Physical mechanisms of taiji movement – examining two classical taiji sayings. Part I: “power is released from the spine.”

I realized we are four articles into our blog, and have not yet addressed any technical aspects of form. So let’s now take a look at physical mechanisms of taiji (tai chi) movement.

There are two primary physical mechanisms of the “elastic” or “internal” power of taiji – or of any internal martial art. They are referenced in the following two sayings known to all students of the taiji classics:

power is released from the spine

and

mind/intention (yi) leads the energy (qi), the body follows

I am a firm believer that if you understand something well, you can explain it simply, in language that is easily understood. The taiji classics can be opaque, to say the least, either intentionally (so the meaning is intelligible only to the initiated) or simply because the authors did not have the vantage of contemporary anatomy and medical science. “The qi did it” may be an accurate statement, on some level, but it serves little useful explanatory purpose. Explanation of physical mechanisms of the power of the internal martial arts is surely well within the realm of anatomy, physiology, and Newtonian mechanics. (I was going to write “simple” Newtonian mechanics but, having recently assisted my daughter with an AP physics course, that would not be an honest descriptor for me.)

In Part I of this blog entry we will look at the first of the two classical sayings quoted above.

Power is released from the spine

 
So what flexes the spine?

The core musculature. The entire taiji form is a rhythmic flexing and releasing of the “spinal bow,” of (gently) practicing storing and releasing energy from the core. I added a parenthetical “gently” because it is quite important not to overemphasize the muscular flexing (storing), or the releasing, of energy when practicing form. Nurturing is always a priority for efficient practice and to avoid injury.

In addition to flexing the spine, the other function of the core musculature is to stabilize the spine and pelvis – essential in maintaining an upright and balanced posture and for the transfer of power through the extremities. To quote from Taijiquan, The Art of Nurturing, The Science of Power: “The core muscles are also critical for the transfer of energy from large to small body parts. Because the peripheral muscles of the shoulders, arms, and legs are anchored to the spine or pelvis, all (emphasis added) power is either generated from or transferred through the core of the body. Greater strength of the core not only yields a greater power output, but also increases the neuromuscular efficiency of peripheral muscles – with a stronger core, less forceful contractions of the peripheral muscles are required to produce a given amount of power.”^[1]

Two physical mechanisms are essential in correct flexion of the spine, or what is referred to as “pulling the bow of the spine” in traditional language: 1) reverse breathing and 2) correct posture.

Reverse Breathing

 
Reverse breathing is the method of breathing for taiji form, and the mechanism by which the rhythmic flexing of the spine is accomplished. In reverse breathing, the lower abdomen is pulled upwards and inwards on inhalation, and allowed to expand outwards and downwards on exhalation. When done properly, on inhalation the spine is gently elongated and flexed – storing energy that is then efficiently transferred through relaxed peripheral muscles. A relaxed body is essential for the efficient transfer of force – tension in the body or peripheral musculature will reduce the magnitude of force expressed.

By far the most efficient way to learn reverse breathing, so that it becomes second nature and happens automatically without thinking about it, is through simple, repetitive qigong exercises. We will explore reverse breathing in more detail in a future post, but for now I will just say that one should not be thinking about breathing during form practice – as will be further addressed in Part 2 of this post.

(As a side note, the traditional instruction to “load the mingmen” point between the kidneys is simply imagery that is also for the specific purpose of teaching reverse breathing and the physical mechanism of flexing the spinal bow.)

Posture

 
In addition to reverse breathing, correct posture is also essential to store and release power from the spine. The posture must be upright, and the spine should be gently elongated upon inhalation. (Again that word “gently.”) 🙂

Sinking the “kua,” or “opening” the hip joint, is necessary to straighten the lower spine and to pull the spinal bow. Upon sinking the kua, the tailbone is allowed to hang in a neutral position, neither pushed forward nor pulled back. The muscles of the hip/pelvis are relaxed, the spine is gently elongated (in coordination with the postural principle of “suspending the head from the crown”), and the body is rooted strongly in the legs/feet. The correct positioning of the kua is difficult to communicate in words, but here I would just caution against one common mistake – that of “tucking” the tailbone under. The advice to “tuck the tailbone” is relative to the depth of stance. In very low postures it may be necessary to tuck the tailbone to keep the spine straight and body upright, but in common stances of moderate height (i.e. most of the form), forcefully tucking the tailbone tenses the muscles of the hip/pelvis and destroys the structure necessary for storing power in the spinal bow and rooting the body. It is also very bad for the lower back.

Just as qigong exercises are used to teach reverse breathing and the rhythmic flexing of the spine, standing meditation is the most efficient way to change the habitual pattern of flexing the peripheral muscles, to gradually learn to relax and adopt the use of core musculature to stabilize the spine and posture, and to learn and internalize postural principles (including the correct position of the kua/lower spine). In standing practices the arms are raised in various positions. Whenever the arm is raised (technically pulled away from the midline, or “abducted”), the center of gravity is altered. EMG studies have shown that, to avoid losing balance, trunk muscles become activated on the opposite (contralateral) side.^[2] All of the various standing meditation postures both teach one to use, and directly strengthen, core musculature.

While core strength training may be a relatively new trend in the Western fitness world, the old martial artists of China certainly knew well how critical (what we today call) the core is for power and athletic performance. Indeed, much of taiji can be described as “core strength training.” From my own experience, the more deeply one understands how “power is released from the spine,” the more powerful and physically intense one’s practice becomes. At this point one begins to understand the power of taiji movement and the corresponding necessity of nurturing, moderation, and avoiding over-use injury from excessive form practice – and the more one needs to add the restorative lying-down qigong to one’s regimen. Always remember – taiji means balance of yin and yang.

Understanding how “power is released from the spine” is necessary to understand the difference, and uniqueness, of how power is generated and expressed in the internal martial arts. Certainly most striking arts teach the importance of core musculature in correct technique. In Western boxing, for example, one is taught to throw a punch “from the hip,” which is meant to teach engagement of the lower core musculature to increase power. (Ponder for a moment the potential force from the major muscles of the lower core, shown in the image below, to the relatively meager musculature of the shoulder/upper arm.) The physical mechanism of “pulling the spinal bow” and “shooting the arrow” is, however, a much more integrated way to store the power of the core musculature, and to release that power, in any direction (with or without the aid of waist turning), and at any range – to strike not only from fist or elbow range, but to generate and express the explosive “one inch power” of the internal arts. “Releasing power from the spine” yields the greatest possible acceleration of the trunk and extremities and therefore, according to F=ma, the greatest force humanly achievable given a constant mass. And it is, as the classics also say, a power that has to be learned.

From a more practical daily-life perspective, the core strength training of taiji and qigong affords better posture (and therefore circulation), and the maintenance of and improvements in physical balance.

In Part 2 of this post we will look at another physical mechanism alluded to in the classics – the priority and purpose of mind/intention in form movement.

References

^[1] Taijiquan: The Art of Nurturing, The Science of Power. Yang, Y. and Grubisich, S. Zhenwu Publications, Champaign, Illinois. 2005, 2nd Edition, p. 85. ISBN 0-9740990-0-19.

^[2] Activation of Back Muscles During Voluntary Abduction of the Contralateral Arm in Humans. Spine. 27(12):1355-1360, June 15, 2002. Davey, Nick J. PhD; Lisle, Rebecca M. BSc; Loxton-Edwards, Ben BSc; Nowicky, Alex V. PhD; McGregor, Alison H. PhD.