In hockey, players experience different compliances during impacts to the head, from stiff ice to compliant collisions against other players. The objective of this study was to examine the effect of striking compliance in ice hockey impacts and its influence on dynamic response and brain tissue strain. Three striking caps of low, medium, and high compliances were used to impact a helmeted 50th-percentile Hybrid III headform. The headform was impacted at five locations at three velocities, representative of collision scenarios in hockey. The dependent variables, peak resultant linear and rotational acceleration as well as maximum principal strain were analyzed using a multivariate analysis of variance to determine significant differences between the compliances. The results indicated a significant effect of compliance on the responses of the headform. As expected, low-impact compliance resulted in higher linear and rotational accelerations when compared to the medium and high compliance conditions. However, while the linear and rotational acceleration responses of the medium and high compliance conditions would indicate a low chance of brain injury, the maximum principal strain magnitudes indicated a high likelihood of concussion. Medium- and high-impact compliances are a factor that has not been considered when designing and testing helmet technology in sport, with current methods reflective of low compliance surfaces, that is, those with high stiffness and rigidity. The results of this study demonstrate that an impact compliance is an important factor in producing brain injury and should be considered when certifying helmets through standard testing to mitigate the risk of brain injury.
CollinsMIversonGLLovellMR, et al. On-field predictors of neuropsychological and symptom deficit following sports-related concussion. Clin J Sport Med2003; 13(4): 222–229.
2.
LangloisJRutland-BrownWWaldM. The epidemiology and impact of traumatic brain injury: a brief overview. J Head Trauma Rehabil2006; 21(5): 375–378.
3.
MoriTKatayamaYKawamataT. Acute hemispheric swelling associated with thin subdural hematomas: pathophysiology of repetitive head injury in sports. Acta Neurochir Suppl2006; 96: 40–43.
4.
KohJCassidyJWatkinsonE. Incidence of concussion in contact sports: a systematic review of the evidence. Brain Inj2003; 17: 901–917.
WennbergRTatorC. National Hockey League reported concussions, 1986-87 to 2001-02. Can J Neurol Sci2003; 30(3): 206–209.
7.
HoshizakiBBrienS. The science and design of head protection in sport. Neurosurgery2004; 55(4): 856–966.
8.
HutchisonMComperPMeeuwisseW, et al. A systematic video analysis of National Hockey League (NHL) concussions, part II: how concussions occur in the NHL. Br J Sports Med2015; 49(8): 552–555.
9.
HoshizakiTBPostAKendallM, et al. The development of a threshold curve for the understanding of concussion in sport. Trauma2017; 19(3): 196–206.
10.
HutchisonMComperPMeeuwisseW, et al. A systematic video analysis of National Hockey League (NHL) concussions, part I: who, when, where and what?Br J Sports Med2015; 49(8): 547–551.
11.
HoshizakiTBPostAOeurA, et al. Current and future concepts in helmet and sports injury prevention. Neurosurgery2014; 75(4): S136–S148.
12.
PostAHoshizakiTBGilchristMD, et al. The influence of acceleration loading curve characteristics on traumatic brain injury. J Biomech2014; 47(5): 1074–1081.
GurdjianESRobertsVLThomasLM. Tolerance curves of acceleration and intracranial pressure and protective index in experimental head injury. J Trauma1966; 6(5): 600–604.
15.
GennarelliT. Head injury in man and experimental animals: clinical aspects. Acta Neurochir Suppl1983; 32: 1–13.
16.
WillingerRRyanGAMcLeanAJKoppCM. Mechanisms of brain injury related to mathematical modelling and epidemiological data. Accid Anal Prev1994; 26(6): 767–779.
17.
GilchristMD. Modelling and accident reconstruction of head impact injuries. Key Eng Mat2003; 245: 417–430.
18.
PadgaonkarAKreigerKKingA. Measurements of angular accelerations of a rigid body using linear accelerometers. J Appl Mech1975; 42: 552–556.
19.
WalshESKendallMPostA, et al. Comparative analysis of Hybrid III neckform and an unbiased neckform. Sport Eng2018; 21(4): 479–485.
20.
WalshERousseauPHoshizakiTB. The influence of impact location and angle on the dynamic impact response of a Hybrid III headform. Sport Eng2011; 13(3): 135–143.
21.
PostAOeurAHoshizakiTB, et al. Examination of the relationship between peak linear and angular accelerations to brain deformation metrics in hockey helmet impacts. Comput Methods Biomech Biomed Engin2013; 16(5): 511–519.
22.
RousseauP. Analysis of concussion metrics of real-world concussive and non-injurious elbow and shoulder to head collisions in ice hockey. PhD Thesis, University of Ottawa, Ottawa, ON, Canada, 2014.
