Backs are kind of wonderful. They enable us to walk after all (just try it when your back is out) and they go on expressing a whole lot more than we think, behind our backs, as it were.
Sometimes it’s determination
and sometimes just attitude
or conscientiousness
or maybe, resignation
or that end of the day thing
which everybody gets
Whaddya Mean Rosebuds? 
Backs express a lot. Sometimes taking pictures in the streets I don’t dare to shoot in the face:)…