Snap, crackle, pop: study reveals secret behind knuckle-cracking | http://j.mp/1D5JmAa http://j.mp/1D5JmQo

Snap, crackle, pop: study reveals secret behind knuckle-cracking | http://j.mp/1D5JmAa http://j.mp/1D5JmQo:

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April 20, 2015 at 12:37PM