Is Active Muscular Extension Possible?

©Copyright 2008 by Robert Chuckrow (revised on 7/9/18)

We will explore the hypothesis that muscles can actively extend, namely, that muscle tissue can expand under the action of neural stimulation. I have thought about and experimented with this hypothesis since the mid 1970s and have become increasingly convinced of its truth. Until recently, the evidence was based on what I and others have been experiencing. Now the experiential evidence is supported by scientific research at the University of Washington, led by Dr. Gerald Pollack. That research on water and its effect on cellular action provides a mechanism by which tissues can lengthen that corresponds closely to what I have been experiencing and describing for decades and what others can experience if so taught.

First, I will explain how I was introduced to the concept of active muscular extension (AME). Next, I will respond to questions that have been posed to challenge the hypothesis. Then, I will provide some experiential evidence for AME. Finally, I will summarize a promising mechanism for AME.


I started my study of Kinetic Awareness® (KA) in 1974 under Elaine Summers (1925–2014). KA is a system of natural movement and self-discovery originated by Summers, which includes the concept that muscles can actively extend. Summers called this phenomenon extension tension. Much of her work in analyzing bodily movement and helping injured dancers recover was based on this concept. There is great therapeutic benefit to relinquishing the contractive strength (to which most of us are habituated) and slowly and mindfully extending the muscles that are in trauma.

Decades ago, I began to realize that AME was the key to what in T’ai Chi is called jin or “educated strength” (as opposed to li or “ordinary strength”). This realization greatly enhanced my progress in T’ai Chi (read about Peng, Jin, and Li). More recently, I have come to understand that AME beautifully describes an important state in T’ai Chi called kai (open, expanded, activated), which is the yang counterpart to sung (release) (read about Sung Kai).

In my book, Tai Chi Dynamics,1 which was published in July, 2008, I stated the hypothesis that muscles can actively extend. I utilized that concept to explain natural and reverse breathing and also the important distinction between jin and li. Moreover, I applied that concept to a number of other often-elusive T’ai-Chi applications. I stated then that I experienced muscular extension as hydraulic pressure wherein a change in pressure at any part of the body is transmitted to every other part of the body.

Shortly after publication of Tai Chi Dynamics, reviews of it appeared that asserted the scientific impossibility of AME. It was stated that muscle-cell activity is fully understood and that it is impossible for muscles to actively extend. I was able to answer questions challenging the possibility of AME, but at that time, only experiential evidence was available, and a satisfactory physiological mechanism for AME was lacking. I have since learned of a promising mechanism, which is summarized toward the end of this article.

The Current View of Muscular Action:

(a) Muscular action results solely from the contraction of muscle fibers along their length.

(b) The contraction of muscle fibers is activated by neural impulses from the brain, spinal cord, or other muscles.

(c) Muscles are arranged in opposing pairs.

(d) The contraction of a muscle on one side causes the muscle(s) on the other side to elongate (extend).

The discussion that follows agrees with the above view except for the word solely in (a). Namely, we advance the hypothesis that there is an additional way in which muscles elongate (other than solely by the contraction of opposing muscles); that is, contraction is not the only feature of muscular action, and muscles can actively extend.

Questions and Responses to Them

(i) How can it be that there is a new mode of muscular action when the mechanism of muscular movement is well described in cellular and molecular biology?

Not everything is known about the physiology of muscular action. Moreover, throughout the history of science and medicine, phenomena have periodically been found that were originally thought to be impossible, and new ideas and concepts have replaced old ones.

Only extensive scientific investigation can rule out the possibility of something. Even then, the “door” is left open as many phenomena that were thought to be impossible have later been found to be possible. Thus, nowadays, scientists make a statement of the impossibility of something very cautiously and only after extensive and objective study of the allegedly impossible phenomenon. Instead of automatically rejecting something that is outside the current conceptual framework, true scientists express doubt, skepticism, or curiosity—and often welcome apparent contradictions as an opportunity to pursue a new, valuable line of research.

