Haglund's syndrome is named after Swedish orthopedic surgeon Patrick Haglund (1870-1937), who first described the condition in 1927.
An Achilles' heel is a metaphorical expression referring to a person's or thing's specific weakness or vulnerable point, despite being strong or powerful overall. The term originates from the Greek myth of Achilles, who was made invulnerable by his mother, Thetis, except for his heel, which she held when dipping him in the River Styx. Achilles was later killed by a poisoned arrow to that very heel.