Ode to the muscles in my upper back

You've got a bloody nerve you have
Trapped between you
Which one's a rock
And which is a hard place
You're a pain in the neck
See, if I move this way it hurts
This way it's worse
I AM that nerve
You've got me surrounded
Up and down are RIGHT out
There are two ways that I can go
Both hurt a bit
I'm off work ill
It's a pain in the neck
It reflects how I feel
About life but I can't stay still
One way hurts least
That way I pick
So you're directing me
You're a pain in the neck