Objective: To measure and analyze head accelerations during American collegiate football practices and games.
Methods: A newly developed in-helmet 6-accelerometer system that transmits data via radio frequency to a sideline receiver and laptop computer system was implemented. From the data transfer of these accelerometer traces, the sideline staff has real-time data including the head acceleration, the head injury criteria value, the severity index value, and the impact location. Data are presented for instrumented players for the entire 2003 football season, including practices and games.
Setting: American collegiate football.
Subjects: Thirty-eight players from Virginia Tech's varsity football team.
Main Outcome Measurements: Accelerations and pathomechanics of head impacts.
Results: A total of 3312 impacts were recorded over 35 practices and 10 games for 38 players. The average peak head acceleration, Gadd Severity Index, and Head Injury Criteria were 32 g ± 25 g, 36 g ± 91 g, and 26 g ± 64 g, respectively. One concussive event was observed with a peak acceleration of 81 g, a 267 Gadd Severity Index, and 200 Head Injury Criteria. Because the concussion was not reported until the day after of the event, a retrospective diagnosis based on his history and clinical evaluation suggested a mild concussion.
Conclusions: The primary finding of this study is that the helmet-mounted accelerometer system proved effective at collecting thousands of head impact events and providing contemporaneous head impact parameters that can be integrated with existing clinical evaluation techniques.
From the *Virginia Tech-Wake Forest Center for Injury Biomechanics, Blacksburg, VA; the †Edward Via College of Osteopathic Medicine, Blacksburg, VA; the ‡Virginia Tech Department of Sports Medicine, Blacksburg, VA; §Simbex, Lebanon, NH; the ∥Thayer School of Engineering, Dartmouth College, Hanover, NH; and the ¶Department of Orthopaedics, Brown Medical School/Rhode Island Hospital, Providence, RI.
Received for publication May 2004; accepted September 2004.
The Head Impact Telemetry System development was funded in part by NIH R43HD40743. Additional support for this project was provided by the Edward Via College of Osteopathic Medicine, the Virginia Tech College of Engineering and the Department of Sports Medicine, and Simbex.
Richard M. Greenwald, PhD, is president of Simbox LLC, and has a commercial interest in the technology used in this research study.
Reprints: Stefan M. Duma, PhD, Virginia Tech, 114 Randolph Hall, Blacksburg, VA 24061 (e-mail: email@example.com).