0 able to move and bend the body's joints (= places where bones join such as in your fingers, at your knees, etc.) more than is usual: --
Children on the autistic spectrum are often hypermobile and he became a great yogi.
Multiple musculoskeletal problems can occur in hypermobile individuals.
Lots of people have relatively hypermobile areas of their spine, which they find very easy to stretch.
Long, thin, hypermobile fingers are characteristic of Marfan Syndrome.