title: Analysis and evolution of head injury in football.
abstract: OBJECTIVE
  To review head injury in football through historical, anatomic, and physiological analysis.
  
  
  METHODS
  We obtained data from a thorough review of the literature.
  
  
  RESULTS
  The reported incidence of concussion among high school football players dropped from 19% in 1983 to 4% in 1999. During the 1997 Canadian Football League season, players with a previous loss of consciousness in football were 6.15 times more likely to experience a concussion than players without a previous loss of consciousness (P < 0.05). Players with a previous concussion in football were 5.10 times more likely to experience a concussion than players without a previous concussion (P = 0.0001). With the implementation of National Operating Committee on Standards for Athletic Equipment standards, fatalities decreased by 74% and serious head injuries decreased from 4.25 per 100,000 to 0.68 per 100,000.
  
  
  CONCLUSIONS
  Significant declines in both the incidence and severity of head injury have been observed. The enhanced safety records in football can be attributed to the application of more stringent tackling regulations as well as the evolving football helmet. The role of a neurosurgeon is critical in further head injury prevention and guidelines in sport.
authors.affiliation: Division of Neurosurgery, University of California at San Diego School of Medicine, San Diego, California, USA. mlevy@chsd.org
authors.forename: Michael L
authors.initials: ML
authors.lastname: Levy
authors.forename: Burak M
authors.initials: BM
authors.lastname: Ozgur
authors.forename: Cherisse
authors.initials: C
authors.lastname: Berry
authors.forename: Henry E
authors.initials: HE
authors.lastname: Aryan
authors.forename: Michael L J
authors.initials: ML
authors.lastname: Apuzzo
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001265:Athletic Injuries / Q000453:epidemiology* / Q000503:physiopathology / Q000517:prevention & control; D001696:Biomechanical Phenomena; D001921:Brain / Q000503:physiopathology; D001924:Brain Concussion / Q000453:epidemiology* / Q000503:physiopathology / Q000517:prevention & control; D002170:Canada; D003430:Cross-Sectional Studies; D004195:Disease Models, Animal; D005538:Football / Q000293:injuries*; D006260:Head Protective Devices / Q000592:standards; D006801:Humans; D012008:Recurrence; D012307:Risk Factors; D019876:Sports Equipment / Q000592:standards; D014481:United States