ATLANTA – According to a study led by researchers at the CDC, the number of children treated for playground related brain injuries increased significantly between 2005 and 2013. Government data shows more than 21,000 kids 14 and under, suffered a head injury during this period. More than half were between five and nine years old and 58% were males. Monkey bars, playground gyms and swings were most frequently linked to these accidents. Two thirds of the injuries happened at school or recreational sports facilities. Most injuries happened on weekdays in April, May and September.