"Size and physical conditioning techniques in sports at all levels have evolved to create an intense athlete," Levine said. "They're able to create more force, power and speed than ever before and that leads to harder hits and a greater number of hits."
According to the National Center for Catastrophic Sport Injury Research's 2012 Annual Survey of Catastrophic Football Injuries, the majority of catastrophic injuries for football players occur while playing defense. Since 1977 there have been 228 players with permanent cervical cord injuries on the defensive side of the ball and 55 on the offensive side.
Turman was considered a top college football prospect and had won Top Defensive Back at Atlanta's MVP camp in June.
ABC News' Liz Neporent contributed to this report.