Quite correct SusieQ.
What I meant, but was not very clear about, was that the level of discussion on the reasons for non-standard rise and fall etc is only something that comes in at Fellowship level.
Up to there you are not expected to have an opinion.

SD. Can there really be any residual momentum left from the preceding figure by the time you reach e/o 2 of a drag hesitation.I would have thought frictional forces arising as the last step of the precede is placed would have dissipated that. Surely the thing about human gait is you have to keep generating force to keep moving - a bit like a pin in honey.

"SD. Can there really be any residual momentum left from the preceding figure by the time you reach e/o 2 of a drag hesitation."

Sure. In the swinging waltz figures, that residual momentum carried through from the previous downswing is where the upswing comes from. Since this is not as swingy in character there would be less residual momentum, but there may still be some. Actually, a common problem would be retaining to much of it.

"I would have thought frictional forces arising as the last step of the precede is placed would have dissipated that."

Only if the dancer specifically intends to dissipate it. And it's not dissipated into "friction" against the floor, because there is no weighted sliding action where floor friction would become dissipative. Instead it's dissipated by using the muscles to resist the movement.

"Surely the thing about human gait is you have to keep generating force to keep moving"

This is extremely mistaken. The human gait is effective at retaining movement energy across steps, and the dance version of it even more so. That's what makes good dancing look smooth and effortless - the highly developed ability to carry the energy from a downswing through a step or two and then into an upswing, WITHOUT dissipating and regenerating it.

But as the drag hesitation is not a very swingy figure, most of its commencing momentum will be dissipated, and the eventual rise will instead come mostly from the muscles rather than from an upswing release of retained momentum.

At the end of a Double reverse spin the alignment is say DC. The first step of the Drag Hesitation then also has a DC alignment. So the turn of the DRS has stopped whilst step 1 of the next figure is placed. What stops the turn ? If I do not lower at the end of the DRS I tend to carry on spinning past my alignment (like on an overspin). The forces generated by muscles during the lowering only work forwards and upwards not towards the centre of rotation - so they do not stop me rotating. Surely, only friction is left. I always assumed that this is the reason turn was always lead on the toes [ie to reduce friction}. The relative movement of surfaces to generate friction comes from the rotation.

Even with regards forwards motion, wouldnt there be a limit on the extent to which momentum can be maintained.
I can see that following a DRS the centre of gravity would continue to move forward as result of the downswing at the end of the figure and that this is where the energy carried into the first part of the next step comes from. BUT, as soon as weight is transferred, the reaction force from the floor would tend to oppose the forwards motion and the energy would be dissipated doing work against that force. By this time the centre of gravity would be roughly above the feet, and, in normal gait, you would reach a stable equilbrium at this position. And just as in normal gait, if you want to carry on moving forwards, surely you have to flex your muscles all over again ?

(this argument my well be flawed, i'm
really just trying to think this through ! )

I found some scientific figures on this (that come from measuring muscle activity and overall movement kinetics during gait). During normal gait, some energy is carried into the next step, typically some 50%.This is because although work is done against the ground on landing, the landing can be softened by using the knee, so that not all of the energy from the original downswing is used up. A skilled dancer probably uses this effect to some advantage and I guess this is crucial to the quality of softness. I guess the % carry over will also be increased if more energy is generated in the first place (ie through a powerful swing). The carry over also seems to be quite critically dependent on the speed (cf running where it is hard work to actually stop) i guess because more energy is created initially.

This means that to maintain a steady speed the downswing on the first step needs to be more powerful than that on subsequent steps.

Of course this will be tempered by the fact that in dancing you are not always swinging one continuous line (or maybe you are and this is the reason you should be - this perhaps goes back to anymouses idea of a swing to a side position being totally forwards).

However it does mean that only 25 % of energy is carried forward ober three steps and even less of this can be exploited if there are directional changes.

Anyway, this explains why walking aimlessly (ie stopping and starting) around the shops is more tiring than walking continuously in a straight line. It is also the reason why reabilitation after leg injury is best acheived through establishing a rhythmical and sustained pattern of activity.

"I found some scientific figures on this (that come from measuring muscle activity and overall movement kinetics during gait). During normal gait, some energy is carried into the next step, typically some 50%."

