We may earn a commission from links on this page.

What if a prosthetic could work not as a substitute for a missing body part, but as a useful extension of the body? Imagine having an extra digit on your hand to play the guitar, or to get a better grip while squeezing a lemon, for example.

That’s the promise of the “Third Thumb.” Product designer Dani Clode created the controllable 3D-printed thumb while doing her graduate studies at the Royal College of Art in London.

“I did come across the origin of the word ‘prosthesis,’ and I found that it meant, ‘in addition to,’ so I really like this idea of reframing prosthetics as extensions to the body, rather than anything that fixes or replaces,” said Clode. “We’re just extending their current ability of their body.”

The device is worn like a watch, with the extra thumb sticking out next to the smallest, or pinky, finger. Bluetooth connects the extra thumb to sensors on the person’s shoe, which control the grip and release of the extra thumb. The foot motion is similar to driving a car, using a sewing machine, or pushing the pedals on piano.

Watch our video to see the Third Thumb in action.