[Tango-L] Women's technique

[Konstantin Zahariev]

Dear Trini,

I find the quote you provide very surprising.I think its context might
be different in that it focuses exclusively on the spine movement and
ignoring anything else (see below).

Separately, I find the explanation a bit confusing or misleading.
Here's what I mean:

> "For example, turning the shoulders to face the left is a
> joint action involving a maintenance of extension and
> active rotation to the left. (Remember that gravity is a
> flexor of the spine in an upright position.)

The only way this logcally flows together is if the view taken is that
of the spine exclusively, and the author thinks of it as a compressed
(by gravity) column which needs to extend first to be able to rotate.
So far so good.

> This would require a static contraction of the extensor muscles
> (extension fibers of erector spinae, deep posterior muscles
> and semispinalis)

So far this is naming the muscles the author thinks are involved in
the extension of the spine before its rotation.

BTW, I find usage of phrases like "extension fibers" and (below)
"rotation fibers" misleading. Muscle fibers only contract; it is the
3-D position of the origin and insertion points that determines what
we might call the resulting motion (twisting, bending, extending,
rotating, etc.)

> and shortening contraction of the left
> rotators (left rotation fibers of the erector spinae and
> the deep posterior muscles, and the right side of the
> semispinalis.)"

No idea what rotation fibers are, but we here agree on the small
involvement of the erector spinae (not in rotation, though).

Semispinalis (dorsi, cervicis, capitis) muscles cannot be main movers
in the twisting motion of upper versus lower torso, as they are all in
the thoracic region and up. I can see how they are involved in making
sure the vertebrae acommodate the twisting, though.

Deep posterior muscles -  maybe the author is talking about the
rotatores (but again these are small muscles in the thoracic region
that focus on lifting and/or rotating adjacent vertebrae locally so
cannot be prime movers) or multifidus, which is also not a very large
muscle, acts more locally and probably has a secondary role compared
to the obliques.

What is missing is any discussion of the abdominal muscles,
specifically the external and internal obliques (Obliquus externus
abdominis and Obliquus internus abdominis). I believe this is because
the author focuses only on the vertebral column.

None of this is some new or controversial theory, as far as I know.
You can find it in Gray's anatomy or in any discussion on the action
and function of the obliques.

You are right that it is hard to get to that level of discussion with
students, but I think everyone knows what you mean if you mention the
obliques and avoid too much detail.

With best regards,

Konstantin
Victoria, Canada


On 7/17/07, Trini y Sean (PATangoS) <patangos at yahoo.com> wrote:
> Hi Konstantin,
>
> --- Konstantin Zahariev <anfractuoso at gmail.com> wrote:
>
> > My understanding is that if you twist only your upper
> > body so that your right shoulder rotates forward and to
> the left (from your POV), or, equivalently, when you twist
> only your lower body so that your left knee/leg rotates
> forward and to the right, you involve mainly the
> > right external oblique, the left internal oblique, and to
> > a smaller degree the rectus abdominis and the left spinal
> erectors. So the main movers are nowhere near the spine,
> and the spine errectors do not twist it, even though the
> spine may get a twist in it as a _consequence_ of the
> contraction of the obliques.
> >
> > With best regards,
> >
> > Konstantin
> > Victoria, Canada
>
>
> Trini, here.  Actually, in moving efficiently, it's muscles
> deeper than the obliques that produce rotation.  Here's a
> quote from my Dance Kinesiology book, which is used as a
> textbook in many university dance programs.
>
> "For example, turning the shoulders to face the left is a
> joint action involving a maintenance of extension and
> active rotation to the left.  (Remember that gravity is a
> flexor of the spine in an upright position.)  This would
> require a static contraction of the extensor muscles
> (extension fibers of erector spinae, deep posterior muscles
> and semispinalis) and shortening contraction of the left
> rotators (left rotation fibers of the erector spinae and
> the deep posterior muscles, and the right side of the
> semispinalis.)"
>
> Nowhere does she mention obliques.  The erector spinae is a
> group of vertical muscles that attach to various points of
> the ribcage and spine.  Deep posterior muscles go from
> vertebrae to vertebrae.
>
> When we teach, we don't get into that level of detail,
> except for our most dedicated students.  We simply let
> students think about their spine and loosening it up enough
> to enable more movement.  Beginning lessons with a massage
> helps them understand this.
>
> Keith has obviously not reached a level of dancing that
> teachers are willing to discuss these details with him.
> When instructors from Argentina visit, we discuss things
> like this all the time.  And they get excited and pleased
> that some people care to really learn the details.  Which
> is why they like coming back here to teach.  So they often
> feel comfortable bringing out these issues with our
> students during workshops or privates.
>
> Some of these instructors know so much, it's a shame when
> they are not able to share their knowledge.
>
> Trini de Pittsburgh