The Physics of Jing

by John Chang

Martial arts bookshelves abound with books and magazine articles about the ancient secrets of chi and hidden mysteries of jing. For my part, I believe much of this pseudo-mystical information can obscure the true nature of important internal martial arts principles like chi and jing. My personal hope is that the martial arts world will increasingly understand internal martial arts principles in more scientific terms. I believe that the truth can bring just as great a sense of fascination and awe as mystical legends.

Many legends tell the tale of the 90-year-old master delivering a single punch that kills an accomplished Kung Fu champion rippling with muscles in the prime of his life. Legends often attribute the master’s seemingly supernatural abilities to chi and jing as if the two are interchangeable. Yet, the truth is at least as exciting as legend.

The truth is that it really is possible for the old master to deliver greater power in a single punch than the muscle-bound opponent in his prime. Someone incapable of lifting a 200-pound weight may deliver a punch with 200 pounds of pressure. It is possible for a female to exhibit greater power than a male, and for a smaller person to wield more powerful punches than a larger person. Better still, the truth is that attaining fa jing (explosive power) does not require spiritual oneness with the cosmos, but can be readily explained by the laws of physics.

While chi stems entirely from the mind, jing results when the mind precisely controls the body. Although chi has often been equated with jing, the two are actually quite different. Ultimately, after many years of practice, the martial artist may combine the two together. I prefer to begin my students with jing to prepare them for chi. Later, I teach them to use chi to lead jing. Only much later are chi and jing combined.

Jing is considered an “internal” martial arts principle because it is mostly invisible. However, this invisibility does not mean that jing is not the result of the body’s physical movements. Jing is invisible only because it is the product of very subtle alignments in the body.

To understand the physics of jing, let’s first look at the physics of an “external” punch. External punches derive power from speed and body weight. Since Sir Isaac Newton, we have known that inertia—in this case, the transfer of power from fist to the opponent’s body—is a function of mass and velocity. When the fist carries a greater mass at a faster speed toward the opponent’s body, the punch packs greater power. For time immemorial, martial artists have maximized the power of their punches by throwing their weight into their punches, thus adding more mass to the punch, and by building their muscular strength, thus developing the ability to hit the opponent at greater velocity.

A punch that uses jing is quite different from a punch that uses external power, but is still subject to the same Newtonian laws of physics. Ideally, a punch with jing uses the earth for leverage. A punch with jing uses the mass of the earth as its base of power instead of the mass of one’s upper body. Clearly, using the mass of the earth for leverage can deliver far greater power than will ever be generated by the weight of the upper body.

Unfortunately, there is also a hard truth behind why the old masters of legends are always 90 years old. Consistently producing jing is no trivial skill that can be accomplished overnight, and often takes a lifetime of learning and practice. To deliver a punch with jing, the body must create a tight connection between the earth and the opponent’s body. If this connection is broken at any point in the body, the amount of power delivered decreases dramatically. In effect, the martial artist must turn his body into a continuous solid rod stretching from the heal of the back foot to the first two knuckles of the punching hand in the case of a straight punch. This is achieved only by precisely aligning numerous bones, joints, and other parts of the body. The connection between the earth and the opponent is most often broken at the wrist, elbow, shoulder, hip, knee, or ankle, but can also be broken at other points along the continuum. The angles of the legs, body, and arms can also greatly impact whether the power of the punch is directed into the opponent.

To illustrate the physics of jing, let’s consider a popular experiment in physics known as Newton’s Cradle. A series of metal balls are lined up, suspended by strings. When the balls touch each other, creating a solid connection from one end of the line to the other, then dropping one of the end balls will cause the force to be instantly transmitted to the opposite end ball while losing very little power. Both end balls bounce back and forth while the middle balls remain still. However, when the middle balls are spaced apart even slightly, the connection between end balls is broken and power is quickly lost when traveling from one end ball to the other. Similarly, a martial artist using jing uses his body to create an unbroken connection of bones and joints between the ground and his fist. As this connection expands with the punch, the mass of the earth is used like a lever, directing the full power of the punch into the opponent’s body.

Photo: Newton's cradle

While it is a pleasant thought that a smaller person using jing can deliver a more powerful punch than a much larger, more muscular person by using the mass of the earth, it is a mistake to think that muscular power plays no role in generating jing. Although muscular strength is not as important for jing as it is for external punches, muscles are still an important part of the physics of jing. You’ll notice the careful use of the word, “leverage” thus far. An external punch literally “throws” body weight at an opponent, but jing does not throw the earth at the opponent. Once a punch using jing has created a solid connection between the earth and the fist, that connection must quickly expand to deliver the fist to the opponent’s body. While expanding, the connection must never be broken. The faster the expansion, the more power the punch will pack. Remember, power is always a function of both mass and velocity, whether in an external punch or in a punch using jing, and velocity is always a function of muscular strength.

Muscular strength and whole-body coordination are also important in creating what we refer to as zhen jing in the 8 Step Praying Mantis community. Instead of deriving power by using the earth for leverage, zhen jing creates power from the sudden uncoiling of twisted joints. Using zhen jing alone, one can generate great power while sitting in a chair with no feet on the ground. As with using the earth for leverage, zhen jing relies on muscular strength to continue adding power to a strike as it is delivered.

Still, the 90-year-old martial artists among us can take comfort in the fact that knowledge is generally more important than muscle when using jing. There is an old saying that, “external power is created by muscle, but jing is created by bone.” Again it comes down to simple physics. Even a slight break in the connection between the earth and the opponent can significantly reduce the power of a punch using jing. Similarly, power can be greatly increased by improving how precisely the body’s bones and joints are aligned, twisted, and uncoiled, and by maintaining the correct alignment as the body uncoils and expands to deliver the punch. Superior jing is created only by a sharp mind with detailed knowledge and a lifetime of practice.