For 50 years this man cracked his knuckles on one hand only to see if it would lead to arthritis of his fingers. - discu.eu

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For 50 years this man cracked his knuckles on one hand only to see if it would lead to arthritis of his fingers. http://www3.interscience.wiley.com/cgi-bin/fulltext/86510619/pdfstart 600 comments 17/11/2009 science