I have enclosed a link from an article that we read in Popular Science Magazine and a question that we are asked often.  The article looked at the research behind knuckle cracking and arthritis.  Research shows that people who crack their knuckles are not at a greater risk for osteoarthritis of the fingers.  Osteoarthritis of a joint is caused by trauma to the joint and while it sounds bad – cracking your knuckles does not generate the necessary force.  It might annoy parents but your kids can be doing worse things with their hands.

https://www.popsci.com/knuckle-cracking-health-myths