Achilles tendinitis. Artwork of the human foot muscles, tendons & bones, depicting acute inflammation of the achilles tendon, known as achilles tendinitis. The purple achilles tendon is seen running from the bone at the heel of the foot (the calcaneus, lower right) up to the calf muscle (red, at top right). At its attachment site with the calcaneus, the achilles tendon is inflamed & breaking up. A partial rupture has also resulted in inflammatory tissue half-way up the tendon (at centre right). Such inflammation is the result of minor injuries caused by excessive or incorrect exercise or wearing incorrect footwear. Treatment is usually by rest or physiotherapy.