A New Assessment of Bicycle Helmets: The Brain Injury Mitigation Effects of New Technologies in Oblique Impacts

Abayazid, Fady F.; Ding, Ke Qin; Zimmerman, Karl; Stigson, Helena; Ghajari, Mazdak

doi:10.1007/s10439-021-02785-0

Cited by 34 publications

(51 citation statements)

References 45 publications

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“…The H€ ovding protective gear had a lower PLA, PRA, and GAMBIT as compared to the other helmets. The reasons for this performance stem from the helmet's large size and low stiffness (Kurt et al, 2017;Abayazid et al, 2021). Such properties result in an increased duration of the impact and significantly lower peak acceleration values (Kurt et al, 2017;Abayazid et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

“…The reasons for this performance stem from the helmet's large size and low stiffness (Kurt et al, 2017;Abayazid et al, 2021). Such properties result in an increased duration of the impact and significantly lower peak acceleration values (Kurt et al, 2017;Abayazid et al, 2021). Despite the substantial mitigation of PLA and PRA, it should be noted that the prolonged duration of the impact could potentially result in a high PRV, which could carry increased injury risks (Ommaya and Hirsch, 1971;Margulies and Thibault, 1992;Rowson et al, 2012;Hernandez et al, 2015a;Abayazid et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

“…Such properties result in an increased duration of the impact and significantly lower peak acceleration values (Kurt et al, 2017;Abayazid et al, 2021). Despite the substantial mitigation of PLA and PRA, it should be noted that the prolonged duration of the impact could potentially result in a high PRV, which could carry increased injury risks (Ommaya and Hirsch, 1971;Margulies and Thibault, 1992;Rowson et al, 2012;Hernandez et al, 2015a;Abayazid et al, 2021). Additionally, the H€ ovding's large size and its increased duration of the impact, could mean increased coupling of the neck and shoulder during real-life impacts (Abayazid et al, 2021).…”

Section: Discussionmentioning

confidence: 99%

“…SPIN is a technology that replaces comfort padding with silicone padding (Bottlang et al, 2020). These specially developed pads are placed in critical locations in the helmet under the EPS layer and can shear in any direction to produce the same effect as a moving slip liner (Bliven et al, 2019;Abayazid et al, 2021). ODS utilizes two EPS liners that are connected by an array of elastomeric dampers (Bottlang et al, 2020).…”

Section: Types Of Impact Mitigation Technologies In Bicycle Helmetsmentioning

confidence: 99%

“…The collapsible structure mitigation systems we considered in this paper are WaveCel and Koroyd technologies. WaveCel is made from a cellular copolymer material that flexes and glides to absorb energy from impacts and redirect energy away from the head (Bliven et al, 2019;Abayazid et al, 2021). The V-shaped collapsible cellular structure is recessed within the helmet liners and provides rotational suspension (Bliven et al, 2019).…”

Section: Types Of Impact Mitigation Technologies In Bicycle Helmetsmentioning

confidence: 99%

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An Overview of the Effectiveness of Bicycle Helmet Designs in Impact Testing

Abderezaei

Rezayaraghi

Kain

et al. 2021

Front. Bioeng. Biotechnol.

