The study of 222 adult amateur soccer players who played at least six months of the year on leagues or clubs in the New York city area, found that "of those with head impacts, 20 percent had moderate to severe symptoms. Seven people had very severe symptoms. Of those, six people had two or more unintentional head impacts during the two weeks; four were in the group that headed the ball the most and three were in the group with the second-most headers."
The risk of concussions and injuries is even greater for youth players. A 2016 study by researchers from the Center for Injury Research and Policy of The Research, found that youth soccer emergency room cases rose 78 percent from 1990 to 2014 and concussions went up almost 1,600 percent. Reports have found that youth are more at risk of head injuries. In 2015 a rural Kentucky paper ran a series looking at concussions on high school athletes. University of Kentucky researchers in 2014 looked at the impact of concussions on youth.