Browse Topic: Neck

Items (473)

Analysis of Occupants' Responses in Frontal Sled Tests under a Reclined Rigid Seat Environment

2025-01-8734

04/01/2025

With the increasing adoption of Zero-Gravity Seats in intelligent cockpits, there is a growing concern over the safety of occupants in reclined postures during collisions. The newly released anthropomorphic test device (ATD), THOR-AV, has modified the neck, spine, and pelvis structures to better match reclined postures. This study aims to investigate the changes in kinematic response and injury metrics for occupants in reclined postures, through high-speed frontal sled tests utilizing the THOR-AV. The tests were conducted using an adjustable rigid seat with a zero-gravity characteristic and an integrated three-point seat belt. Six tests were performed across four seat configurations: Standard, Semi-Reclined, Reclined, and Zero-gravity postures. The input acceleration pulse for these tests was derived from the equivalent double trapezoidal waveform of the Mobile Progressive Deformable Barrier (MPDB) test. Data from sensors and high-speed video were collected for analysis. The results

Wang, Qiang, Liu, Yu, Fei, Jing, Yang, Xiaoting, Wang, Peifeng, Bai, Zhonghao

Literature Review and Framework for Identifying Seat Belt Misuse and Misrouting in Frontal Collisions

2025-01-8721

04/01/2025

The effect of seat belt misuse and/or misrouting is important to consider because it can influence occupant kinematics, reduce restraint effectiveness, and increase injury risk. As new seatbelt technologies are introduced, it is important to understand the prevalence of seatbelt misuse. This type of information is scarce due to limitations in available field data coding, such as in NASS-CDS and FARS. One explanation may be partially due to assessment complexity in identifying misuse and/or misrouting. An objective of this study was to first identify types of lap-shoulder belt misuse/misrouting and associated injury patterns from a literature review. Nine belt misuse/misrouting scenarios were identified including shoulder belt only, lap belt only, or shoulder belt under the arm, for example, while belt misrouting included lap belt on the abdomen, shoulder belt above the breasts, or shoulder belt on the neck. Next, the literature review identified various methods used to assess misuse

Gu, Emily, Parenteau, Chantal

The Influence of out-of-Position Displacement during Emergency Braking on Occupant Whiplash Injury in Subsequent Rear-End Collisions

2025-01-8720

04/01/2025

In the pre-crash emergency braking scenario, the occupant inside the vehicle will move forward due to inertia, deviating from the standard upright seating position for which conventional restraint systems are designed. Previous studies have mainly focused on the influence of out-of-position (OOP) displacement on occupant injuries in frontal collisions, and provided solutions such as active pretensioning seatbelts (APS). But little attention has been paid to the influence of OOP on whiplash injury during a subsequent rear-end collision. To investigate the forward OOP impact on whiplash injuries and the effectiveness of APS in this accident scenario, a vehicle interior model with an active human body model (AHBM) was setup in the MADYMO simulation platform. Different braking strengths (0.8g and 1.1g), APS triggering times (from 0.2s before to 0.2s after the braking initiation) and pretensioning forces (from 100N to 600N) were input to the simulation matrix. The occupant’s forward OOP

Fei, Jing, Qiu, Hang, Wang, Peifeng, Liu, Yu, Cheng, James Chih, Zhou, Qing, Tan, Puyuan

A Study on Affections of Active Neck Muscle Force on Neck Injury Responses in Frontal Impact with Automatic Emergency Braking Conditions

2025-01-8742

04/01/2025

Neck injury is one of the most common injuries in traffic accidents, and its severity is closely related to the posture of the occupant at the time of impact. In the current era of smart vehicle, the triggered AEB and the occupant's active muscle force will cause the head and neck to be out of position which has significant affections on the occurrence and severity of neck injury responses. Therefore, it is very important to study the influences of active muscle force on neck injury responses in in frontal impact with Automatic Emergency Braking conditions. Based on the geometric characteristics of human neck muscles in the Zygote Body database, the reasonable neck muscle physical parameters were obtained firstly. Then a neck finite element model (FEM) with active muscles was developed and verified its biofidelity under various impact conditions, such as frontal, side and rear-end impacts. Finally, using the neck FEM with or without active muscle force, a comparative study was

Junpeng, Xu, Gan, Qiuyu, Jiang, Binhui, Zhu, Feng

The Biomechanical Effects of Neck and Back Cushion / Pillow / Support Devices in Low-Speed Rear Impacts

2025-01-8728

04/01/2025

There are numerous commercially available neck and back support/cushion/pillow devices which are commonly attached to seats by vehicle owners. To our knowledge, there has been no published research on the biomechanical effects of these devices in low-speed rear impacts. To address this, a series of 54 simulated low-speed rear impact tests were conducted using a validated remote-controlled crash sled system. All tests utilized an instrumented BioRID II rear impact anthropomorphic test device (ATD) restrained using a 3-point seatbelt system in a 2018 Toyota Camry LE driver’s seat. Two delta-V ranges were used: a lower range from 7.2 to 8.0 kph (4.5 to 5.0 mph) and a higher range from 10.5 to 11.3 kph (6.5 to 7.0 mph). Six neck only devices, one combination neck and back device, and three back only devices were assessed. Two tests per delta-V range for each device and each device adjustment position were conducted and compared against five reference tests without any devices at each delta

Phan, Andrew, Gross, Jamie, Umale, Sagar, Crowley, Shannon, Glasser, Gabriel, Furbish, Christopher

Comprehensive Injury Assessment of Reclined Occupants across Varied Seat Configurations with the THUMS Human Body Model

2025-01-8739

04/01/2025

The development of autonomous driving technology will liberate the space in the car and bring more possibilities of comfortable and diverse sitting postures to passengers, but the collision safety problem cannot be ignored. The aim of this study is to investigate the changes of injury pattern and loading mechanism of occupants under various reclined postures. A highly rotatable rigid seat and an integrated three-point seat belt were used, with a 23g, 50kph input pulse. Firstly, the sled test and simulation using THOR-AV in a reclined posture were conducted, and the sled model was verified effective. Based on the sled model, the latest human body model, THUMS v7, was used for collision simulation. By changing the angle of seatback and seat pan, 5 seat configurations were designed. Through the calculation of the volunteers' pose regression function, the initial position of THUMS body parts in different seat configurations was determined. The responses of human body parts were output

