Inflammation of your fibrous band of tissue which spans from the bottom of your heel to the ball of the foot as a result of an overuse There is frequently pain in the Achilles tendon insertion to the calcaneus (heel bone) posteriorly (driving). The Achilles tendon can be thickened (swollen) https://www.theorthopaedicandpainpractice.com/why-does-the-back-of-my-heel-hurt/