Recognizing and Practicing Jin (Correct Strength)

©Copyright 2010 by Robert Chuckrow

Updated 3/31/10


Taiji practitioners tend to differ on how much strength should be used when doing the solo form. Some practitioners strive to be super-relaxed, and others believe in using force against an imagined opponent. This article is intended to stimulate thought and provide insight about the use of strength in Taiji. First, some of the associated Chinese terminology will be clarified. Next, exercises will be provided for recognizing jin (correct strength). Then, we will explore the idea that jin can be practiced in the Taiji solo form, and exercises will be given for such practice.

Peng, Jin, and Li

Peng (pronounced pung) is exemplified by an upward, outward, sweeping motion of an arm, as in doing the Taiji movement “Ward off Left.” In fact, the Chinese name for “Ward off Left” has the character peng at the end.

Characters for “Ward Off Left”

Chinese characters1 for “Ward Off Left” (Lan Que Wei Zuo Peng)

Ward Off Left

Robert Chuckrow in “Ward off Left.”2

Peng requires muscular action, as does any active movement. In correct Taiji movement, however, peng should be initiated by jin rather than li. When doing the movements of the form, a small amount of jin is required for raising your arms against gravity, lowering them more slowly than they would fall, rotating your wrists, and changing the motion of limbs. Moreover, in push-hands practice, the neutralizing and pushing forces must be initiated by jin, not li.

Taiji practitioners often find the distinction between jin and li difficult to grasp, and even those who can manifest jin often have a hard time explaining it. Li is the untrained strength that most people are accustomed to using in daily life. Jin, on the other hand, is strength that is cultivated through sustained practice—usually of Taiji movement. Jin can be maintained for much longer periods of time than li and is much more beneficial to the body (more conducive to the flow of qi). When it comes to using strength against another person, li is brittle and awkward, but jin is unified and enables the one who uses it to be rooted. Thus, li is sometimes characterized as “awkward” force and jin as “correct” force. I learned a similar distinction regarding muscular action in my study of Kinetic Awareness® under Elaine Summers, which I discussed in my book Tai Chi Dynamics.3

My first teacher, Cheng Man-qing (1900–1975), who studied under Yang Cheng-fu (1883–1936), talked about developing “tenacious strength,” or “tenacity.” According to Prof. Cheng,

“Tenacity [jin] is the resistance or tonicity of living muscles. The muscles being relaxed, tenacity cannot involve the bones. Force, [li] on the other hand, is derived from muscles, binding the bones together into a wooden (rigid) system.”4

The above quote suggests that jin does not involve the contraction of muscles but li does.

Characters for peng, li, and jin.

Left to right: the characters for peng, li, and jin.

Peng jin is the application of jin to upward, outward movement, usually involving a strong action. Cheng Man-qing was renowned for his peng jin. He would demonstrate that skill by assuming a “Ward-Off” posture and inviting as many as four strong people to push his extended arm. During such demonstrations his arm did not collapse and his body moved only slightly.

Prof. Cheng demonstrating pengjin

Cheng Man-qing demonstrating peng jin.5

Recognizing the Distinction Between Jin and Li

The following is a method I have developed for teaching the difference between jin and li:

Two students pair off in a harmonious stance. One student (A, on the left) stands in “Ward Off Right,” and the other student (B, on the right) stands in “Push,” as shown below:

Two students practicing jin recognition

Two students attempting to recognize the difference between jin and li.6

Student A determines the amount of force to exert on B’s hands, and B only presents resistance to whatever force A decides to exert. A must first relax as completely as possible and then slowly build up slight force against B’s hands. The force exerted by A’s elbow on B’s palm should be equal to that of A’s wrist on B’s other hand. If A uses li (muscular contraction) to exert force, B will feel a rigidity, and if A uses jin, B will feel a spring-like, unified resistance. That is, the use of li by A feels to B as though only A’s arms were producing the force, but the use of jin by A feels to B as though A’s whole body were involved.

