Incidence and Severity of Head Impact during Freestyle Aerial Ski Jumping

1999 ◽  
Vol 15 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Matthew D. Mecham ◽  
Richard M. Greenwald ◽  
James G. Macintyre ◽  
Stephen C. Johnson
Keyword(s):  
Head Injury ◽  
Severity Index ◽  
Head Impact ◽  
Head Acceleration ◽  
Acceleration Signal ◽  
Injury Criteria ◽  
Ski Jumping ◽  
Acceleration Data ◽  
Head Injury Criteria ◽  
Life Threatening

A field study was performed using freestyle aerial ski jumpers to determine the incidence of head impact (slapback) and to record head acceleration data during slapback episodes for the 1994–1995 and 1995–1996 winter seasons. A total of 382 slapbacks were recorded from 2,352 jumps for an observed slapback incidence of 16.2%. Head acceleration data were recorded for 5 slapback events. Maximum head acceleration magnitudes for the 5 impacts ranged from 27 to 92 gs and impact durations ranged from 12 to 96 μsec. Standard severity indices including the Gadd Severity Index and Head Injury Criteria were calculated from the resultant acceleration signal and ranged from 57 to 223, and 21 to 159, respectively, which are considered low in terms of life threatening injury levels.

Design and Validation of a Component Head Injury Criteria Tester for Aerospace Applications

2005 ◽  
Author(s):  
Hamid M. Lankarani ◽  
C. S. Koshy ◽  
C. K. Thorbole
Keyword(s):  
Head Injury ◽  
Seat Belt ◽  
Impact Angle ◽  
Head Impact ◽  
Aircraft Cabins ◽  
Aerospace Applications ◽  
Injury Criteria ◽  
Test Conditions ◽  
Head Injury Criteria ◽  
Impact Events

The compliance with Head Injury Criteria (HIC) specified in 14 CFR 23.562 [1] and CFR 25.562 [2] poses a significant problem for many segments of the aerospace industry. The airlines and the manufacturers of jet transports have made claims of high costs and significant schedule overruns during the development and certification of 16G seats because of the difficulties encountered in meeting this requirement. The current practice is to conduct Full Scale Sled Tests (FSST) on impact sleds. This approach can be expensive, since a new seat may be needed for each test. Moreover, some consider the HIC sensitive to changes in the test conditions, such as sled pulse, seat belt elongation, etc., resulting in HIC results from FSSTs showing poor repeatability. These difficulties make it desirable to devise a cheaper, faster, and more repeatable alternative to FSSTs. This paper describes an attempt to address these issues by designing a device, the National Institute for Aviation Research (NIAR) HIC Component Tester (NHCT) using various multibody tools. This device was then fabricated and its performance evaluated against FSSTs conducted under similar test conditions for some typical impact events that occur in an aircraft cabins e.g. impact with bulkheads. The factors compared for this evaluation are the head impact angle, head impact velocity, HIC, HIC window, peak head C.G. resultant acceleration, average head C.G. resultant acceleration, and head C.G. resultant acceleration profiles. The results of these evaluations show that the NHCT already produces test results that correlate significantly with FSST results for impact targets such as bulkheads and its target envelope is expected eventually to include objects such as seat backs.

scholarly journals ASSESSMENT OF HEAD INJURY CRITERIA AND CHEST SEVERITY INDEX FOR FRONTAL IMPACT

2015 ◽  
Vol 8 ◽  
pp. 1376-1382 ◽  
Author(s):  
M.S. Salwani ◽  
◽  
B.B. Sahari ◽  
Aidy Ali ◽  
A.A. Nuraini ◽  
...  
Keyword(s):  
Head Injury ◽  
Severity Index ◽  
Frontal Impact ◽  
Injury Criteria ◽  
Head Injury Criteria

scholarly journals Limiting Performance of Helmets for the Prevention of Head Injury

