Helmet Impact Research Articles

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

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.

BICYCLE HELMET DESIGN AND THE VIRTUAL VALIDATION OF THE IMPACT, AERODYNAMICS AND PRODUCTION PROCESS

This paper presents the development process of a bicycle helmet through individual research, creation, presentation and analysis of the results of the most important product development stages. The quality of the development and manufacturing process of the protective equipment for extreme sports is an imperative for a successful product and its flawless function. The design of the bicycle helmet is made following the rules of the design in order to create a well-founded and functional product. After creating design sketches, a virtual prototype was developed in "SolidWorks" using the required ergonomic dimensions. 3D printed model of the human head with adapted ergonomic dimensions and the designed bicycle helmet was developed in order to verify the applied ergonomic measures. The virtual model will be used as an input in the finite element analysis of the helmet impact test based on the EN1078 standard and the aerodynamic simulations executed in "SolidWorks Simulation and Flow Simulation", for verification of the impact and aerodynamic properties. Virtual testing of aerodynamic features and the ability of the bicycle helmet to allow ventilation of the user's head indicate that the helmet performs its function in the desired way. Also, the virtual prototype will be used for the production process simulation in "SolidWorks Plastics" in order to analyze the production of the bicycle helmet. The polycarbonate helmet outer shell is subject to a number of simulations for the sake of analyzing the production process in order to obtain the desired characteristics of the polycarbonate outer shell and to avoid the disadvantages that occur in the manufacturing process. The main goal of this paper is to develop a safety bicycle helmet with improved ergonomic, validation of impact, aerodynamic characteristics and production process in order to produce a high quality product for mass use.

Impact of helmet use on traumatic brain injury from road traffic accidents in Cambodia

ABSTRACTObjective: Rapid urbanization and motorization without corresponding increases in helmet usage have made traumatic brain injury due to road traffic accidents a major public health crisis in Cambodia. This analysis was conducted to quantify the impact of helmets on severity of injury, neurosurgical indication, and functional outcomes at discharge for motorcycle operators who required hospitalization for a traumatic brain injury following a road traffic accident in Cambodia.Methods: The medical records of 491 motorcycle operators who presented to a major tertiary care center in Cambodia with traumatic brain injury were retrospectively analyzed using multivariate logistic regression.Results: The most common injuries at presentation were contusions (47.0%), epidural hematomas (30.1%), subdural hematomas (27.9%), subarachnoid hemorrhages (12.4%), skull fractures (21.4%), and facial fractures (18.5%). Moderate-to-severe loss of consciousness was present in 36.3% of patients. Not wearing a helmet was associated with an odds ratio of 2.20 (95% confidence interval [CI], 1.15–4.22) for presenting with moderate to severe loss of consciousness compared to helmeted patients. Craniotomy or craniectomy was indicated for evacuation of hematoma in 20.0% of cases, and nonhelmeted patients had 3.21-fold higher odds of requiring neurosurgical intervention (95% CI, 1.25–8.27). Furthermore, lack of helmet usage was associated with 2.72-fold higher odds of discharge with functional deficits (95% CI, 1.14–6.49). In total, 30.1% of patients were discharged with severe functional deficits.Conclusions: Helmets demonstrate a protective effect and may be an effective public health intervention to significantly reduce the burden of traumatic brain injury in Cambodia and other developing countries with increasing rates of motorization across the world.

Analysis of a bicyclist’s head injury in lateral and frontal impact using the human full-body model

Helmets reduce the frequency and severity of head and brain injuries resulting from bicycle crashes. To ensure that all bicycle helmets provide a certain level of effectiveness, helmets are required to satisfy certain standards of construction and material design before they can be sold in the market. Impact protection is the primary consideration of nearly every helmet standard. The general terms for a test for assessing impact protection involve shock absorption. A helmeted headform is dropped onto an anvil and the headform acceleration is measured. However, the test procedures of the existing standards do not properly assess the protection level of helmets against oblique impacts. To investigate bicycle helmets in a real accident scenario, this study simulated the full body of a bicyclist when free falling onto a road. This study considered the normal velocity (VN) of 5.66 m/s and tangential velocity (VT) values of 0, 5, and 10 m/s. Finite element analyses of helmet impact tests were conducted using LS-DYNA software. Moreover, the impact responses obtained using full-body and detached-headform models were compared under identical impact conditions. The analysis results obtained herein can be useful for evaluating helmet quality and guiding future developments in helmet innovation.

