You've probably heard from your parents to stop cracking your knuckles because it could do harm to your joints or even give you arthritis. Well, that old wives' tale has no validity to it.

Studies have proven that cracking your knuckles does not do you any harm. You're just popping air bubbles when you do that and not harming your joints.

Technically, when you crack a knuckle, you're forming and then popping an air bubble in what's called your synovial fluid, the stuff that reduces friction in your joints.

So kids, pop away!

[MSN]