OverviewThe Achilles tendon is the largest and strongest tendon in the human body. It is the ?cord? in the back of the leg that inserts into the back of the heel. The Achilles tendon got its name, according to Greek legend, when the Greek warrior, Achilles, was dipped into the River Styx by Thetis, his mother. This rendered him invincible with the exception of his unsubmerged heel. Unfortunately, he went on to get mortally wounded during the siege of Troy when he was struck in that heel by an arrow. Achilles tendinitis is inflammation and partial tearing of the Achilles tendon. It can occur with overuse of the tendon such as when starting or increasing the intensity of an exercise program or performing impact loading activities that include a lot of running and/or jumping.