Yang, Xiaoting, Wang, Qiang, Liu, Yu, Fei, Jing, Wang, Peifeng, Li, Zhen, Bai, Zhonghao

Occupant Responses in High-Speed Rear Sled Tests: Focus of Initial Position, Seat Strength and ATD Size

2025-01-8731

04/01/2025

The National Highway Safety Administration (NHTSA) recently published an Advanced Notice of Proposed Rulemaking (ANPRM) to evaluate seat performance in rear impacts [1]. The ANPRM was issued partially in response to two petitions requesting an increase in seatback strength requirements and high-speed testing with various size Anthropometric Test Devices (ATDs). To better understand the effect of these requests, this study evaluates ATD responses with two high-speed rear sled conditions, three occupant sizes and various seat designs. Seat designs varied from modern conventional seats with yielding properties to stronger and stiffer seats represented by seat integrated restraint (SIR) designs, and rigidized SIR seats. Twenty-four rear sled tests were analyzed. The tests were matched by crash severity, seat designs (strength), ATD sizes and initial postures (nominal/in-position, leaned forward and leaned outboard). The test data and videos were reviewed to identify time coinciding with

Parenteau, Chantal, Burnett, Roger

Integration of Muscle Pre-tension and Activation to Evaluate Neck Muscle Strain Injury Risk during Simulated Rear Impacts Using a Finite Element Neck Model

2025-22-000102/07/2025

Prevention of rear-impact neck injuries remains challenging for safety designers due to a lack of understanding of the tissue-level response and injury risk. Soft tissue injuries have been inferred from clinical, cadaveric, and numerical studies; however, there is a paucity of data for neck muscle injury, commonly reported as muscle pain. The goal of this study was to investigate the effect of muscle pre-tension and activation on muscle strain and injury risk resulting from low-severity rear impacts using a detailed finite element head and neck model (HNM). The HNM was extracted from the GHBMC average stature male model and re-postured to match a volunteer study, with measured T1 kinematics applied as boundary conditions to the HNM. Three cases were simulated for three impact severities: the baseline repostured HNM, the HNM including muscle pre-tension, and the HNM with muscle pre-tension and muscle activation. The head kinematics, vertebral kinematics, muscle strains, and three neck

Correia, Matheus A., McLachlin, Stewart D., Cronin, Duane S.

Toward a Test-Based Methodology to Evaluate Unrestrained Torso Neck Braces Using the Hybrid III ATD and MATD Neck

09-12-03-0012

11/23/2024

The introduction of unrestrained torso neck braces as a safety intervention for helmeted motorcycle riders has introduced a set of unsolved challenges. Understanding the injury prevention afforded by these devices depends on a reliable test methodology by which to critically evaluate their efficacy against the most common mechanisms of neck injury. An inverted pendulum test is proposed to evaluate compression flexion (CF), tension flexion (TF), and tension extension (TE) of the neck using a Hybrid III anthropomorphic test device (HIII ATD) neck and a motorcycle-specific ATD (MATD) neck. In addition to investigating methods to quantify the beneficial effects of a neck brace, potential adverse effects of such a device are evaluated by measuring and evaluating relevant neck response measures. To that end, measured data using a current neck brace were analyzed and applied to various injury criteria related to the ATD neck used to compare the injury risk predicted by each parameter. The

de Jongh, Cornelis U., Basson, Anton H., Knox, Erick H., Leatt, Christopher J.

Finite Element Comparison of Human and Hybrid III Responses in the Airworthiness Certification of Normal Aircraft

2024-01-7018

11/15/2024

With the capability of predicting detailed injury of occupants, the Human Body Model (HBM) was used to identify potential injuries for occupants in car impact events. However, there are few publications on using HBM in the aviation industry. This study aims to investigate and compare the head, neck, lumbar spine and thoracic responses of the Hybrid III and the THUMS (Total Human Model for Safety) model in the horizontal 26g and vertical 19g sled tests required by the General Aviation Aircraft Airworthiness Regulations. The HIC of THUMS and Hybrid III did not exceed the requirements of airworthiness regulations. Still, THUMS had higher intracranial pressures and intracranial stresses, which could result in brain injury to the occupants. In vertical impact, the highest stress of the neck of THUMS appears at the cervical spine C2 and the upper neck is easily injured; in horizontal impact, the cervical spine C7 has the highest load, and the lower neck is easily injured. Due to the low

Shi, Xiaopeng, Ding, Xianghe, Guo, Kai, Liu, Tianfu, Xie, Jiang

Neck Injury Risk in Out-of-Position Rear Impact Scenarios Using a Reference Geometry-Based Head Repositioning

09-12-02-0020

11/12/2024

Rear-end vehicle collisions may lead to whiplash-associated disorders (WADs), comprising a variety of neck and head pain responses. Specifically, increased axial head rotation has been associated with the risk of injuries during rear impacts, while specific tissues, including the capsular ligaments, have been implicated in pain response. Given the limited experimental data for out-of-position rear impact scenarios, computational human body models (HBMs) can inform the potential for tissue-level injury. Previous studies have considered external boundary conditions to reposition the head axially but were limited in reproducing a biofidelic movement. The objectives of this study were to implement a novel head repositioning method to achieve targeted axial rotations and evaluate the tissue-level response for a rear impact condition. The repositioning method used reference geometries to rotate the head to three target positions, showing good correspondence to reported interverbal rotations

Reis, Matheus Seif, Cronin, Duane

Quantifying and Comparing the Intersegmental Kinematics of the Pediatric Whole Cervical Spine to Individual Motion Segment Kinematics in a Six-Year-Old Postmortem Human Surrogate

09-12-02-0010

11/12/2024

Mitigating both neck and head injuries in the pediatric population relies heavily on improving our understanding of the underlying biomechanics of the pediatric cervical spine. The tensile response for individual motion segments and the whole cervical spine (WCS) has been reported, but there is no data characterizing the intersegmental kinematics of pediatric WCS under axial loading conditions. The structural response of motion segments and WCS provide valuable data for the design and validation of biofidelic physical and computational models for the pediatric population. However, the use of motion segment data to construct WCS response or the use of WCS axial response to accurately characterize intersegmental response may present limitations to accurately modeling the pediatric cervical spine response. In this secondary analysis of the work of Luck et al. (2008, 2013), the fixed-fixed, low load, quasi-static tensile response of the WCS and individual motion segments (O-C2, C4-C5, and

Liu, Miranda, Luck, Jason F.

