Risk Of Neck Injury Research Articles

Effects of laptop screen height on neck and shoulder muscle fatigue and spine loading for office workers.

Due to the unfavourable neck-shoulder muscle loads caused by poor posture, the people who use the laptop for a long time may face the risk of neck and shoulder injuries. The purpose of this study investigates the impact of the screen height on the muscle activation of head flexion, neck and shoulder, and the cervical spine torque to provide the favorite screen height for laptop user. Twelve healthy young participants completed a15-minute task of the reading at the four different screen heights. sEMG signals of the splenius capitis (SC) and upper trapezius (UT) were measured and calculated the root mean square (RMS) and mean power frequency (MPF) to determine muscle fatigue. The different height of laptop users was simulated and the forces on the spine of users at different screen heights were analyzed by Jack. Adjusting the height of the laptop screen can effectively reduce head flexion and muscle activity of SC and UT, and has a positive effect on reducing fatigue of SC, but has no significant effect on UT. Adjusting the height of the laptop screen can delay the occurrence of SC muscle fatigue to a certain extent. The joint analysis of sEMG spectrum and amplitude reports that the screen heights of D15 and D45 have the highest and the lowest frequency of fatigue, respectively. At the same time, the moment of spineT1/T2 and spineL4/L5 decrease with the increase of screen height.

Head and neck injury risk resulting from impact with small unmanned aerial vehicles: effect of impact speed, angle, and location

It is necessary to analyse the injury risk caused by UAV to establish management standards. A lightweight quadrotor UAV was used to assess the risk of human head and neck injury, taking the impact speed, UAV position, and impact angle into account. First, the MAVIC2 UAV- Hybrid III dummy impacting FE model was developed and verified against the UAV impact tests. Second, lots of simulations were conducted under different impact scenarios to analyse the head and neck injury. Under vertical impact condition, HIC and Nij grew exponentially as the impact speed increased. While under the horizontal impact condition, HIC increased in the form of the power function and Nij increased exponentially. Under vertical impact condition at 20 m/s (maximum flight speed, corresponding to the impact energy of 181.4 J), the HIC was 54% of the threshold, while the Nij was 88% of the threshold, which illustrated that the injury risk of the neck was high, while that of the head was low. Under horizontal impact condition at 20 m/s (181.4 J), the HIC was 51% of the threshold, and the Nij was 24% of the threshold, which illustrated that the injury risk of both the head and neck was low. HIC declined exponentially as the impact angle increased, whereas Nij increased in the form of the power function. Among all the impact positions, the UAV’s arm caused the least injury risk, while the transverse falling attitude between the two arms and the reverse vertical falling attitude generated higher injury risks.

Assessing the COVID-19 pandemic's impact on pediatric baseball and basketball-related craniofacial and neck injuries treated in United States emergency departments, 2003-2022.

A large proportion of United States (U.S.) youth play basketball, baseball, softball, or T-ball. Each of the activities poses a documented risk of craniofacial and neck injuries. However, few studies have assessed the national prevalence of pediatric craniofacial and neck injuries in this population, particularly following the COVID-19 pandemic. The National Electronic Injury Surveillance System (NEISS) dataset was used to identify pediatric craniofacial and neck injuries associated with basketball, baseball, softball, or T-ball from 2003-2022 in a cross-sectional study. The annual number of injuries before and after the onset of the COVID-19 pandemic with 95% confidence intervals were calculated. Interrupted time series analysis (ITSA) was used to estimate the pandemic's impact on the monthly number of injuries incurred nationally. Both overall and stratified by sport involvement, the annual number and rate of injuries identified in NEISS decreased significantly after the COVID-19 pandemic. ITSA demonstrated that the monthly number of injuries decreased -4094.4 (95% CI = -5100, -3088.7) immediately after the beginning of the pandemic. The number of injuries began increasing towards pre-pandemic levels at a rate of 110.6 (95% CI = 64, 157.2) injuries per month after the initial plunge. Prior to the-pandemic, there was a steady decline in craniofacial and neck injuries due to basketball, baseball, softball and T-ball among children, aged <18 years. The shutdown during the initial months of the COVID-19 pandemic resulted in a precipitous drop in such injuries. Current rates are approaching pre-pandemic levels and may exceed them. Continued efforts are needed to keep the pre-pandemic progress.