The following is a useful test: If A uses li, and B suddenly lets up her resistance, A will tend to fall forward. However, if A uses jin, then if B suddenly lets up her resistance, A’s body will be stable, but her outstretched arm may expand outward. This exercise enables both students to experience the difference between the two types of strength, and after exchanging roles several times, the difference should be clear. Of course, if a practitioner who already can manifest jin is present, that person should work with each student in the above manner.

Practicing Jin in the Taiji Form

For a long time, I tried to resolve what seemed to be a Taiji contradiction: On one hand, I knew that doing the Taiji form is supposed to involve no strength beyond the minimum. On the other hand, I knew that one of the purposes of Taiji practice is to develop strength. As a senior classmate of mine, Stanley Israel (1941–1999), convincingly put it, “Taijiquan is a martial art. How can there be a martial art that does not involve strength?” The three quotes below embody the seeming contradiction between no strength and strength:

(1) The following is from the Taiji Classics:

“A feather cannot be added; nor can a fly alight.”7

—Wang Tsung-yueh

This statement is sometimes taken to mean that the body should be so delicately balanced and free-moving that the weight of a feather will be felt and that a fly alighting will set the whole body into motion.

(2) Chen Wei-ming says in his commentary of Yang Cheng-fu’s ten important points:

“Someone who has extremely good T’ai Chi Ch’uan kung fu has arms like iron wrapped with cotton and the weight is very heavy.”8

(3) Cheng Man-qing talked about “swimming in air:”

“Man lives on land. His long familiarity with air often makes him forget about its existence. Since it lacks solidity and shape, it eludes attention or easy mental grasp by the beginner. To liken air to water aids the imagination. It is like water in the sense that if one pretends to swim while out of water, his movements automatically conform to the principles of T’ai Chi. By this practice, the novice will ultimately “feel” the air to be heavy in the sense that he feels water to be heavy. At this stage his body has become lighter and more pliable than that of the average man. This feeling of buoyancy and suppleness derives from firmly rooting the feet and using the body in “dry swimming.” Functionally, this slow movement against an imagined resistance will ultimately create great speed in responding to a fighting situation.”9

Prof. Cheng considered “swimming in air” to be so important that he devoted a whole chapter to it in his Thirteen Treatises.10 In that chapter, Prof. Cheng says:

“As you make progress the air will not only feel heavier than water, it will feel like iron.”11

On one hand, the body must be so free of tension that the slightest touch will cause the body to move. On the other hand, the body must be able to manifest strength—even while doing the Taiji form! These two ideas seem contradictory because if any muscular action occurs in the absence of an actual external resistance, then there must be a corresponding internal counter resistance. But that would involve pitting one muscle group against another, which would prevent the body from moving freely (and would also be against the principle of non-action). Here is my attempt to reconcile the above enigma:

It is known that the mere thought of doing a physical action is accompanied by minute nerve impulses sent to exactly the muscles that would be involved in that action. These nerve impulses are so weak that the muscles in question do not respond—or respond so weakly that there is no noticeable outer movement. Said alternatively, the nerve impulses are below the threshold for producing external muscular action. But if these impulses were strong enough, the muscular response would be that of doing exactly the physical action in mind. Note that Prof. Cheng used the words imagination, pretends, and imagined and at no point talked about using actual strength (see article: “Swimming on Land”).

Consider next, another statement from the Classics in light of the above paragraph:

“Internal power should remain in a state of equilibrium between relaxed and not-yet-relaxed. Even if internal power is interrupted, the mind should remain in continuous action.”12

—Wu Yu-hsiang

Here is another translation of the above statement:

“The chin [jin] (internal strength) is sung [song] (relaxed), but not sung; it will extend, but it is not extended.”13

—Wu Yu-hsiang

It does not take much of a stretch to interpret Wu Yu-hsiang’s meaning to be that the mind is creating implied action of the body.

Untrained people usually use li for exerting strength in voluntary physical actions, so their thoughts of doing a physical action are accompanied by nerve impulses corresponding to muscular actions involving li, not jin. But if a Taiji practitioner imagines doing an action while involved in relaxed movement, then the resulting nerve impulses will tend to cultivate muscular actions involving jin, not li.