"The carry over also seems to be quite critically dependent on the speed (cf running where it is hard work to actually stop) i guess because more energy is created initially."

"This means that to maintain a steady speed the downswing on the first step needs to be more powerful than that on subsequent steps."

In ordinary walking or running, we tend to analyze step by step, as each step is identical.

But to analyze dancing we have to look at most situations as a cycle over three steps, that together make one energy cycle - one downswing, coast through, and upswing cycle. The leg action used is one that largely hides the fact that there are three steps, and instead makes the resulting body movement almost that of taking a single impossible large step per measure.

"However it does mean that only 25 % of energy is carried forward over three steps"

The movement over three steps in dancing does not have the per-step "bump" rise of arrival due to the leg action evening everything out into a big smooth swing.

"and even less of this can be exploited if there are directional changes."

This is a good concern. If you take that concern and analyze where the line segments making up the characteristic swing dance figures break - where the actual changed of direction are, you find that they almost always occur at the point of maximum rise. At that point, most of your energy is in gravitational potential energy form, which has no direction across the floor, and very little of your energy is in kinetic form, which does have a direction.

You CBM while you are moving, but you don't actually change direction of movement until that point in the swing cycle where the majority of your energy is in non-directional form. You then convert the energy back into kinetic form by executing a downswing in the new direction.

"So the turn of the DRS has stopped whilst step 1 of the next figure is placed. What stops the turn ?"

The forward drive generated by letting the body weight get ahead of the standing foot overcomes the angular momentum and converts it to a more linear movement. The body however will keep rotating somewhat during this nearly linear movement, the body rotation now being known as the CBM of the new figure.

"The forces generated by muscles during the lowering only work forwards and upwards not towards the centre of rotation - so they do not stop me rotating."

You are trying to analyze rotate and translation seperately, but any translation force that is not applied exactly through the center of rotation will in fact alter the rotation.

"Surely, only friction is left."

Floor friction can only dissipate energy if you allow movement (rotation) of the foot against the floor. During the toe spin you will have some frictional losses. But when the foot lowers, even though your body may still be turning, you are no longer letting the foot rotate on the floor, so no energy is lost to floor friction. Friction is merely holding your foot in place. No movement of foot against the floor = no mechanical work = no loss.

"I can see that following a DRS the centre of gravity would continue to move forward as result of the downswing at the end of the figure and that this is where the energy carried into the first part of the next step comes from. BUT, as soon as weight is transferred, the reaction force from the floor would tend to oppose the forwards motion and the energy would be dissipated doing work against that force."

What reaction force?

If you place your leg ahead of you and brace the knee, then you will see a reaction force that slows you, because it is causing your path to curve upwards - you are coasting up hill, and indeed that is one of the ways we can rise in dancing (leading a heel turn would be a good example). But if you let your knee flex as you arrive over it, you will not rise and you will not slow.

That's more typical of step one in for example waltz - limited rise and limited slowing during step one, more dramatic rise and more dramatic slowing during step 2.

OK, I probably do two variants of the DH.
The more standard one to be followed with a back lock does not carry in much inertia and uses no sway.
The more dynamic variant carries inertia through from the DRS, as though dancing a second one, only for it stall in the hesitation. Any sway probably comes from the need for a wide second step, and again I probably take this wider than necessary as I tend to finish in line to follow with a contracheck. Not strict syllabus I'm afraid.

surely if you follow with a contra check you are in effect doing something more like a change of direction. i myself often use the change of direction on non-standard alignments.

"surely if you follow with a contra check you are in effect doing something more like a change of direction."

Yes it is very similar to steps 1&2 of a CoD extending the second step with the hesitation. I did suggest comparing and contrasting the two figures because AFAIK the CoD is not listed as a waltz figure, or QS for that matter.

"I often hear it said that the technique specifies the status at the end of a step."
Yes, see Guy Howard's definition of foot position.
"Then I hear people saying the end of a step is defined as when the feet pass (or close)."
Different book and different situation.

"So how you define the end of the step depends on what aspect of technique you are considering."

At last someone who understands the problem of taking one person's definition and applying it to another's description. Although maybe we see this when trying to follow some of Polished's posts.