8. Baoding (Meditation) Balls
Well, these are metal balls that you can spin around in your hand theoretically to improve your attention span. It sounds skeptical but actually, these balls have been around for centuries. Doctors in China sometimes recommend Baoding balls to patients who suffer from fatigue, believing that these balls activate different therapeutic pressure points of the hand. There are many different kinds – steel and hollow, beautifully engraved metal ones, or made from heavy stones to help you exercise your hand muscles.
Initially, the balls maintain contact even as they are rotated. With practice, your hands eventually learn to manipulate these balls without having them touch each other. This exercise purportedly improves brain function and exercises the hand muscles.
Learn more about the different kinds of Baoding balls here!