Tai Chi as an eccentrically-biased movement patterns

[daniel pfister]

I'm still having trouble with the term "eccentrically-biased movement patterns." How is it that Tai Chi is eccentrically-biased? Like other movements, there is eccentric and concentric contraction going on all the time. What makes Tai Chi different in this regard?

[Yeung]

Here is an example of rotating the crotch (angle or region of the angle formed by the junction of two parts or members,such as two legs or branches.):

https://www.facebook.com/39716348706001 ... 414084219/

Maybe you can compare that with some videos on Taijiquan as they push concentrically forward instead of rotating the crotch to generate power.

[yeniseri]

I'm still having trouble with the term "eccentrically-biased movement patterns." How is it that Tai Chi is eccentrically-biased? Like other movements, there is eccentric and concentric contraction going on all the time. What makes Tai Chi different in this regard?

This is true but specific postures within the training paradigm (be taijiquan, pilates, etc) assists in "improvement" of the movement (read musculoskeletal strengthening) over time. The exact oppose is that no movement/sedentary lifestyle destroys the foundation thereby allowing for greater sarcopenia (loss of muscle strength over time) while incrementally damaging the root (lower body) and increasing falls resulting in lifelong incapacitation, Then your quality of life decreases, then depression/anxiety sets in, which will increase morbidity in varied realms of function and psychological wellbeing.

[Yeung]

Maybe the fact of residual force enhancement will help you to differentiate Taijiquan from other exercises:

The residual force enhancement after stretch, FEresid, was first demonstrated on isolated whole muscles of the frog (Fenn, 1924; Abbott & Aubert, 1952; Hill & Howarth, 1959), and has later been subjected to detailed studies on isolated single muscle fibres (Sugi, 1972; Edman et al. 1978, 1982; Julian & Morgan, 1979; Sugi & Tsuchiya, 1988; Morgan, 1990, 1994; Edman & Tsuchiya, 1996; Rassier & Herzog, 2004a,b; Herzog et al. 2006) and, more recently, on isolated cardiac and skeletal muscle myofibrils (Rassier et al. 2003a,b; Telley et al. 2006; Joumaa et al. 2008; Rassier & Pavlov, 2012).

https://www.ncbi.nlm.nih.gov/pmc/articl ... 0-1339.pdf

[daniel pfister]

Maybe the fact of residual force enhancement will help you to differentiate Taijiquan from other exercises:

https://www.ncbi.nlm.nih.gov/pmc/articl ... 0-1339.pdf

Residual force enhancement is a very interesting topic! A lot more research needs to be done on it to fully understand physiological mechanisms, but it could be a way of understanding what's going on when we train TJQ. Whether or not this training is beneficial in other ways as remains to be seen apparently. Definitely good to keep in mind though.

I found a more recent review of the topic:

https://www.ncbi.nlm.nih.gov/pubmed/25956547

[Yeung]

I think it is just a question of identifying techniques in TJQ that utilizing eccentric contraction to produce enhanced force.

J Appl Physiol (1985). 2014 Jun 1;116(11):1407-17. doi: 10.1152/japplphysiol.00069.2013. Epub 2013 Feb 21.
Mechanisms of enhanced force production in lengthening (eccentric) muscle contractions.
Herzog W1.
Author information
1Faculty of Kinesiology, University of Calgary, Alberta, Canada [email protected].
Abstract
In contrast to isometric and shortening contractions, many observations made on actively lengthening muscles cannot be readily explained with the sliding filament and cross-bridge theory. Specifically, residual force enhancement, the persistent increase in force following active muscle lengthening, beyond what one would expect based on muscle length, has not been explained satisfactorily. Here, we summarize the experimental evidence on residual force enhancement, critically evaluate proposed mechanisms for the residual force enhancement, and propose a mechanism for residual force enhancement that explains all currently agreed upon experimental observations. The proposed mechanism is based on the engagement of the structural protein titin upon muscle activation and an increase in titin's resistance to active compared with passive stretching. This change in resistance from the passive to the active state is suggested to be based on 1) calcium binding by titin upon activation, 2) binding of titin to actin upon activation, and 3) as a consequence of titin-actin binding--a shift toward stiffer titin segments that are used in active compared with passive muscle elongation. Although there is some experimental evidence for the proposed mechanism, it must be stressed that much of the details proposed here remain unclear and should provide ample research opportunities for scientists in the future. Nevertheless, the proposed mechanism for residual force enhancement explains all basic findings in this area of research.

