In Part I we examined the classical saying “power is released from the spine,” noting how flexion of the spine and core strength are integral mechanisms of “internal” power. This could be described as the “yang” of taiji (tai chi) movement, the physical mechanism of storing and releasing power. We’ll look more at the correct expression of force in a future article on fa jin (explosive energy).
Let’s now take a look at a second reference to the mechanisms of taiji movement in the classics – the “yin” of form:
“Mind/intention (yi) leads the energy (qi), the body follows.”
If I had to paraphrase my teacher’s admonition for how to practice taiji form in two brief sentences, it would be this:
Intention is primary – every movement must be full of intention. Make the energy of every second of every movement very clear.
Another famous saying also stresses the primary importance of intention in form practice:
If you practice li (muscular strength) it will break; if you practice qi (breathing/energy) it will be stiff; if you practice yi (intention) it will flow smoothly. (Lian li ze duan; lian qi ze zhi; lian yi ze huo.)
So what is the intention of every form movement?
Very simply, it is to move in the intended direction of the form movement. That, after all, is the purpose or “application” of the movement – to move, and therefore express force, in an intended direction, over a specific distance (short, medium and/or long range), and to express that force with a specific part of the body (shoulder, elbow, hand, hip, knee, foot).
Emphasis on this intention to move is what makes form or qigong movement a “moving meditation.” Intention is also the essential bridge from wuji (no differentiation of yin/yang) to taiji (differention of everything as yin/yang complementary opposites). Form meditation therefore has two parts:
- the single-minded awareness/focus on the intention of the direction/expression of the movement, and;
- creating the rhythmic dance of yin and yang: soft/hard, storing/releasing, inhale/exhale, defense/offense etc.
The first point requires that the practitioner has passed the initial stage of learning the basic choreography of the movement. Regarding the second, I have been told that Grandmaster Feng Zhiqiang’s most frequent form correction for students was to note that the yin and yang energy of their form was not clearly distinguished. It is intention that determines yin or yang.
The yin/yang energy of every part of every movement must be clearly distinguished to deepen one’s understanding and skill level. It can be difficult for practitioners to understand and realize the possibilities for the correct and balanced expression of yin/yang rhythm, perhaps especially with the circular movements of the Chen style form. Many movements, or even parts of movements, can be either neutralizing (yin) or attacking (yang). It is for this reason that Dr. Yang teaches the “essential” movements of the form before adding “refined” circular silk-reeling movements. In this way the student can efficiently (and more deeply) learn the basic intention and energy of the movement before incorporating more complex circular movements (which can often be “copied & pasted” anywhere in the form).
To put it simply: it’s all about knowing/understanding the energy of the movement, and creating that energy with intention. Like other aspects of taiji practice the two are mutually supportive; feeling the energy helps to better understand that energy, and knowing/understanding the energy helps to create more energy.
Of course it is also fine to focus on one technical aspect of form when practicing (e.g. correct posture or movement initiating from the center (dantian)). But to go deeper in practice and skill and make form practice an intense energy nurturing/gathering qigong exercise one should meditate on the intention, and differentiation of the yin/yang energy, of the movement.
It is very intense practice to “make the energy of every moment of every form movement very clear.” (As might be inferred from the number of “every’s” and “very’s” in that sentence.) Just as with the physical power of core strength learned and maximized by standing meditation, qigong and form practice, one cannot practice form with relaxed but focused intention for an extended period of time. I frequently remind my class to try to keep the same mental intensity throughout the form – one complete form. If you tell me you did 20 form repetitions today, I will not believe that the intensity or quality of that practice was maximized. Your time would likely have been better spent on other essential components of practice.
(One word of caution. Just as taiji form requires a relaxed body, the intention should be focused but also relaxed. “Mental” tension is to be avoided. It is a fine line between a “focused” and a “tense” mind. To add to the many other reasons for its importance, meditation (sitting and standing) is the most efficient path to understanding that line.)