In order to add the dimension of jin activation while doing Taiji movements, the practitioner must first practice the form for a period of time in as relaxed a manner as possible. Of course, when you do the form, some muscular action is required, but the basic idea is that an empty cup holds the most, so to learn an unfamiliar type of muscular action (jin), it is first necessary to use minimum strength for a sufficient length of time. Finally, it is of value to practice push-hands using jin, not li. Whether or not you have a partner with whom to practice push-hands, you should practice jin while doing the form in the manner discussed next.

Each movement of the Taiji form corresponds to one or more possible self-defense applications. Even if you are not studying Taiji as a martial art (quan), knowledge of some of the self-defense applications is of value. If a practitioner who is adept at using jin imagines doing each application of each movement while doing the form (or simply imagines moving against a slight resistance), then, doing the movements of the form that way exercises the processing, sending, and receiving of neural impulses corresponding to jin. Thus, you can cultivate jin by doing the solo form by using minimum muscular exertion and activating additional neural impulses corresponding to moving against a resistance. Practicing this way is important because you can cultivate jin on your own terms, at your own rate. Practicing with a partner is also essential, but in doing push-hands there is a tendency to become competitive and revert to using li.

Achieving such a feeling of resistance cannot involve any actual muscular strength, which, as we said earlier, would require pitting one part of the body against another. Thus, the intensity of the neural impulses involved here must always be below the threshold of muscular exertion. Increasing the exertiion of actual physical strength involves increasing the number of nerve impulses to a muscle. Therefore, the increase in “heaviness” of the air that Prof. Cheng talked about must be achieved by increasing the number of nerve impulses that are so activated, thus leading to the perception of increased heaviness.

Even the concept of suspending the crown may be along similar lines. Please note the use of the word effortlessly in the following quote:

“Effortlessly the chin [jin] reaches the headtop.”14

—Wu Yu-hsiang

Another dimension of practice is expressed as follows:

“ The upright body should be stable, and comfortable to be able to support (force from) the eight directions.”15

—Wang Tsung-yueh

Literally, “the eight directions” are the four cardinal and four intercardinal directions in the horizontal plane. However, by extension, “the eight directions” can be interpreted to mean every possible direction in three dimensions. Thus, in terms of the above discussion concerning imagined resistance, “controlling the eight directions” can be interpreted that, in doing Taiji movement, jin should be manifested in every direction as you move. That is, every outer surface of your body and limbs should exhibit implied strength through imagined jin. Also, to balance yin and yang, there should be implied backward jin when moving forward, and there should be an implied outward jin while bringing arms inward (to absorb an opponent’s force without collapsing).

“Up or down, front or back, left or right, are all the same.
These are all i (mind) and not external.
If there is up, there is down; if there is forward, then there is backward; if there is left, then there is right.”
If the i wants to move up, it contains at the same time the downward idea.”16

—Chang San-feng

Please note the sentence, “These are all i (mind) and not external,” and the use of the word idea.

Exercises for Imagining Resistance

1) Here is an example of the use of imagined jin in the Taiji form along the lines that I was taught by Cheng Man-ch’ing and Harvey I. Sober: When doing the “Beginning” posture, as your hands descend, imagine them falling through water, with its characteristic resistance to motion. After the hands have descended, the palms face the rear, and the shoulders and arms have a rounded shape. Next imagine the water rushing from behind you, pushing your hands and arms forward. At the end of that posture, without actually tensing anything, imagine that you need to push your hands and arms backward to prevent the water from pushing them forward. When the same stance reoccurs at the very end of the form, it is good to remain there in a meditative state while “feeling” the water pushing your hands forward.

Author in “Beginning” Posture

The author standing in “Beginning” posture, imagining water pushing his hands and arms from behind.

(2) When doing the movements of the solo form, imagine a rising limb to be very heavy, but be careful to make this perception occur without tensing anything.

(3) Each movement of the solo form involves alternating rotations of the wrists. Imagine that there is a resistance to these alternations beyond that of the natural elasticity of the tissues of your forearms.

(4) The following is an exercise that my classmate, Lawrence Galante, Ph.D., taught me: When doing Taiji movement—or when just standing still—relax your hands and imagine the space between your fingers to be springy. Without actually tensing anything, alternately imagine squeezing and stretching the space between your fingers.

I think that you will find each of the above exercises very stimulating to the sensation of qi in the hands and arms. A possible reason for this additional benefit is explored next.

Imagining Resistance and qi

Practicing Taiji or Qigong involves doing natural movement while releasing excess tension in every part of the body. It is thought that this release enables qi to flow more freely and with greater intensity. Even those who are not adept at concentrating qi can still gain the benefits of increased qi from doing Taiji or Qigong. In fact, you need not even recognize the sensation of qi to receive its benefits.

For those who are adept at concentrating qi and in sending it to a particular area of their bodies or to another person, something occurs beyond just relaxing and doing natural movement—both mind and body must be actively involved. Thus, when you concentrate qi, it is likely that, among other things, your brain is sending neural (electrical) impulses to the tissues involved. These electrical impulses are not sufficiently intense to cause your muscle fibers to contract but may well cause excitation on a cellular level. The resulting tingling sensation, perceived as faint electrical stimulation, may well result from the neural excitation of the cells and their consequent increase in the specific cellular activity discussed next.

In The Tai Chi Book,17 I wrote about Elaine Summers’ idea that qi may involve protoplasmic streaming, which is the movement of the fluid substance (cytoplasm) within a plant or animal cell. Such streaming facilitates the exchange of cellular waste products for oxygen and nutrients. Interestingly, single-celled life forms locomote by means of changes in cellular shape resulting from protoplasmic streaming. I also wrote that glands and organs may intercommunicate and balance their functions through wave motion produced by synchronous changes in shape of groups of cells. These proposed activities account for some of the benefits attributed to qi and may be enhanced through conscious neural stimulation of cells.

Thus, if (a) moving against an imagined resistance involves sending neural impulses that stimulate protoplasmic streaming and (b) qi is related to protoplasmic streaming, then “swimming in air” can increase qi and its resulting benefits. My experience certainly bears out this conclusion.

In Closing

It should be recognized that the images of using strength against an external resistance described in this article are just teaching devices. They should be “put in your back pocket” once the skills learned from them become second nature.


1The Chinese characters in this article were drawn by Jizhen Sun Bredeche.

2From Robert Chuckrow, Tai Chi Dynamics, YMAA Publication Center, Inc., PO Box 480, Wolfeboro NH 03894, 2008, cover.

3Ibid., pp. 4–7.

4Cheng Man-qing, Taiji Ch’uan: A Simplified Method of Calisthenics for Health & Self Defense, North Atlantic Books, Berkeley, CA, 1981, pp. 16–17.

5From Taiji Ch’uan, Body and Mind, published by Tai Chi Chuan Association, 211 Canal Street, New York, NY, 1968, p. 32.

6From Robert Chuckrow, Tai Chi Dynamics, p.51.

7Lee Ying-arng, Lee’s Modified Tai Chi for Health, Mclisa Enterprises, P.O. Box 1755, Honolulu, HA 96806, 1968, p. 39.

8The Essence of Taiji Ch’uan, The Literary Tradition, Edited by Benjamin Pang-jeng Lo, North Atlantic Books, Berkeley, CA, 1985, p. 87.

9Cheng Man-qing & Robert Smith, Taiji: The “Supreme Ultimate” Exercise for Health, Sport, and Self-Defense, Charles E. Tuttle Co., Rutland, VT, 1969, p. 10.

10Cheng Man-qing, Cheng Tzu’s Thirteen Treatises on Taiji Ch’uan, North Atlantic Books, Berkeley, CA, 1985, pp. 36–39.

11Ibid., p. 39.

12Waysun Liao, Taiji Classics, Shambhala, Boston, MA, 2000, p.120.

13The Essence of Taiji Ch’uan, The Literary Tradition, Edited by Benjamin Pang-jeng Lo, p. 50.

14Ibid., p. 33.

15Ibid., p. 22.

16Ibid., p. 55.

17 Robert Chuckrow, The Tai Chi Book, YMAA Publication Center, Inc., PO Box 480, Wolfeboro NH 03894, 1998, p. 20.


©Copyright 2010 by Robert Chuckrow. Revised 5/16/11.


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