That's one of a series of exercises that a physical therapist gave me for a 40 year old football injury that started hurting a few years ago. Evidently there's scar tissue from a badly broken collar bone.

Another similar exercise is to rest both elbows and arms on a door opening and lean through the opening.

I also do something he called 'the turtle' where I lift my shoulders up to my ears as much as possible. Sometimes there's one heck of a popping sound but it feels better afterwards.

I also try to lean my head on one shoulder then the next.

I hold all these positions at least 10 seconds or more and repeat a few times each.