Citation

Beckwith JG, Greenwald RM, Chu JJ, Crisco JJ, Rowson S, Duma SM, Broglio SP, McAllister TW, Guskiewicz KM, Mihalik JP, Anderson S, Schnebel B, Brolinson PG, Collins MW. Med. Sci. Sports Exerc. 2013; 45(4): 747-754.

Affiliation

1 Simbex, Lebanon, NH, USA 2 Thayer School of Engineering, Dartmouth College, Hanover, NH, USA 3 Alpert Medical School of Brown University and Rhode Island Hospital, Providence, RI, USA 4 Virginia Tech-Wake Forest, Center for Injury Biomechanics, Blacksburg VA, USA 5 University of Michigan School of Kinesiology 6 Michigan NeuroSport 7 Department of Psychiatry, Dartmouth Medical School, Hanover, NH, USA 8 Matthew Gfeller Sport-Related Traumatic Brain Injury Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA 9 Department of Intercollegiate Athletics, University of Oklahoma, Norman, OK, USA 10 Departments of Orthopedics and Athletics, University of Oklahoma, Norman, OK, USA 11 Edward Via College of Osteopathic Medicine, Blacksburg VA, USA 12 Departments of Orthopaedic Surgery and Neurological Surgery, University of Pittsburgh Medical Center, Pittsburgh PA, USA.

Copyright

(Copyright © 2013, Lippincott Williams and Wilkins)

DOI

10.1249/MSS.0b013e3182793067

PMID

23135364

Abstract

PURPOSE: Concussions are commonly undiagnosed in an athletic environment because the post-injury signs and symptoms may be mild, masked by the subject, or unrecognized. This study compares measures of head impact frequency, location and kinematic response prior to cases of immediate and delayed concussion diagnosis. METHODS: Football players from eight collegiate and six high school teams wore instrumented helmets during play (n=1,208),of which ninety-five were diagnosed with concussion (105 total cases). Acceleration data recorded by the instrumented helmets was reduced to five kinematic metrics: peak linear and rotational acceleration, GSI, HIC15, and change in head velocity (Δv). Additionally, each impact was assigned to one of four general location regions (Front, Back, Side, and Top), and the number of impacts sustained prior to injury was calculated over two time periods (one and seven days). RESULTS: All head kinematic measures associated with injury, except peak rotational acceleration (p = 0.284), were significantly higher for cases of immediate diagnosis than delayed diagnosis (p<0.05). Players with delayed diagnosis sustained a significantly higher number of head impacts on the day of injury (32.9 ±24.9; p < 0.001) and within seven days of injury (69.7 ±43.3; p = 0.006) than players with immediate diagnosis (16.5 ±15.1 and 50.2 ±43.6). Impacts associated with concussion occurred most frequently to the Front of the head (46%) followed by the Top (25%), Side (16%), and Back (13%) with the number of impacts by location independent of temporal diagnosis (χ(3) = 4.72; p= 0.19). CONCLUSION: Concussions diagnosed immediately after an impact event are associated with the highest kinematic measures, while those characterized by delayed diagnosis are preceded by a higher number of impacts.

Keywords: American football;

Language: en