Heel Pain in Children
Heel pain, unlike the heel spurs, that occur in adults is very uncommon in children. Of those children who do get heel pain, by far the most common cause is a disturbance to the growing area at the back of the heel bone (calcaneus) where the strong achilles tendon attaches to it. This is known as Sever's disease or calcaneal apophysitis (inflammation of the growth plate). It is most common between the ages of 10 to 14 years of age. These are one of several different 'osteochondroses' that can occur in other parts of the body, such as at the knee (Osgood-Schlatters Disease).
To read the rest of the article, click on the link above. It has great information about the formation of growth plates,what causes heel pain, etc.