Weird shoulder pain

[Pob13]

This sounds really random but all advice welcome.
Whenever i go to the cinema i get pain under left boob and in my left shoulder. The shoulder pain is really bad. The pain can be eased with an icepack when i go home, but normally takes a couple of hours to go.
Im guessing it might be to do with being sat in a tight space for a couple of hours.

Any ideas?

Bump

Could it be a twisted rib? Might be worth seeing an osteopath.

It sounds musculoskeletal so chiropractor/osteopath would be best placed to help.