The part of the back (or backbone) between the shoulder blades and the loins which an animal cannot reach to scratch; the part of the human back between the shoulder blades.
“acnestis, n.” OED Online. Oxford University Press, June 2016. Web. 29 June 2016.
Hmm… I did not realise that I have no idea what the human body looks like until I had to draw it from different angles. I will have to spend more time drawing from angles. I am trying to take some of my experience from my photography classes to make more expressive postures and gestures, but it is proving to be more difficult than I first imagined.