Armed With Legos.

• Position: THE BIG PICTURE - David Aguilar

David Aguilar, 19, was born without a right forearm. Growing up in Andorra (a tiny country between Spain and France), his rare genetic condition made him feel different around other kids. So at age 9, he used Legos, his favorite toy, to build his first artificial arm. The design was rudimentary, but it served its purpose: "I wanted to ... see myself in the mirror like I see other guys, with two hands," Aguilar told Reuters. Over the years, he created three more prostheses out of Legos, improving the technology with each version. The more recent models rely on motors from various Lego kits to bend the arm at the elbow joint and flex the pieces that act as fingers. Aguilar wears the prostheses only occasionally; they're usually on display in his dorm room at the Universitat Internacional de...