Experimental Validation of a Driver Monitoring System

This paper presents an analysis of the risk of neck injury in vehicle occupants as a consequence of an impact. A review of the formulation of indexes that are used in the assessment and investigation of neck injury risk is discussed with the aim of providing a new, more appropriate index using suitable sensorized equipment. An experimental analysis is proposed with a new driver monitoring device using low-cost sensors. The system consists of wearable units for the head, neck, and torso where inertial measurement sensors (IMU) are installed to record data concerning the occupant’s head, neck, and torso accelerations while the vehicle moves. Two laser infrared distance sensors are also installed on the vehicle’s steering wheel to record the position data of the head and neck, as well as an additional IMU for vehicle acceleration values. To validate both the device and the new index, experiments are designed in which different sensorized volunteers reproduce an emergency braking maneuver with an instrumented vehicle at speeds of 10, 20, and 30 km/h before the beginning of any braking action. The neck is particularly sensitive to sudden changes in acceleration, so a sudden braking maneuver is enough to constitute a potential risk of cervical spine injury. During the experiments, large accelerations and displacements were recorded as the test speed increased. The largest accelerations were obtained in the experimental test at a speed of 30 km/h with values of 19.17, 9.57, 9.28, and 5.09 m/s2 in the head, torso, neck, and vehicle, respectively. In the same experiment, the largest displacement of the head was 0.33 m and that of the neck was 0.27 m. Experimental results have verified that the designed device can be effectively used to characterize the biomechanical response of the neck in car impacts. The new index is also able to quantify a neck injury risk by taking into account the dynamics of a vehicle and the kinematics of the occupant’s head, neck, and torso. The numerical value of the new index is inversely proportional to the acceleration experienced by the vehicle occupant, so that small values indicate risky conditions.

Numerical Reconstruction of Cyclist Impact Accidents: Can Helmets Protect the Head-Neck of Cyclists?

Cyclists are vulnerable road users and often suffer head-neck injuries in car-cyclist accidents. Wearing a helmet is currently the most prevalent protection method against such injuries. Today, there is an ongoing debate about the ability of helmets to protect the cyclists' head-neck from injury. In the current study, we numerically reconstructed five real-world car-cyclist impact accidents, incorporating previously developed finite element models of four cyclist helmets to evaluate their protective performances. We made comparative head-neck injury predictions for unhelmeted and helmeted cyclists. The results show that helmets could clearly lower the risk of severe (AIS 4+) brain injury and skull fracture, as assessed by the predicted head injury criterion (HIC), while a relatively limited decrease in AIS 4+ brain injury risk can be achieved in terms of the analysis of CSDM0.25. Assessment using the maximum principal strain (MPS0.98) and head impact power (HIP) criteria suggests that helmets could lower the risk of diffuse axonal injury and subdural hematoma of the cyclist. The helmet efficacy in neck protection depends on the impact scenario. Therefore, wearing a helmet does not seem to cause a significant neck injury risk level increase to the cyclist. Our work presents important insights into the helmet's efficacy in protecting the head-neck of cyclists and motivates further optimization of protective equipment.

Restraint System Optimizations Using Diverse Human Body Models in Frontal Crashes

