All thumbs bad, third thumb good.

Science Adviser has news (and video) of a handy little upgrade invented by robotics researcher Tamar Makin and her colleagues. They’re calling it the Third Thumb because that’s what it is – a sixth digit that helps a human hand carry, hold, and manipulate better than ever:

The Third Thumb was designed to expand a person’s motor abilities, providing improved grasping and increasing the ability to carry things in hand. It’s operated with pressure sensors under a person’s feet, which can either be external or worn inside a shoe.

Out of nearly 600 testers—who ranged in age from 3 to 96 and included people of multiple genders and ethnicities as well as disabilities—only four were unable to use the additional finger. Younger children struggled the most, and older adults also had some difficulty. But overall, most were able to get the hang of the device and use it to perform tasks like moving pegs in a pegboard or picking up and placing oddly shaped objects into a basket.

You can read more about the third-thumb augmentation tech here, in Science Robotics.