Football helmet impact standards in relation to on-field impacts.

Youth football helmets currently undergo the same impact testing and must satisfy the same criteria as varsity helmets, although youth football players differ from their adult counterparts in anthropometry, physiology, and impact exposure. This study aimed to relate football helmet standards testing to on-field head impact magnitudes for youth and varsity football helmets. Head impact data, filtered to include only impacts to locations in the current National Operating Committee on Standards for Athletic Equipment standard, were collected for 48 collegiate players (ages 18-23 years) and 25 youth players (ages 9-11 years) using helmet-mounted accelerometer arrays. These on-field data were compared to a series of National Operating Committee on Standards for Athletic Equipment standard drop tests with a youth and varsity Riddell Speed helmet. In the on-field data, the adult players had a higher frequency of impact than the youth players, and a significant difference in head acceleration magnitude only existed at the top location (p < 0.001). In the laboratory drop tests, the only significant difference between the youth and varsity helmets was at the 3.46 m/s (61 cm) impact to the front location (p = 0.0421). Drop tests generated head accelerations within the top 10% of measured on-field impacts, at all locations and drop heights, demonstrating that drop tests are representative of the most severe head impacts experienced by youth and adult football players on the field. Current standards have been very effective at eliminating skull fracture and severe brain injury in both populations. This analysis suggests that there is not currently a need for a youth-specific drop test standard. However, there may be such a need if helmet testing standards are updated to address concussion, paired with a better understanding of differences in concussion tolerance between youth and adult populations.

Quantifying the effect of the facemask on helmet performance

Evaluating and improving helmet design play a crucial role in reducing sports-related concussions. Despite widespread use of facemasks by football and hockey players, no helmet standards currently exist to test helmets equipped with facemasks. The purpose of this study was to determine the effect that attached facial protection has on the head kinematics resulting from impacts to the helmet shell. Helmets were fit to a modified NOCSAE (National Operating Committee on Standards for Athletic Equipment) headform and subjected to blows from a pneumatic impactor. A total of 240 impact tests were performed to evaluate the effect of the facemask on four helmet models (two for football, two for hockey). For each helmet model, one sample was tested with a facemask and another without a facemask. Tests were conducted at two impact velocities (6, 9 m/s) and three impact locations (front, side, and rear boss) for a total of six impact conditions. Five trials were performed for each helmet sample at each condition. Two-factor analyses of variance were used to quantify effects on linear and rotational head acceleration and Severity Index due to impact location and facemask presence. Significant effects varied by helmet model and impact location and were more commonly associated with football helmets. Differences in facemask effects between sports are likely attributed to differences in facemask-shell attachment mechanisms, and differences in the structure of the facemask itself. The effects of the facemask on linear and rotational acceleration were small, approximately 5% for both football and hockey helmets. On average, peak accelerations were decreased with the addition of a facemask, but individual differences were mixed and varied by helmet type and impact location. These small differences would not greatly affect impact performance tests in the lab. The results of this study have direct applications toward helmet standard development.

Predicting Cumulative and Maximum Brain Strain Measures From HybridIII Head Kinematics: A Combined Laboratory Study and Post-Hoc Regression Analysis

Due to growing concern on brain injury in sport, and the role that helmets could play in preventing brain injury caused by impact, biomechanics researchers and helmet certification organizations are discussing how helmet assessment methods might change to assess helmets based on impact parameters relevant to brain injury. To understand the relationship between kinematic measures and brain strain, we completed hundreds of impacts using a 50th percentile Hybrid III head-neck wearing an ice hockey helmet and input three-dimensional impact kinematics to a finite element brain model called the Simulated Injury Monitor (SIMon) (n = 267). Impacts to the helmet front, back and side included impact speeds from 1.2 to 5.8 ms−1. Linear regression models, compared through multiple regression techniques, calculating adjusted R2 and the F-statistic, determined the most efficient set of kinematics capable of predicting SIMon-computed brain strain, including the cumulative strain damage measure (specifically CSDM-15) and maximum principal strain (MPS). Resultant change in angular velocity, ΔωR, better predicted CSDM-15 and MPS than the current helmet certification metric, peak g, and was the most efficient model for predicting strain, regardless of impact location. In nearly all cases, the best two-variable model included peak resultant angular acceleration, αR, and ΔωR.

