Biomechanical Forces of Concussions. February 20, 2013 Martin Mrazik, PhD, R.Psych. University of Alberta

Transcription

1 Biomechanical Forces of Concussions February 20, 2013 Martin Mrazik, PhD, R.Psych. University of Alberta

2 Acknowledgements

3 The Problem

4 In the News The Globe and Mail (March 15, 2011): Bob Probert s brain damage a cautionary tale for today s NHLers

5 Head Hits at Their Worst

6 Concussion? A complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces. McCrory et al, CJSM, 2009

7 Chronic Traumatic Encephalopathy

8 Look on the bright side For a few seconds you forgot you were a Calgary Flame

9 Current Challenges

10 Sport Concussion Hockey Canada: 550,000 + minor hockey players Hockey USA: 583,000 + minor hockey players Estimated 3.8 million sports head injuries/year (CDC, 2010) Guskiewicz (2010); 6% of college athletes NHL: Benson et al (2011, CMAJ) 1.8 concussions/1000 player hours or 7.7 % of players 70% had resolution: 7 to 10 days

11 Elite Hockey Concussion Study (Emery et al ) Calgary (17.78 concussions/100 players) Edmonton (19.16 concussions/100 players) Overall concussions/100 players 2X previously reported rate

12 To tell or not to tell? Or if an athlete is injured.

13 The Challenge of Concussions Mrazik & Perra 2012 What would you do? Total Male Female Stop playing and tell the 143(78.6) 124(80.1) 19(70.4) coach or trainer What did you do? Total Male Female Stopped playing and told my coach or trainer 28(43.8) 22(42.3) 6(50.)

14 In the March 2012 Clinical Journal of Sports Medicine, 3 Richard M. Greenwald, PhD of the Thayer School of Engineering at Dartmouth College, says the best way to reduce underreporting of brain injury in sports is widespread real-time monitoring of head impact exposure (e.g. number, severity, location, and cumulative impact)

15 How to Measure Biomechanical Force

16 Biomechanical Force Pudenz & Shelden (1970 s) Primate studies using cinematography of the brain Theorized 2 types of forces causing damage to brain tissue Linear Rotational acceleration Genneralli et al (1980 s) Impact of acceleration forces in primates

17 Biomechanical Force National Football League (Pellman et al., 2003) Video Surveillance to reproduce biomechanical force Developed the Wayne State Tolerance Curve Relationship between physical force and head trauma

18 Biomechanical Force Computer generated models Lack generalizability (Guskiewicz et al., 2011) Naunheim et al. (2000) Football player (29.2g) Hockey player (35.0g) Soccer (unreliable measures) Mihalik et al (2008) 88 football players Peak impact < 20 g s

19 Biomechanical Force Mihalik et al. (2008) 13 fourteen year-old hockey players Peak force was < 20g s Mihalik et al. (2010) 16 fourteen year-old hockey players Anticipated had less severe impacts than unanticipated Open ice had higher force than by the boards

20 Current Questions/Controversies Is there a threshold of a concussion? When should a player be checked for a possible concussion? What is the outcome of multiple, high intensity hits during the course of a season? Career?

21 Safebrain Systems

22 Safebrain specs Light weight (< 8 g s); attached to outside of helmet The C.I.A. Sensor patented 3-axis accelerometer based on a powerful 16-bit microprocessor. a data-logger and real-time clock to provide time-stamped G force-readings Adjustable threshold

23 Safebrain Systems

24 Safebrain Systems

25 Safebrain Systems

26 Safebrain Systems

27 The Data Sample: 4 teams Alberta, Saskatchewan & Ontario 3 Boys teams, 1 Girls Team Biomechanical Data N = 11, 445 hits among 72 athletes Average season = 21 games Average of hits per game over 15g Average = 7.57 hits/player per game; Range = 0 to 50

28 The Data Biomechanical Data Average G-force = G s (total force) Average Duration = 9.93ms (Range 2ms 64ms)

29 The Data Heavy vs light heavy light heavy light heavy light Frequency Duration Intensity

30 The First Hit

31 The Data 30 A Typical Hit G-Force 10 5 Series1 Series2 Series3 Series

32 The Second Hit

33 The Data 40 Concussion Series1 G-Force Series2 Series3 Series

34 Results Neurocognitive Testing Series1 Series Verbal Memory Visual Memory Visual Motor Reaction Time Impulse Control Symptoms

35 Protecting Future Brains

36 A Solution?

37 Education: Recovery Model Concussion Recovery Model vs. Orthopedic Recovery Model Concussions need to be managed differently than orthopedic injuries. No pain. No gain. Does not apply.

38 When in Doubt, Sit Them Out! No athlete with a concussion should continue to play or return to a game after sustaining a concussion.

39 Summary Concussions are a significant concern in sport Modern technology is allowing us to manage concussions better than ever We can all contribute to promoting good education and safeplay

40 Thank-You for Coming! Dr. Martin Mrazik Education North Department of Educational Psychology University of Alberta Phone: