Reflections on the Internal Dynamics

Video Title: Classical Wu Style Tai Chi Square and Round Form

Channel: Classical Tai Chi (Official Channel)

The Architecture of the Core: Reflecting on the Internal Dynamics of Classical Wu Style Tai Chi

A Personal Preface: 24 Years of Lineage and Friendship

As a dedicated practitioner, you eventually reach a crossroad where choreography is no longer enough. You realize that simply moving your limbs in beautiful patterns leaves the true engine of the art completely untouched.

This exact realization is what makes the historical writings of mine as well as my family’s dear friends, E. Marie Koepsell, and Stephen Hwa so enduringly vital. It was for  20 years, right there in the Buffalo and Rochester, New York community, now 3 years later in Acton, California. I have had the profound honor of sharing a deep friendship with both Eva and her husband, Dr. Stephen Hwa. Having spent nearly a quarter-century absorbing the spirit of this lineage, as his first certified teacher,  revisiting Eva’s classic essay, "Learning the Internal Dynamics of Tai Chi," always feels less like reading text and more like sitting down with family.

Eva wrote this piece to chronicle her transition away from abstract, external forms under the guidance of Dr. Hwa—a retired chemical engineer from Wuxi  then Rochester Xerox Corporation,  who brought the direct lineage of WuJianquan via Wabu Young to Upstate NY. Today, I want to share the exact, uncut text of her insights, paired with my own reflections on why these concrete mechanics matter for your daily practice.

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The Article: "Learning the Internal Dynamics of Tai Chi"

By E. Marie Koepsell (with commentary)

“Although I had studied Tai Chi Ch'uan for a number of years with a few different instructors, I had reached the point where I felt that I could be getting more out of my practice—I did not know what was missing, but I was determined to find out more about the art... The internal physical discipline of T'ai Chi Ch'uan, according to Dr. Stephen Hwa, involves the intensive training of the body and mind to develop discipline in movements so that the movements originate from the abdomen (dantien) and back...”

My Reflection:
Notice how Eva begins by exposing the universal frustration of the intermediate student: knowing something is missing but not having the vocabulary to name it. Dr. Stephen Hwa Ph.D. (Classical Tai Chi Master Hwa), immediately removes the mystery by anchoring the art in structural biology. True internal work isn't a mystical cloud of energy; it is the mental/physical re-education of your musculoskeletal system.

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1. The Torso as the Engine, Limbs as Appendages

“As a reference point for correct movement, Dr. Hwa used the example of the movement of children, who use much more of their torso for initiating action... As we start aging, less and less of our movements come from the waist and back. We hold our middle stiffly, and more of our movements originate from the shoulders and the hip joints. This puts pressure on joints and we lose strength and mobility.”

I use his PH.D. title as Eva Koepsell did in her publication.  Dr. Hwa proved this to students with a simple test: he would have them raise their arms and push forward. Inevitably, they pushed entirely from the isolated shoulder joint and arm muscles. When Dr. Hwa demonstrated the internal alternative, his shoulders and arms remained completely relaxed, while the massive, deep muscle chains of his back and abdomen drove the force.

Similarly, he taught that a true Tai Chi step does not begin in the leg:

“T'ai Chi steps should involve the muscles of the torso, the large abdominal and pelvic girdle muscles, to lift and push the leg forward and back... The muscles of the torso do the work of lifting, positioning the leg, and planting the foot. The weight shifts after the leading foot is planted solidly on the ground.”

My Reflection:
This is where standard fitness training fails us. As adults, we lock our cores stiffly and overuse our peripheral joints. By treating the limbs as completely passive appendages, the torso is forced to take over the heavy lifting. If you are muscularly gripping your shoulder or throwing your leg forward with your quad, you are bypassing the Dantian entirely.

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2. The Mechanics of the Abdominal Counter-Rotation

When it comes to changing direction, Eva captured an incredibly rare, concrete description of Dr. Hwa’s teaching of the art’s physical mechanics:

“Turning movements of the body... are done with the feet stationary and the body swivelling at the waist. It should not be a twisting motion where the hips or legs turn the body, but rather an abdominal movement. When he demonstrates the movement, his lower and upper abdominal muscles appear to rotate in opposite directions, thus indicating all the power that this movement generates at the waist.”

