I had a very similar experience in a Costco when this all started years ago. I found myself doubled over in pain near my left ribs/chest. I went to the ER and they said "kidney stones." In about an hour, the pain was gone.

Several months later I was diagnosed with TOS. I had a left rib resection and scalenectomy more than two years ago. Unfortunately, I'm in more pain now than I was before the surgery.

I would urge you to see a neurologist for a diagnosis. I had PT and other therapy before I really knew what was going on and it only made matters worse. Proceed with caution and trust your own intuition. If it hurts, don't do it.

Good luck.

Kelly