A Methodology to Evaluate Unrestrained Torso Neck Braces for Near Vertex Impacts

09-12-03-0010

08/22/2024

The advent of neck braces for the helmeted motorcycle rider has introduced a pertinent research question: To what extent do they reduce measures related to the major mechanism of neck injury in unrestrained torso accidents, i.e., compression flexion (CF)? This question requires a suitable method of testing and evaluating the measures for a load case resulting in the required mechanism. This study proposes a weighted swinging anvil striking the helmeted head of a supine HIII ATD by means of a near vertex impact with a low degree of anterior head impact eccentricity to induce CF of the neck. The applied impact was chosen for the baseline (no neck brace) so that the upper and lower neck axial forces approached injury assessment reference values (IARV). The head impact point evaluated represents those typically associated with high-energy burst fractures occurring within the first 20 ms, with possible secondary disruption of posterior ligaments. The proposed test can be used to evaluate

de Jongh, Cornelis U., Basson, Anton H., Knox, Erick H., Leatt, Christopher J.

Seatback Failures and Human Tolerance in Severe Rear Impacts

2024-26-0003

01/16/2024

Seatback and head restraints are the primary restraining devices in rear-impact collisions. The seatback failures expose front seat occupants to dive deep into the rear compartment survival space. Furthermore, it allows the occupants to get in a position with lower spinal tolerance to the impact direction. This paper employs sled tests to demonstrate the dangers of seatback failures in severe rear impact by allowing the occupants to orient their spine in its lowest tolerance zone to the impact direction. Furthermore, the sled test shows the potential of head pocketing phenomena and torso augmentation producing compressive cervical spine loading enough to cause first-order neck buckling. Finally, the results of collapsing seatback dynamics are compared to the strong seatback performance by conducting a similar test with a strong ABTS seatback. The study demonstrates that the strong seatbacks in severe rear impacts produce favorable outcomes while keeping the occupant in their higher

Thorbole, Chandrashekhar

Virtual Reality Based Study on Pre-Impact Position of Auto Rickshaw Driver

2023-28-0118

11/10/2023

The role of Virtual Reality (VR) platform for experimental studies to mitigate severe injuries is known. A Virtual Reality (VR) module was developed to provide an Indian auto-rickshaw driver experience using commercially available Oculus Quest 2 VR headset. A Driver Behaviour Questionnaire (DBQ) was developed and a study carried out among 20 auto-rickshaw drivers in Thanjavur, India. The DBQ questions provided data to shortlist the most likely near crash experiences among the surveyed drivers. A virtual reality environment was created using UNITY HUB software for one selected scenario from the DBQ survey analysis. A group of 10 volunteers to experience the event using VR gear in the biomechanical laboratory with reflective markers fixed on the body joints of the volunteers to obtain corresponding joint angles in the Neck, Lumbar, Shoulder, Hip, and Knee regions. This study identified various pre-crash reactions from drivers and compared them to the normal driving posture to determine

S, Ragul, G, Sundhareswaran, Sankarasubramanian, Hariharan, Prasanna, Selva, Vijayaraghavan, Sriram

Summary of Poster Abstracts

09-11-02-0022

09/20/2023

Eighteen research posters were prepared and presented by student authors at the 18th Annual Injury Biomechanics Symposium. The posters covered a wide breadth of works-in-progress and recently completed projects. Topics included a variety of body regions and injury scenarios such as: Head: Defining the mass, center of mass, and anatomical coordinate system of the pig head and brain; the influence of friction on oblique helmet testing; validation of an in-ear sensor for measuring head impact exposure in American football Neck and spine: Design of paramedic mannequin neck informed by adult passive neck stiffness and range of motion data; identifying injury from flexion-compression loading of porcine lumbar intervertebral disc Thorax: Tensile material properties of costal cartilage perichondrium; finite element models of both an ovine thorax and adipose tissue for high-rate non-penetrating blunt impact Pelvis: Injurious pelvis deformation in high-speed rear-facing frontal impacts Lower

Mueller, Becky, Bautsch, Brian, Mansfield, Julie

Comparison of Head, Neck, and Chest Injury Risks between Front- and Rear-Seated Hybrid III 50th-Percentile Male ATDs in Matched Frontal NCAP Tests

09-12-01-0001

09/19/2023

The objective of this study was to compare head, neck, and chest injury risks between front and rear-seated Hybrid III 50th-percentile male anthropomorphic test devices (ATDs) during matched frontal impacts. Seven vehicles were converted to rear seat test bucks (two sedans, three mid-size SUVs, one subcompact SUV, and one minivan) and then used to perform sled testing with vehicle-specific frontal NCAP acceleration pulses and a rear seated (i.e., second row) Hybrid III 50th male ATD. Matched front seat Hybrid III 50th male ATD data were obtained from the NHTSA Vehicle Crash Test Database for each vehicle. HIC15, Nij, maximum chest acceleration, and maximum chest deflection were compared between the front and rear seat tests, as well as between vehicles with conventional and advanced three-point belt restraint systems in the rear seat. Additionally, a modified version of the NCAP frontal star rating was calculated for the front and rear seat tests. All injury metrics, except for chest

Bianco, Samuel T., Albert, Devon L., Guettler, Allison J., Hardy, Warren N., Kemper, Andrew R.

