question: I was jumping on a trampoline and did a backflip.and landed on the back of my neck and my chin hit my chest and my neck popped.Now my chest hurts to cough and cross my arms.Can I please get an explanation as to what may be the cause of my chest pain.i have looked at other websites for explanations and they seem to all have similarities with a hurt arm also.my arm is not in pain just my chest.