Video analysis of high-magnitude head impacts in men’s collegiate lacrosse

Background/aimLacrosse is one of the fastest growing sports in the USA. Efforts to minimise head injuries focus on promoting safe play through player and coach education, rules enforcement and use...

Comparison of shell-facemask responses in American football helmets during NOCSAE drop tests

This study compares drop tower tests of four commonly used football helmets, under the National Operating Committee on Standards for Athletic Equipment (NOCSAE) football helmet standard, to show that the tests need modification to include the facemask. In our study, the need for a more robust systematic approach to football helmet testing procedures is emphasized by comparing the Head Injury Criterion (HIC), the Gadd Severity Index (SI), and peak acceleration values for different helmets at different locations on the helmet under modified NOCSAE standard drop tower tests. Drop tests were performed on four modern football helmets at eight impact locations (front, front boss, side, rear, rear boss, top, front top, and front top boss), two different impact velocities (5.46 and 4.88 m/s), and two helmet configurations (“with facemasks” and “without facemasks”). Statistically significant differences (p < 0.05) were found in 41% of the comparisons between “with facemasks” and “without facemasks”. Addition of the facemask resulted in an increased HIC, SI, and peak acceleration response measures in 62% of these cases. For example, the stiffening boundary conditions arising from the attached facemask can decrease the helmet performance by up to 50% depending on the impact location when considering the peak acceleration (p < 0.001) as a metric. In terms of location, the top and front top impacts gave the largest HIC, SI, and peak acceleration values. In summary, these comparative drop test results revealed that the current NOCSAE test methods need improvement by attaching the facemasks to helmets and by including two new helmet impact locations (front top and front top boss). The modified NOCSAE football helmet standard test gives a more accurate representation of a helmet’s performance and its ability to mitigate on-field impact.

Modified Drop Tower Impact Tests for American Football Helmets.

A modified National Operating Committee on Standards for Athletic Equipment (NOCSAE) test method for American football helmet drop impact test standards is presented that would provide better assessment of a helmet's on-field impact performance by including a faceguard on the helmet. In this study, a merger of faceguard and helmet test standards is proposed. The need for a more robust systematic approach to football helmet testing procedures is emphasized by comparing representative results of the Head Injury Criterion (HIC), Severity Index (SI), and peak acceleration values for different helmets at different helmet locations under modified NOCSAE standard drop tower tests. Essentially, these comparative drop test results revealed that the faceguard adds a stiffening kinematic constraint to the shell that lessens total energy absorption. The current NOCSAE standard test methods can be improved to represent on-field helmet hits by attaching the faceguards to helmets and by including two new helmet impact locations (Front Top and Front Top Boss). The reported football helmet test method gives a more accurate representation of a helmet's performance and its ability to mitigate on-field impacts while promoting safer football helmets.

Whiplash Injury or Concussion? A Possible Biomechanical Explanation for Concussion Symptoms in Some Individuals Following a Rear-End Collision.

Study Design Finite element modeling of experimental data. Background The clinical presentations of whiplash injury and concussion have considerable overlap. Both diagnoses are generally based on presenting signs and symptoms, and a history of neck or head trauma. With incomplete knowledge of the trauma, differentiating between whiplash injury and concussion can be clinically challenging. Objectives To estimate the brain strains that develop during rear-end car crashes, evaluate how these strains vary with different head kinematic parameters, and compare these strains to those generated during potentially concussive football helmet impacts. Methods Head kinematic data were analyzed from 2 prior studies, one that focused on head restraint impacts in rear-end crash tests and another that focused on football helmet impacts. These data were used as inputs to a finite element model of the human brain. Brain strains were calculated and compared to different peak kinematic parameters and between the 2 impact conditions. Results Brain strains correlated best with the head's angular velocity change for both impact conditions. The 4 crashes with head angular velocity changes greater than 30 rad/s (greater than 1719°/s) generated the highest brain stains. One crash, in which the head wrapped onto the top of the head restraint, generated brain strains similar to a 9.3-m/s rear football helmet impact, a level previously associated with concussion. Conclusion This work provides new insight into a potential biomechanical link between whiplash injury and concussion, and advances our understanding of how head restraint interaction during a rear-end crash may cause an injury more typically associated with sports-related head impacts. J Orthop Sports Phys Ther 2016;46(10):874-885. doi:10.2519/jospt.2016.7049.