User’s Manual for the Small Adult Female Hybrid III Test Dummy

J2862_202305 (Current)

05/22/2023

This user’s manual covers the small adult female Hybrid III test dummy. It is intended for technicians who work with this device. It covers the construction and clothing, disassembly and reassembly, available instrumentation, external dimensions and segment masses, as well as certification and inspection test procedures. It includes instructions for safe handling of the instrumented dummy, repairing dummy flesh, and adjusting the joints throughout the dummy.

Dummy Testing and Equipment Committee

Hybrid III Ten-Year Old Child Dummy User’s Manual

J2858_202305 (Current)

05/01/2023

This user's manual covers the Hybrid III 10-year old child test dummy. The manual is intended for use by technicians who work with this test device. It covers the construction and clothing, assembly and disassembly, available instrumentation, external dimensions and segment masses, as well as certification and inspection test procedures. It includes guidelines for handling accelerometers, guidelines for flesh repair, and joint adjustment procedures. Finally, it includes drawings for some of the test equipment that is unique to this dummy.

Dummy Testing and Equipment Committee

Evaluation of Drivers of Very Large Pickup Trucks: Size, Seated Height and Biomechanical Responses in Drop Tests

2023-01-0649

04/11/2023

This study focused on occupant responses in very large pickup trucks in rollovers and was conducted in three phases. Phase 1 - Field data analysis: In a prior study [9], 1998 to 2020 FARS data were analyzed; Pickup truck drivers with fatality were 7.4 kg heavier and 4.6 cm taller than passenger car drivers. Most pickup truck drivers were males. Phase 1 extended the study by focusing on the drivers of very large pickup trucks. The size of 1999-2016 Ford F-250 and F-350 drivers involved in fatal crashes was analyzed by age and sex. More than 90% of drivers were males. The average male driver was 179.5 ± 7.5 cm tall and weighed 89.6 ± 18.4 kg. Phase 2 – Surrogate study: Twenty-nine male surrogates were selected to represent the average size of male drivers of F-250 and F-350s involved in fatal crashes. On average, the volunteers weighed 88.6 ± 5.2 kg and were 180.0 ± 3.2 cm tall with a 95.2 ± 2.2 cm seated height. The volunteers were lap-shoulder belted in the driver seat of a 2002 Ford F

Burnett, Roger, Parenteau, Chantal, Vogler, Michelle, Toomey, Daniel, Orlowski, Kenneth, Krishnaswami, Ram

Development of a Neck Finite Element Model with Active Muscle Force for the THOR-50M Numerical Dummy

2023-01-0002

04/11/2023

With the development of active safety technology, effort has gradually shifted to preventing or minimizing car crashes. Automatic Emergency Braking Technology (AEB) can avoid accidents by warning and even automatic braking, but there is a contradiction between the accompanying occupant out-of-position and traditional passive safety design. In addition, the 2025 version of C-NCAP plans to add neck injury assessment requirements for AEB [1]. In order to study the kinematic response of the occupant's neck under AEB, a neck finite element model with active muscle force is established in this paper. Firstly, the open-source THOR-50M neck geometric model is used for finite element discretization. Secondly, the neck FE model of THOR-50M is verified through the qualification procedure of the NHTSA standard. Thirdly, according to the geometric features of human neck muscles in Zygote Body database, the neck muscle parameters are preliminarily determined. Finally, the neck muscle parameters are

Wu, Xiaofan, Jiang, Binhui, Bai, Zhonghao, Zhang, Guanjun

ES2re, WS50M, and Human Body Models in Far-Side Pole Impacts

2023-01-0558

04/11/2023

Driver oblique far-side sled impacts were simulated with three surrogates. The EuroSID side impact dummy with rib extension (ES2re), the WorldSID side impact 50th percentile male dummy (WS50M), and the Global Human Body Modeling Consortium’s 50th percentile male human body (GHBM) models. The versions of the surrogates’ models were 7.0, 7.5.1, and 5.0, respectively. Surrogates were seated in the front left driver seat in a virtual generic crossover sled environment. The Finite Element (FE) based environment consisted of a driver seat, a center console, and a passenger seat. Two restraint systems were considered for each surrogate: belt only (BO) and belt plus a generic seat-mounted far-side impact airbag (BB). Surrogates were restrained using a 3-point belt that has a digressive shoulder force load limiter, and retractor, and anchor pretensioners. The far-side airbag used was a 37-liter in volume and has two chambers. Surrogate head excursions and injury indices for each surrogate were

El-Jawahri, Raed E.

Development and Calibration of the Large Omnidirectional Child ATD Head and Neck Complex Finite Element Model

2023-01-0557

04/11/2023

The National Highway Traffic Safety Administration (NHTSA) has developed the Large Omnidirectional Child (LODC) Anthropomorphic Test Device (ATD) to improve the biofidelity of the currently available Hybrid III 10-year-old (HIII-10C) ATD. The improvements of the LODC over the HIII-10C include changes in sub-assemblies such as the head and neck, where the LODC head is a redesigned HIII-10C head with pediatric mass properties and the neck has a modified atlanto-occipital joint to replicate observations made from human specimens. The current study focuses on developing a dynamic, nonlinear finite element (FE) model of the LODC ATD head and neck complex. The FE mesh is generated using HyperMesh based on the three-dimensional CAD model. The material data, contact definitions and initial conditions are defined in LS-PrePost and converted to LS-Dyna solver input format. The initial and boundary conditions are defined to replicate the neck flexion experimental tests. Next, an inverse method is

Yang, Peiyu, Katangoori, Divya Reddy, Noll, Scott

Lumbar Flexion Test Procedure for the Hybrid III 50th Male Dummy

J3074_202303 (Current)

03/20/2023

This procedure establishes a recommended practice for performing a lumbar flexion test to the Hybrid III 50th male anthropomorphic test device (ATD or crash dummy). This test was created to satisfy the demand from industry to have a certification test which characterizes the lumbar without interaction of other dummy components. In the past, there have not been any tests to evaluate the performance of Hybrid III 50th lumbar.

