@nickchapman I used to do the 2nd one all the time in school, when the chairs were the right height :P office chairs, not so much. I just grab the chair and twist my torso. Always grosses people out cuz it cracks like a machine gun - usually at least 5 or 6 audible pops, sometimes more. I have a ligament disorder so my spine/joints are kinda messed up - they crack loudly and frequently.