Instrumented Mouthguard Acceleration Analyses for Head Impacts in Amateur Rugby Union Players Over a Season of Matches

Abstract

Background:

Direct impacts with the head (linear acceleration or pressure) and inertial loading of the head (rotational acceleration or strain) have been postulated as the 2 major mechanisms of head-related injuries such as concussion. Although data are accumulating for soccer and American football, there are no published data for nonhelmeted collision sports such as rugby union.

Purpose:

To quantify head impacts via instrumented mouthguard acceleration analyses for rugby union players over a season of matches.

Study Design:

Descriptive epidemiology study.

Methods:

Data on impact magnitude and frequency were collected with molded instrumented mouthguards worn by 38 premier amateur senior rugby players participating in the 2013 domestic season of matches.

Results:

A total of 20,687 impacts >10g (range, 10.0-164.9g) were recorded over the duration of the study. The mean ± SD number of impacts per player over the duration of the season of matches was 564 ± 618, resulting in a mean ± SD of 95 ± 133 impacts to the head per player, per match over the duration of the season of matches. The impact magnitudes for linear accelerations were skewed to the lower values (S_p = 3.7 ± 0.02; P < .001), with a mean linear acceleration of 22.2 ± 16.2g. Rotational accelerations were also skewed to the lower values (S_p = 2.0 ± 0.02; P < .001), with a mean rotational acceleration of 3902.9 ± 3948.8 rad/s².

Conclusion:

The acceleration magnitudes and number of head impacts in amateur rugby union players over a season of matches, measured via instrumented mouthguard accelerations, were higher than for most sports previously reported. Mean linear acceleration measured over a season of matches was similar to the mean linear accelerations previously reported for youth, high school, and collegiate American football players but lower than that for female youth soccer players. Mean rotational acceleration measured over a season of matches was similar to mean rotational accelerations for youth, high school, and collegiate American football players but less than those for female youth soccer players, concussed American collegiate players, collegiate American football players, and professional American football players.

Keywords

injury linear rotational impact instrumented mouthguard

Get full access to this article

View all access options for this article.

References

Bailes

Petraglia

Omalu

Nauman

Talavage

. Role of subconcussion in repetitive mild traumatic brain injury. J Neurosurg. 2013;119(5):1235-1245.

Baugh

Stamm

Riley

. Chronic traumatic encephalopathy: neurodegeneration following repetitive concussive and subconcussive brain trauma. Brain Imaging Behav. 2012;6(2):244-254.

Bazarian

Zhu

Blyth

Borrino

Zhong

. Subject-specific changes in brain white matter on diffusion tensor imaging after sports-related concussion. Magn Reson Imaging. 2012;30(2):171-180.

Beckwith

Greenwald

Chu

. Measuring head kinematics in football: Correlation between the head impact telemetry system and hybrid III headform. Ann Biomed Eng. 2012;40(1):237-248.

Beckwith

Greenwald

Chu

. Head impact exposure sustained by football players on days of diagnosed concussion. Med Sci Sport Exerc. 2013;45(4):737-746.

Beckwith

Greenwald

Chu

. Timing of concussion diagnosis is related to head impact exposure prior to injury. Med Sci Sport Exerc. 2013;45(4):747-754.

Bernstein

. Information processing difficulty long after self-reported concussion. J Int Neuropsychol Soc. 2002;8(5):673-682.

Breedlove

Robinson

Talavage

. Biomechanical correlates of symptomatic and asymptomatic neurophysiological impairment in high school football. J Biomech. 2012;45(7):1265-1272.

Broglio

Eckner

Kutcher

. Field-based measures of head impacts in high school athletes. Curr Opin Pediatr. 2012;24(6):702-708.

10.

Broglio

Schnebel

Sosnoff

. Biomechanical properties of concussions in high school football. Med Sci Sports Exerc. 2010;42(11):2064-2071.

11.

Broglio

Sosnoff

Shin

Alcaraz

Zimmerman

. Head impacts during high school football: a biomechanical assessment. J Athl Train. 2009;44(4):342-349.

12.

Broglio

Eckner

Martini

Sosnoff

Kutcher

Randolph

. Cumulative head impact burden in high school football. J Neurotrauma. 2011;28(10):2069-2078.

13.

Brolinson

Manoogian

McNeely

Goforth

Greenwald

Duma

. Analysis of linear head accelerations from collegiate football impacts. Curr Sports Med Rep. 2006;5(1):23-28.

14.

Camarillo

Shull

Mattson

Schultz

Garza

. An instrumented mouthguard for measuring linear and angular head impact kinematics in American football. Ann Biomed Eng. 2013;41(9):1939-1949.

15.

Cobb

Urban

Davenport

. Head impact exposure in youth football: elementary school ages 9–12 years and the effect of practice structure. Ann Biomed Eng. 2013;21(12):2463-2473.

16.

Crisco

Chu

Greenwald

. An algorithm for estimating acceleration magnitude and impact location using multiple nonorthogonal single-axis accelerometers. J Biomech Eng. 2004;126(6):849-854.

