Unlike sports programs that target adults, programs that cater to children have the added pressure of taking into consideration "developmental and growth-related issues that predispose them to unique injuries" (Wilson, 2002). Wilson (2002) suggests that program planners keep in mind the following general guidelines when designing activities for specific ages. For the 3- to 5-year-old age group, fundamental skills include throwing, walking, running and wheeling. Activities should be uncomplicated and repetitive, emphasizing mobility. Children in the 6- to 9-year-old age group have developed foundational movement skills. This might be the time to try recreational sports. This is the key time for integrating more complex skills and trying out several different types of activities. This is also the age that jump-starts athletic careers and forms attitudes about physical activity that continue into adulthood. Full-fledged participation in sports is found in the 10- to 12-year-old population as these children are mastering complex motor skills. As competition increases, it is still appropriate to focus on technique and skills refinement. Some children begin to specialize in one or two sports at this stage (Wilson, 2002).