My Reflection:
Read that sentence carefully. This is the absolute antidote to the shallow "wannabe philosophy" often found in online forums. Internal turning is not an abstract concept—it is a literal, visible counter-rotation of the upper and lower abdominal walls. It stretches the internal fascia, opening what Dr. Hwa calls the Yin-Yang junctions of the torso.

He masterfully compared this to a door: the stable structure of the body is the doorframe (Yin), the moving part is the door (Yang), and the internal junctions of the torso serve as the highly pressurized hinges. That intense, structural stretch at the hinge is the physical reality of Chi.

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3. The Power of the "Square Form" Template

For those wondering how to actually build this counter-intuitive control, Eva shares Dr. Hwa's foundational training methodology: the strict utilization of the Square Form.

“One cannot really learn T'ai Chi by just imitating the smooth-flowing movements. One has to start with an isolated movement to learn the Yin and Yang of that movement and then thread the movements together... Dr. Hwa learned T'ai Chi as a 'square form' first, breaking down the postures into individual, simple moves, preceding and ending each movement with a full stop.”

While the square form looks discrete, mechanical, and rigid compared to a flowing "round form," its purpose is absolute: it tames the nervous system. By pinpointing the exact, extreme structural boundaries of a posture and coming to a complete stop, it forces the brain to establish clear lines of communication with deep, neglected joints.

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4. The Evolution to Mind-Intent (Yi) and the Small Circle

As a practitioner advances over years of dedicated training, the external expressions of the form naturally compress:

“For the advanced T'ai Chi practitioner, the form itself becomes less expansive externally (so-called 'small circle' or 'compact form'), and more angular. As such, yi [intention] takes on increasing importance in playing the form. There is less movement and more yi. Also, to have smaller external movements and yet reach to all angles in the form requires greater internal movement, more stretching at the Yin-Yang junctions, and more internal energy flow.”

Ultimately, this lifelong journey evolves from a highly conscious struggle into a deeply unified, subconscious state. The fragmented mind settles into a singular intent, the movement becomes effortlessly fluid, and the practitioner enters a semi-meditative state anchored by enjoyable, internal feedback loop.

Concluding Thoughts

Eva ends her brilliant article with words that perfectly mirror my own feelings after 24 years within this circle: “My prior T'ai Chi exposure was enveloped in a philosophical and abstract context. But now I see that T'ai Chi can be explained in scientific, concrete terms and it is no longer such a mystery to me.”

We do not need mysticism to explain true power. We need structural alignment, dedicated torso mechanics, and the patience to tame our movements through the square form. I am endlessly grateful to Eva and Dr. Hwa for keeping this scientific, concrete light burning bright for nearly a quarter of a century.

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To my blog subscribers: Thank you for being a part of this dedicated space. Please leave your thoughts, training insights, and constructive comments directly below in the comment section so we can keep our high-level dialogue going!

References

Hwa, S. (2010). Uncovering the treasure: Classical Tai Chi's path to internal energy & health. CreateSpace Independent Publishing.

Hwa, S. [Classical Tai Chi]. (2009, August 28). Classical Wu style Tai Chi square and round form[Video]. YouTube. youtube.com

Hwa, S. [Classical Tai Chi]. (2010, October 15). Internal discipline in classical Tai Chi [Video]. YouTube. youtube.com

Koepsell, E. M. (1998, August). Learning the internal dynamics of Tai Chi. Tai Chi Magazine, 22(4).

Koepsell, E. M. (2009, May 24). Learning the internal dynamics of Tai Chi (S. Hwa, Ed.). Cook Ding's Kitchen. archive.org (Original work published August 1998)

TURN DOWn The volume

The Weber-Fechner Law explains why you must practice Tai Chi with deep relaxation and minimal muscle tension to develop advanced internal awareness and power. 

