This is a great discussion:
Let's not get hung up by what 'torque' actually means. The discussion is about whether the upper and lower torso are rotated by differing amounts - i.e is the shouder line always the same as the hip line. Isn't this what we're discussing?
there was reference a little while back to there not being any evidence of this in the foxtrot videos on this site. But there is. And clearly so. In the feather step, Jonathan has his shoulder line beautifully rotated as he dances outside his partner. His hips are not rotated to the same extent. Hence the 'twist' that we're talking about. Torque, being strictly a force, is the force exerted by his muscles to make this happen. But the effect could be called twist.
Try this experiment. Keep your feet pointing to the 12 o'clock position. Rotate to the 1 o'clock position (30 degrees). Hips and shoulders rotated by same amount - Yes. (of course there's a twist somewhere but it's 'lost in the ankles and legs).
Now rotate your shoulders to 2 o'clock, which is the sort of rotation jonathan is using (actually, i think he's 2.30, but never mind). Are your hips at 2 o'clock?. I doubt it. But if they are, could you dance forward with your feet still aligned at 12 o'clock. Not a chance.

I do not believe one can dismiss so lightly understanding cause and effect .

Therein lies the problem with most theoretical exercises .

If the foundation is not delineated, then an incorrect result may occur .

Terence. I will repeat your contribution 4/7/08. Which in my opinion is absolutly correct.
" Torque is an action that is created by rotation against a stationary point-
as in -place the feet ( foot ) in a fixed position, and rotate the body from the ANKLE(S) upwards to the desired degree, in the opposite direction (L or R ) ".
It might be worth pointing out that direction is now measured from the position of the feet, which is a little disconcerning at first. It would appear to be easier to take the amount of turn for instance from where the body is facing but in practice this becomes even more complicated.
So to put it another way by making a model . If I had a broom stick which half way down has a male to female thread. At the ankle level we have another. If I read Terence correctly he will rotate from the bottom connection and not the middle conection. Phil Do you disagree with that . Or anybody else for that matter.

Hi Serendipity.
I don't agree with Terence's definition of "torque". The normal meaning of the word is as follows (this is from Wikipedia)
"""In physics, a torque (ô) is a vector that measures the tendency of a force to rotate an object about some axis [1] (center). The magnitude of a torque is defined as force times the length of the lever arm [2] (radius). Just as a force is a push or a pull, a torque can be thought of as a twist."""
I've not added nor subtracted anything from the Wikipedia definition. Torque is a rotational force about a centre, but that centre need not be stationary.
I also don't understand the idea that part of the body rotates "in the opposite direction (L or R)" to the feet. Why is the word "opposite" in there?.
On your last broom stick model, i would say there is rotation at both connections. But also say that the rotation is distributed (i.e. not at a small number of points)
If you have your feet facing forward but rotate your pelvis, your muscles have to work hard to keep your feet forward (i.e. they apply a torque). When i do this, there is a rotation which feels distributed along my leg (from the stretch i feel) but clearly only happens at the ankle, knee and hip joints.
With the torso, the spine has lots of 'joints'.....
By the way, rotating the spine with good posture is not, or should not be, damaging to the spine.

The definition is an applied engineering one.

We are talking about " dance" and in the application that we are attempting to define , the point that was trying to be made was simply this--

if I place my weight firmly on the standing leg , and rotate from the ankle , upwards , in a given position a torquing action will result.

The use of the word " twist " in the definition, is generally applied to specific dance variations combined with torque ( as in a twist turn etc. ) , rather than actions danced independantly of same

I do not think in essence ,that disagrees with your excerpt .

Hi Terence
I agree that's it's not a great idea to use strict engineering concepts for dancing. I really didn't want to use the term 'torque' at all to be honest.
The original discussion centred around a straightforward question - do the shoulders always stay parallel to the hips ('aligned with the hips') in movements such as natural turns, feather steps etc.
I was arguing that they don't - they are often rotated more than the hips. When i look at top dancers i see this extra rotation.

Scriv. even used the word torque in his explanations .

But-- but his cautionary bye words, " less is more " should always be upper most ..

there are inherent dangers when advising someone to use " shldrs " that is why the word was removed from descriptions in the Rev. techn. and they substituted L/ R side .

Lastly, I am not over keen to give descriptions of such a complex nature, in written formats.
Some things just need to be seen .

"Lastly, I am not over keen to give descriptions of such a complex nature, in written formats.
Some things just need to be seen ."

Or felt.

The problem I have with Serendipity's posts on this subject is the absoluteness of his prohibition on incorporating certain elements. It's not that beginners should be trying to incorporate them, or even necessarily be told about them, it's that someone with relatively little experience should not be declaring absolutely that something has no role in dancing, when - if they had a bit more experience - they'd know that in the end it does have a small but important role.

So for example, if someone hypothetically said:

"Rotation generally encompasses both hips and shoulders"

I would applaud

But if they said:

"The hips and shoulders must always be at the same angle so that there is no twist in the spine"

I would point out that they are in fact wrong.

Something that's quite notable in Moore's page on CBM is the lack of absolutes. He makes a variety of points, which if treated as absolutes would conflict with each other (don't turn shoulders without hips, vs. feel some turns starting in hips and others in shoulders), but when weighed together as a collection give a general guidance.

Twist is equall to a dirty word. On this site it seems to be using its popularity.
There is a lot more to this subject than meets the eye. In the same vein a question. Why do we on a Curving Feather do two straight steps and then turn. You can include with this the ladies steps on a Wing. Why don't we start turning on the first step.One word beginning with T is the answer.

"There is a lot more to this subject than meets the eye. In the same vein a question. Why do we on a Curving Feather do two straight steps and then turn. You can include with this the ladies steps on a Wing. Why don't we start turning on the first step.One word beginning with T is the answer."

You are confusing two very different concepts.

The presence or absence of rotational twist in the body is a very different thing from the decision to use traditional CBM vs. the decision to move in a curved track.

In traditional CBM, you take two steps in the same direction while turning the body. In the so-called curved CBM, the path of travel curves during those steps .

Jonathan and Melissa are a good example of the curved-CBM school of thought. I personally find it to be an inferior approach for most applications, though there are a few places where it is preferable.

But the important thing in the context of this thread is that they manage to use their curved CBM method in places where a traditionalist would use two straight steps, WITHOUT significantly changing their body configuration as a result of the curve - in other words, the two concepts really are fairly separate.

(If anything, curving your CBM will mean the direction of movement changes with the body orientation so that the body is closer to constantly facing squarely into the instantaneous direction of travel than it would be in the case of traditional CBM, which would mean that the configuration of the body can be simpler than would be necessary for close cooperation with a partner when using traditional CBM)