Body Hacks

Improve Your Body & Life

While I’ve always felt a third arm could come in handy (get it?), life could get easier with something less obtrusive, an extra digit,... Forget Third Arms, What About a Third Thumb?

While I’ve always felt a third arm could come in handy (get it?), life could get easier with something less obtrusive, an extra digit, perhaps.

When designer Dani Clode created what he calls the Third Thumb Project, it was to further the definition of what it means to be human. This is, in essence, the core of the transhumanist movement.

The third thumb project does what the name implies. It gives wearers a third thumb for doing… whatever it is one does with a third thumb.

While the execution of the prosthetic thumb from Clode is not perfect, in its simplicity it does more right than it does wrong. It is the tomorrow you worried about yesterday.


The thumb itself is one piece in three simple segments, like the sections of a finger, connected but independent. There is a tether running the length of the digit that articulates the thumb.

Using a simple hand strap, the thumb anchors to the wrist, opposite one’s actual thumb. From there it connects to a more complex wrist strap, which houses the brain of the thumb.

The design so well equivocates the position of one’s real thumb, that if it were equal in strength to the real one, human grip strength would be uncanny. As it is, from the demo videos, it doesn’t seem to quite have the same strength.

From the wrist attachment, there is a wireless Bluetooth connection to a device that clips to one’s footwear. A pressure sensor goes in the shoe, allowing the user to activate a series of movements with the third thumb.

What Clode has so far is a simple working prototype. His intention is to make it open source so that other can download and 3D print their own.


Surprisingly, the third thumb is mostly three 3D-printed parts. The structural parts of the device, like the parts that wrap around the wrist and hand, Clode intended for printing out of Formlabs gray resin.

The finger he made from a flexible filament called Ninjaflex. They connect via simple wires, easy to acquire from any electronic parts supplier.

The housing and parts for the Bluetooth parts of the device and the foot sensor, Clode doesn’t discuss on his site, but one assumes he intends to disclose them at a later date.

There’s no sense in owning a Bluetooth activated prosthetic finger one printed at home, but with no way to activate it.


From Clode’s site, he says;

“The origin of the word ‘prosthesis’ meant ’to add, put onto’; so not to fix or replace, but to extend. The Third Thumb is inspired by this word origin, exploring human augmentation and aiming to reframe prosthetics as extensions of the body.”

This captures the basic purpose of the third thumb. For those who would add a thumb to their existing digits, the opportunities only suffer the limitations of imagination and the structure of the thumb.

It would be unwise to hang from a 40-story girder from only the third thumb at this point, not if one intended to survive. That said, everyday activities, like holding one’s smartphone to playing the guitar could enjoy the enhancement of one more opposing digit.

Reading through the thoughts of Clode on his site is a trip through the mind of a creative, but design-obsessive person. It’s not for everyone.

This writer gets the sense that Clode imagines a distant (or not distant) future where this sort of augmentation normalizes. Everyone will add limbs as they see fit.

There, in that timeline, someone will search for the origins of adding limbs. They’ll happen upon an archive of Clode’s work, revealing it to all the world, treating it as a sacred text about the future.

In the future, humans will talk about designers like Clode using terms expressions like, “ahead of his time,” and “fashion forward.”

For now, the idea of adding a third thumb sounds about as forward-thinking as adding a third arm or any other extra limb; handy, but silly-looking.