Little else can match that feeling you get when you crack your knuckles, especially after you've spent hours pecking at a keyboard or playing angry birds. The sound that follows, however, is a bit cringe-worthy. Have you ever wondered what that sound actually is, or why some joints even pop at all?
This video from TED-Ed, narrated by Eleanor Nelsen, delves into the mystery of cracked knuckles, whilst examining common myths and misconceptions (like "will cracking your knuckles ultimately give you arthritis," and "is it bad for your body?").
WATCH: "Why do your knuckles pop? - Eleanor Nelsen"
As an interesting aside, researchers recently watched and studied the effect of cracking your knuckles using an MRI (Magnetic Resonance Imaging) machine. The before and after shots ultimately revealed something fascinating—that cracking your knuckles is similar in mechanics to a vacuum. Basically, when a person scratches the itch, a cavity is created within the joint's fluids, Greg Kawchuk (the Professor of Rehabilitation Medicine from the University of Alberta) explains. "As the joint surfaces suddenly separate, there is no more fluid available to fill the increasing joint volume, so a cavity is created, and that event is what's associated with the sound."