Pain in the Achilles tendon or in its bursa; achillobursitis: Nigel couldn't take part in the long-distance competition because he suffered from achillodynia, which was extremely sore and tender.

The Achilles tendon is one of the better-known anatomic features in sports medicine because of the nature of some unexpected injuries to this tendon. It is in the back of the lower leg and connects the calf muscle (the "triceps surae") with the calcaneus bone in the heel.

This tendon is so named for the hero whose heel, according to Greek mythology, was the only part of his body where he was unprotected from harm.