Double-jointed describes someone whose joints can bend much farther than most people's. If you can bend your thumb backward to touch your wrist, or hyperextend your elbows so they curve the wrong way, people might say you're double-jointed.

The term is actually misleading: double-jointed people don't have extra joints or different bones. Instead, they have unusually flexible connective tissues (the stretchy, rubber-band-like structures that help hold joints together). This allows their joints to move through a wider range of motion than typical.

Some double-jointed abilities look almost magical: bending fingers backward at odd angles, folding into pretzel-like yoga poses, or doing that party trick where you clasp your hands and step through your own arms. Gymnasts, dancers, and contortionists often have this natural flexibility, which they develop further through training.

Being double-jointed might seem like a superpower, but it comes with trade-offs. Those extra-flexible joints can be less stable, making them more prone to sprains or dislocations. The medical term for extreme joint flexibility is hypermobility, and doctors take it seriously when assessing someone's overall health.