National Geographic has a 2014 article about Hugh Turvey, a British photographer who uses a fusion of x-rays and visible light to create art. In particular, a photo of his wife's foot in a stiletto heel caught my eye.
|"Femme Fatale", Hugh Turvey|
After some internet searching, it's not a fancy flexure that allows the heel shank to snap off before the ankle twists...
It's actually the five nails used to attach the shank to the shoe!
Pressure under one of these stiletto heels can be more than 3000 kPa!