Effect of helmet liner systems and impact directions on severity of head injuries sustained in ballistic impacts: a finite element (FE) study.

The current study aims to investigate the effectiveness of two different designs of helmet interior cushion, (Helmet 1: strap-netting; Helmet 2: Oregon Aero foam-padding), and the effect of the impact directions on the helmeted head during ballistic impact. Series of ballistic impact simulations (frontal, lateral, rear, and top) of a full-metal-jacketed bullet were performed on a validated finite element head model equipped with the two helmets, to assess the severity of head injuries sustained in ballistic impacts using both head kinematics and biomechanical metrics. Benchmarking with experimental ventricular and intracranial pressures showed that there is good agreement between the simulations and experiments. In terms of extracranial injuries, top impact had the highest skull stress, still without fracturing the skull. In regard to intracranial injuries, both the lateral and rear impacts generally gave the highest principal strains as well as highest shear strains, which exceed the injury thresholds. Off-cushion impacts were found to be at higher risk of intracranial injuries. The study also showed that the Oregon Aero foam pads helped to reduce impact forces. It also suggested that more padding inserts of smaller size may offer better protection. This provides some insights on future's helmet design against ballistic threats.

June 2016 - This Month in JoVE: Blueberry Analysis, Impact Testing Football Helmets, Stencil Micropatterning of Stem Cells, and a Test for Soil Plasticity

Here's a look at what's coming up in the June 2016 issue of JoVE: The Journal of Visualized Experiments. In JoVE Chemistry, just in time for blueberry season, we feature a method for predicting the constituents of blueberries while keeping them intact. Bai et al. use near-infrared spectroscopy to obtain spectra of individual blueberries, then use high-performance liquid chromatography (HPLC) to measure their actual contents. They build models that use the near-infrared spectra to predict the levels of sugar, the organic acids that impart tartness, and the anthocyanins that have antioxidant properties. This method aids the selection and distribution of only the most delicious blueberries with guaranteed qualities. JoVE Engineering includes a test protocol that simulates on-field impacts of football helmets to help reduce the risks of head injuries. Current performance standards for football helmet certification don't require the faceguard to be attached during impact tests; however, attaching a faceguard dramatically changes the helmet's mechanical properties. Therefore, Rush et al. propose a modified test that includes the faceguard. They also test two new helmet impact locations. This method provides more robust helmet safety standards that will drive safer helmet designs. In JoVE Developmental Biology, human pluripotent stem cells (hPSCs) can differentiate into all three developmental germ layers. However, in vitro differentiation of hPSCs tends to be a disorganized process. This month, Sahni et al. describe stencil micropatterning-a method that can spatially control stem cell microenvironments and organize their differentiation fates. This elegant method provides a valuable experimental model for tissue organization and patterning in embryonic development. In JoVE Environment, soil plasticity is a concept inspired by the craft of pottery. It refers to the clay-like behavior of certain soils at particular water content levels. The plastic limit of soil is an important parameter in geotechnology, but traditional assessment methods are highly subjective. Thus, Moreno-Maroto and Alonso-Azcarate present an alternative method based on objective measures. This method allows the plastic limit of soil to be obtained with clear and objective criteria. You've just had a sneak peek of the June 2016 issue of JoVE. Visit the website to see the full-length articles, plus many more, in JoVE: The Journal of Visualized Experiments.

Virtopsy material testing: Bicycle helmet inspection after an apparently minor fall

With Virtopsy defining a comprehensive (not exclusively radiological) approach to tissue examination [1] but also material testing, we tested a bicycle helmet (Model “Sweep”, Bell Helmets, Bell Sports, BRG Sports, Scott Valley, CA, USA) whose user (40 year old woman, riding a race bike on Swiss winter roads partly covered with snow, ice and sleet) had sustained a fall when slipping in a curve. The fall mainly resulted in soft tissue contusions over the left hip and thigh. No bicycle damage, apparent helmet impact, head injury, headache, neck or face injury, loss of consciousness, nausea or dizziness were reported. The helmet was subjected to CT-scanning (Fig. 1A–R; Fig. 2V, W, and Y) as well as visual inspection both in self-contained (Fig. 2S and T) and strain loaded (Fig. 2U) state. The helmet exhibited a plastic net (E–H; cross sections of the plastic net shown in I, and in part in K–P, V, W and Y) that appeared to be fully embedded in the styrofoam shape (Fig. 1A–E). The combination of both is crucial to understand the problem: with the plastic net constraining the styrofoam parts, the

