Pain at the top of the heel that is aggravated by activity is likely to be a result of Achilles Tendinitis. Correct answer: C Achilles tendinitis is an acute, inflammatory injury of the Achilles tendon which occurs when the tendon that attaches the calf muscles to the heel becomes painful or inflamed. It most commonly affects athletes, especially runners, or people who play sports that require lots of starting and stopping, such as tennis.