This robotic extra thumb can be controlled by moving your toes

People equipped with an additional, robotic thumb learned to control it with their toes – but prolonged used may come at a cost of their brains being less certain about how their hands work. Danielle Clode at University College London and her colleagues gave 36 people a prosthetic thumb that wrapped around their wrist and sat underneath their little finger. All were right-handed, and wore the device on their dominant hand. The third thumb's movement was controlled by sensors attached to the user's big toes, and communications were sent using wireless technology affixed at the wrist and ankle. By wiggling each toe, the augmented humans could move the thumb in different directions and clench its grip.