The Achilles tendon is a large powerful tendon that connects the calf muscles to the back of the heel bone. The tendon can become inflamed at the insertional aspect on the heel. This can cause aching and burning type pain along with stiffness. This can lead to difficulties with ambulation especially ascending and descending stairs. Over time the acute inflammation can lead to chronic changes in the tendon (tendinosis). This can cause tearing, thickening, and calcifications. Causes include tight calf muscles, overuse, change in activity, and flatfeet.