Well I know that before I started getting anxiety, I went to the doctor for having trouble breathing, the doctors believed it was acid reflux. This can cause trouble breathing and soreness as you said. Once again acid reflux is also a symptom of anxiety. So this is really when I first started to know I had anxiety.
I am experiencing the exact same thing right now and also suffer from anxiety and panic attacks. I haven't been to the doctor about it. It just started on Thursday and is a little better today. I also have acid reflux which I am told can cause soreness in the back and chest. I unfortunatly don't have an answer just wanted to share that I am feeling the same thing. It also feels like pulled muscles but I just had surgery and haven't been doing much so I don't think it is. Let me know if you find out what it is. Good luck!!
No one knows except for a doctor and that is just to be on the safe side. I know however that anxiety can bring on a wide range of symptoms. I for one at times feel like i lose my breath for a second, not to mention many other symptoms when my anxiety is high. I also think when we are dealing with anxiety we tend to focus on things more and make something out to be more then it is. I know that I have done this several times, plus anxiety does cause tension which would explain your back and chest problem. I hope this helps.