(ii) Even if such a muscular extension could occur, it would mean that the muscle would have to exert force to the bones by pushing the bones with the use of the tendons. A tendon is like a cable, which is good at pulling, not pushing. How can a tendon push?

A cable can exert a pushing force. Cables are used to exert pushing force in machinery and automobiles. A cable can push if it is enclosed in a sheath that keeps it from buckling. In the human body, tendons lie within tunnels consisting of highly resilient tissue surrounding them. These tunnels keep tendons, which do not lie along straight lines, from undergoing any lateral movement— either straightening (“bowstringing”) or buckling—thereby enabling them to pull or push bones.

(iii) If AME is so powerful, why are all axial skeletal muscles arranged in opposing pairs? Why not a single muscle that can do both active contraction and extension?

An analogous question can be asked of why we have two eyes, two nostrils, two ears, two kidneys, two testicles/ovaries, etc., one on each side, when one would do. The answer is that functional redundancy is common in the human body. Having eyes and ears on both sides adds the perception of visual depth and auditory directionality, respectively. Similarly, having opposing muscles provides much greater strength and more movement options.

Most of us fall far short of our full movement potential. One of the very purposes of studying T’ai Chi and similar arts is to learn to utilize and cultivate unconventional movement options.

(iv) If AME is possible, wouldn’t it be possible to do a pull-up without using the biceps, and wouldn’t not being able to do a pull-up without using the biceps rule out any possibility of AME?

Contractive strength is ideally suited for doing large-range movements during a short amount of time and without the need for sensitivity or precision. On the other hand, expansive strength is better for sensitively doing short-range, precise excursions for sustaining a position against an opposing force or neutralizing an incoming attack. Short-range movement is consistent with the T’ai-Chi principle that neutralizing and striking originates in the legs and “waist” and not in the arms. By contrast, a pull-up involves a highly localized, large-range muscular action of the arms requiring a relatively large amount of strength for a short time. Contractive strength excels for that kind of action. In contrast, expansion excels for T’ai-Chi movements, which involve small excursions of all body parts in a unified manner. In a self-defense modality, small unified excursions send a wave through the body, causing arms to have large, relaxed, explosive movement, ending in a strike involving the whole body, connected as a unit. Such movement was in large part responsible for the highly successful, deceptive aspect of T’ai Chi Ch’uan as an internal martial art (strength concealed in softness).

Not being able to do a pull-up without using the biceps would not rule out the existence of AME; it would only mean that not every action can be done with AME alone. Some actions such as pull-ups may well require utilizing both AME and contractive muscular action.

Some Experiential Evidence for AME

Note: To maximize the desired effect in the following explorations, it is important to do the following throughout:

(1) Relax contractive tension of the part(s) being moved as much as possible.

(2) Imagine movement while in a relaxed state without doing any actual movement, which results in neural electricity being sent from the brain and spinal cord to the part imagined.

(3) Feel the state achieved in (1) and (2), and capture that feeling.

(4) Only then do actual movements while recreating the feeling attained through imagination.

Trying the following exercises (some of which are described in Tai Chi Dynamics) should, at the very least, lead you to be skeptical of the conventional idea that muscles cannot actively extend:

1. Opening Your Hand. Sit or stand in as relaxed a manner as possible. Hold your arm in front of you such that your relaxed hand is about 12 inches from your body. Imagine that you are holding a balloon in that hand and that the expansion of the balloon is opening your hand. Remember that it is important not to do any actual movement at first. Then, slowly open your hand a tiny amount, paying special attention to the feeling of the palm of the hand and the inside of the forearm as compared to the back of the hand and the outside of the forearm. See how open you can make your hand without losing the feeling just referred to.

