Welcome to MedHelp's Senior Health Community. I am glad you found s and took the time to post your question and concern.
I do not have the condition you describe nor have I heard of it. However after fifty plus years on this planet I have learned that nothing very little is impossible. I believe you are experiencing this phenomenon.
Have you told your Chiropractor about these symptoms? If not I would do so. I would also consult a D. O. (Doctor of Osteopathy). The DOs that perform OMT (Osteopathic Manipulation Therapy) truly know how the body is aligned and should function.
Your muscles may be very weak and allow your ribs to feel as if they "cross over" or indeed it could be occurring. I hope you will pursue an answer. Be assertive and don't continue with a physician that "laughs" at your concerns.
Please let us know how you are doing. I will look forward to your updates.
Take Care and Good Luck,
When my son was about 7 he had rib spasms and they would cross. Very painful. He ended up have a couple inches cut off 2 ribs. No problems after that.