my husband had weird shoulder blade pain

my husband recently got this pain wedged into one of his shoulder blades in his back. it hurt him when it lays back in a certain way putting pressure on it and when he lays on his chest he feels it hurt too. I've tried giving him Ibuprofen, massages and hot showers but it's still just there for like 3-4 weeks now. I asked him if it hurts when he breathes because he has bronchitis but he said no (when he got diagnosed they did a chest x-ray and was cleared of any pneumonia) the pain came like 2 weeks after and he says it doesn't hurt when he breathes, what could this be, he doesn't want to go to the doctors for nothing so we were wondering if this is just some strain or something?