The Three Tissues of the Body
The first article in this series, Learning Yin and Yang, asked the question "How does my body move?" Before we could examine this question in any depth we needed to review the Taoist ideas of Yin and Yang. We are now going to shift to the question most relevant to hatha yoga practitioners: "Why doesn't my body move the way I want it to?"
To answer this question, we will look at our joints. There are many tissues that form a joint: bone, muscle, tendon, ligament, synovial fluid, cartilage, fat, and sacks of fluid called bursae. Of all of these, three are most important for teaching and practicing yoga: muscle, connective tissue, and bone. Each of these tissues has different elastic qualities and each responds differently to the stresses placed upon them by yoga postures. By learning to feel the differences between these three tissues, yogis can save themselves a great deal of frustration and possible injury.
Each of the three tissues has a different quality and can be classified differently through the Taoist model. Muscle is soft; it is the most elastic and mobile. Because of that, it is the most Yang of the three. Bone is hard; it is the least elastic and pliable. It is, in fact, immobile. So bone is the most Yin. Connective tissue lies between the two extremes.
It is interesting to note that this classification of the three tissues remains the same when we examine them not by quality but by location. The muscles are the most external and exposed, making them Yang. The bones are the most internal, the least accessible, making them Yin. The connective tissue lies literally between the two.
Why bother with this analysis? Because Yang tissues should be exercised in a Yang way and Yin tissues should be exercised in Yin way. The characteristics of Yang exercise are rhythm and repetition. The characteristic of Yin exercise is prolonged stasis or stillness. We are all familiar with Yang exercises like running, swimming, and weight training. All of these activities are rhythmic. We alternate the contraction and relaxation of our muscles to run or swim or lift. It would be unproductive to just contract a muscle and hold it until it spasms. It would be equally unproductive to just let a muscle stay relaxed. Healthy muscle requires the rhythmic contraction and relaxation that Yang exercise provides. The rhythm is very important. Indeed, it could be said that it is rhythm that distinguishes exercise from simple manual labor.
Manual labor is rarely of the proper rhythm or of adequate repetition to make a person "feel good." It is usually a haphazard mix of too much of some movements and not enough of others. This leaves us feeling sore and "kinked" at the end of our labors, not pleasantly perspired and relaxed. In cultures where long days of manual labor are unavoidable, human beings have responded by making up "Work Songs" and soldiers have invented an endless variety of "Marching Songs." The purpose of these songs is to create a rhythm to work to. Labor is still labor, but it is made more palatable and less destructive by moving, singing, and breathing with a rhythm.
Yang exercise is easy to define and identify. It is what we are all familiar with. In contrast, Yin exercise seems a contradiction in terms. How can something that is gentle and static even be called "exercise"? In order to balance, heal, and open our bodies, we must expand our conception of exercise to be more inclusive. Yang exercise is not the only form of exercise.
The characteristic of Yin exercise is stasis or stillness for long periods of time. Yin exercise has a rhythm, but it is a much, much longer rhythm than Yang activities like running. A common misinterpretation of Yin stillness is as "passivity" or "inactiveness." This misconception is due to our cultural bias toward muscular, Yang activities. But Yin activities have important effect. They stress the tissues of the body, particularly connective tissue.
The most common example of Yin exercise is traction. If someone's leg were broken, it would not be beneficial to rhythmically pull on the injured area. But gentle, steady, continuous traction might be absolutely necessary for healthy recovery.
An even more common and less dramatic example of the Yin principle of prolonged stasis is orthodontia—braces on our teeth. Teeth are bone anchored in more bone and yet even they respond to the practice of Yin Yoga which we call "braces." Bone is the ultimate Yin tissue of the body. Exercising our teeth in a Yang way would be disastrous.
Imagine an enthusiastic body builder taking what she learned from the gym and applying it to her mouth. If she had decided she was going to straighten her crooked teeth by rhythmically wiggling them back and forth in multiple sets, it would not be long before her teeth fell out. The lesson here is a simple anatomical one: Yang tissues should be exercised in a Yang way and Yin tissues should be exercised in a Yin way.
It's important to keep in mind the Taoist conceptions of Yin and Yang. When we analyze things, we are comparing them to something else. There is no absolute Yin. There is no absolute Yang. If we recall the Tai Ji symbol of spiraling half circles of black and white, we must remember that there is a black dot within the white spiral and a white dot within the black. This is to remind us that when we use language such as "Yang is rhythmic, but Yin is not," this is not absolutely true. Yin has a rhythm but it is much longer than Yang. Likewise, it is not absolutely correct to say "Yang is active but Yin is not." There is activity in Yin, but it is of a different type. It can be tedious to be meticulously accurate in our speech. One of the great benefits of Yin/Yang terminology is that we can express ourselves in terse, memorable ways, but always with the understanding that this is not the final word. As with poetry, a deeper analysis might be necessary for different purposes, but the basics should suffice for most day to day communication.
This article is part 2 of the 2-part Taoist Analysis series. Read part 1: Learning Yin and Yang.