The Influence of Impact Angle on the Dynamic Response of a Hybrid III Headform and Brain Tissue Deformation

Concern about the consequences of head impacts in US football has motivated researchers to investigate and develop instrumentation to measure the severity of these impacts. However, the severity of head impacts in unhelmeted sports is largely unknown as miniaturised sensor technology has only recently made it possible to measure these impacts in vivo. The objective of this study was to measure the linear and angular head accelerations in impacts in mixed martial arts, and correlate these with concussive injuries. Thirteen mixed martial arts fighters were fitted with the Stanford instrumented mouthguard (MiG2.0) participated in this study. The mouthguard recorded linear acceleration and angular velocity in 6 degrees of freedom. Angular acceleration was calculated by differentiation. All events were video recorded, time stamped and reported impacts confirmed. A total of 451 verified head impacts above 10g were recorded during 19 sparring events (n = 298) and 11 competitive events (n = 153). The average resultant linear acceleration was 38.0624.3g while the average resultant angular acceleration was 256761739 rad/s2. The competitive bouts resulted in five concussions being diagnosed by a medical doctor. The average resultant acceleration (of the impact with the highest angular acceleration) in these bouts was 86.7618.7g and 756163438 rad/s2. The average maximum Head Impact Power was 20.6kW in the case of concussion and 7.15kW for the uninjured athletes. In conclusion, the study recorded novel data for sub-concussive and concussive impacts. Events that resulted in a concussion had an average maximum angular acceleration that was 24.7% higher and an average maximum Head Impact Power that was 189% higher than events where there was no injury. The findings are significant in understanding the human tolerance to short-duration, high linear and angular accelerations.

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“…Impact location is significant as impacts in the temporal region have been shown to be more likely to result in a concussion. 56,20…”

Section: Discussionmentioning

confidence: 99%

Concussion and the severity of head impacts in mixed martial arts

Tiernan

Meagher

O’Sullivan

et al. 2020

Proc Inst Mech Eng H

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“…These impact conditions are essentially the same angle but from different directions on the headform and the response will be governed by the geometry of the head and the geometry of the neck. Work conducted by Oeur 48 demonstrated that since the neck is asymmetrical, these two angle conditions can produce different results as a result of this neck construction. This observation is confirmed in these data, where impact locations 1–4 could be influenced by the asymmetry of the neck (Figure 10).…”

Section: Discussionmentioning

confidence: 99%

Determination of high-risk impact sites on a Hybrid III headform by finite element analysis

Post

Rousseau

Kendall

et al. 2014

Proceedings of the Institution of Mechanical Engineers, Part P:

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The current standards and methods to evaluate helmet performance remain focused on traumatic brain injuries and not concussive injuries. This is reflected in the methodologies currently used and the injury metrics employed to determine the pass/fail criteria for the helmets being tested. To address the problem surrounding concussion and helmets, a method reflecting high risk of concussive injury must be developed. The purpose of this research was to identify high risk of concussive injury impact sites on the Hybrid III headform using the Wayne State head injury finite element model. The Hybrid III headform was impacted using a linear impactor in five different sites with four angles per site at 5.5 m/s. The resulting acceleration loading curves were used as input for brain deformation analyses using the Wayne State University Brain Injury Model. The brain deformation results indicated that there are 12 impact conditions on the Hybrid III headform which reflect a risk of concussion above 80% when compared with the literature. The method used and impact sites discovered by this research differ significantly from the current standard method and may be used to guide future impact sites for the evaluation of helmet performance.

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“…After determining the mechanical properties of the system components (Table 1), the motion constraints of the set were created. The hand moves along the shoulder using a linear spring with a stiffness of k. This design was used based on the experimental methods in previous studies (Oeur, 2012). After determining the desired model, a direct punch was applied to the lateral of the head in simulation conditions, because most of the blows to the head in martial arts are applied in the lateral direction of the head.…”

Section: Methodsmentioning

confidence: 99%

Investigation of the Head’s Dynamic Response to Boxing Punch Using Computer Simulation

Boroushak¹,

Khoshnoodi²,

Rostami³

2021

Monten. J. Sports Sci. Med.

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Head injuries are dangerous injuries that are common in combat sports. Nevertheless, the mechanisms of concussion in sport have are not precisely known. Thus, this study aimed to investigate the dynamic response of the head based on linear and rotational accelerations in boxing using computer simulation. The ADAMS software model was used to determine the linear and rotational acceleration of boxing’s straight punch. The peak linear acceleration, average linear acceleration, peak rotational acceleration, and average rotational acceleration resulted from the straight punch to head were obtained: 75 g, 20 g, 4036 rad/s², 1140 rad/s², respectively; the impact times were 30 ms and 3 ms, respectively. The comparison of acceleration tolerance thresholds of head injury and obtained results of this study showed the rotational acceleration only leads to head injury. Furthermore, it is biomechanically improbable that the head would be moved only translationally or rotationally as a result of a straight punch. Therefore, both rotational and linear accelerations should be observed together for future studies.

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The Influence of Impact Angle on the Dynamic Response of a Hybrid III Headform and Brain Tissue Deformation

Cited by 6 publications

References 28 publications

Concussion and the severity of head impacts in mixed martial arts

Concussion and the severity of head impacts in mixed martial arts

Determination of high-risk impact sites on a Hybrid III headform by finite element analysis

Investigation of the Head’s Dynamic Response to Boxing Punch Using Computer Simulation

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