Calcaneal (Achilles) Tendon
The calcaneal (or Achilles) tendon is the thickest and strongest in the
human body and is about 15 cm in length. This tendon connects the calf
muscle to the heel bone. It puts a spring in the step and helps one to
stand on tiptoe. Unlike the other tendons in the body, though, it has no
protective covering and is therefore very vulnerable to inflammation and
injury. Even shoes which don't fit correctly can inflame or tear the
tendon.
The Greek warrior, Achilles, was the son of a sea goddess and of a
mortal father. When he was a baby, his mother tried to make him immortal
by dipping him in the River Styx. She held him by his heel, which never
touched the water, becoming his only vulnerable spot. Years later, he
died in the Trojan War when his enemy shot him in the heel with an arrow.