title: Cumulative head impact burden in high school football.
abstract: Impacts to the head are common in collision sports such as football. Emerging research has begun to elucidate concussion tolerance levels, but sub-concussive impacts that do not result in clinical signs or symptoms of concussion are much more common, and are speculated to lead to alterations in cerebral structure and function later in life. We investigated the cumulative number of head impacts and their associated acceleration burden in 95 high school football players across four seasons of play using the Head Impact Telemetry System (HITS). The 4-year investigation resulted in 101,994 impacts collected across 190 practice sessions and 50 games. The number of impacts per 14-week season varied by playing position and starting status, with the average player sustaining 652 impacts. Linemen sustained the highest number of impacts per season (868); followed by tight ends, running backs, and linebackers (619); then quarterbacks (467); and receivers, cornerbacks, and safeties (372). Post-impact accelerations of the head also varied by playing position and starting status, with a seasonal linear acceleration burden of 16,746.1g, while the rotational acceleration and HIT severity profile burdens were 1,090,697.7 rad/sec(2) and 10,021, respectively. The adolescent athletes in this study clearly sustained a large number of impacts to the head, with an impressive associated acceleration burden as a direct result of football participation. These findings raise concern about the relationship between sub-concussive head impacts incurred during football participation and late-life cerebral pathogenesis, and justify consideration of ways to best minimize impacts and mitigate cognitive declines.
authors.affiliation: Neurotrauma Research Laboratory, University of Michigan, Ann Arbor, Michigan 48109-2013, USA. broglio@umich.edu
authors.forename: Steven P
authors.initials: SP
authors.lastname: Broglio
authors.forename: James T
authors.initials: JT
authors.lastname: Eckner
authors.forename: Douglas
authors.initials: D
authors.lastname: Martini
authors.forename: Jacob J
authors.initials: JJ
authors.lastname: Sosnoff
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Kutcher
authors.forename: Christopher
authors.initials: C
authors.lastname: Randolph
mesh_terms: D000054:Acceleration; D000293:Adolescent; D001696:Biomechanical Phenomena; D001924:Brain Concussion / Q000453:epidemiology / Q000473:pathology; D020208:Brain Injury, Chronic / Q000453:epidemiology; D017281:Cost of Illness; D006259:Craniocerebral Trauma / Q000453:epidemiology / Q000473:pathology*; D003627:Data Interpretation, Statistical; D005538:Football / Q000293:injuries* / Q000706:statistics & numerical data; D006260:Head Protective Devices; D006801:Humans; D008297:Male; D012008:Recurrence; D012399:Rotation