Frequency and Location of Head Impact Exposures in Individual Collegiate Football Players

Department of Orthopaedics, The Warren Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI 02903, USA.
Journal of athletic training (Impact Factor: 2.02). 11/2010; 45(6):549-59. DOI: 10.4085/1062-6050-45.6.549
Source: PubMed


Measuring head impact exposure is a critical step toward understanding the mechanism and prevention of sport-related mild traumatic brain (concussion) injury, as well as the possible effects of repeated subconcussive impacts.
To quantify the frequency and location of head impacts that individual players received in 1 season among 3 collegiate teams, between practice and game sessions, and among player positions.
Cohort study.
Collegiate football field.
One hundred eighty-eight players from 3 National Collegiate Athletic Association football teams.
Participants wore football helmets instrumented with an accelerometer-based system during the 2007 fall season.
The number of head impacts greater than 10 g and location of the impacts on the player's helmet were recorded and analyzed for trends and interactions among teams (A, B, or C), session types, and player positions using Kaplan-Meier survival curves.
The total number of impacts players received was nonnormally distributed and varied by team, session type, and player position. The maximum number of head impacts for a single player on each team was 1022 (team A), 1412 (team B), and 1444 (team C). The median number of head impacts on each team was 4.8 (team A), 7.5 (team B), and 6.6 (team C) impacts per practice and 12.1 (team A), 14.6 (team B), and 16.3 (team C) impacts per game. Linemen and linebackers had the largest number of impacts per practice and per game. Offensive linemen had a higher percentage of impacts to the front than to the back of the helmet, whereas quarterbacks had a higher percentage to the back than to the front of the helmet.
The frequency of head impacts and the location on the helmet where the impacts occur are functions of player position and session type. These data provide a basis for quantifying specific head impact exposure for studies related to understanding the biomechanics and clinical aspects of concussion injury, as well as the possible effects of repeated subconcussive impacts in football.

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    • "Sports such as football and soccer are troubled with head impacts. NCAA defensive line football players receive up to 1440 head impacts per year (Forbes et al. 2010), with about 280 of the hits to the more sensitive lateral areas of the brain (Crisco et al. 2010). Modern helmet lines are unable to reduce the propagation of all of the accelerations and forces associated with these impacts to non-injurious levels (Viano et al. 2006). "
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    • "Ten active UR varsity football players were asked to participate and all agreed. These athletes were chosen for the variety of positions and anticipated head impacts they would experience during the season, which was informed by prior studies [3], [26]. Controls were selected based on response to a campus-wide call for research volunteers. "
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    PLoS ONE 04/2014; 9(4):e94734. DOI:10.1371/journal.pone.0094734 · 3.23 Impact Factor
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    • "It has been estimated that elementary school-aged football players (ages 9–12 years) average 240 head impacts per season (Cobb et al. 2013). Individual high school football players can receive between 650 and 900 head impacts per season (Broglio et al. 2011a, 2012) or greater than 25 impacts per game plus practice sessions (Urban et al. 2013) and some collegiate football players have sustained upwards of 1440 head impacts in a single season (Crisco et al. 2010). Each of these studies derived the number of head impacts sustained by individual players by using helmets instrumented with the Head Impact Telemetry system. "
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