Once you are familiar with this action, try the following other way: Open your hand by pulling it open with the muscles that attach to the back of your hand. Again, as your hand opens, pay special attention to the feeling of the palm of the hand and the inside of the forearm as compared to the back of the hand and the outside of the forearm. See how open you can make your hand without losing this new feeling.

Compare the difference in feeling between the first and second ways of opening your hand. Moreover, extension results only in opening the hand but not straightening your fingers whereas contraction can cause your fingers to actually hyperextend (bend backwards). Last, compare the feeling of ch’i in the two hands for both ways. I think that you will find that extension provides much more ch’i.

It might seem that you can’t open your hand as much the first way because you are stuck with the image of a balloon opening it, and a balloon is always convex. Actually, the image is only a way of identifying the feeling of a different way of using your muscles. Once that feeling is experienced—and it may take quite a few tries before it is—you should put the image aside, and work only from the feeling.

2. Opening the Space Between Your Fingers. Repeat the elements of the previous exercise, this time opening the space between your fingers.

3. Rotating Your Wrists. Stand with feet parallel. Extend one arm (say, your left arm) forward of the body. Let the wrist find its neutral orientation (neither rotated to the right or left). Next, rotate your palm downward in two different ways:

One way is to to pull your left palm heel downward by contracting the muscles on the inside of your forearm and to pull your left little finger upward by contracting the muscles on the outside of your forearm. This is the conventional way of moving.

The other (unconventional) way is to push your left palm heel downward by extending the muscles on the outside of your forearm and to push your left little finger upward by extending the muscles on the inside of your forearm. Notice that in the second way of moving, the hand does not rotate fully , but in the first case it does. Also compare the amount of ch’i in your hand for the two ways.

4. Extending Your Hamstrings. Stand with feet parallel. Lean forward and let your upper body hang from your hip joints, knees somewhat bent. Relax the head, arms, and back as much as possible. Remaining so, next try lifting the pelvis in two different ways:

One way is to push the knees back, causing your legs to straighten. In this case, the muscles on the back of the legs are forced to lengthen by the contraction of muscles on the front of the legs. This is the conventional way of stretching.

The other (unconventional) way is to extend the legs by lifting the sitz bones (the two bony lobes of the pelvis that rest on a chair while sitting). In this case, the muscles on the front of the legs are not actively involved. Instead, the muscles on the back of the legs lengthen by their own action. Notice that in the second way of moving, the legs do not totally straighten, but in the first case they do.

5. Extend Your Hamstrings Again. Lie on your back on the floor, knees up. If you need to, place a pillow under your head to achieve an optimal alignment of the cervical vertebrae. After attaining the most-relaxed state you can, slowly lift one knee, balancing that leg on the pelvis, relaxing it as much as possible, and feeling the weight of your leg resting on the pelvis. Next, slowly extend the heel upward. When you start to feel resistance, that is your working point. The goal now is to ease your heel upward without tensing the muscle on the front of your leg but by extending the muscles on the back of your leg. That is, the muscles that are getting longer are doing so at their own rate rather than being bullied by the opposing muscles. Should you start to feel the knee clench, you have substituted contractive movement for AME.

6. Extending Your Hip Adductors. The hip adductors are muscles on the insides of your thighs, which when contracted rotate your knees inward. Lie on your back on the floor, legs straight out, with heels touching each other. If you need to, place a pillow under your head to achieve an optimal alignment of the cervical vertebrae. Without moving your pelvis or the heel of one foot, extend that knee horizontally a tiny amount away from the axis of your body. Even if you have trouble at first, you should be able to eventually learn to move your knee an inch or more in this manner.

The conventional view of the above experiment is that contracting (shortening) muscles on the outside of the thigh is the only action that can cause the opposing hip adductors to lengthen. However, in the above action, the muscles on the insides of the leg are lengthening, but those on the outside are relaxed. If you feel the muscle on the inside of your left thigh with your hand, you will notice that it is activated and lengthening when you move your knee outward by extension. If you feel (or have another person feel) the muscles on the outside and bottom of your left thigh, those muscles should be totally relaxed. These occurrences cannot be explained by the conventional view of muscular action.

