Chronic neck pain
Let’s get two things straight
Breathing dictates posture. standing up straight (whenever you remember too wont fix anything)
Belly breathing isn’t good breathing - usually is coincides with a bad rib flair which is not good
Why does someone with acute neck pain become chronically painful?
They are stuck - Their ribs are stuck flared upwards, their sternum, their collar bone are all stuck in a bad position. The position they are stuck in is a state of inspiration and chronic neck pain patients can't exhale fully.
The most important thing for chronic neck pain clients is to teach their ribcage to move towards the pelvis and not the head.
In the video below you can see the flared rib cage - By blowing through a balloon this will allow for the obliques to contract and cause the upper neck musculature to relax and lengthen.