The spot where the Achilles tendon attaches to the heel bone is called the Achilles insertion, and it can be the location of pain for many patients. The pain usually comes about increasingly over time in the back of the heel. A tight calf muscle can accelerate these symptoms. In some cases, physical therapy to stretch the calf muscle can relieve the symptoms of insertional Achilles tendinitis. In other cases, if left unchecked, it can develop into a bony prominence on the back of the heel, called a Haglund’s deformity, which can be very painful and cannot be treated with physical therapy.