23.
HorganTGilchristMD. The creation of three-dimensional finite element models for simulating head impact biomechanics. IJCrash2003; 8(4): 353–366.
24.
NahumASmithRWardC. Intracranial pressure dynamics during head impact. In: 21st Stapp Car Crash Conference, New Orleans, LA, 1977, https://saemobilus.sae.org/content/770922
25.
HardyWNFosterCDMasonMJ, et al. Investigation of head injury mechanisms using neutral density technology and high-speed biplanar X-ray. Stapp Car Crash J2001; 45: 337–368.
26.
DoorlyMCGilchristMD. The use of accident reconstruction for the analysis of traumatic brain injury due to head impacts arising from falls. Comput Methods Biomech Biomed Engin2006; 9: 371–377.
27.
PostAHoshizakiTBGilchristMD, et al. The influence of dynamic response and brain deformation metrics on the occurrence of subdural hematoma in different regions of the brain. J Neurosurg2014; 120(2): 453–461.
28.
RuanJ. Impact biomechanics of head injury by mathematical modelling. PhD Thesis, Wayne State University, Detroit, MI, 1994.
29.
WillingerRTalebLKoppC. Modal and temporal analysis of head mathematical models. J Neurotrauma1995; 12: 743–754.
30.
ZhouCKhalilTBKingAI. A new model comparing impact responses of the homogeneous and inhomogeneous human brain. In: 39th Stapp Car Crash Conference, Coronado, CA, 1 November, 1995. Warrendale, PA: SAE International.
31.
KleivenSVon HolstH. Consequences of head size following trauma to the human head. J Biomech2002; 35(2): 153–160.
32.
MendisKKStalnakerRLAdvaniSH. A constitutive relationship for large deformation finite element modeling of brain tissue. J Biomech Eng1995; 117: 279–285.
33.
HorganTGilchristMD. Influence of FE model variability in predicting brain motion and intracranial pressure changes in head impact simulations. IJCrash2004; 9(4): 401–418.
34.
ThomasLMRobertsVLGurdjianES. Impact-induced pressure gradients along three orthogonal axes in the human skull. J Neurosurg1967; 26(3): 316–321.
35.
ZhangLYangKHKingAI. A proposed injury threshold for mild traumatic brain injury. J Biomech Eng2004; 126: 226–236.
36.
PattonDMcIntoshAKleivenS. The biomechanical determinants of concussion: finite element simulations to investigate tissue-level predictors of injury during sporting impacts to the unprotected head. J Appl Biomech2015; 31(4): 264–268.
37.
Forero RuedaMACuiLGilchristMD. Finite element modelling of equestrian helmet impacts exposes the need to address rotational kinematics in future helmet designs. Comput Methods Biomech Biomed Engin2011; 14(12): 1021–1031.
38.
McIntoshAPattonDFréchèdeB, et al. The biomechanics of concussion in unhelmeted football players in Australia: a case–control study. BMJ Open2014; 4(5): e005078.
39.
McAllisterTWFordJCJiS, et al. Maximum principal strain and strain rate associated with concussion diagnosis correlates with changes in corpus callosum white matter indices. Ann Biomed Eng2012; 540: 127–140.
40.
Van LierdeC. Biomechanics of head injury—damage criteria for skull and brain lesions. PhD Thesis, KU Leuven, Leuven, 2005.
41.
KleivenS. Predictors for traumatic brain injuries evaluated through accident reconstruction. Stapp Car Crash J2007; 51: 81–114.
42.
PostAHoshizakiTBGilchristMD, et al. Peak linear and rotational acceleration magnitude and duration effects on maximum principal strain in the corpus callosum for sport impacts. J Biomech2017; 61: 183–192.
43.
StemperBDShahASPintarFA, et al. Head rotational acceleration characteristics influence behavioral and diffusion tensor imaging outcomes following concussion. Ann Biomed Eng2015; 43(5): 1071–1088.
44.
KendallMPostARousseauP, et al. A comparison of dynamic impact response and brain deformation metrics within the cerebrum of head impact reconstructions representing three mechanisms of head injury in ice hockey. In: Proceedings of the IRCOBI conference, Dublin, 12–14 September 2012. IRCOBI.
45.
HoJ. Generation of patient specific finite element head models. PhD Thesis, Royal Institute of Technology, Stockholm, 2008.
46.
YangJ. Investigation of brain trauma biomechanics in vehicle traffic accidents using human body computational models. In: WittekANielsenPMFMillerK (eds) Computational medicine: soft tissues and the musculoskeletal system. New York: Springer, 2011, pp.5–14.
