Derby the dog was born with no front paws and malformed front legs. But that's not stopping him from running with the big dogs, thanks to his very own pair of 3-D printed legs.

For the first few years of Derby's life he had to crawl to get around. But he met Tara Anderson in 2014 when she took him in as a foster. In addition to being a caring foster mom, Anderson also happened to be an employee at 3D Systems, a 3-D design and printing company.

Anderson and the staff at 3D Systems initially designed a set of legs for Derby that were low to the ground, so that the change would not be too drastic for the pup. Right from the start, Derby loved his legs and took off running, to the surprise of not only Anderson and the 3D Systems team, but also Derby's new adoptive parents Dom and Sherry Portanova.

"I don't become impressed very quickly, but when I saw him sprinting like that, it was amazing," said Dom.

But Anderson and her team had to go back to the drawing board to design the set of legs that would help Derby run and play with better posture. As Anderson shares in the video below, she at first thought that she could take the design of Derby's first pair of legs and just make them larger.

But the design was awkward and Derby didn't quite know what to make of it. After some more trial and error, the team landed on a figure-eight design that gave Derby legs at the right height and with a inner joint that functioned more like a real knee.

Here's a closer look design:

Derby the dog's redesigned prosthetic legs.This figure-eight design took Derby to new heights, while giving him a joint similar to a knee. (Photo: 3D Systems/YouTube)

Derby's new legs allow him to stand tall and run and jump with better posture. Now Derby runs two to three miles everyday with Sherry and Dom, running faster and always ready to go even farther than they do.