About 4 years ago, I was in a bad car accident where my car slid off a icy road and into a tree, I was taken to the nearest hospital by ambulance. I told them of the pain in my back and my knee. When I got to the hospital, and they did took xrays of everything except my ribs! It was sore for about 2 months after my accident, where I couldn't bend down, cough, sneeze, or breathe without it hurting. Eventually the pain stopped. I've noticed that there is a little knot where my rib hurts, it still hurts when people touch or push on it. I went to a chiropractor about 6 months ago and he had told me that my rib had been popped out of the socket and was resting on top. He's tried to pop it back in place several times, with no luck. As I've said, it's been like this for almost 4 years now. Just the other day, I stretched and I felt a sudden sharp pain on that rib, and for the past few days it's been slightly painful, but just mostly uncomfortable if I sneeze, yawn, cough, or even stretch. What could have caused it to start hurting again?