Perhaps there is a verb that already does this, but I don't know of it. If there is, please let me know. :c)
This would only work on yourself.
Crack <body part>
Crack neck:
Others see: You hear a loud popping as Klahrine stretches her neck from side to side.
You see: You tilt your head from side to side stretching your neck. Snap! Crackle!
Pop! That had to feel good!
Other body parts would be hands, back... you get the picture.