1999 ◽  
Vol 6 (5-6) ◽  
pp. 299-320 ◽  
Author(s):  
Z.Q. Cheng ◽  
W.D. Pilkey ◽  
J.R. Crandall ◽  
C.R. Bass ◽  
K. Darvish
Keyword(s):  
Head Injury ◽  
Skull Fracture ◽  
Head Acceleration ◽  
Head Injury Criterion ◽  
Bicycle Helmets ◽  
Injury Criteria ◽  
Injury Model ◽  
Head Injury Criteria ◽  
The Impact ◽  
The Brain

This is a study of the theoretical optimal (limiting) performance of helmets for the prevention of head injury. A rigid head injury model and a two-mass translational head injury model are employed. Several head injury criteria are utilized, including head acceleration, the head injury criterion (HIC), the energy imparted to the brain which is related to brain injury, and the power developed in the skull that is associated with skull fracture. A helmeted head hitting a rigid surface and a helmeted head hit by a moving object such as a ball are considered. The optimal characteristics of helmets and the impact responses of the helmeted head are investigated computationally. An experiment is conducted on an ensemble of bicycle helmets. Computational results are compared with the experimental results.

scholarly journals Sex Differences in Head Acceleration During Heading While Wearing Soccer Headgear

2008 ◽  
Vol 43 (6) ◽  
pp. 578-584 ◽  
Author(s):  
Ryan T. Tierney ◽  
Michael Higgins ◽  
Shane V. Caswell ◽  
Jessica Brady ◽  
Krista McHardy ◽  
...  
Keyword(s):  
Head Injury ◽  
Repeated Measures ◽  
Head Impact ◽  
Soccer Players ◽  
Neck Muscle ◽  
Head Acceleration ◽  
Cross Sectional ◽  
Head Injury Criteria ◽  
Cross Sectional Design ◽  
Soccer Heading

Abstract Context: Researchers have indicated that female soccer players may be at greater risk of concussion compared with their male counterparts. Soccer headgear is marketed for reducing head acceleration and risk of concussion. Objective: To determine the effect of sex and soccer headgear on head impact kinematics and dynamic stabilization during soccer heading. Design: Cross-sectional design. Setting: Research laboratory. Patients or Other Participants: Forty-four college-aged soccer players (29 women, 15 men). Intervention(s): Using a head impact model, participants performed 4 soccer headers under 3 headgear conditions (control, Head Blast Soccer Band, and Full90 Select Performance Headguard). Main Outcome Measure(s): Dependent variables assessed before soccer heading were head-neck anthropometrics and isometric neck muscle strength, and those assessed during soccer headers were resultant linear head acceleration, Head Injury Criteria (HIC36), and superficial neck muscle electromyography. Statistical analyses included multivariate and univariate analyses of variance with repeated measures, independent-samples t tests, appropriate follow-up analyses of variance and post hoc t tests, and Pearson product moment correlations (α  =  .05). Results: Head acceleration in women was 32% and 44% greater than in men when wearing the Head Blast (21.5 g versus 16.3 g) and Full90 Select (21.8 g versus 15.2 g), respectively (P < .05). Compared with men, women exhibited 10% greater head accelerations (20.2 g versus 18.2 g) during the control condition (P  =  .164). Conclusions: Female soccer players exhibited greater head accelerations than their male counterparts when wearing headgear. Our results are important clinically because they indicate that soccer headgear may not be an appropriate head injury prevention tool for all athletes.

scholarly journals Effect of Automotive Side Member Materials on the Head Injury Criteria (HIC) and Chest Severity Index (CSI) of Adult Passenger

2016 ◽  
Vol 7 ◽  
pp. 47-59
Author(s):  
M.S. Salwani ◽  
Aidy Ali ◽  
B.B. Sahari ◽  
A.A. Nuraini
Keyword(s):  
Aluminum Alloy ◽  
Head Injury ◽  
Severity Index ◽  
Side Member ◽  
Element Analysis ◽  
Injury Criteria ◽  
Different Types ◽  
Minimum Requirements ◽  
Head Injury Criteria ◽  
Materials Used

