More Concussions When NFL Games Played in Below Freezing Temperatures Interview with:
Dr. David W. Lawrence, MD
Department of Family & Community Medicine
St Michael’s Hospital, University of Toronto
Toronto, Ontario, Canada What is the background for this study? What are the main findings?

Dr. Lawrence: The risk of all-cause injury and concussion for NFL athletes is significant. There has been a lot of discussion recently about this risk of injury in the NFL and general player safety, particularly regarding concussions. The first step in improving player safety and lowering that risk is to identify the factors affecting injury rates. Once we can answer those questions, we can begin to modify player exposure. What is the background for this study? What are the main findings?

Dr. Lawrence: The main findings are a 2-fold increased risk of concussion for teams playing games at less than ~ 10 C compared to > 21 C and a 1.5-fold increase risk of ankle injuries at the same temperature. We also found an increased risk of shoulder injuries for teams that played games on grass compared to synthetic surfaces. We also failed to find a relationship between days-off-between games, distance traveled to games, altitude of game, and time-zone change prior to a game and risk of injury. These are also interesting findings given the leagues motivation to expand the geographic border of where NFL games are played. What should clinicians and patients take away from your report?

Dr. Lawrence: At this time, further research needs to be conducted to either replicate or refute these results before any recommendations can be made. What recommendations do you have for future research as a result of this study?

Dr. Lawrence: These results needs to be replicated with a larger more robust NFL injury database. We are continuing to collect data prospectively and with repeat this study over a 5 year period. The NFL should consider implementing a similar methodology to their NFL Injury Surveillance data. This would also be interesting to study in other sports. Thank you for your contribution to the community.


David W. Lawrence, Paul Comper, and Michael G. Hutchison
Influence of Extrinsic Risk Factors on National Football League Injury Rates

Orthopaedic Journal of Sports Medicine March 2016 4: 2325967116639222, first published on March 31, 2016 doi:10.1177/2325967116639222

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Last Updated on April 1, 2016 by Marie Benz MD FAAD