Symptoms of concussion can include headache, light sensitivity, fatigue, and problems with balance, concentration, and memory. A study of college football players over three seasons found that players with previous concussions were three times more likely to sustain a concussion than players who had never had a concussion. Consider these data in light of chronic traumatic encephalopathy (CTE). Do you think rules of practice or games need to change for children playing contact sports? What about for high school, college, or professional contact sports?