Baoding balls are two metal balls that are rotated over and over again in one hand for meditation, exercise or rehab purposes. A lot of dexterity and focus and strength is necessary to pull of the rotation. Not everyone can do it! This robotic arm controlled by wires can though. Look at those fake flexible fingers move.
To be clear, in advanced exercises the Baoding balls shouldn’t be touching but I’ll cut the robot arm some slack since it’s a beginner. The robotic hand is impressive because it does such a good job of replicating the nimbleness and flexibility of our human hands.
It’s pretty fascinating how the hand was made, the researchers first created a dummy hand and then tracked and measured six different poses of the hand necessary to rotate the meditation balls so they could design a specific transmission system that would control the prosthetic. You can read more about the project here.