Test: Move your neck around in a bunch of cardinal planes. How loose does it fee? Can you see how a tight neck could make your shoulder position more sucky?
Mwod: 1) 2 minutes each side doing Hand behind back stretch while working on your neck.
2) Open up your thoracic spine on the paired lacrosse balls. 1-2 min
3) Practice a little overhead lat stretch 2 min
4) Try and staple that lacrosse ball to the wall with your chesticle (pec).
Retest: How awesome do you feel?

http://www.mobilitywod.com/2010/09/episode-27-necking-its-a-curling-iron-stretch-mark-neck/