Hypermobility describes joints that stretch farther than is normal. For example, some hypermobile people can bend their thumbs backwards to their wrists, bend their knee joints backwards, or put their leg behind the head. It can affect a single joint or multiple joints throughout the body. Hypermobility generally results from one or more of the following: , Misaligned joints , Abnormally-shaped ends of one or more bones at a joint...