Dummy Testing and Equipment Committee

Performance Standards for Side-Facing Seats in Civil Rotorcraft, Transport Aircraft, and General Aviation Aircraft

AS8049/1B (Current)01/20/2023

This SAE Aerospace Standard (AS) defines Minimum Performance Standards (MPS), qualification requirements, and minimum documentation requirements for side-facing seats in civil rotorcraft, transport aircraft, and general aviation aircraft. The goal is to achieve comfort, durability, and occupant protection under normal operational loads and to define test and evaluation criteria to demonstrate occupant protection when a side-facing seat/occupant/restraint system is subjected to statically applied ultimate loads and to dynamic test conditions set forth in Title 14, Code of Federal Regulations (CFR) Part 23, 25, 27, or 29. While this document addresses system performance, responsibility for the seating system is divided between the seat supplier and the installation applicant. The seat supplier’s responsibility consists of meeting all the seat system performance requirements and obtaining and supplying to the installation applicant all the data prescribed by this document. The

Aircraft Seat Committee

Development of a New Human Thoracic Equivalent Model during Frontal Impact

09-11-02-0007

01/13/2023

Human thoracic injury under frontal collisions is an inevitable problem in vehicle safety research. Compared with the Multiple Rigid-Body Models (MRBMs) and Finite Element Human Body Models (FEHBMs), Mathematical Equivalent Models (MEMs) can not only provide important data but also improve the research efficiency. The current thoracic MEMs usually adapted the mechanical isolation method to isolate the thorax from the human body; therefore, the effects of the head, neck, and lower body internal organs on the mechanical responses of the thorax are not considered. In this article, a new thoracic MEM, named as Improved Consistent Lobdell Model (ICLM), is developed based on the concentrated mass-spring-damping system to consider the energy absorbed by the deformation of the internal soft tissue and the motion hysteresis of the head, neck, and lower body. Thorax equivalent stiffness curve predicted by the ICLM has a good fit with the corridor obtained by the Post-Mortem Human Subjects (PMHS

Liu, Zhixin, Zheng, Hong, Ma, Weijie

User’s Manual for the 50th Percentile Male Hybrid III Dummy

J2856_202211 (Current)

11/22/2022

The purpose of this document is to provide the user with the procedures needed to properly assemble and disassemble the 50th percentile male Hybrid III dummy, certify its components and verify its mass and dimensions. Also within this manual are guidelines for handling accelerometers, repairing flesh and setting joints.

Dummy Testing and Equipment Committee

Instrumentation for Impact Test Part 1 - Electronic Instrumentation

J211/1_202208 (Current)08/19/2022

Safety Test Instrumentation Standards Committee

Low Speed Thorax Impact Test Procedure for the HIII5F Dummy

J2878_202206 (Current)

06/09/2022

This procedure establishes a recommended practice for performing a Low Speed Thorax Impact Test to the Hybrid III Small Female Anthropomorphic Test Device (ATD or crash dummy). This test was created to satisfy the demand by the industry to have a certification test which results in peak chest deflection similar to current full vehicle, frontal impact tests. An inherent problem exists with the current certification procedure because the normal (6.7 m/s) thorax impact test has test results for peak chest deflection that are greater than those currently seen in full vehicle, frontal tests. The intent of this document is to develop a low speed thorax certification procedure for the H-III5F dummy with a 3.0 m/s impact similar to the SAE J2779 procedure for the H-III50M dummy.

Dummy Testing and Equipment Committee

Biomechanical Responses of the THOR-AV ATD in Rear Facing Test Conditions

2022-01-0836

03/29/2022

The THOR-AV dummy is a modified THOR dummy being developed for occupant safety testing in upright and reclined seating postures. The dummy has a new neck with improved biofidelity in rear impact, a pelvis/abdomen/lumbar design to improve seating posture, and a pelvis anthropometry that mimics human submarining responses for reclined seat testing. The dummy was evaluated against postmortem human subject (PMHS) corridors in rearward facing impact conditions (56 km/h impact speed, 38g acceleration) in both 25° and 45° seatback configurations. Biofidelity Ranking System (BRS) scores were calculated in accordance with NHTSA’s latest calculation algorithm. The BRS scores for THOR-AV seat loading are 1.58 (“good” biofidelity) and 2.94 (“marginal” biofidelity) for the 25° and 45° configurations respectively. The BRS scores for THOR-AV occupant responses are 1.95 and 1.38 for the 25° and 45° configurations respectively, both corresponding to “good” biofidelity. From the evaluation, the dummy

Wang, Zhenwen Jerry

Multi-Objective Optimization Study on Ligament Characteristics of Neck Finite Element Model

2022-01-0862

03/29/2022

This paper proposes a new method to improve the fit between the neck finite element calculation results and the experimental data through multi-objective optimization of cervical ligament parameters. By refining a previously established finite element model of the neck and improving the fineness of vertebrae and other structures, a new finite element model of the neck was established. The new model adopts the same material property parameters as the previous model. We performed many simulation calculations, each time only one ligament in the model was removed, leaving other structures unchanged. By observing the changes in the angle of the neck joints in the neck torsion experiment of the model before and after the ligament was removed, the influence of the ligament on the model was obtained. The six ligaments with the largest contribution are selected, and their laxity is optimized for multi-objective research, and the optimal solution for the laxity of the selected ligaments is

Yang, Shuaijun, Song, Xuewei, Wang, Peng, Wang, Nan

Development of Biomechanical Computational Models of Six-Year-Old Child Occupant with Different Sitting Postures and Application in the Study of Whiplash Injuries

2022-01-0869

03/29/2022

With the development of intelligent cockpit, child occupants will engage in traffic operation in various sitting postures. Therefore, studying the mechanism and risk of whiplash injury of child occupants with different sitting postures has important application value for the research and development of child restraint system. In this study, the 120° and 135° sitting postures of six-year-old child occupant were developed based on the validated 105° sitting posture finite element model with detailed anatomical structure. The whiplash test in Euro NCAP was reconstructed to evaluate the influence of sitting posture angle on the risk of whiplash injury. In the three groups of simulation experiments, the Upper Neck Tension (Fz) was far less than the higher limit of Euro NCAP evaluation although the Fz value increased as the upper torso angle increases. However, the Upper Neck Shear (Fx) and Neck Injury Criterion (NIC) values from the 105° sitting posture exceeded the higher limit of Euro

