Complex sentence: First discovered in 800 B.C. concussions named after the Roman word concussed are one of the greatest causes of death among football players they happen when you hit your head and it rolls around until it completly stops functioning hence the black out (CTE).
Split into simpler sentences: First discovered in 800 B.C. concussions, named after the Roman word concussed, are one of the greatest causes of death among football players. They happen when you hit your head and it rolls around until it completly stops functioning hence the black out (CTE).