17.

Crisco

Fiore

Beckwith

. Frequency and location of head impact exposures in individual collegiate football players. J Athl Train. 2010;45(6):459-559.

18.

Crisco

Wilcox

Beckwith

. Head impact exposure in collegiate football players. J Biomech. 2011;44(15):2673-2678.

19.

Crisco

Wilcox

Machan

. Magnitude of head impact exposures in individual collegiate football players. J Appl Biomech. 2012;28(2):174-183.

20.

Daniel

Rowson

Duma

. Head impact exposure in youth football. Ann Biomed Eng. 2012;40(4):976-981.

21.

Dashnaw

Petraglia

Bailes

. An overview of the basic science of concussion and subconcussion: where we are and where we are going. Neurosurg Focus. 2012;33(6):E5.

22.

Delaney

Puni

Rouah

. Mechanisms of injury for concussions in university football, ice hockey, and soccer: a pilot study. Clin J Sport Med. 2006;16(2):162-165.

23.

Duhaime

A-C

Beckwith

Maerlender

. Spectrum of acute clinical characteristics of diagnosed concussions in college athletes wearing instrumented helmets. J Neurosurg. 2012;117(6):1092-1099.

24.

Duma

Manoogian

Bussone

. Analysis of real-time head accelerations in collegiate football players. Clin J Sport Med. 2005;15(1):3-8.

25.

Eckner

Sabin

Kutcher

Broglio

. No evidence for a cumulative impact effect on concussion injury threshold. J Neurotrauma. 2011;28(10):2079-2090.

26.

Fréchède

McIntosh

. Numerical reconstruction of real-life concussive football impacts Med Sci Sport Exerc. 2009;41(2):390-398.

27.

Fuller

Ashton

Brooks

Cancea

Hall

Kemp

. Injury risks associated with tackling in rugby union. Br J Sports Med. 2010;44(3):159-167.

28.

Gadd

. Use of a weighted impulse criterion for establishing injury hazard. Paper presented at: Proceedings of the 10th STAPP Car rash conference, Society of Automotive Engineers; 1966; New York, NY. http://papers.sae.org/660793/. Accessed September 1, 2013.

29.

Gavett

Stern

McKee

. Chronic traumatic encephalopathy: a potential late effect of sport-related concussive and subconcussive head trauma. Clin Sports Med. 2011;30(1):179-188.

30.

Giza

Kutcher

Ashwal

. Summary of evidence-based guideline update: evaluation and management of concussion in sports: report of the Guideline Development Subcommittee of the American Academy of Neurology. Neurology. 2013;80(24):2250-2257.

31.

Greenwald

Chu

Beckwith

Crisco

. A proposed method to reduce underreporting of brain injury in sports. Clin J Sport Med. 2012;22(2):83-85.

32.

Greenwald

Gwin

Chu

Crisco

. Head impact severity measures for evaluating mild traumatic brain injury risk exposure. Neurosurgery. 2008;62(4):789-798.

33.

Guskiewicz

Mihalik

Shankar

. Measurement of head impacts in collegiate football players: relationship between head impact biomechanics and acute clinical outcome after concussion. Neurosurgery. 2007;61(6):1244-1253.

34.

Gysland

Mihalik

Trulock

Shields

Guskiewicz

. The relationship between subconcussive impacts and concussion history on clinical measures of neurologic function in collegiate football players. Ann Biomed Eng. 2012;40(1):14-22.

35.

Hanlon

Bir

. Real-time head acceleration measurements in girls youth soccer. Med Sci Sports Exerc. 2012;44(6):1102-1108.

36.

Harpham

Mihalik

Littleton

Frank

Guskiewicz

. The effect of visual and sensory performance on head impact biomechanics in college football players [published online August 6, 2013]. Ann Biomed Eng. doi:10.1007/s10439-013-0881-8.

37.

Hopkins

Marshall

Batterham

Hanin

. Progressive statistics for studies in sports medicine and exercise science. Med Sci Sports Exerc 2009;41(1):3-12.

38.

Hopkins

Marshall

Quarrie

Hume

. Risk factors and risk statistics for sports injuries. Clin J Sport Med 2007;17(3):208-210.

39.

King

Yang

Zhang

Hardy

. Is head injury caused by linear or angular acceleration?

Paper presented at: IRCOBI Conference;

September 24, 2003; Lisbon, Portugal. http://www.researchgate.net/publication/242211067_IS_HEAD_INJURY_CAUSED_BY_LINEAR_OR_ANGULAR_ACCELERATION? Accessed September 1, 2013.

40.

Macciocchi

Barth

Alves

Rimel

Jane

. Neuropsychological functioning and recovery after mild head injury in collegiate athletes. Neurosurgery. 1996;39(3):510-514.

41.

Martini

Eckner

Kutcher

Broglio

. Sub-concussive head impact biomechanics: comparing differing offensive schemes. Med Sci Sport Exerc. 2013;45(4):755-761.

42.

Mattson

Schultz

Goodman

Anderson

Garza

. Validation of a novel mouth guard for measurement of linear and rotational accelerations during head impacts. Clin J Sport Med. 2012;22(3):294.