This paper presents the results for Head Injury Criteria (HIC) and Chest Severity Index (CSI) of an adult occupant in frontal impact. The component being studied is side member as impact energy absorber. Steel side member is used as the benchmark material, whereas aluminum alloy is used as lightweight material. Crash analyses are conducted using nonlinear finite element analysis software Ls-dyna. The effect of different types of aluminum alloy and component thickness on the HIC, CSI, weight and energy absorbed is assessed and discussed. A cost function is then formulated with the geometrical average method to solve the multi-objective problem. The HIC36 and CSI are set as minimum requirements in the optimization. The materials used was Aluminium alloy of AA 5182 AA5751. It was found that AA5751 with inner and outer thickness of 2.8 mm and 4.9 mm respectively, provides a reduction in mass of 1.03 kg compared with steel and has energy absorbed of 11.9 kJ. The lowest values of HIC36 and CSI obtained are 1146 and 665.4 respectively.

scholarly journals Evaluation of Head Injury Criteria for Injury Prediction Effectiveness: Computational Reconstruction of Real-World Vulnerable Road User Impact Accidents

2021 ◽  
Vol 9 ◽  
Author(s):  
Fang Wang ◽  
Zhen Wang ◽  
Lin Hu ◽  
Hongzhen Xu ◽  
Chao Yu ◽  
...  
Keyword(s):  
Head Injury ◽  
Real World ◽  
Head Injuries ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Road User ◽  
Injury Criteria ◽  
Brain Deformation ◽  
Vulnerable Road User ◽  
Head Injury Criteria

This study evaluates the effectiveness of various widely used head injury criteria (HICs) in predicting vulnerable road user (VRU) head injuries due to road traffic accidents. Thirty-one real-world car-to-VRU impact accident cases with detailed head injury records were collected and replicated through the computational biomechanics method; head injuries observed in the analyzed accidents were reconstructed by using a finite element (FE)-multibody (MB) coupled pedestrian model [including the Total Human Model for Safety (THUMS) head–neck FE model and the remaining body segments of TNO MB pedestrian model], which was developed and validated in our previous study. Various typical HICs were used to predict head injuries in all accident cases. Pearson’s correlation coefficient analysis method was adopted to investigate the correlation between head kinematics-based injury criteria and the actual head injury of VRU; the effectiveness of brain deformation-based injury criteria in predicting typical brain injuries [such as diffuse axonal injury diffuse axonal injury (DAI) and contusion] was assessed by using head injury risk curves reported in the literature. Results showed that for head kinematics-based injury criteria, the most widely used HICs and head impact power (HIP) can accurately and effectively predict head injury, whereas for brain deformation-based injury criteria, the maximum principal strain (MPS) behaves better than cumulative strain damage measure (CSDM0.15 and CSDM0.25) in predicting the possibility of DAI. In comparison with the dilatation damage measure (DDM), MPS seems to better predict the risk of brain contusion.

scholarly journals Numerical Simulation of Airbag and Study on the Effect of Airbag Parameters on Head Injury Criteria

2021 ◽  
Vol 9 (9) ◽  
pp. 1654-1666
Author(s):  
Aakash R
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Traffic Safety ◽  
Critical Role ◽  
Highway Traffic ◽  
Element Analysis ◽  
National Highway Traffic Safety ◽  
Occupant Safety ◽  
Injury Criteria ◽  
Head Injury Criteria

Abstract: In the case of an accident, inflatable restraints system plays a critical role in ensuring the safety of vehicle occupants. Frontal airbags have saved 44,869 lives, according to research conducted by the National Highway Traffic Safety Administration (NHTSA).Finite element analysis is extremely important in the research and development of airbags in order to ensure optimum protection for occupant. In this work, we simulate a head impact test with a deploying airbag and investigate the airbag's parameters. The airbag's performance is directly influenced by the parameters of the cushion such as vent area and fabric elasticity. The FEM model is analysed to investigate the influence of airbag parameter, and the findings are utilised to determine an optimal value that may be employed in the construction of better occupant safety systems. Keywords: airbag, finite element method, occupant safety, frontal airbag, vent size, fabric elasticity, head injury criteria