&lt;div&gt;&lt;b&gt;Objective:&lt;/b&gt; This study aimed to optimize restraint systems and improve safety equity by using parametric human body models (HBMs) and vehicle models accounting for variations in occupant size and shape as well as vehicle type.&lt;/div&gt; &lt;div&gt;&lt;b&gt;Methodology:&lt;/b&gt; A diverse set of finite element (FE) HBMs were developed by morphing the GHBMC midsize male simplified model into statistically predicted skeleton and body shape geometries with varied age, stature, and body mass index (BMI). A parametric vehicle model was equipped with driver, front passenger, knee, and curtain airbags along with seat belts with pretensioner(s) and load limiter and has been validated against US-NCAP results from four vehicles (Corolla, Accord, RAV4, F150). Ten student groups were formed for this study, and each group picked a vehicle model, occupant side (driver vs. passenger), and an occupant model among the 60 HBMs. About 200 frontal crash simulations were performed with 10 combinations of vehicles (n = 4) and occupants (m = 8). The airbag inflation, airbag vent size, seatbelt load limiter, and steering column collapse force were varied to reach better occupant protection. The joint injury probability (Pjoint) combining head, neck, chest, and lower extremity injury risks was used for the design optimization. Injury risk curves were scaled based on the skeleton size and shape of each HBM.&lt;/div&gt; &lt;div&gt;&lt;b&gt;Results and Conclusions:&lt;/b&gt; We observed that tall and heavier male occupants tend to strike through the airbag leading to higher head injury risk; older and female occupants tend to sustain higher chest injury risk, while obese occupants tend to have higher lower extremity injury risk. After design optimizations, the average &lt;i&gt;P&lt;/i&gt;joint was reduced from 0.576 ± 0.218 to 0.343 ± 0.044. The airbag inflation and venting were found to be highly effective in head protection, while the belt load limit and steering column force were sensitive to chest injury risks. Conflicting parameter effects were found between head and chest injuries and among different occupants, highlighting the complexity of achieving safety equity across a diverse population. This study demonstrated the benefit of adaptive restraint systems for a diverse population.&lt;/div&gt;

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

&lt;div&gt;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 acceleration, were higher in the rear seat compared to the front. In addition, injury thresholds were exceeded or nearly exceeded in the rear seat for Nij in three vehicles, chest acceleration in one vehicle, and chest deflection in three vehicles, while no thresholds were exceeded in the front seat. When comparing advanced and conventional restraints in the rear seat, all injury metrics were higher in the vehicles with conventional restraints. All vehicles with conventional restraints in the rear had a star rating of 1, while those with advanced restraints in the rear ranged from 2 to 3. Conversely, all vehicles had 5 stars for the front seat, except one that had 4 stars. Overall, these data highlight the disparity between front and rear seat occupant protection and the benefits of advanced rear seat safety restraints, and the need for future testing.&lt;/div&gt;

Study on the head and neck injury risk impacted by UAV: effect of impact velocity, angle, location, and mass

The number of the collision accidents between Unmanned Aerial Vehicle (UAV) and people on the ground increase in recent years. It is necessary to clarify human injury characteristics brought by the impact of UAV and promote its management. This study focuses on head and neck injury risk resulted from the impact of the UAV with a relatively large mass, and the difference brought by the UAV with a small mass. First, the model of the Y3-dummy (Hybrid III 50th) is developed. Second, simulations are conducted to analyse head and neck injury characteristics from Y3’s impact under different velocities, angles, and locations. With increasing the impact velocity, HIC and Nij increase with an exponential function and a power function, respectively. When the vertical impact velocity exceeds 5 m/s, both head and neck have a high probability of injury, while for the horizontal impact, the corresponding velocity is 9 m/s. As the impact angle increases, the changes of HIC satisfy the form of the sum of two exponential functions, and Nij changes in the form of the sum of a power function and a quadratic polynomial function. When the impact angle is close to 0°, the head injury risk is relatively high, while for 58°, the neck is more likely to be injury. The injuries induced by the top of mainframe and the front of the long arm are more serious. Finally, the differences in head and neck injury characteristics under different velocities and locations for UAVs with different masses are compared.

Study of the head and neck injury risk under impact conditions of the light UAV with a medium weight

Study of the head and neck injury risk under impact conditions of the light UAV with a medium weight

Examining the Association Between Adverse Childhood Experiences and Lifetime History of Head or Neck Injury and Concussion in Children From the United States.

