article_snippet.sent: The real reasons behind what causes knuckles to crack has long been the topic of dispute  among researchers.
article_snippet.sent: a group of scientists from the University of Alberta in Canada claim to have settled the debate once and for all study finds the cracking is caused by the rapid formation of a gas-filled cavity within a slippery substance called synovial fluid that lubricates the space between the finger bones.
article_snippet.sent: Research found that the cracking is caused by the rapid formation of a gas-filled cavity within a slippery substance called synovial fluid that lubricates the space between the finger bones .
article_snippet.sent: Their study also found that the knuckle cracks in less than 310 milliseconds and that immediately before the popping sound there is a white flash, believed to be from water rushing together.
article_snippet.sent: The next burning question: Is cracking your knuckles harmful?
article_snippet.sent: ‘Why do the same joints crack in some people and not others?
article_snippet.sent: A knuckle cracks in less than 310 milliseconds and water rushing together causes a white flash .
article_snippet.sent: Although speculative, we wonder if being able to crack ones joints is a sign that the joint is actually healthy and that the inability to do so could be a sign of joint problems to come.
highlights_snippet.sent: Research found why knuckles really crack .
  
highlights_snippet.sent: Study found  cracking is caused by rapid formation of gas-filled cavity .
  
highlights_snippet.sent: Research also discovered a knuckle cracks in less than 310 milliseconds .
  