Please check out this very informative blog that discusses heel pain in adolescents. We see many young athletes that present in our offices with heel pain. A good majority of the time it is a growth plate injury of the heel called Calcaneal apophysitis or Sever's disease. Fortunately this is a treatable condition if recognized early.
If your child is suffering from heel pain that has not improved after a few weeks please call our offices so that we can resolve this specific injury.

http://www.drblakeshealingsole.com/2011/11/severs-disease-growth-plate-injury-in.html