Our objective was to determine whether there is an association between adverse childhood experiences (ACEs) and lifetime history of early childhood mild head or neck injury and concussion in a nationally representative US cohort. This is a cross-sectional study using data from the Adolescent Brain Cognitive Development (ABCD) Study (data release 3.0), a prospective investigation of child brain development and health. There were 11 878 children aged 9 or 10 years at baseline, recruited from 21 school-based sites in the United States. After excluding children with missing questionnaires for the primary exposure variable and children with severe brain injuries involving more than 30-minute loss of consciousness, the final sample size was 11 230 children. The primary exposure variable was ACEs. We measured eight ACEs: sexual abuse, physical abuse, emotional neglect, parent domestic violence, parent substance use disorder, parental mental illness, parent criminal involvement, and parent divorce. The primary outcomes were head or neck injury and concussion, measured using the Ohio State University Traumatic Brain Injury Screen-Identification Method Short Form. The sample ( N = 11 230) was 52% boys with a mean age of 9.9 years (SD = 0.62 years). The racial and ethnic makeup was reflective of national demographics. Having a higher overall ACE count was associated with higher odds of head or neck injury, with greater odds with more ACEs reported. Children with 2 ACEs had 24% greater odds of head or neck injury (AOR = 1.24, 95% confidence interval [CI] = 1.06-1.45) and 64% greater odds of concussion (AOR = 1.64, 95% CI = 1.18-2.22), and children with 4 or more ACEs had 70% greater odds of head or neck injury (AOR = 1.7, 95% CI = 1.14, 2.49) and 140% greater odds of concussion (AOR = 2.4, 95% CI = 1.15-4.47). The individual ACE categories of sexual abuse, parent domestic violence, parental mental illness, and parent criminal involvement were significantly associated with increased risk of head or neck injury and parental mental illness with increased risk of concussion. ACEs are associated with early childhood mild head or neck injury and concussion and should be integrated in head injury prevention and intervention efforts.

Analysis of Front Roof Header of Vehicle for Rollover Protection by using Ansys Software

Abstract: Inadequate roof strength in vehicles is a major concern as it greatly increases the risk of head and neck injuries for passengers involved in even minor rollover accidents. Despite this, many manufacturers continue to produce cars with inadequate roof strength. Rollover accidents are unfortunately quite common and often result in serious injuries, such as spinal and neck trauma. Even when wearing a seatbelt, front seat passengers can still be at risk of injury as they may be thrown from the vehicle or experience significant forces during the rollover. The key to reducing these risks lies in ensuring that the roof of the vehicle is strong enough to withstand the compressive forces of a rollover and provide enough living space for the occupants. While airbags and seat belts are important safety features, a strong roof is equally essential to protecting passengers. For this reason, we have undertaken a project to improve the strength of the front roof header in order to enhance the safety of vehicle occupants.

Effect of Active Muscles on Astronaut Kinematics and Injury Risk for Piloted Lunar Landing and Launch While Standing.

While astronauts may pilot future lunar landers in a standing posture, the response of the human body under lunar launch and landing-related dynamic loading conditions is not well understood. It is important to consider the effects of active muscles under these loading conditions as muscles stabilize posture while standing. In the present study, astronaut response for a piloted lunar mission in a standing posture was simulated using an active human body model (HBM) with a closed-loop joint-angle based proportional integral derivative controller muscle activation strategy and compared with a passive HBM to understand the effects of active muscles on astronaut body kinematics and injury risk. While head, neck, and lumbar spine injury risk were relatively unaffected by active muscles, the lower extremity injury risk and the head and arm kinematics were significantly changed. Active muscle prevented knee-buckling and spinal slouching and lowered tibia injury risk in the active vs. passive model (revised tibia index: 0.02-0.40 vs. 0.01-0.58; acceptable tolerance: 0.43). Head displacement was higher in the active vs. passive model (11.6 vs. 9.0cm forward, 6.3 vs. 7.0cm backward, 7.9 vs. 7.3cm downward, 3.7 vs. 2.4cm lateral). Lower arm movement was seen with the active vs. passive model (23 vs. 35cm backward, 12 vs. 20cm downward). Overall simulations suggest that the passive model may overpredict injury risk in astronauts for spaceflight loading conditions, which can be improved using the model with active musculature.

