I agree with leonid, there is a distinction (albeit often a blurry one) between heightening the effect, making the same gesture simply bigger and actually
changing a posture or step. Or to put it another way:
Sometimes more feels like more....... but sometimes more looks more like
different.........and sometimes that different just looks plain
wrong!
I find it strange how some professional dancers can actually get away with cranking up certain steps - there's one beautiful moment in the balcony PDD of Macillan's R+ J (the moment when he first seriously takes hold of her by the waist) which is often ruined by a Juliet taking her leg way up and in front of her face instead of leaving it at around hip level. That is in my book an example of
changing the choreography, and worse into something totally innappropriate, and making no sense. It's no different to changing an arm from second to fifth just because you are flexible enough to do so, or singing an octave higher than on the score.
We may have a better understanding of the human body than, say, 50 years ago, in terms of understanding fitness, health, conditioning, injury diagnosis/ repair/ prevention, diet, safety etc as well as more advanced technology/ medicines and equipment and so on.... but these could all just as easily result in simply fitter, healthier, less injury prone dancers. I don't see why they should
necessarily translate to changes on stage, even if they do result in more flexible dancers. There has to be something else driving it.
I've been reading up a bit recently about other past civilizations - what drove them and how they functioned, that sort of thing - (I'm thinking of setting up my own new civilization - anyone want in?

) Anyway one idea which really struck me was the idea that we are currently living in a world which values 'progress' above all other values. Moreover, we have all accepted that 'progress' has always (and will always) be the driving force / goal of civilisation and that we have in fact 'progressed' steadily and linearly from living in caves to right up to this very moment - this moment being naturally the peak of all civilizations so far achieved! LOL
But looking at other much earlier civlizations - as far back as we can look -it becomes so clear that their value systems were quite different to ours - they must have been - for example they might have rated 'purpose' higher than 'progress'. It's a fascinating area to explore - especially in these current times we live in! Anyway the point being 'progress' when you actually examine it turns out to be pretty reckless, uncontrolable and unforgiving value on which to base a civilization. 'Progress' demands a constant and, well I guess you'd have to say,
progressive change even beyond the point when change is still needed or even desirable. It is by adhering so strictly and rigidly to the goal of 'progress' that we have arrived at our current model of civilization where science and technology totally dominates art and culture at least a million to one in terms of funding and human activity - which indicates how much the arts are
really valued in this model of civilization. (this isn't a political point by the way, it's much more abstract than that).
So the idea is we are compelled (conditioned) to either accept as normal or to demand as necessary 'progress' in all things even if those things (and ourselves) suffer as a result. If something is wrong in the world it is because we 'obviously' haven't progressed far enough in the direction we are going and if we could just progress a little bit more we will eventually find the solution... rather like standing in the shower and turning the dial towards 'hot' and as it passes pleasant and starts to get uncomfortably hot, then scalding we keep turning the dial further and further looking to solve this problem without even thinking to try turning it back the other way.
This attitude of automatic, unquestioning acceptance of the need for 'progress' is so ingrained we don't seem to be able to even see it, or see it for what it really is - let alone imagine an alternative. The reasoning goes that all must modernize, change, accelerate, exaggerate just to stay relevant, to keep up with the, er, ever changing (ie 'progressing') times. All must be meddled with or else it will become obsolete. By not allowing things to ever remain 'static' we automatically disregard perfection whenever we do happen to reach it.... we keep going! ....... for the sake of progress.....
And most crucially of all this attitude has lead to a gradual shift in consciousness so that
time itself is no longer experienced (felt) as the moment to moment bestowal of glorious, ecstatic 'newness' to all things by itself............ but instead it is regarded (thought of) as a sort of never ending vacuum opening up in front of us demanding to be filled moment to moment with some evidence of more 'progress' .... almost as if we need to make offerings of 'change' to it just to keep the clocks ticking.
I believe it is this increasing shift in consciousness (which has accelerated alongside technology, both driving/feeding off each other) which is being reflected in
all the arts and in
all aspects of our civilization. My shower analogy applies just as well to consumerism or the current economic crisis and proposed 'solutions' or ridiculously unecessary extensions in ballet ... "keep turning that dial!". Everything is louder, faster, more in your face and so on ..... 'Progress' over 'purpose' everywhere you look.
Coming back to focus on ballet.

and I see this whole shift in consciousness expressed not just with this apparent 'need' for unnecessary extreme extensions all the time but also with the whole lack of musicality thing. (I see it all as the same thing). Musicality and that onstage
presence which is so hard to define are in my opinion fundamentally about the dancer's relationship with
time.... with the moment - it's about whether they are able to
let the moment fill them or whether they feel
they have to fill the moment. And this ties in perfectly with the way our fixation on 'progress' has altered our relationship with time, as mentioned earlier. Dancers (and everyone else) now think more in terms of their relationship with space, expressed in time, and not in terms of their relationship with time, expressed in space. The former tends to express discomfort and dissatisfaction, the latter harmony and elegance.
Interestingly I think classical ballet, classical music and any art form still with a well maintained 'heritage' actually suffers less because these traditions act as an breaking force to these urges for such unecessary 'progress'. And yet they are also where the effects are most noticeable (due to being able to reference the same works expressed by different generations over long periods of time) just as seen in the study being discussed on this thread.
In dance styles where traditions do not apply there is no such breaking force to slow down 'progress' and so we now will often see limbs not just extended to the extreme, but pulled aggressively almost as if the desire is for the dancers to 'progress' beyond the human form. The ultimate progressive modern ballet would probably be a dancer just walking on to centre stage and then just exploding into the wings to the soundtrack of white noise and heavy industry.
Anyway with that image I will finish! These are my thoughts, I don't know if I explained them very well.
Something tells me that even if we act linearly nature will always stay circular ..... maybe as art is a reflection of our civilization those legs were just telling us we'd reached some kind of zenith! (Let's hope so!) And I've seen plenty of
more than 180 degree penchés which suggest it we are already coming full circle.