate Championships. This extraordinary skill uses Fa Jin "explosions" to generate tremendous striking force at extremely close ranges.
In Fa Jin, the power from the legs is the main one. This power is then directed from the waist and is usually transmitted through the hands, although other parts of the body can be used. However, to generate Fa Jin, you need to transfer Qi from the dantian to the “limb or body part that will perform the technique with explosive force (e.g. shoulder, head, hip).” If a practitioner is unbalanced or stiff, the Qi cannot penetrate the muscle and the Jin that would generate power will not come out.
If there is not enough Qi, there is no Fa Jin.