How does he go about doing it? :?:

Some guy here can crack his you-know-what and you haven't said that Laughing

No way! How is that possible!?

I know someone who cracks their knuckles like every 10 minutes with out failure. She cracks fiercely too. I have noticed over time, her knuckles sound different now when she cracks them, almost like something is coming loose. I have read here and many other places that it doesn't cause any negative effects. She doesn't seem worried about it, but I was wondering why the crack has changed sound and sounds worse and worse over time.