The Achilles tendon derives its name from a hero in Greek mythology. As a baby, Achilles was dipped into magic water that made him invulnerable to harm everywhere it touched his skin. His mother, however, was holding him by the back of his heel and overlooked submerging his heel under the water. Consequently, his heel was vulnerable and proved to be his undoing. Achilles was shot in the heel with an arrow at the battle of Troy and died. By saying that someone has an “Achilles heel” means that the person has a weak spot that can be attacked.