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International consensus definitions of video signs of concussion in professional sports
  1. Gavin A Davis1,2,
  2. Michael Makdissi1,3,
  3. Paul Bloomfield4,
  4. Patrick Clifton5,
  5. Ruben J Echemendia6,
  6. Éanna Cian Falvey7,
  7. Gordon Ward Fuller8,
  8. Gary Green9,
  9. Peter Harcourt5,
  10. Thomas Hill10,
  11. Nathan McGuirk11,
  12. Willem Meeuwisse12,
  13. John Orchard13,
  14. Martin Raftery7,
  15. Allen K Sills14,
  16. Gary S Solomon14,
  17. Alex Valadka9,
  18. Paul McCrory15
  1. 1Florey Institute of Neuroscience and Mental Health–Austin Campus, Heidelberg, Victoria, Australia
  2. 2Neurosurgery, Cabrini Hospital, Malvern, Victoria, Australia
  3. 3La Trobe Sport and Exercise Medicine Research Centre, Melbourne, Victoria, Australia
  4. 4National Rugby League (NRL), Sydney, New South Wales, Australia
  5. 5Australian Football League, Melbourne, Victoria, Australia
  6. 6National Hockey League, Philadelphia, Pennsylvania, USA
  7. 7World Rugby, Dublin, Ireland
  8. 8School of Health and Related Research, University of Sheffield, Sheffield, UK
  9. 9Major League Baseball, New York, New York, USA
  10. 10Cricket Australia, Melbourne, Victoria, Australia
  11. 11National Rugby League, Sydney, New South Wales, Australia
  12. 12National Hockey League, Calgary, Alberta, Canada
  13. 13Cricket Australia, Sydney, New South Wales, Australia
  14. 14National Football League, New York, New York, USA
  15. 15Melbourne Brain Centre, Florey Institute of Neuroscience and Mental Health–Austin Campus, Heidelberg, Victoria, Australia
  1. Correspondence to Professor Gavin A Davis, Suite 53 - Neurosurgery, Cabrini Malvern, Wattletree Road, Malvern, Victoria 3144, Australia; gavin.davis{at}


Background The use of video to assist professional sporting bodies with the diagnosis of sport-related concussion (SRC) has been well established; however, there has been little consistency across sporting codes with regards to which video signs should be used, and the definitions of each of these signs.

Aim The aims of this study were to develop a consensus for the video signs considered to be most useful in the identification of a possible SRC and to develop a consensus definition for each of these video signs across the sporting codes.

Methods A brief questionnaire was used to assess which video signs were considered to be most useful in the identification of a possible concussion. Consensus was defined as >90% agreement by respondents. Existing definitions of these video signs from individual sports were collated, and individual components of the definitions were assessed and ranked. A modified Delphi approach was then used to create a consensus definition for each of the video signs.

Results Respondents representing seven sporting bodies (Australian Football League, Cricket Australia, Major League Baseball, NFL, NHL, National Rugby League, World Rugby) reached consensus on eight video signs of concussion. Thirteen representatives from the seven professional sports ranked the definition components. Consolidation and refinement of the video signs and their definitions resulted in consensus definitions for six video signs of possible concussion: lying motionless, motor incoordination, impact seizure, tonic posturing, no protective action—floppy and blank/vacant look.

Conclusions These video signs and definitions have reached international consensus, are indicated for use by professional sporting bodies and will form the basis for further collaborative research.

  • concussion
  • consensus
  • sports analysis in different types of sports
  • assessment

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  • GAD and MM are joint first authors.

  • Contributors GAD and MM contributed to the conception of the work. All authors contributed to the acquisition, analysis or interpretation of data, drafting the work or revising it critically for important intellectual content, final approval of the version published and agreement to be accountable for all aspects of the work.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests GAD is an Honorary member of the Australian Football League (AFL) Concussion Working Group. MM is an Honorary member of the AFL Concussion Working Group. PB is Chief Medical Officer of National Rugby League (NRL). PC is Head of Health, Safety and Laws, AFL. RJE is Co-Chair, National Hockey League (NHL)/NHL Players Association Concussion Subcommittee and Chair of the MLS Concussion Committee. ECF is Member of World Rugby concussion working group. GWF is Member of World Rugby concussion working group. GG is Medical Director, Major League Baseball. PH is AFL Medical Director. TH is State Medical Officer, Cricket Australia. NM is General Manager, Competitions and Operations, Football, NRL. WM is NHL Medical Director. JO is Chief Medical Officer, Cricket Australia. MR is Chief Medical Officer, World Rugby. AKS is Chief Medical Officer, National Football League (NFL). GSS is Senior Advisor, NFL Department of Health and Safety. AV is a consultant for Mild Traumatic Brain Injury, Major League Baseball. PM is an Honorary member of the AFL Concussion Working Group. ICJME disclosure forms have been provided.

  • Patient consent for publication Not required.

  • Ethics approval As this study does not contain any patient data, research ethics committee approval was not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.