Possible Neural Mechanisms of Intention Practice
Motor Control and Mechanical Efficiency
While “the neuroplasticity mechanisms underlying the therapeutic efficacy of motor function rehabilitation, exercise training, or motor learning on the neuromuscular system are not well understood,”  and few studies exist on neural mechanisms underlying taiji practice in particular, by understanding the methods and purpose of form practice it is quite easy to hypothesize that the mindful practice of the intention of the movement, coupled with relaxation, directly affects motor control or “neuromuscular coordination.”
Motor control is comprised of two components:
1. intra-muscular coordination – the recruitment, firing rate and synchronization of motor units; and
2. inter-muscular coordination – the interactions of agonist, antagonist, and stabilizer muscle groups.
While Part I of this article focused on physical mechanisms for generating maximum power through engagement of the core musculature, the combined effect of the different aspects of muscular coordination determine the efficiency of strength/power.
A couple studies have directly indicated motor control mechanisms of taiji practice. One very interesting study found that taiji subjects, but not controls, significantly reduced ankle muscle response time and occurrence of co-contraction of antagonist muscles in response to a laboratory induced slip.  This is indicative of improvements in both intra- and inter- muscle coordination. Dr. Yang’s own research demonstrated that taiji and qigong practice both increases strength and decreases force variability  – something that, to my knowledge, has never been demonstrated by any other exercise. (Greater force output is typically associated with an increase in force variability). Clearly this is also evidence of motor control mechanisms.
Through our own experience and understanding of practice, we can also deduce other motor control mechanisms. Taiji form is, of course, training synchronized movement – the coordinated complex motor unit of the kinetic chain that yields the spiraling silk-reeling energy and affords efficient transfer of force through the body.
It could be hypothesized that the “shaking” of the legs common in beginners when first practicing standing meditation postures may be indicative of poor intramuscular coordination, where groups of motor units turn on and off in an uncoordinated manner.
And, almost certainly, the emphasis on relaxation in standing meditation, qigong, and forms affords more optimal tuning of agonist/antagonist muscular coordination.
From the above discussion we can see that the meaning of the classical saying “mind/intention (yi) leads the energy (qi), the body follows” is really quite simple (though the premises and implications may not necessarily be 🙂 ). We may summarize it as:
Mind/intention fires the energy signals, transmitted along neural pathways, that cause the muscles to contract (or relax) and move the body. The principles of taiji practice (maintenance of optimum posture with emphasis on relaxed intention) yields efficient movement and power output through improvements in intra- and inter- neuromuscular coordination.
And that is why the form is done slowly – such improvements in neuromuscular coordination are effected in slow movement. Once you have internalized the movement you can do it very quickly and move with power and efficiency, which of course is the purpose.
The purpose of this two-part article was to focus on the physical mechanisms targeted by principles unique to the internal arts and referenced in the classics: how “power is released through the spine” and the primary emphasis on intention (yi) to improve motor control. There are, of course other physical mechanisms of taiji training, some of which have been documented in research while others are easily hypothesized by those familiar with taiji and science: muscle strengthening (especially lower body and core musculature), sensory mechanisms (proprioception and vestibular function), and the heightening of feed-forward/feed-backward neural responses trained in push hands. Additional effects of meditation and taiji on the nervous system, specifically the autonomic nervous system and motor programming, will be examined in a future post on taiji as a martial art.
 Guang H. Yue, Brian C. Clark, Sheng Li, and David E. Vaillancourt. Understanding Neuromuscular System Plasticity to Improve Motor Function in Health, Disease, and Injury. Neural Plasticity, vol. 2017, Article ID 2425180, 2 pages, 2017. doi:10.1155/2017/2425180
 Gatts, Strawberry. (2008). Neural Mechanisms Underlying Balance Control in Tai Chi. Medicine and sport science. 52. 87-103. 10.1159/000134289.
 Christou, Evangelos & Yang, Yang & Rosengren, Karl. (2003). Rapid Communication. Taiji Training Improves Knee Extensor Strength and Force Control in Older Adults. The journals of gerontology. Series A, Biological sciences and medical sciences. 58. 763-6. 10.1093/gerona/58.8.M763.