Li, Haiyan, Wang, Yanxin, He, Lijuan, Lv, Wenle, Cui, Shihai, Ruan, Jesse Shijie

The Role of Three-Point Restraints for Occupants in Moderate Severity Frontal Collisions

2022-01-0845

03/29/2022

Field accident data and vehicle crash and sled testing indicate that occupant kinematics, loading, and associated injury risk generally increase with crash severity. Further, these data demonstrate that the use of restraints, such as three-point belts, provides mitigation of kinematics and reduction in loading and injury potential. This study evaluated the role of seat belts in controlling occupant kinematics and reducing occupant loading in moderate severity frontal collisions. Frontal tests with belted and unbelted anthropomorphic test devices (ATDs) in the driver and right front passenger seats were performed at velocity changes (delta-Vs) of approximately 19 kph (12 mph) and 32 kph (20 mph) without airbag deployment. At the lower-moderate severity (19 kph), motion of the belted ATDs was primarily arrested by seat belt engagement, while motion of the unbelted ATDs was primarily arrested by interaction with forward vehicle structures. Occupant loading and injury risk was generally

Isaacs, Jessica L., George, Juff, Campolettano, Eamon, Cutcliffe, Hattie, Miller, Bruce

Seatback Strength and Its Effect on In-Position and Out-of-Position ATD Loading in High-Speed Rear Impact Sled Tests

2022-01-0856

03/29/2022

Vehicle rear structure stiffness has increased as a result of the requirements in the FMVSS 301R, which has also corresponded to an increase in front-row seat strength. This study evaluates the structural behavior and occupant response associated with production-level seats equipped with body-mounted D-rings, and very stiff all-belt-to-seat (ABTS) in a group of 12 deceleration sled tests. A double-haversine pulse with approximately 100-msec duration was used for all tests, with peak accelerations of approximately 19 g for the 40 km/h (25 mph) tests and peak accelerations of 28 g for the 56 km/h (35 mph) test. This generic pulse was designed to represent a severe rear impact crash involving vehicles with stiffer rear structures. The tests compared occupant responses and resulting structural deformation of an original equipment manufacturer (OEM) production-level driver seat from a pickup and a very stiff modified ABTS. Both seating systems were equipped with dual recliners. Various

Croteau, Jeffrey, Toney-Bolger, Megan, Isaacs, Jessica L., Shurtz, Ben, Zolock, John

Human Head and Neck Kinematics during Autonomous and Human Braking in Three Initial Head Positions

09-10-02-0007

03/28/2022

Whiplash injuries resulting from vehicle collisions are still a significant socio-economic issue across the world. Years of research has resulted in the development of injury criteria, restraint systems and a deeper understanding of the injury mechanism. However, some grey areas remain and, in the context of the increasing automation of vehicles, one can wonder how the injury mechanisms may change due to changes in collision forces or directions. This article presents an experiment with ten volunteers subjected to two braking modes, including automated braking preceded by an alarm warning or robot human braking, in three different initial head positions: forward facing, lateral rotation and flexion rotation. The volunteers were equipped with inertial measurement units to record their head and neck dynamics. Results show that the initial position of volunteers implies differences in the volunteer head dynamics. Also, the auditory alarm emitted prior to the emergency braking may have

Mackenzie, Jamie, Dutschke, Jeffrey, Di Loreto, Cédric, Forrest, Matthew, Van Den Berg, Andrew, Merienne, Frédéric, Chardonnet, Jean-Rémy, Sandoz, Baptiste

Muscle Activation Affects Kinematic Response and Injury Risk in Non-Traditional Oblique Impact Scenarios Assessed with a Head and Neck Finite Element Model

09-10-02-0008

03/23/2022

Detailed finite element human body models (HBMs), and neck models (NMs) in particular, have been used to assess response and injury risk with a focus on frontal, lateral, and rear impact conditions. Although HBMs have successfully predicted kinematics and the importance of active muscle in simple loading conditions, they have generally not been assessed for more complex loading conditions such as non-traditional oblique loading that may be encountered in future vehicles equipped with automated driving systems. In this study, a contemporary NM was assessed using oblique human volunteer sled test data. Average head and first thoracic vertebra kinematics were determined from the volunteer tests and applied as a boundary condition to the NM. An open-loop co-contraction muscle activation scheme with four activations times within reported human limits (50, 75, 100, no activation) was used to investigate the effect on response and potential for injury risk. The T1 and head kinematics from 45

Barker, Jeffrey, Cronin, Duane S.

Reconstruction of an Auto-Rickshaw Frontal Crash using FE Simulation with Validation using Captured Crash Video from India

2021-28-0257

10/01/2021

The three-wheeled "Auto-Rickshaws" [Auto] plays a significant role in road transportation, especially in India. The crash safety and reconstruction studies have been widely used in four-wheelers, whereas the availability of such data for Auto was limited. In recent times, accident data processing from available videos is being utilized to observe the crash scenario. The crash parameters can be given as inputs to the crash analysis. This paper focuses on the process the real-world accident data and study crash characteristics. With limitation in the availability of detailed injuries post-crash, the study was restricted to reconstructing crash kinematics and estimating indicative injuries to the driver. The source of video data is videos of crash available in public domains like YouTube. PYTHON video processing tool has been used to process the set of real-world accident video data. Object detection, Pixel per meter computation and object tracking are the significant steps to process the

S, Ragul, Sankarasubramanian, Hariharan, Kondaveeti, N S V Nikas, Yadav, Pandugayala Nithin

Robotic Neck Brace Can Help Analyze the Impact of Cancer Treatment

TBMG-4002910/01/2021

A new robotic neck brace from researchers at Columbia Engineering and their colleagues at Columbia’s department of otolaryngology may help doctors analyze the impact of cancer treatments on the neck mobility of patients and guide their recovery.

