Frida Kahlo, The Broken Column, 1944
All her life, Frida had been in incredible pain due to an early accident on a trolley bus that left her with many back and uterine problems. She had to suffer through A LOT of awful surgeries, so as a result, quite a few of her paintings were depictions of her pain. This one was done in response to the back brace she wore which, apparently, hurt like a motherfucker.
The nails piercing her skin are a reference to St. Sebastian and his traditional depiction with arrows.