Knuckle cracking may sound horrible, but these scans show knuckle cracking is actually good for your hands.
원문출처 : http://www.cnn.com/2016/08/18/health/knuckle-cracking-good-not-bad/index.html
원문출처 : http://www.cnn.com/2016/08/18/health/knuckle-cracking-good-not-bad/index.html