You may know someone who has been diagnosed with Achilles tendonitis. Or maybe you were. If not diagnosed, the symptoms may be familiar…. pain and stiffness in the back of the heel particularly in the morning, swelling or thickening of the Achilles tendon, pain after activity. Achilles tendonitis is a common condition, especially in the spring as the weather warms up and people quickly increase their activity levels significantly above what they were during the cold winter months. It can also occur in individuals who have chronic tightness in their calf muscles.