title: Head impacts during high school football: a biomechanical assessment.
abstract: BACKGROUND
  Little is known about the impact biomechanics sustained by players during interscholastic football.
  
  
  OBJECTIVE
  To characterize the location and magnitude of impacts sustained by players during an interscholastic football season.
  
  
  METHODS
  Observational design.
  
  
  METHODS
  On the field.
  
  
  METHODS
  High school varsity football team (n = 35; age = 16.85 +/- 0.75 years, height = 183.49 +/- 5.31 cm, mass = 89.42 +/- 12.88 kg).
  
  
  METHODS
  Biomechanical variables (linear acceleration, rotational acceleration, jerk, force, impulse, and impact duration) related to head impacts were categorized by session type, player position, and helmet impact location.
  
  
  RESULTS
  Differences in grouping variables were found for each impact descriptor. Impacts occurred more frequently and with greater intensity during games. Linear acceleration was greatest in defensive linemen and offensive skill players and when the impact occurred at the top of the helmet. The largest rotational acceleration occurred in defensive linemen and with impacts to the front of the helmet. Impacts with the highest-magnitude jerk, force, and impulse and shortest duration occurred in the offensive skill, defensive line, offensive line, and defensive skill players, respectively. Top-of-the-helmet impacts yielded the greatest magnitude for the same variables.
  
  
  CONCLUSIONS
  We are the first to provide a biomechanical characterization of head impacts in an interscholastic football team across a season of play. The intensity of game play manifested with more frequent and intense impacts. The highest-magnitude variables were distributed across all player groups, but impacts to the top of the helmet yielded the highest values. These high school football athletes appeared to sustain greater accelerations after impact than their older counterparts did. How this finding relates to concussion occurrence has yet to be elucidated.
authors: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL 61801, USA. broglio@uiuc.edu
authors: Steven P
authors: SP
authors: Broglio
authors: Jacob J
authors: JJ
authors: Sosnoff
authors: SungHoon
authors: S
authors: Shin
authors: Xuming
authors: X
authors: He
authors: Christopher
authors: C
authors: Alcaraz
authors: Jerrad
authors: J
authors: Zimmerman
mesh_terms: D000054:Acceleration; D000293:Adolescent; D001696:Biomechanical Phenomena; D001924:Brain Concussion / Q000453:epidemiology*; D005538:Football / Q000293:injuries*; D006260:Head Protective Devices; D006801:Humans; D007087:Illinois / Q000453:epidemiology; D015994:Incidence; D008297:Male; D012307:Risk Factors; D012574:Schools; D013223:Statistics as Topic; D013686:Telemetry