Soreness in the rearfoot of children isn't common, but when it does happen, the most prevalent reason is a problem referred to as Severs disease. It is not a real “disease”, but it is the label which has regrettably widely used. It is actually correctly termed calcaneal apophysitis. It is a problem with the growing area at the rear of the heel bone. Because it is a problem, of the growing bone, the disorder is self-limiting and will no longer be a concern once the growth of that bone has completed. It is more prevalent around the ages of 10-12 years.
The typical sign of Severs disease is discomfort on exercise and discomfort on compressing the sides of the rear area of the heel. At first the discomfort is relatively minor and doesn't impact activity much, however later it becomes more severe and impacts exercise participation and may even cause limping. The precise cause of it is not clear, but it is obviously an excessive use type condition as it is more prevalent in kids who play more sport and more frequent in children who have a higher body weight. Kids with tighter leg muscles can also be at a increased risk for the chances of this problem.
Commonly, treating Severs disease is load management. The child is encouraged to remain active, but simply scale back exercise levels to a level which can be tolerated and not too painful. A cushioning heel pad in the footwear might be helpful to cushion it. Ice following activity may also be useful to help the inflammation. If the calves are tight, then a stretches needs to be used. At times foot orthotics can be helpful if the arch of the foot is overpronated. On rare occasions a splint can be utilized, and all sport stopped until it gets better. By the mid-teens the growing area that this takes place at merges with the rest of the heel bone, which means this stops being an issue at those age groups.