Performance of Hood System and Head Injury Criteria Subjected to Frontal Impacts

2012 ◽  
Vol 165 ◽  
pp. 270-274 ◽  
Author(s):  
J. Mai Nursherida ◽  
Sahari B. Barkawi ◽  
A.A. Nuraini ◽  
Aidy Ali ◽  
A.A. Faieza ◽  
...  
Keyword(s):  
Head Injury ◽  
Mild Steel ◽  
Epoxy Composite ◽  
Important Variable ◽  
Plane Failure ◽  
Head Injury Criterion ◽  
Frontal Impacts ◽  
Injury Criteria ◽  
Head Injury Criteria ◽  
Protective Performance

The aim of this study is to analyze the effect of steel and composite material on pedestrian head injury criteria of hood system. The hood is made of mild steel and aluminum, e-glass/epoxy composite and carbon epoxy composite are studied and characterized by impact modeling using LS-DYNA V971 in accordance with United States New Car Assessment Program (US-NCAP) frontal impact velocity and based on European Enhanced Vehicle-safety Committee. The most important variable of this structure are mass, material, internal energy, and Head Injury Criterion (HIC). The results are compared with hood made of mild steel. Three types of materials are used which consists of mild steel as reference materials, Aluminum AA5182, E-glass/epoxy composite and carbon fiber/epoxy composite with four different fiber configurations. The in-plane failure behaviors of the composites were evaluated by using Tsai Wu failure criterion. The results for the composite materials are compared to that of steel to find the best material with lowest HIC values. In order to evaluate the protective performance of the baseline hood, the Finite Element models of 50th percentile an adult pedestrian dummy is used in parallel to impact the hood. It was found that aluminum AA5182 hood can reduce the Head Injury Criterion (HIC) by comparing with the baseline hood. For pedestrian crash, it is observed that Aluminum AA5182 hood gave the lowest HIC value with 549.70 for HIC15 and 883.00 for HIC36 followed by steel hood with 657.40 for HIC15 and 980.90 for HIC36, e-glass/epoxy composite hood with 639.60 for HIC15 and 921.70 for HIC36 and carbon/epoxy composite hood with 1197.00 for HIC15 and 1424.00 for HIC36.

FOCUS Headform Testing Used to Evaluate Head Injury Risk for Ejected Riders of Personal Watercraft

2017 ◽  
Author(s):  
Chimba Mkandawire ◽  
Eric S. Winkel ◽  
Nicholas A. White ◽  
Edward Schatz
Keyword(s):  
Brain Injury ◽  
Head Injury ◽  
Injury Risk ◽  
Skull Fractures ◽  
Facial Fractures ◽  
Injury Criteria ◽  
Facial Skull ◽  
Personal Watercraft ◽  
Wide Variability ◽  
Head Injury Criteria

Operators of personal watercraft (PWC) can perform maneuvers that may result in riders separating from the moving watercraft; the tested hypothesis was whether substantial brain injury concurrent with substantial facial and skull fractures can occur from contact with the PWC during a fall. The present study reports the potential for AIS2+ facial/skull fractures and AIS2+ traumatic brain injury (TBI) during a generic fall from the PWC in the absence of wave-jumping or other aggressive maneuvers. While it is well known that PWC can be used for wave-jumping which can result in more severe impacts, such impacts are beyond the scope of the present study because of the wide variability in occupant and PWC kinematics and possible impact velocities and orientations. Passenger separation and fall kinematics from both seated and standing positions were analyzed to estimate head impact velocities and possible impact locations on the PWC. A special purpose headform, known as the Facial and Ocular CountermeasUre Safety (FOCUS) device was used to evaluate the potential for facial fractures, skull fractures and TBI. Impacts between the FOCUS headform and the PWC were performed at velocities of 8, 10, and 12 miles per hour at 5 locations near the stern of a PWC. This study reports impact forces for various facial areas, linear and angular head accelerations, and Head Injury Criteria (HIC). The risk for facial fracture and TBI are reported herein. The results of this study indicate that concurrent AIS2 facial fractures, AIS2+ skull fractures, and AIS2+ TBI do not occur during a simple fall from a PWC.

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