What kids can gain: Balance. Foot dexterity is a must to juggle the ball while finding teammates to pass to or a goal to shoot at. And the constant running is a big boon to their endurance levels and cardiovascular health.
What kids risk: Routine hazards include shin splints (pain in the front of and inside the lower legs), ankle twists, and the like. The bigger issue stems from heading the ball, which has been linked to concussions and possible brain injury. And it can happen whether the move is done correctly or not.