https://www.youtube.com/watch?v=1KbL-7OeHX4
good explanation and demo of differences between structure and no structure
"peng jin"
Interesting article, that might help to explain the actions in the clip.
Zhong Ding (Equilibrium)
Adam displayed a clear understanding of Zhong ding numerous times throughout the practical demonstrations, including answering a dedicated question on the meaning of Zhong ding in part two of the interview. I will try my best to explain how it feels when I attempted to attack Sifu Mizner’s center of equilibrium during filming. First of all, this may sound strange to anyone that has not had first-hand experience in working with someone with this skill.
Please bear with me as I try to explain. Each time I attempted to push Sifu Mizner, my force seemed to remain on the outside of his body, making it feel impossible to find his center and affect his balance in any way. Usually, when pushing a person, you are aware if they are bracing to resist your force, and you can feel the moment they begin to fold and yield. However, with Adam, that is not the case. You can not detect any bracing or the use of holding a fixed structure.
His center is hidden. It is an experience that is very difficult to put into words, as it is unlike anything else I have previously encountered. No matter how hard I attempted to push or pull, my force did not affect him. Even with Adam sat on a wall with his legs dangling off the ground, he continued to display the ability not to be pushed backward and continued to retain his ‘Zhong Ding.’ If you think this is some trick or possibly the use of core strength, I will invite you to grab a partner and give it a try for yourself.
https://themartialman.com/how-does-it-f ... am-mizner/