Comparative analysis of helmeted impact response of Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms

Cobb, Bryan R.; Zadnik, Abigail M; Rowson, Steven

doi:10.1177/1754337115599133

Cited by 24 publications

(20 citation statements)

References 42 publications

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“…The Hodgson-WSU is 7% heavier than the Hybrid III, and the attachment for the Hybrid III neck is positioned roughly 19 mm posteriorly relative to the attachment of the Hybrid III. 30 The differences in neck position may alter the effective masses or moment of inertia of the two head forms on the monorail apparatus compared to the Hybrid III, perhaps engaging more or less of the neck and carriage attachment. The average linear acceleration traces show a second small increase in response for the Hodgson-WSU head form at the tail end of the acceleration pulse, not seen for the Hybrid III.…”

Section: Discussionmentioning

confidence: 99%

Comparison of two anthropomorphic test devices using brain motion

Koncan

Post

Gilchrist

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part P:

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The use of anthropomorphic test devices in head impact biomechanics research is common; however, each device has unique properties based on its construction. When conducting reconstructions, choice of head form is at the discretion of the researcher. In addition, different data collection methods are often used. The influence of different test devices can affect comparisons between studies, as each device elicits different impact responses due to different physical properties. This study describes a method of comparison for anthropomorphic test devices based on finite element response of brain motion. Occipital impacts were conducted on a monorail drop rig, following impact parameters similar to a cadaveric impact that has been used for validation of finite element models of the brain. Two commonly used anthropomorphic test devices, the Hodgson-WSU and Hybrid III, were impacted. These head forms were evaluated by dynamic responses, brain motion via neutral density target traces, and maximum principal strain for two impact velocities. The Hybrid III head form showed lower magnitude results compared to the Hodgson-WSU for peak linear and rotational accelerations, rotational velocity, maximum principal strain, and neutral density target excursions. The smallest differences in response were 11% for peak linear acceleration with differences in neutral density target excursions reaching 60%. Maximum principal strain is suggested as the most comparable metric between anthropomorphic test devices after peak linear acceleration, with expectation of lower responses from the Hybrid III as compared to those of the Hodgson-WSU.

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Section: Discussionmentioning

confidence: 99%

Comparison of two anthropomorphic test devices using brain motion

Koncan

Post

Gilchrist

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part P:

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“…21,22 The NOCSAE headform was selected for its skull deflection properties, improved anthropometry, mass, and moment of inertia, including a glycerin ''brain.'' 23,24,25 The NOCASE headform was attached to a Hybrid III neck assembly in this work, despite known deficiencies in side flexion, 26,27 because of its use in the only extant oblique helmet standard 20 and other oblique impact studies. 6 While headform impact response may be different for tests conducted with a different headform, different neck or without a neck, the aim of this work was to characterize the impact surface friction and its influence on headform impact response.…”

Section: Methodsmentioning

confidence: 99%

The effect of surface roughness on oblique bicycle helmet impact tests

Petersen

Smith

Nevins

2020

Proceedings of the Institution of Mechanical Engineers, Part P:

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The friction between a helmet and impact surface affects the accelerations imparted to the head. The roughness of the impact surface is, therefore, a consideration when developing oblique impact standards. An 80-grit abrasive paper is commonly used in oblique impact tests to simulate a road surface, but has not been validated for bicycle impacts and may not accurately represent real road surfaces. In the following study, a helmeted NOCSAE headform with a Hybrid III neck was dropped onto a 45° anvil at 6.5 m/s using a twin wire guided drop tower. Helmeted drops were performed in two orientations (frontal and side) on road surfaces, roughened steel surfaces, 80-grit abrasive paper and a low friction surface. For each impact, measures of linear and rotational acceleration were obtained. These metrics were compared across impact orientations and surfaces to assess the influence of surface roughness on headform impact response. Frontal impacts were less sensitive to the impact surface roughness than side impacts across metrics. Among metrics, rotational acceleration showed the largest effect due to surface roughness. Compared to the road surface, peak rotational acceleration from impacts on the 80-grit surface were 6.5% less and 48% greater for frontal and side impacts, respectively. Based on consideration of the peak and cumulative impact measures, steel impact surfaces appear to better simulate road impact than the commonly used 80-grit abrasive paper.

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“…Pendulum systems have been used with a variety of impactor masses, ranging from 4.3 to 31 kg. 14,17,24,26 In addition to adding impactor mass, the impactor material can be selected to maximize energy transfer from the impactor to the headgear of interest. An impact between two helmeted headforms means that impact energy will be attenuated by both helmets.…”

Section: Head Impact Reconstruction Methodsmentioning

confidence: 99%

“…28,38 A nylon cap, meant to represent the outer shell of a football helmet, has also been used. 26 In conclusion, care must be taken to use an impactor that will not absorb energy upon impact.…”

Section: Head Impact Reconstruction Methodsmentioning

confidence: 99%

A review of laboratory methods and results used to evaluate protective headgear in American football

Bina

Batt

DesJardins

2018

Proceedings of the Institution of Mechanical Engineers, Part P:

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As head trauma becomes more firmly associated with American football, research has focused on improving the impact performance of protective headgear. Since helmet use became mandatory in 1939-1940, both helmet design and laboratory methods used to evaluate helmet impact performance have evolved. Through a comprehensive review of the literature, this article analyzes the impact results from laboratory evaluations of helmet performance, including a look at the evolution of protective headgear performance in football. In total, 35 separate studies conducted between 1975 and 2017 were used to examine current testing methodologies and reported impact results from headgear performance laboratory assessments. This review showed that the evolution in helmet design over the last 50 years has resulted in a decrease in linear and rotational acceleration of an impacted headform. The most common laboratory methods used to reconstruct football-specific head impacts included (1) linear drop methods, (2) pendulum methods, and (3) pneumatic ram methods. Each method provided greater understanding of helmet impact performance, helmet design, and use in football, with each method having specific limitations in the evaluation of protective headgear performance.

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Comparative analysis of helmeted impact response of Hybrid III and National Operating Committee on Standards for Athletic Equipment headforms

Cited by 24 publications

References 42 publications

Comparison of two anthropomorphic test devices using brain motion

Comparison of two anthropomorphic test devices using brain motion

The effect of surface roughness on oblique bicycle helmet impact tests

A review of laboratory methods and results used to evaluate protective headgear in American football

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