Ten years later: Ice hockey helmet impact mechanics change with age

This longitudinal 10-year study investigated the effects of inventory aging on ice hockey helmets’ impact attenuation characteristics. Three unused helmet models with different foam padding materials (vinyl nitrile, multi-density vinyl nitrile, and expanded polypropylene) were impact tested at six sites around a surrogate headform on years 2, 6, and 10 (Y2, Y6, and Y10) after the date of manufacture. In general, peak acceleration (g) Y10 measures were greater than those reported in Y2 and Y6, although well below standard impact criteria levels. Visual inspection of helmets post-impact showed no conspicuous damage to liner or shell, although in several instances the binding glue had disintegrated allowing liners to shift or fall away from the shell. In summary, contemporary ice hockey helmets retain most of their robust impact attenuation characteristics 10 years in storage after manufacture date; however, adhesive tearing of padding from the shell needs to be addressed. Regular inspection of the helmet integrity by players, coaches, and trainers is paramount. Further testing of used helmets in a similar prospective manner is carried out to ensure safe helmet function.

Bicycle helmets are highly protective against traumatic brain injury within a dense urban setting.

New York City (NYC) has made significant roadway infrastructure improvements, initiated a bicycle share program, and enacted Vision Zero, an action plan to reduce traffic deaths and serious injuries. The objective of this study was to examine whether bicycle helmets offer a protective advantage against traumatic brain injury (TBI) within a contemporary dense urban setting with a commitment to road safety. A prospective observational study of injured bicyclists presenting to a Level I trauma centre was performed. All bicyclists arriving within 24 h of injury were included. Data were collected between February, 2012 and August, 2014 and included demographics, imaging studies (e.g. computed tomography (CT)), injury patterns, and outcomes including Glasgow Coma Scale (GCS) and Injury Severity Score. Of 699 patients, 273 (39.1%) were wearing helmets at the time of injury. Helmeted bicyclists were more likely to have a GCS of 15 (96.3% [95% Confidence Interval (CI), 93.3-98.2] vs. 87.6 [95% CI, 84.1-90.6]) at presentation. Helmeted bicyclists underwent fewer head CTs (40.3% [95% CI, 34.4-46.4] vs. 52.8% [95% CI, 48.0-57.6]) and were less likely to sustain intracranial injury (6.3% [95% CI, 2.6-12.5] vs. 19.7% [14.7-25.6]), including skull fracture (0.9% [95% CI, 0.0-4.9] vs. 15.3% [95% CI, 10.8-20.7]) and subdural hematoma (0.0% [95% CI, 0.0-3.2] vs. 8.1% [95% CI, 4.9-12.5]). Helmeted bicyclists were significantly less likely to sustain significant TBI, i.e. Head AIS ≥3 (2.6% [95% CI: 0.7-4.5] vs.10.6% [7.6-12.5]). Four patients underwent craniotomy while three died; all were un-helmeted. A multivariable logistic regression model showed that helmeted bicyclists were 72% less likely to sustain TBI compared with un-helmeted bicyclists (Adjusted Odds Ratio 0.28, 95% CI 0.12-0.61). Despite substantial road safety measures in NYC, the protective impact of simple bicycle helmets in the event of a crash remains significant. A re-assessment of helmet laws for urban bicyclists is advisable to most effectively translate Vision Zero from a political action plan to public safety reality.

