Recently, I was seated on a plane and bent over to place my handbag under the seat in front of me; when I tried to sit up it was if my left ribs had overlapped each other & I felt excruciating pain & had to stay bent over until the ribs felt like they released from each other ....what caused this as it has happened to me before?
Thanks for your question on Chat Doctor. In my opinion it is not overlapping of ribs. It is due to muscle spasm. It can occur due to any unusual movement. It is actually a protective mechanism to avoid damage to bones. So no need to worry about this. Once spasm of muscles are relieved, you will feel all right. So better to avoid such position. And if you want to do some activity like this than do it gradually.  Don't do it fast. So be relaxed about this.