Applicability of Neck Injury Criteria Critical Intercepts for Human Body Finite Element Models

09-09-02-000808/25/2021

The critical intercepts used for the Neck Injury Criterion (Nij) have not been assessed in computational human body models. Under matched-pair conditions, the response of the head-neck complex was compared between the Livermore Software Technology Corporation (LSTC) Hybrid III (HIII) and Global Human Body Models Consortium’s (GHBMC) 50th percentile, detailed male occupant (M50-O) models. The head and neck of the M50-O and HIII were subjected to the dummy performance calibration test procedure for flexion and extension. As a nominal condition, the HIII model met all calibration specifications. Operationalization of the M50-O’s initial position was defined by equivalent head CG location to the HIII and subsequently compared at nominal, ±10%, ±20%, and ±30% of pendulum displacement. Kinematics of the head CG, forces and moments of the upper neck, and changes in neck angle were post processed and compared between the models. The sagittal velocity of the head CG was found to be greater for

Johnson, Dale, Devane, Karan, Koya, Bharath, Gayzik, F. Scott

Assessment of Acclimation of 5th Percentile Female and 50th Percentile Male Volunteer Kinematics in Low-Speed Frontal and Frontal-Oblique Sled Tests

09-09-01-000105/12/2021

In order to accurately represent the response of live occupants during pre-crash events and frontal crashes, computational human body models (HBMs) that incorporate active musculature must be validated with appropriate volunteer data that represents a wide range of demographic groups and potential crash conditions. The purpose of this study was to quantify and compare occupant kinematic responses for unaware (relaxed) small female and midsize male volunteers during low-speed frontal and frontal-oblique sled tests across multiple test conditions, while recognizing, assessing, and accounting for potential acclimation effects due to multiple exposures. Six 5th percentile female and six 50th percentile male volunteers were exposed to multiple low-speed frontal and frontal-oblique sled tests on two separate test days. Volunteers experienced one test orientation and two pulse severities (1 g and 2.5 g) on each test day. A Vicon motion capture system was used to quantify the three-dimensional

Chan, Hana, Albert, Devon L., Gayzik, F. Scott, Kemper, Andrew R.

Analysis of Biomechanical Neck-Loading Metrics as a Function of Impact Severity in Low-to-Moderate Speed Rear Impacts: Results from Hybrid III 50th Percentile Anthropomorphic Test Devices

09-08-02-0007

04/14/2021

We model neck loading as a function of impact severity in aligned rear impacts. Neck loading is understood and expected to vary as a function of factors including crash severity, occupant compartment design, and occupant metrics. Within occupant compartment design, seat and restraint characteristics are expected to influence the biomechanical response and occupant kinematics. We investigated the relationship between biomechanical neck-loading metrics and impact severity expressed as speed change (delta-V) by examining 47 low to moderate speed rear-impact crash and sled tests utilizing the Hybrid III (HIII) 50th male Anthropomorphic Test Device (ATD). Our hypothesis was that the relationship between severity expressed as delta-V and the neck metrics examined could be modeled as linear consistent with an understanding that neck loading in a rear impact results from the acceleration of the vehicle. As such, linear regressions were used to fit the dataset and examine the relationship

Chhour, Peter, Hoffman, Austin, McGowan, Joseph C.

Assessment of the 50th Hybrid III Responses in Blunt Rear Impacts to the Torso

2021-01-0919

04/06/2021

Blunt impacts to the back of the torso can occur in vehicle crashes due to interaction with unrestrained occupants, or cargo in frontal crashes, or intrusion in rear crashes, for example. Six pendulum tests were conducted on the back of an instrumented 50th percentile male Hybrid III ATD (Anthropomorphic Test Device) to determine kinematic and biomechanical responses. The impact locations were centered with the top of a 15-cm diameter impactor at the T1 or at T6 level of the thoracic spine. The impact speed varied from 16 to 24 km/h. Two 24 km/h tests were conducted at the T1 level and showed repeatability of setup and ATD responses. The 16 and 24 km/h tests at T1 and T6 were compared. Results indicated greater head rotation, neck extension moments and neck shear forces at T1 level impacts. For example, lower neck extension was 2.6 times and 3.8 times greater at T1 versus T6 impacts at 16 and 24 km/h, respectively. A 24 km/h test at T1 was also conducted with a seatback attached to the

Buckman, Jennifer L., Parenteau, Chantal S., Burnett, Roger, Viano, David C., Andrecovich, Christopher

Evaluation of Rotation Reduction Features in Infant and Extended-Use Convertible Child Restraint Systems during Frontal and Rear Impacts

2020-22-0003

04/02/2021

A correctly used child restraint system (CRS) is associated with a substantial reduction of injury and mortality risks in motor vehicle crashes and epidemiologic data suggests that toddlers are provided greater protection when restrained in a rearward-facing CRS compared to a forward-facing CRS. Some ‘extended-use’ European CRS models can accommodate children up to six years rearward-facing and have a support (load) leg and/or a pair of lower (Swedish) tethers to reduce rotation during frontal and rear impacts, respectively. Laboratory studies have found that a support leg reduces head and neck injury metrics of anthropomorphic test devices (ATDs) younger than three years in rearward-facing CRS models during frontal impacts. The objectives of the current study were to perform sled tests to: (1) evaluate the effects of using a support leg in rearward-facing infant and extended-use convertible CRS models during frontal impacts, (2) evaluate the effects of using a pair of lower tethers in

Patton, Declan A., Belwadi, Aditya N., Maheshwari, Jalaj, Arbogast, Kristy B.

Effect of Simulated Muscle Activation Level on Driver Neck Response in Frontal Motor Vehicle Crashes

2021-01-5008

01/22/2021

Future vehicle design for integrated safety requires an accurate assessment of occupants’ realistic behavior. Active muscle, one of the key reflexive actions engaged by vehicle occupants, is a paucity of research data in the conventional safety assessment program due to muscle absence in mechanical crash dummies. This study seeks to explore how muscle activation level affects the neck kinematics and injury risks in frontal collisions with various impact severities via numerical analysis. A validated Finite Element (FE) vehicle model was employed to generate the crash pulse. A MADYMO baseline model interior space was imported from the FE model. A validated vehicle- driver model, including a driver-side interior compartment and a multi-body active human model, was numerically constructed under the MADYMO environment. A full-factorial matrix, including 102 simulations, was designed. Two influencing parameters, including the whole-body muscle activation level (0-1 with a gradient of 0.2

Deng, Gongxun, Gan, Shun, Chen, Wentao, Zhou, Qing, Peng, Yong, Cui, Taisong, Nie, Bingbing

Metamodel Generation for Frontal Crash Scenario of a Passenger Car

2020-28-0504

09/25/2020

A frontal impact scenario was simulated using a Finite Element Model of a Hybrid III 50th percentile male (LSTC, Livermore CA) along with seatbelt, steering system and driver airbags. The boundary conditions included acceleration pulse to the seat and the outputs including injury measures in terms of Head Injury Criterion (HIC), Normalized Neck Injury Criterion (NIJ) and Chest Severity Index (CSI) were extracted from the simulations. The kinematics of the Hybrid III were validated against the kinematics of post mortem human surrogates (PMHS) available in the literature. Using the validated setup, metamodels were generated by creating a design of varying different parameters and recording the responses for each design. First, the X and Z translation of dummy along the seat is provided as input for which there was no variation in the head injury criterion (HIC). Next, the input pulse to the seat is parameterized along with the seatbelt loading and the results are obtained respectively

Shankar, Hari, Selvaraju, Ragul, Sankarasubramanian, Hariharan

Smart Surgical Microscope

TBMG-3746908/01/2020

Researchers have shown that hyperspectral imaging and artificial intelligence could predict the presence of cancer cells with 80 to 90% accuracy in 293 tissue specimens from 102 head and neck cancer surgery patients. The smart surgical microscope could help surgeons better detect cancer during surgery, reduce operating time, lower medical costs, and save lives. Hyperspectral imaging is noninvasive, portable, and does not require radiation or a contrast agent.

The Effects of Active and Conventional Head Restraints on Front Seat Occupant Responses in Rear Impacts

2020-01-1217

04/14/2020

This study assesses front seat occupant responses in rear impacts with active head restraints (AHR) and conventional head restraints (CHR) using field accident data and test data from the Insurance Institute for Highway Safety (IIHS). 2003-2015 NASS-CDS data were analyzed to determine injury rates in 1997+ model year seats equipped with AHR and CHR. Results indicated that less than 4% of occupants were in seats equipped with AHR. Crashes of delta-V <24 km/h accounted for more than 70% of all exposed front seat occupants, irrespective of head restraint design. Rear crashes with a delta-V < 24 km/h included 35.6% fewer occupants who sustained a MAIS 1-2 injury overall and 26.4% fewer who sustained a MAIS 1-2 cervical injury in vehicles equipped with AHR compared to CHR. In IIHS 16 km/h rear sled tests, the biomechanical response of an instrumented BioRID was evaluated on seats with AHR and CHR. HIC15 and concussion risk were calculated from head acceleration data. Test data with AHR and

Parenteau, Chantal, Campbell, Ian C., Pasquesi, Stephanie A.

Occupant Dynamics during Moderate-to-High Speed Rear-End Collisions

2020-01-0516

04/14/2020

Numerous studies have evaluated occupant kinematics and dynamics in “low-speed” rear-end impacts (delta-V ≤ 8 mph). Occupant biomechanics during “moderate-to-high” speed rear impacts (9 ≤ delta-V ≤ 20 mph) has not been thoroughly examined. This study characterized the motions and forces experienced by the head, neck, torso, hip, and left/right femur during these collisions. The publicly available NHTSA rear-end crash test data were examined. More specifically, the FMVSS 301 Fuel System Integrity tests were used. The test procedure involved a 30 mph moving barrier impacting the rear of the vehicles. Instrumented 50th-percentile male (N = 47) or 5th-percentile female (N = 4) Hybrid III ATDs were positioned in the driver seat. Occupant data including head accelerations, upper/lower neck shear and axial forces, upper/lower neck moments, lower neck acceleration, torso accelerations, torso deflection, hip accelerations, and left/right femur axial forces were evaluated and compared to

Atarod, Mohammad

Biomechanics of Passenger Vehicle Underride: An Analysis of IIHS Crash Test Data

2020-01-0525

04/14/2020

Occupant dynamics during passenger vehicle underride has not been extensively evaluated. The present study examined the occupant data from IIHS rear underride crash tests. A total of 35 crash tests were evaluated. The tests were classified as full-width (n = 9), 50% overlap (n = 11), and 30% overlap (n = 15). A 2010 Chevrolet Malibu impacted the rear underride guard of a stationary trailer at 35 mph. Several occupant kinematics and dynamics data including head accelerations, head injury criteria, neck shear and axial forces, neck moments, neck indices, chest acceleration, chest displacement, chest viscous criterion, sternum deflection rate, and left/right femur forces/impulses, knee displacements, tibia axial forces, upper/lower tibia moments, upper/lower tibia indices, and foot accelerations were measured. The vehicle accelerations, delta-Vs, and occupant compartment intrusions were also evaluated. The results indicated that the head and neck injury parameters were positively

Atarod, Mohammad

Innovative Active Head Restraint System in a Car: Safety Assessment with Virtual Human Body Model

2020-01-0979

04/14/2020

The aim of this study is to use numerical simulations for safety assessment of an innovative active head restraint system. This system was developed to protect the head and neck of an occupant in a car without a head airbag during a side impact. Its FE model is created and embedded it in a model of a small car with a side airbag. The dynamics of the head restraint activation are also taken into account. The virtual human body model Virthuman is used to represent occupants. The model is scaled for pre-selected human individuals to cover large numbers of occupants of different sizes. It extends conventional virtual evaluation of new safety designs via existing pre-defined mono-purpose side dummies and their FE models. The benefit of the head restraint system is evaluated in side impact scenarios inspired by the pole tests performed by EuroNCAP. Transversal impacts to a pole at 29 and 32 km/h are considered at 90° and 75° angles from driver and the opposite side. Also, the far side impact

Vychytil, Jan, Hlucha, Jana, Kovar, Ludek, Kostikova, Martina, Moravcova, Pavlina, Bucsuhazy, Katerina

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