Feasibility of optimising bicycle helmet design safety through the use of additive manufactured TPE cellular structures

Bicycle helmets are designed to attenuate forces and accelerations experienced by the head during cycling accidents. An essential element of bicycle helmet design is, therefore, the appropriate manufacturing of energy-dissipating components. The focus of this study was to evaluate the feasibility of using thermoplastic elastomer (TPE) cellular structures (Duraform® Flex), manufactured via a laser sintering (LS) process, as the energy-dissipating inner liner of the bicycle helmet. This study is presented in two sections; the optimisation of the LS process capabilities for the manufacture of cellular structures and an evaluation of the effects of cellular structure density on helmet impact kinematics. Through the fabrication and testing of tensile and compressive specimens, each process parameter (laser power, scanning exposure, build temperature and part orientation) was optimised to maximise compressive strength. The energy-dissipating characteristics of helmet cellular structures, made from this optimised material, were evaluated during simulated helmeted headform impact tests. Reduced accelerations and increased pulse durations were reported for decreased structural densities, demonstrating improved energy-dissipating characteristics for this novel technique. This study demonstrates that cellular structure-based inner liners, manufactured via additive manufacturing processes, have exciting potential towards improving bicycle helmet safety.

Assessment of a bicycle helmet liner with semispherical cones

Helmets reduce the frequency and severity of head and brain injuries resulting from bicycle crashes. Generally, a bike helmet consists of the outer shell, liner, vents and straps. The liner is the major helmet component reducing head injury in an accident. Using superior energy absorbing structures and materials as helmet liners to meet the higher safety standards should thus be considered. In this study, a shock absorption test was performed in accordance with the EN1078 standard to evaluate the energy absorption capability of a helmet on the market. Then, the finite element analyses of helmet impact tests modelled using LS-DYNA software. To verify the accuracy of the model, the simulation results were compared with experimental data. Finally, an innovative design of helmet model with semispherical cone liner was considered in this study. To assess the dynamic energy absorption of this helmet, a simulation was performed in accordance with the EN1087 standard for shock absorption tests. The resultant simulation revealed that the helmet with the semispherical cone liner has the potential to protect the human head. This innovative design for a helmet liner can serve as a valuable idea to assist future development of safety-helmet technologies.

Measurement of Hybrid III Head Impact Kinematics Using an Accelerometer and Gyroscope System in Ice Hockey Helmets.

Helmet-based instrumentation is used to study the biomechanics of concussion. The most extensively used systems estimate rotational acceleration from linear acceleration, but new instrumentation measures rotational velocity using gyroscopes, potentially reducing error. This study compared kinematics from an accelerometer and gyroscope-containing system to reference measures. A Hybrid III (HIII) adult male anthropometric test device head and neck was fit with two helmet brands, each instrumented with gForce Tracker (GFT) sensor systems in four locations. Helmets were impacted at various speeds and directions. Regression relationships between GFT-measured and reference peak kinematics were quantified, and influence of impact direction, sensor location, and helmet brand was evaluated. The relationship between the sensor output and the reference acceleration/velocity experienced by the head was strong. Coefficients of determination for data stratified by individual impact directions ranged from 0.77 to 0.99 for peak linear acceleration and from 0.78 to 1.0 for peak rotational velocity. For the data from all impact directions combined, coefficients of determination ranged from 0.60 to 0.80 for peak resultant linear acceleration and 0.83 to 0.91 for peak resultant rotational velocity. As expected, raw peak resultant linear acceleration measures exhibited large percent differences from reference measures. Adjustment using regressions resulted in average absolute errors of 10-15% if regression adjustments were done by impact direction or 25-40% if regressions incorporating data from all impact directions were used. Average absolute percent differences in raw peak resultant rotational velocity were much lower, around 10-15%. It is important to define system accuracy for a particular helmet brand, sensor location, and impact direction in order to interpret real-world data.

Numerical Simulation of Helmeted Headform Drop Test Based on the EN1078 Standard

The shock absorption test of the EN1078 standard is the focal point of this study. These performances are to setup a shock absorbing system for commercially available helmet, to measure the key parameters when an instrumented helmeted headform drops onto anvils. In this test, the helmet quality is assessed by measuring the acceleration time history of a headform during a helmeted headform impact. Helmet quality is expressed in terms of the injury parameters: maximum resultant linear headform acceleration of the headform's center of gravity and Head Injury Criterion (HIC). Besides, the present study performs to develop and validates a finite element of helmeted headform impact test. The FE model obtains by the scanned shapes of a bicycle helmet. The headform and anvil design in accordance with EN 960: 2006 and the EN1078 specification, respectively. This study performs finite element analyses of helmet impact tests using LS-DYNA software. The results of the present method fit the experimental results well, implying that the numerical method is a practical approach to helmet design problems. Furthermore, the helmet test model proposed here has potential for guiding the future development of helmet technologies.