" ... It could be shown that a significant number of
voice teachers in both surveyed countries regularly use various gestures to enhance and/or illustrate explanation
and/or demonstration; and an almost equal number of voice teachers in both countries regularly encourage their
students to use various gestures and/or body-movements to facilitate understanding and learning of physiological
functions, thought concepts or musical ideas. ... " 
 
Thanks "GUEST,19 Sep".
An interesting article, too many good quotes to put here.

but here's one
" A gesture can help to commit a voice-technical
mechanism to the physiological/kinesthetic
part of the brain so that it can later be called upon. Also – very importantly – a gesture can
(particularly when used to replace useless, tense,
habitual gestures) help to get rid of faulty old
habits.
And another wrote:
A gesture gives very good feedback about a
student’s thoughts about a phrase, his/her
sensation for voice positioning, breath, etc. Hand
and body show a student’s unconscious thoughts,
with which inner image he guides his voice.
Adjusting a movement to a desired gesture also
alters voice positioning and breath. The causal
connection between brain and hand never ceases
to astonish."

It does seem to be focusing on teaching techniques. I, rhetorically, wonder what advice they give for the actual performance?
(it might say... but I'm a slow reader.... 17 pages, I didn't follow every point)