I should observe, before beginning, that physicists have very precise meaning of the words “force” and “energy,” and that I am using them far more loosely and informally here.
You can think of gravity as radiation (radiation which slowly cooks us). We live in a radioactive zone. Our very cells change, and the atoms in the molecules in the cell change. Every living species, while giving a nod to the “immortality” of wood and stone and bronze and iron, have figured out how to survived. We make ourselves from patterns in the radiation itself, and pass those always-changing patterns on through procreation, through our children.
Humans have not only survived, but have built huge and intricate structures against gravity—and we use gravity to help build those structures.
Weights and pulleys, for example.
So it shouldn’t be surprising that yoga, which is, among its other effects, a healing discipline, must deal with gravity. I cannot think of an asana which does not require the use of gravity. Sivasana, the corpse pose (SIV ah s’na), comes to mind: What is sivasana but slackening all the muscles one habitually tenses— letting gravity have its way with your tissues and organs, allowing the skeleton and its ligatures to support the weight?
Arda chandrasana, the half-moon pose, stretches the major hamstrings and muscle-ligament clusters in each hip, and to some extent, the torso. Done well (I’m not-so-good), it uses the weight of the lifted leg to power the stretches.
All forward bends use the weight of the torso and head to stretch various arrangements of hamstrings. Those right and left twists sitting twists use gravity to stretch the tendons in the back and widen the shoulder-blades.
And so on and on. Gravitational force is deployed against itself to stretch a muscle or a muscle group and the associated tendons. (I use the words “muscle” and “muscle group” rather loosely. It seems unlikely to me that an asana would focus on a single muscle. Besides, all of the things we call muscles are themselves made of what amounts to “micromuscle.”)
In some measure yoga sets you free from gravity. You train yourself to the poses, become accustomed to them, fall into them naturally, let go of your usual obssessive fixations, and let gravity do the rest. There’s no right or wrong for individual tries, because every try brings you closer.
I have a hunch that the more nearly one approaches that sort of stable position, the more one settles into the asana “correctly,” the less the pose demands that fierce quivering of counterposed muscle sets with which we approximate it. In fact, I think there are two “successful” asana states. The earliest and more common are those asanas in which you’ve learned how to keep every related muscle in just the right table tension. The later and rarer success is when no muscular force at all is required to hold the pose.
(I do not, by the way, know all the sanskrit names of even the asanas I practice regularly. Said information is easily available, though somehow I sometimes continue to fail to google it all. Educate me.)
Let’s talk bodily self-image, let’s talk accurate models. I said that when we practice yoga, we’re “practicing to learn” something. That is, something real. A discipline that actually and visibly works. What’s more, we can learn the gist by simple (but continual) observation. Practicing yoga, we acquire a much vaster repertoire of moves. We learn the effects of each asana all the way out to the toes and fingers and beyond. We get direct experience with how our own bodies work. We are no longer dependent on the authority of a model or teacher or book (although it helps immensely to be taught by someone who truly understands).
The current model, for westerners, treats the body as a biological “machine,” transmitting “forces.” Our skeletons are sets of levers that deliver the force generated by muscles. This image, of the bones as levers and the muscles as engines (with, I suppose, the tackle of the tendons), is how we explain our all our physical behaviors. Since it’s so obvious that the body’s a machine, we never for check the accuracy of the image, what it might imply or leave out.
I’ve been as dubious as any reductionist about “energy meridians,” waiting to hear some sense, some structure in such chatter. But consider.
In other words, instead of emerging from experience via induction, the image predetermines certain inaccurate ways of thinking.
What if we began with a different image? What if our culture saw the body and the mind as a single if complex thing, and tracked the ways energy flows through the body, rather than speaking in terms of levers and machines?
I bring this up because watching yoga interact with gravity is a lot easier if you have good “flow visualization.”
(In so saying, in preferring, loosely speaking, an “energy flow” model of the body to a more mechanical model, I am not giving up science and rationality. I am in fact using them to create the most accurate model possible.)
If you pay attention to way the different asanas distribute the force of gravity through your body, you are actually directly observing yoga at work, and your regular practice will be more aware and successful.
(And after all, we’re talking yoga here: The practice of the asanas gives you a perfect time for such meditation. I mean, what else can you do while practicing an asana but meditate on the ways it effects your body? And so, meditating as you practice, your practice will become more accurate and more successful.)