Copyright © 2014 the American Physiological Society.

KEYWORDS:
cross-bridge theory; eccentric contractions; residual force enhancement; titin

http://jap.physiology.org/content/jap/1 ... 7.full.pdf

[daniel pfister]

Going from single fiber analysis to complex human movement is hard, especially when this is so little understood.

The only TJQ technique that might apply here is the absorption of anothers force/push while remaining unmoved. However, I generally think that to absorb force is not enough for TJQ, rather we should try to neutralize it and turn it to our advantage. I usually think of the stretch reflexes (or perhaps residual force enhancement) as something that I can manipulate in others, since many don't have awareness of such forces. So it's perhaps its a double-edged sword.

[Yeung]

Absorbing an incoming force is a form of neutralization by simply using the weight of the body before pushing back or deflect it. In the demonstration video is simply stopping the income force and pushing back with little effort. At the same time the incoming force also stretched the subject as he absorbed and the recoil of such stretch enhanced pushing back. You should be in a position to manipulate these forces in the practice of pushing hands.

[robert]

I think it is just a question of identifying techniques in TJQ that utilizing eccentric contraction to produce enhanced force.

Great article referenced in the OP! That explains some of the health/rehab benefits of internal arts. In response to your statement above, if the body is connected then aren't you utilizing eccentric contraction every time you open or close? Doesn't fajin utilize eccentric contraction? Isn't the image of drawing a bow pointing to eccentric contraction? It takes time to learn to move in a connected manner and even longer to relax and loosen enough that the body is connected, but with persistence and a good instructor it should be continuous in IMA.

Thanks for posting that.

[wayne hansen]

The first thing we must do is work out what style of tai chi we are talking about
Then what lineage and what teacher
A few years back I stopped calling what I taught tai chi
Not because I don't teach classical tai chi but because what the general public consider to be tai chi is not what I teach
How modern Chen ,yang and Wu are taught are quite different
Don't even consider sun ,hao or fu
Trying to lay one blanket over the whole gamet is impossible,let alone what people have overlaid from other systems

[robert]

The first thing we must do is work out what style of tai chi we are talking about

I think the idea of the body being connected and opening and closing is applicable to the major taiji styles as well as xinyi and bagua. I don't know styles like baihe, baji, pigua, and so on, very well, but I've seen videos where some practitioners look pretty connected as well. I think in any style there will be people just doing choreography, but that doesn't mean it's representative of how that style should be done.

The guy in this video looks connected.

https://www.youtube.com/watch?v=iQZ3xn-UmjI

[Yeung]

The first thing we must do is work out what style of tai chi we are talking about
Then what lineage and what teacher
A few years back I stopped calling what I taught tai chi
Not because I don't teach classical tai chi but because what the general public consider to be tai chi is not what I teach
How modern Chen ,yang and Wu are taught are quite different
Don't even consider sun ,hao or fu
Trying to lay one blanket over the whole gamet is impossible,let alone what people have overlaid from other systems

It is a question of using brute force or not but it depended very much on the correctness in executing various techniques. In a way the background, lineage and teachings, will help to identify the correctness in not using brute force. The concept of not using brute force is fundamental in Internal Martial Arts and it is not too difficult in workout the differences between using brute force or without using brute force with the current understanding of concentric muscle contraction and eccentric muscle contraction.

[wayne hansen]

What some call subtle energy I see as mere mechanics and degrees of brute force
It is a matter of perception and understanding

[Yeung]

What some call subtle energy I see as mere mechanics and degrees of brute force
It is a matter of perception and understanding

I am not sure what you mean but it was proven in the 80s that eccentric muscle force is 30% more compare to concentric muscle force. And that is how the overloading techniques are developed to increase muscle strength in sports. I think it is just a question of knowing how to use eccentric muscle contraction.