In his teachings Master Stephen Hwa emphasizes "internal discipline"—the ability to control small, hidden movements deep within your core (like your abdominal and back muscles) instead of using raw muscle power.

The Science: What is the Weber-Fechner Law?

The Weber-Fechner Law is a rule of human psychology and biology. It states that the more intense a physical stimulus is, the harder it is for your brain to notice a small change. 

Think of it using these everyday examples:

• The Candle Effect: If you are in a pitch-black room and light a single candle, you notice the change immediately. But if you are standing outside in the blazing midday sun, lighting that same candle is completely invisible to you.
• The Backpack Example: If you are carrying a light empty backpack and someone drops a single apple inside, you will instantly feel the extra weight. If you are already carrying a 50-pound hiking pack, you won't feel that apple at all—you would need someone to drop a heavy textbook in to notice a difference.

The Key Rule: To notice tiny, subtle changes, you must start with a very low baseline of background "noise" or force. 

The Connection to Classical Tai Chi

Master Stephen Hwa teaches that true Classical Tai Chi relies on internal power rather than external muscle flexing. When you apply the Weber-Fechner Law to this style, it completely changes how you train: 

1. Dropping "Muscle Noise" to Feel the Core

If your shoulders, arms, and thighs are tight and tense (high baseline force), your nervous system is completely blinded by that "noise." You won't be able to feel the micro-movements of your spine, pelvis, or core muscles. By consciously relaxing your external muscles, you lower your sensory baseline to "zero." Now, your brain becomes incredibly sensitive, allowing you to feel and control the tiny internal muscle shifts required by Master Hwa's small-circle forms. 

2. Martial Arts Sensitivity (Listening Power)

In Tai Chi martial arts application, practitioners train in "Listening Power" (Ting Jin), which is the ability to sense exactly where an opponent is pushing so you can redirect their energy. 

• If you fight back with 100% stiff muscle force, you block your own senses. An opponent could slightly shift their direction, and you wouldn't notice until it's too late.
• If you remain relaxed and soft, your body becomes ultra-sensitive. According to the Weber-Fechner Law, because your baseline tension is low, you will instantly feel the absolute tiniest change in the direction or weight of your opponent's touch, allowing you to counter them effortlessly. 

3. Moving from "Square" to "Small Circle"

Master Hwa teaches beginners using a clear, deliberate "Square Form" to learn proper alignment, which eventually evolves into a highly concentrated, fluid "Small Circle Form." As the movements get smaller and more internal, external movement looks almost invisible to an outsider. The Weber-Fechner Law dictates that you can only navigate and master this microscopic, high-level internal landscape if you completely strip away heavy, external movements from the limbs.

The Weber-Fechner law is a scientific principle about how your brain and body perceive changes, like weight or brightness.

Imagine you are holding one heavy dictionary in your hands. If someone places a tiny feather on top of it, your brain will not notice any difference. The change is too small. But if someone places another whole dictionary on top, you will instantly feel it has gotten much heavier.

The rule says that to notice a change, the new thing must change by a certain percentage, not just a tiny amount. If you start with a lot, you need a big change to notice it. If you start with almost nothing, you can feel even a tiny change. 

Stephen Hwa is a famous martial arts teacher. He uses this scientific rule to teach Internal Power (called Neijin). Here is how it works in his Tai Chi:

• Relaxing Your Muscles: Most people use way too much muscle force when they move. Their muscles are "loud," like a person screaming. If your muscles are screaming, your brain cannot feel small changes in your balance or an opponent's movement.
• Turning Down the Volume: In Classical Tai Chi, you learn to relax your body completely. Relaxing lowers muscle volume to a whisper.
• Super Sensitivity: Because your body is now so quiet, your brain can feel the tiniest changes. If an opponent touches your arm with just the weight of a feather, you will feel exactly where they are pushing.
• Using Internal Power: By unlocking this superpower of feeling small changes, you learn to move your body using your deep, internal structure instead of big, heavy muscles.

By keeping your body quiet, you train your brain to feel everything around you.