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Cycling accidents are the leading cause of sports-related head injuries in the US. Conventional bicycle helmets typically consist of polycarbonate shell over Expanded Polystyrene (EPS) foam and are tested with drop tests to evaluate a helmet’s ability to reduce head kinematics. Within the last decade, novel helmet technologies have been proposed to mitigate brain injuries during bicycle accidents, which necessitates the evaluation of their effectiveness in impact testing as compared to conventional helmets. In this paper, we reviewed the literature to collect and analyze the kinematic data of drop test experiments carried out on helmets with different technologies. In order to provide a fair comparison across different types of tests, we clustered the datasets with respect to their normal impact velocities, impact angular momentum, and the type of neck apparatus. When we analyzed the data based on impact velocity and angular momentum clusters, we found that the bicycle helmets that used rotation damping based technology, namely MIPS, had significantly lower peak rotational acceleration (PRA) and Generalized Acceleration Model for Brain Injury Threshold (GAMBIT) as compared to the conventional EPS liner helmets (p < 0.01). SPIN helmets had a superior performance in PRA compared to conventional helmets (p < 0.05) in the impact angular momentum clustered group, but not in the impact-velocity clustered comparisons. We also analyzed other recently developed helmets that primarily use collapsible structures in their liners, such as WaveCel and Koroyd. In both of the impact velocity and angular momentum groups, helmets based on the WaveCel technology had significantly lower peak linear acceleration (PLA), PRA, and GAMBIT at low impact velocities as compared to the conventional helmets, respectively (p < 0.05). The protective gear with the airbag technology, namely Hövding, also performed significantly better compared to the conventional helmets in the analyzed kinematic-based injury metrics (p < 0.001), possibly due to its advantage in helmet size and stiffness. We also observed that the differences in the kinematic datasets strongly depend on the type of neck apparatus. Our findings highlight the importance and benefits of developing new technologies and impact testing standards for bicycle helmet designs for better prevention of traumatic brain injury (TBI).

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Types Of Impact Mitigation Technologies In Bicycle Helmetsmentioning

confidence: 99%

Section: Types Of Impact Mitigation Technologies In Bicycle Helmetsmentioning

confidence: 99%

See 3 more Smart Citations

An Overview of the Effectiveness of Bicycle Helmet Designs in Impact Testing

Abderezaei

Rezayaraghi

Kain

et al. 2021

Front. Bioeng. Biotechnol.

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The Effect of MIPS, Headform Condition, and Impact Orientation on Headform Kinematics Across a Range of Impact Speeds During Oblique Bicycle Helmet Impacts

2022

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The Protective Performance of Modern Motorcycle Helmets Under Oblique Impacts

Logan

Sarasola

et al. 2022

Ann Biomed Eng

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Motorcyclists are at high risk of head injuries, including skull fractures, focal brain injuries, intracranial bleeding and diffuse brain injuries. New helmet technologies have been developed to mitigate head injuries in motorcycle collisions, but there is limited information on their performance under commonly occurring oblique impacts. We used an oblique impact method to assess the performance of seven modern motorcycle helmets at five impact locations. Four helmets were fitted with rotational management technologies: a low friction layer (MIPS), three-layer liner system (Flex) and dampers-connected liner system (ODS). Helmets were dropped onto a 45° anvil at 8 m/s at five locations. We determined peak translational and rotational accelerations (PTA and PRA), peak rotational velocity (PRV) and brain injury criteria (BrIC). In addition, we used a human head finite element model to predict strain distribution across the brain and in corpus callosum and sulci. We found that the impact location affected the injury metrics and brain strain, but this effect was not consistent. The rear impact produced lowest PTAs but highest PRAs. This impact produced highest strain in corpus callosum. The front impact produced the highest PRV and BrIC. The side impact produced the lowest PRV, BrIC and strain across the brain, sulci and corpus callosum. Among helmet technologies, MIPS reduced all injury metrics and brain strain compared with conventional helmets. Flex however was effective in reducing PRA only and ODS was not effective in reducing any injury metrics in comparison with conventional helmets. This study shows the importance of using different impact locations and injury metrics when assessing head protection effects of helmets. It also provides new data on the performance of modern motorcycle helmets. These results can help with improving helmet design and standard and rating test methods.

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A New Assessment of Bicycle Helmets: The Brain Injury Mitigation Effects of New Technologies in Oblique Impacts

Cited by 34 publications

References 45 publications

An Overview of the Effectiveness of Bicycle Helmet Designs in Impact Testing

An Overview of the Effectiveness of Bicycle Helmet Designs in Impact Testing

The Effect of MIPS, Headform Condition, and Impact Orientation on Headform Kinematics Across a Range of Impact Speeds During Oblique Bicycle Helmet Impacts

The Protective Performance of Modern Motorcycle Helmets Under Oblique Impacts

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