title: Head Impact Exposure and Neurologic Function of Youth Football Players.
abstract: Football players are subjected to repetitive impacts that may lead to brain injury and neurologic dysfunction. Knowledge about head impact exposure (HIE) and consequent neurologic function among youth football players is limited.
  
  
  OBJECTIVE
  This study aimed to measure and characterize HIE of youth football players throughout one season and explore associations between HIE and changes in selected clinical measures of neurologic function.
  
  
  METHODS
  Twenty-two youth football players (11-13 yr) wore helmets outfitted with a head impact telemetry (HIT) system to quantify head impact frequency, magnitude, duration, and location. Impact data were collected for each practice (27) and game (9) in a single season. Selected clinical measures of balance, oculomotor performance, reaction time, and self-reported symptoms were assessed before and after the season.
  
  
  RESULTS
  The median individual head impacts per practice, per game, and throughout the entire season were 9, 12, and 252, respectively. Approximately 50% of all head impacts (6183) had a linear acceleration between 10g and 20g, but nearly 2% were greater than 80g. Overall, the head impact frequency distributions in this study population were similar in magnitude and location as in high school and collegiate football, but total impact frequency was lower. Individual changes in neurologic function were not associated with cumulative HIE.
  
  
  CONCLUSIONS
  This study provides a novel examination of HIE and associations with short-term neurologic function in youth football and notably contributes to the limited HIE data currently available for this population. Whereas youth football players can experience remarkably similar head impact forces as high school players, cumulative subconcussive HIE throughout one youth football season may not be detrimental to short-term clinical measures of neurologic function.
authors.affiliation: 1Sanford Sports Science Institute, Sanford Health, Sioux Falls, SD; 2Sanford Research, Sioux Falls, SD; 3Department of Pediatrics, University of South Dakota Sanford School of Medicine, Sioux Falls, SD; and 4Methodology and Data Analysis Division, Sanford Research, Sioux Falls, SD.
authors.forename: Thayne A
authors.initials: TA
authors.lastname: Munce
authors.forename: Jason C
authors.initials: JC
authors.lastname: Dorman
authors.forename: Paul A
authors.initials: PA
authors.lastname: Thompson
authors.forename: Verle D
authors.initials: VD
authors.lastname: Valentine
authors.forename: Michael F
authors.initials: MF
authors.lastname: Bergeron
mesh_terms: D000293:Adolescent; D056352:Athletes; D001696:Biomechanical Phenomena / Q000502:physiology; D001924:Brain Concussion / Q000503:physiopathology; D002648:Child; D056344:Executive Function / Q000502:physiology*; D005538:Football / Q000293:injuries*; D016489:Head Injuries, Closed / Q000503:physiopathology*; D006801:Humans; D008297:Male; D018570:Risk Assessment; D057566:Self Report