43.

McCrory

Meeuwisse

Aubry

. Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012. Br J Sports Med. 2013;47(5):250-258.

44.

McCrory

Meeuwisse

Kutcher

Jordan

Gardner

. What is the evidence for chronic concussion-related changes in retired athletes: behavioural, pathological and clinical outcomes? Br J Sports Med. 2013;47(5):327-330.

45.

Meaney

Smith

. Biomechanics of concussion. Clin Sports Med. 2011;30(1):19-31.

46.

Mihalik

Bell

Marshall

Guskiewicz

. Measurements of head impacts in collegiate football players: an investigation of positional and event type differences. Neurosurgery. 2007;61(6):1229-1235.

47.

Mihalik

Blackburn

Greenwald

Cantu

Marshall

Guskiewicz

. Collision type and player anticipation affect head impact severity among youth ice hockey players. Pediatrics. 2010;125(6):e1394-e1401.

48.

Mihalik

Greenwald

Blackburn

Cantu

Marshall

Guskiewicz

. Effect of infraction type on head impact severity in youth ice hockey. Med Sci Sport Exerc. 2010;42(8):1431-1438.

49.

Mihalik

Guskiewicz

Marshall

Blackburn

Cantu

Greenwald

. Head impact biomechanics in youth hockey: comparisons across playing position, event types, and impact locations. J Biomed Eng. 2012;40(1):141-149.

50.

Moon

Beedle

Kovacic

. Peak head accelerations of athletes during competition. Med Sci Sports. 1971;3(1):44-50.

51.

Bussone

Duma

. The effect of gender and body size on linear accelerations of the head observed during daily activities. Biomed Sci Instrum. 2006;42:25-30.

52.

Ocwieja

Mihalik

Marshall

Schmidt

Trulock

Guskeiwicz

. The effect of play type and collision closing distance on head impact biomechanics. Ann Biomed Eng. 2012;40(1):90-96.

53.

Patton

McIntosh

Kleiven

Fréchède

. Injury data from unhelmeted football head impacts evaluated against critical strain tolerance curves. Proc Inst Mech Eng P J Sports Eng Technol. 2012;226(3-4):177-184.

54.

Pellman

Viano

Tucker

Casson

. Concussion in professional football: location and direction of helmet impacts—part 2. Neurosurgery. 2003;53(6):1328-1341.

55.

Pellman

Viano

Tucker

Casson

Waeckerle

. Concussion in professional football: reconstruction of game impacts and injuries. Neurosurgery. 2003;53(4):799-814.

56.

Pellman

Viano

Withnall

Shewchenko

Bir

Halstead

. Concussion in professional football: helmet testing to assess impact performance—part 11. Neurosurgery. 2006;58(1):78-96.

57.

Reed

Taha

Keightley

. Measurement of head impacts in youth ice hockey players. Int J Sports Med. 2010;31(11):826-833.

58.

Reid

Tarkington

Epstein

O’Dea

. Brain tolerance to impact in football. Surg Gynecol Obstet. 1971;133(6):929-936.

59.

Rowson

Brolinson

Goforth

Dietter

Suma

. Linear and angular head acceleration measurements in collegiate football. J Biomed Eng. 2009;131(061016):1-7.

60.

Rowson

Duma

. Brain injury prediction: assessing the combined probability of concussion using linear and rotational head acceleration. Ann Biomed Eng. 2013;41(5):873-882.

61.

Rowson

Duma

Beckwith

. Rotational head kinematics in football impacts: an injury risk function for concussion. Ann Biomed Eng. 2012;40(1):1-13.

62.

Schnebel

Gwin

Anderson

Gatlin

. In vivo study of head impacts in football: a comparison of National Collegiate Athletic Association division I versus high school impacts. Neurosurgery. 2007;60(3):490-496.

63.

Spiotta

Shin

Bartsch

Benzel

. Subconcussive impact in sports: a new era of awareness. World Neurosurg. 2011;75(2):175-178.

64.

Urban

Davenport

Golman

. Head impact exposure in youth football: high school ages 14 to 18 years and cumulative impact analysis. Ann Biomed Eng. 2013;41(12):2474-2487.

65.

Versace

. A review of the severity index. In: 15th Stapp Car Crash Conference, Society of Automotive Engineers. North Highlands, CA: Snell Memorial Foundation; 1971:771-796. http://www.smf.org/docs/articles/hic/Versace_1971_Review_of_Severity_Index.pdf. Accessed September 1, 2013.

66.

Wilcox

Beckwith

Greenwald

. Head impact exposure in male and female collegiate ice hockey players. J Biomech. 2013;47(1):109-114.

67.

Wong

Bailes

. Frequency, magnitude, and distribution of head impacts in Pop Warner football: the cumulative burden. Clin Neurol Neurosurg. 2014;118:1-4.

68.

Zhang

Yang

King

. A proposed injury threshold for mild traumatic brain injury. J Biomed Eng. 2004;126(2):226-236.