Linear and Angular Head Acceleration Measurements in Collegiate Football

Abstract

Each year, between 1.6x10(6) and 3.8x10(6) concussions are sustained by athletes playing sports, with football having the highest incidence. The high number of concussions in football provides a unique opportunity to collect biomechanical data to characterize mild traumatic brain injury. Human head acceleration data for a range of impact severities were collected by instrumenting the helmets of collegiate football players with accelerometers. The helmets of ten Virginia Tech football players were instrumented with measurement devices for every game and practice for the 2007 football season. The measurement devices recorded linear and angular accelerations about each of the three axes of the head. Data for each impact were downloaded wirelessly to a sideline data collection system shortly after each impact occurred. Data were collected for 1712 impacts, creating a large and unbiased data set. While a majority of the impacts were of relatively low severity (<30 g and <2000 rad/s2), 172 impacts were greater than 40 g and 143 impacts were greater than 3000 rad/s2. No instrumented player sustained a clinically diagnosed concussion during the 2007 season. A large and unbiased data set was compiled by instrumenting the helmets of collegiate football players. Football provides a unique opportunity to collect head acceleration data of varying severity from human volunteers. The addition of concurrent concussive data may advance the understanding of the mechanics of mild traumatic brain injury. With an increased understanding of the biomechanics of head impacts in collegiate football and human tolerance to head acceleration, better equipment can be designed to prevent head injuries.

Impact on the head during collisions between university American football players - focusing on the number of head impacts and linear head acceleration -

“…For the peak LA frequency distribution, both during the games and practice sessions, the range of 10 g ≤ X < 15 g was the most frequent, and the distributions were largely skewed towards low values, supporting previous reports [11][12][13][19][20][21][22][23][24][25] . However, the played over four 15-min quarters in the USA, it is played over four 12-min quarters in Japan, a shorter time period.…”

“…Recently, the development of HITS, which collects impact information from the acceleration sensor attached inside the helmet and the sideline response system, which transmits the data, has made it possible to collect collision data from players on actual fields [9][10][11][12][13][19][20][21][22][23][24][25][26][27][28] . However, HITS only measures LA, and RA had to be estimated 28) .…”

“…In the 2000s, many researchers started to use a headimpact telemetry system (HITS, Simbex, Lebanon NH) equipped with an acceleration sensor installed inside a Riddell (Elyria, OH) helmet to collect real-time headacceleration data during head collisions between American football players [9][10][11][12][13][19][20][21][22][23][24][25][26][27][28] . The data collected by HITS is transmitted to a PC application in real time via a sideline response system (Riddell, Chicago, IL).…”

“…Later, an improved version of HITS, 6DOF, which is equipped with a three-axis acceleration sensor and a three-axis gyro sensor, was developed. Rowson et al (2009) recorded head collisions during practice sessions and games for 10 university American football players using 6DOF 23) . The results show that the peak LA during most of the collisions was below 20 g 23) .…”

The Influence of Head Impact Threshold for Reporting Data in Contact and Collision Sports: Systematic Review and Original Data Analysis

“…An area of increasing interest in these injuries are the forces involved and research 5,20,24,38,41,45,53,65,78,87,88,90,91,97,109,110,112,113,119,120 has been sought to better determine the head linear and rotational accelerations involved in these injuries. Head impact dynamics have been analysed through the use of video analysis, 65 in game measurements, 20,24,32,53,76,90,91,94,96,112,119 numerical methods 5,38,97,120 and reconstructions using anthropometric test devices 41,78,87,88,109,110,113 in helmeted sports such as American football 20, 24, 91, 119 and ice hockey 90,112 and in un-helmeted sports such as soccer 45 and rugby union. 53 The on-field assessment of head impacts has been captured with a head impact telemetry system (HITS) (Simbex, LLC, Lebanon, NH) using helmet mounted accelerometers enabling determination of the head linear and rotational accelerations in American foot...…”