title: Concussion in professional football: epidemiological features of game injuries and review of the literature--part 3.
abstract: OBJECTIVE
  A 6-year study was performed to determine the circumstances, causes, and outcomes of concussions in the National Football League.
  
  
  METHODS
  Between 1996 and 2001, the epidemiological features of concussions were recorded by National Football League teams with a standardized reporting form. Symptoms were reported and grouped as general symptoms, cranial nerve symptoms, memory or cognitive problems, somatic complaints, and loss of consciousness. The medical actions taken were recorded. In total, 787 game-related cases were reported, with information on the players involved, type of helmet impact, symptoms, medical actions, and days lost. Concussion risks were calculated according to player game positions.
  
  
  RESULTS
  There were 0.41 concussions per National Football League game. The relative risk was highest for quarterbacks (1.62 concussions/100 game-positions), followed by wide receivers (1.23 concussions/100 game-positions), tight ends (0.94 concussion/100 game-positions), and defensive secondaries (0.93 concussion/100 game-positions). The majority of concussions (67.7%) involved impact by another player's helmet. The remainder involved impact by other body regions of the striking player (20.9%) or ground contact (11.4%). The three most common symptoms of mild traumatic brain injury were headaches (55.0%), dizziness (41.8%), and blurred vision (16.3%). The most common signs noted in physical examinations were problems with immediate recall (25.5%), retrograde amnesia (18.0%), and information-processing problems (17.5%). In 58 of the reported cases (9.3%), the players lost consciousness; 19 players (2.4%) were hospitalized. A total of 92% of concussed players returned to practice in less than 7 days, but that value decreased to 69% with unconsciousness.
  
  
  CONCLUSIONS
  The professional football players most vulnerable to concussions are quarterbacks, wide receivers, and defensive secondaries. Concussions involved 2.74 symptoms/injury, and players were generally removed from the game. More than one-half of the players returned to play within 1 day, and symptoms resolved in a short time in the vast majority of cases.
authors.affiliation: Mild Traumatic Brain Injury Committee, National Football League, New York, New York, USA.
authors.forename: Elliot J
authors.initials: EJ
authors.lastname: Pellman
authors.forename: John W
authors.initials: JW
authors.lastname: Powell
authors.forename: David C
authors.initials: DC
authors.lastname: Viano
authors.forename: Ira R
authors.initials: IR
authors.lastname: Casson
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Tucker
authors.forename: Henry
authors.initials: H
authors.lastname: Feuer
authors.forename: Mark
authors.initials: M
authors.lastname: Lovell
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Waeckerle
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Robertson
mesh_terms: D001924:Brain Concussion / Q000453:epidemiology* / Q000209:etiology* / Q000628:therapy; D005538:Football / Q000293:injuries*; D006801:Humans; D008297:Male; D012307:Risk Factors; D013997:Time Factors; D015599:Trauma Severity Indices; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology