As if it has never been different: scientists give people an extra thumb

An extra thumb turns out to be super handy! It allows people to perform tasks that would normally be difficult or even impossible with just one hand. In fact, with an extra thumb you can perform tasks that would otherwise require multiple hands.

Maybe you’re wondering if the five fingers we have aren’t already enough. But you may think differently after reading this article. Researchers have developed an extra robot thumb that not only helps grasp objects, but also makes it possible to lift more things at the same time. Pretty handy, right?

The robot duim
The robot thumb is worn on the opposite side of the palm to the natural thumb. You operate it using a pressure sensor under your feet. When you press with your right toe, the thumb moves over your hand. And when you press with your left toe, the thumb goes up to your fingers. How much the thumb moves depends on how hard you press. And when you stop pressing, the thumb returns to its original position.

The extra thumb allows users to hold several things at the same time. Image: Dani Clode Design / The Plasticity Lab

To study how useful an extra thumb is, the researchers conducted an experiment with 596 participants of different ages (from three to 96 years old) and from different backgrounds. The team tested the robotic device on a diverse group of participants, which they say is key to ensuring new technologies are inclusive and can work for everyone.

Two tasks
The participants were given one minute to get to know the device. They then had to perform two different tasks. In the first task, participants had to pick pegs one by one from a pegboard (a board with holes) and then place them in a basket. They were given 60 seconds to do this. In the second task, participants had to move five or six different objects. Because these objects had various shapes, participants had to perform different actions, which made the task more difficult. Once again, the goal for the participants was to place as many objects as possible in a basket within one minute.

The results are astonishing. 333 participants completed the first task and 246 the second. But almost anyone could use the device almost immediately. Nearly all participants, 98 percent, were able to successfully move objects within the first minute of use. There were only 13 participants who could not do this. Participants showed different skill levels, but there were no performance differences between men and women. It also did not matter whether someone was left or right-handed, even though the robot thumb was always worn on the right hand. Furthermore, the researchers also found no clear evidence that people considered “handy” – such as musicians or people with manual occupations – were better at the tasks.

You get used to it quickly!
All in all, the researchers show with this funny experiment that people get used to an extra thumb surprisingly quickly. The participants mastered using the thumb to pick up and move objects remarkably quickly. And an extra thumb turns out to be super useful. It helps the wearer to grip things better and hold more things at the same time. This allows the user to do things that would otherwise be difficult or impossible with one hand, or even perform tasks that would normally require multiple hands.

This study is not only funny, but also has serious implications. More and more technologies are coming onto the market that allow us to improve our movements. Take, for example, exoskeletons or robotic body parts, which can strengthen our motor skills and exceed our physical limits. These devices can be useful both for healthy people who want to increase their productivity, and for people with disabilities. “Technology is changing our definition of what it means to be human,” says researcher Tamar Makin. “Machines are increasingly part of our daily lives. These technologies offer exciting new opportunities that can benefit society.”

The study illustrates how quickly people can adapt to new technological possibilities, such as the use of an extra thumb. And perhaps it provides a glimpse of the future, where human capabilities are enhanced not only by biological evolution, but also by symbiotic cooperation with advanced technologies. Time will tell.