User blog comment:TitanicMixGirl/Episode 11 I Made Up/@comment-5539085-20130120213843/@comment-5093389-20130123033131

I doubt it's true. Cartilage acts as a cushion between bones, so they don't rub together when you move. Cartilage actually takes damage over the years due to prolonged use. Not only that, but the ear lobe and the nose are actually made of certillage. If cartilage really did harden after an hour on no movement, our noses and earlobes would have all hardened by now.

So, I'm doubtful cartilage actually hardens.