Finite element analysis of the cervical spine and soft tissue of the neck at different flexion angles

Aim: This study aims to investigate the impact of von Mises stress distribution on the cervical spine and soft tissue of the neck at different flexion angles of 0°, 15°, 30°, 45°, and 60°. Materials and Methods: Finite element analysis of the neck's cervical spine and soft tissue was performed separately in Ansys Discovery Live software, a possible approach for simulating the mechanical behavior of the neck. Three-dimensional (3D) models were created in 3D Max software and static structural analyses of soft tissues were performed in ANSYS by using the Finite Element Method. The maximum stress distributions of the cervical spine in cervical vertebra bodies at different flexion angles were analyzed at the lowest and highest stress values of 0° and 30°, respectively. For the intervertebral contact surfaces, the lowest and highest stress values were determined at 0° and 45°, respectively. Results: The value of stress showed a linear increase with increasing flexion angles in the soft tissue of the neck. The observation that the stress values obtained at different flexion angles were arbitrarily in either positive or negative directions when compared to the upright posture suggests that the effect of neck flexion on stress distribution in the cervical spine is complex and multifactorial. The change in stress values in the soft tissue of the neck was always positive and linear with increasing flexion angles. Conclusion: People who work with technological devices are prone to a musculoskeletal disorder associated with forward flexion of the neck, and individuals are encouraged to adopt a neck flexion angle between 0° and 15°. This finding could help guide the development of strategies to reduce the risk of neck injury or damage in different postures.

An investigation of elderly occupant injury risks based on anthropometric changes compared to young counterparts

Objective The objective of the study was to investigate the difference between elderly and young occupant injury risks using human body finite element modeling in frontal impacts. Methods Two elderly male occupant models (representative age 70–80 years) were developed using the Global Human Body Consortium (GHBMC) 50th percentile as the baseline model. In the first elderly model (EM-1), material property changes were incorporated, and in the second elderly model (EM-2), material and anthropometric changes were incorporated. Material properties were based on literature. The baseline model was morphed to elderly anthropometry for EM-2. The three models were simulated in a frontal crash vehicle environment at 56 km/h. Responses from the two elderly and baseline models were compared with cadaver experimental data in thoracic, abdominal, and frontal impacts. Correlation and analysis scores were used for correlation with experimental data. The probabilities of head, neck, and thoracic injuries were assessed. Results The elderly models showed a good correlation with experimental responses. The elderly EM-1 had higher risk of head and brain injuries compared to the elderly EM-2 and baseline GHBMC models. The elderly EM-2 demonstrated higher risk of neck, chest, and abdominal injuries than the elderly EM-1 and baseline models. Conclusions The study investigated injury risks of two elderly occupants and compared to a young occupant in frontal crashes. The change in the material properties alone (EM-1) suggested that elderly occupants may be vulnerable to a greater risk of head and thoracic injuries, whereas change in both anthropometric and material properties (EM-2) suggested that elderly occupants may be vulnerable to a greater risk of thoracic and neck injuries. The second elderly model results were in better agreement with field injury data from the literature; thus, both anthropometric and material properties should be considered when assessing the injury risks of elderly occupants. The elderly models developed in this study can be used to simulate different impact conditions and determine injury risks for this group of our population.

COVID-19 pandemic and lockdown increase the frequency and severity of periorbital dog bite injuries in children.

ObjectiveTo determine whether the COVID-19 pandemic and lockdown increase the risk of head, neck, and face (HNF) dog bite injuries in children.MethodsUsing a retrospective cohort study design, the investigators enrolled a sample of children presenting with HNF dog bite injuries during 22 weeks before and 22 weeks during the COVID-19 pandemic in a German level 1 trauma center. The predictor variables were COVID-19 pandemic and lockdown. The outcome variables were grouped into demographic, anatomic, injury-related, and therapeutic. Appropriate statistics were computed, and statistical significance was set at P ≤ .05.ResultsThe sample included 36 subjects (19.4% girls; 97.2% Caucasians; 50% isolated periorbital injuries; 61.1% during the lockdown; 16.7% after the lockdown) with an average age of 8 ± 3.3 years. Compared to the pre-COVID-19 period, pediatric HNF dog bite injuries increased ca. 5.5- and 1.5-fold during and after the lockdown, respectively. The COVID-19 pandemic was significantly associated with severe household injury from a pet dog, number of inpatients and treatments in the operating room, and prolonged hospitalization. Isolated periorbital injury was common during the COVID-19 pandemic (P = 0.04; relative risk [RR], 4.86; 95% confidence interval [95% CI], 0.76 to 31.12), especially during the lockdown (P = 0.02; RR, 4.36; 95% CI, 0.72 to 26.6).ConclusionDuring the COVID-19 pandemic, especially during the lockdown, there is an increasing tendency of frequency and severity of domestic HNF dog injuries in children, and periorbital region is the most injury-prone.

