WHAT'S UP WITH...HITCHHIKER'S THUMB

If your thumb looks as if it's doing a backbend, here's why.

- BY KAYLA BLANTON

GO AHEAD AND GIVE your-self a thumbs-up—and then take a closer look. The majority of human thumbs go straight up, with a slight curve back at the top knuckle. But for roughly one in three people, the thumb bends much farther back—if yours goes more than 50 degrees, making what looks almost like an upside-down “L” shape, you have distal hyperextensibility, which simply means super-flexible ligaments. The condition is also known by the apt description “hitchhiker’s thumb.” Hop in as experts explain what this means.

WHY SO BENDY?