Moreover, in doing this exercise, you should also be able to feel that your left thigh joint is actually opening slightly. It is unlikely that these actions could occur by contracting (shortening) muscles.

7. Extending Your Abdominal Muscles. Experiment with your abdominal muscles by contracting or expanding your lower abdomen. You can do both of these actions just by using the same set of muscles and no others including the muscles for breathing.

8. Extending Your Sphincter Muscles. When you urinate or move your bowels, pay attention to what you do with your sphincter muscles, which are normally relaxed but taut. When you excrete, you extend these muscles and can directly feel that extension. Next, try contracting these same muscles. Note the difference in the feeling.

9. Extending Your Diaphragm. Feel your diaphragm expand upward and outward when you cough or breathe out sharply.

10. Extending Your Trachea. Feel your trachea (wind pipe) expand when you breathe in—and even more so when you yawn.

11. Extending Your Nostrils and Nasal Passages. Feel your nostrils flare and your nasal passages expand when you inhale.

12. Extending Your Head Upward. While standing in your best, relaxed posture, extend your head upward by creating subtle expansion of the space between the cervical vertebrae. The movement should be almost microscopic.

13. Tilting Your Head Sideways. While standing in your best, relaxed posture, tilt your head two ways:

One way is to pull your head to the side by contracting the muscles on the side toward which your head is tilting. That way forces the muscles on the other side to lengthen.

The other (unconventional) way is to extend the muscles on the side that is getting longer and just relax the muscles on the other side.

A Promising Mechanism for AME

Dr. Gerald Pollack has been directing research on hitherto disregarded properties of water and cellular phenomena at Washington State University for decades and has discovered an important feature based on the restructuring of water under certain conditions (see video on some unusual aspects of water). Our cells are primarily water, and his research indicates that neural electricity can restructure water in cells, resulting in their expansion and the consequent lengthening of muscles (read a review of one of Dr. Pollack’s books, Cells, Gels, and The Engines of Life).2

I have been pondering Dr. Pollack’s research for the past several years. The concept that water in the cells can be made to expand is quite satisfying because it closely matches what I experience with AME; namely, I feel as though I am sending neural electricity to my muscle cells, and it feels as though the water in those cells is expanding as a consequence. In fact, I experienced those effects for quite some time and described them in similar terms before learning of Dr. Pollack’s research.

If the concept that the expansion of cellular water can result from the application of neural electricity, it nicely explains why AME can be sustained without fatigue for much longer periods of time than muscular contraction: Aside from the relatively small amount of chemical energy required for its neural activation, muscular contraction requires chemical energy and results in the production of lactic acid, which is irritating. Contraction restricts the circulation of blood that transports nutrients into muscles and waste products out. Thus, chemicals needed for contraction soon become depleted, and irritating waste products soon build up. These factors limit the time that contraction can be sustained. On the other hand, if extension is based on an intrinsic property of water, it only requires neural electricity for its activation—no chemical energy other than that for neural activation is required, and no irritating waste products result. In fact, a wonderful byproduct of extension is that circulation of blood is not restricted but actually increased, and the accompanying neural electricity is highly therapeutic.

In Closing

Any questions, comments, or references to scientific articles that shed light on AME will be welcome (email: rmp at bestweb dot net).

1Robert Chuckrow, Tai Chi Dynamics, YMAA Publication Center, Wolfeboro, NH, 2008, pp. 1–23.

2Gerald H Pollack, Cells, Gels, and the Engines of Life, Ebner and Sons Publishing, Seattle, Washington, USA, 2001.

Related Articles

Cultivating the Correct Internal State in T’ai-Chi Movement

Muscular expansion vs. contraction in T’ai-Chi Movement

“Swimming on Land”

More Articles on T’ai Chi

Tai Chi Dynamics Book

Home Page