Here's a poem by Chase Twichell from her Dog Language volume that offers an answer to those questions, at least for me.
Because I have arthritis in three
vertebrae, I do yoga and lift
small weights. Strange,
what the exercises dislodge:
a Popeye cartoon,
pirates and skeletons--
what's so indelible about that?
Or the way a dog's eye looked
in a painting, how it followed me.
I like the spinal rotations,
the flex in the tree of history,
part green, part stiffened by bark.
It sprouts a shoot of memory,
a line I once abandoned:
all their hope in their shoulder blades--
it came from seeing some fifteen-
or sixteen-year-old girls on a summer dock--
why should that survive? I guess
it's why I'm standing here before you,
pumping the tiny barbells.
--Chase Twichell
