A recent article in the New York Times highlights the need for athletic fields to be well maintained to prevent concussion in athletes at all levels, including professionals. Many concussions occur when the head impacts the ground, and poorly maintained fields, both natural turf and synthetic, can become these absorbing of impact.
Read the full article here: http://www.nytimes.com/2015/12/30/sports/football/concussion-report-highlights-field-maintenance.html?smid&_r=0