Sunday, March 7, 2010

Lower Back: Arch, Drop, and Tuck

One of the first lessons I learned as a beginning Tai Chi Chuan student twenty years ago was to "tuck under" to flatten the back. I hope this isn't still being taught because twenty years of "tucking under" ingrained a muscular habit that I had to unlearn when I began seriously practicing Zhan Zhuang. What I'm calling lower back arch, drop and tuck are also known as pelvic anterior tilt, neutral, and posterior tilt.

When I began Wujifa stance practice, I was told to "drop". I thought "tuck" meant "drop" so I tucked and I was told to not tuck but to drop. I really didn't know what my instructor wanted. What was the difference between drop and tuck? Was drop akin to un-tuck? Was drop just a little less arch? What was the difference in the feeling of arch, drop and tuck?

I struggled with this puzzle for years, never being able to really kinesthetically feel the difference. Only in recent months have I been able to distinguish these different feelings and to a lesser degree, the feeling of the intention to arch, drop and tuck.

The following videos explain the mechanics of pelvic positioning through the frame of "Muscle Balancing". (I never heard of muscle balancing before writing this article. As a layman, I like these explanations and I think they fit here.)

Even though these videos discuss muscle imbalance for the purpose of relieving back pain, the discussion seems relevant to understanding the structural, mechanical aspects of Zhan Zhuang particularly in regards to the muscular forces acting on the pelvis which helps explain why this section of the body, the tan-tian, is so challenging to calibrate. What is interesting to me is that I can now notice that arch and tuck each require a bit of muscular force. And since one of the principles of Zhan Zhuang is to relax, it doesn't make sense to use one muscular force (tuck) to counter another muscular force (arch) when the goal is to relax with balance and structure. From the Wujifa Triangles article:
"If one understands relax and structure, this leads to an understanding of balance. If one understands balance and relax, it leads to an understanding of structure. Understanding structure and balance leads to an understanding of relax. Remember, relax is not limp. Structure is not rigid. Balance is not polarity."
Noticing that arch and tuck each require muscular force, I now know that tuck is not relax. Tuck did not lead me to the feeling of drop or sink. Also, I now notice that when I arch, I feel a "pulling up" from my heals and when I "tuck" I feel a pulling up from the front of my thighs. Only inbetween, in drop, do I not feel that "pulling up" feeling but rather an openness, an opportunity to not pull up, to drop. Going a step further, when I'm practicing stance in class, my instructor will notice ever subtler levels of my residual tuck habit. Where I think and feel like I'm in drop (relaxed between arch and tuck), he will notice that my intention is off the bulls-eye of drop and is slightly into arch or tuck. Sometimes a very slight physical movement is needed to make the correction and sometimes a slight recalibration of my intention is all that is needed. I cannot yet notice myself where my "intention" is mis-calibrated.

The below stick figure diagram attempts to illustrate the direction of the intention to tuck, the intention to drop, and the intention to arch (the red arrows). Over time and with practice I've been able to "loosen my hips" without control, to developing some kinesthetic control, calibrating from gross mechanical muscular movements to finer discernment of where the "intention to" is focused; moving from the outer arrows to becoming more perpendicular to the ground.

This is one aspect of my ever changing Zhan Zhuang practice. This is where I am now. Happy practicing everyone!


  1. Thanks for sharing this. The stick figure drawings are very helpful.

    There's something I've noticed in my practice, and was wondering if this corresponds to your experience... (and I ask this because you don't explicitly show it in the stick figures)

    ... and that's that the tuck tends to co-exist with a tendency to bring the head forward to compensate, while the arch leads to the head leaning slightly backwards.

    My Alexander Technique teacher doesn't use the terms "Tuck, Drop and Arch". Rather, he speaks in terms of the dangers of excessive concavity in the back, and how a slight intention of convexity is healthier.

  2. Ulyart,
    I played with what you described and it feels like tucking tends to tension and concavity in the front pulling the head forward, and arching tends to tension and concavity in the back thrusting the chest out and head back. Both these positions feel "natural" to me probably due to my particular muscular holding patterns and habits.

    I played combining these two structures; with tucking and pushing the chest out with head back and with arching and hunching with head forward, and in both, I feel quite a bit of "un-natural" tension.

    What I'm looking for is that place where the muscle balance is equally relaxed because the more the top relaxes (without losing structure), the more weight sinks into my legs.


  3. The tuck is supposed to help you connect the top half of your body to the body half. Does doing the drop achieve the same effect? Does the body structure hold up to a push? I'm also having difficulties around these same points? Thanks ofr sharing.

  4. Learner,
    I hear you! The pelvis is a really tricky area to figure out!

    As your relaxing progresses, the arch in the lower back can flatten naturally. I think many teachers try to force this flattening by forcing the other direction. You can't force relax!

    Connection throughout the body is achieved through relaxing with intention. Drop is achieved through relax.

    When tuck is forced and not relaxed, tuck introduces a break in the "connection chain" between top and bottom and so those who tuck can actually have weaker structures than those who drop/relax.


  5. Very helpful post. I Study Yi-Chuan. Hurt lower back recently shoveling, yard work last week.

    My teacher only encouraged the 'tuck' first couple of years, as back loosened and 'dropped' he stopped mentioning it to me.

    My injury though felt like a ligament, a connection below the spine on the left, top of the pelvic girdle. Probably part of the psoas. I'm wondering if I over extended something that I've recently loosened from 4 years of zan zhuang.

    The folks who do Rolfing talk about releasing habitual tension in the tendons and ligaments. I think that happens with zz, too, and that we have to be careful as we retrain our 'connections' for inner strength.

    Thanks for this post.