Well, it appears that while advice from singer Jim Croce remains solid (don't tug on Superman's cape, don't spit into the wind, don't pull the mask off that old Lone Ranger, etc.), your mom and/or grandmother's advice to stop cracking your knuckles (because you'll get arthritis) is not quite so solid.

As a matter of fact, it appears that mom and grandma's info wasn't all--wait for it---it's cracked up to be (sorry).

So, check this out, then...crack away, my friends, crack away: