For over a year now I've been having upper back issues. I get a dull ache between my spine and left shoulder blade. I've recently started seeing a physio who has said it's stiffness in one of the joints. He gave me some stretches to do such as thoraic extension. This relieves the ache but only for a short time and it comes back. I'm aware it is possibly down to a posture issue but can not seem to make the problem go away.

Anyone had any similar issues or ideas on how to get rid of the problem?