Evaluation of Urban Traffic Accidents Based on Pedestrian Landing Injury Risks

In comparison with vehicle-to-pedestrian collision, pedestrian-to-ground contact usually results in more unpredictable injuries (e.g., intracranial, neck, and abdominal injuries). Although there are many studies for different applications of such methods, this paper conducts an in-depth analysis of urban traffic pedestrian accidents. The effects of pedestrian rotation angle (PRA) and pedestrian facing orientation (PFO) on head and neck injury risk in a ground contact are investigated by the finite element numerical models and different probabilistic analyses. It goes without saying that this study provides a theoretical basis for the prediction and protection study of pedestrian ground contact injury risk. In our experiments, 24 pedestrian-to-ground simulations are carried out by the THUMS v4.0.2 model considering eight PRAs (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°, 360°) and three PFOs (x+, x−, y+). Each test was simulated with loading the average linear and rotational velocities that obtained from real-world pedestrian accidents at the pedestrian’s center of gravity. The results show that both PRAs and PFOs have significant impacts on head and neck injuries. Head HIC value caused by PRA 0–135° is much higher than that caused by PRA 180–315°. Neck injury risk caused by PRA 180° is the greatest one in comparison with other PRAs. The PRAs 90° and 270° usually induce a relatively lower neck injury risk. For PFO, the risk of head and neck injury was lower than PFOy+ and PFOx+ or PFOx−, which means PFOy+ was a safer landing orientation for both head and neck. The potential risk of head and neck injuries caused by the ground contact was strongly associated with the symmetry/asymmetric features of human anatomy.

Research on Neck Response of Elderly Drivers in Rear Collision.

In order to study the neck response of elderly drivers in rear collision, a finite element model for elderly neck was built. By comparing the cadaver experiment data in the literature, the simulation reliability of the head and neck model of the elderly under dynamic load was verified. Through the C-NCAP rear-end collision test on the elderly model, the study showed that the neck of the elderly driver had good dynamic response characteristics. The verified finite element model was used to analyze the head and neck collision response and injury risk of the elderly under different distances between the head and the headrest (vertical distance and horizontal distance). By analyzing the head and neck injuries of occupants at different distances, it was found that when the horizontal distance was 50 mm, and the vertical distance was between +10 and ~+20 mm, the headrest could play the best role in protecting the neck of the elderly driver and could reduce the degree of injury of the elderly driver in the process of rear collision.

Safety of active pre-collision seat rotation strategies for autonomous vehicles: injury risk evaluation of occupant’s neck

The development of autonomous driving technology has engendered new requirements for the safety of the occupants of autonomous vehicles. Different variants of seat configurations, including face-to-face rides and rotating seats, have been implemented in autonomous vehicles. Furthermore, pre-collision active seat rotation strategies have been proposed for the safety of the occupants of autonomous vehicles. However, further evaluations are required to determine whether the active seat rotation strategy could cause injuries to the occupants during a significantly rapid rotation process. In this study, two types of multi-rigid body seat-occupant models and a finite element model of the occupant’s cervical spine were designed. The validity of the multi-rigid body model for the seat occupant was verified through a frontal collision simulation test. Considering the influence of different seat types and rotation directions on the risk of neck injuries to the occupants, four simulations were conducted based on the condition that the seat rotated by 90° in 200 ms. The kinematic and biomechanical aspects of the risk of injuries to the occupant’s cervical spine during the active seat rotation strategy were assessed, and the essential causes of these injuries were discussed. The results indicate that, in the absence of leg baffles and foot supports, seat rotation toward the diagonal line of the seatbelt poses different degrees of risk of injuries to the cervical spine, platysma, sternocleidomastoid, common carotid artery, external jugular vein, and internal jugular vein. Therefore, the seats of highly or fully autonomous vehicles should be designed to prevent this scenario.

Neck Loads During Head-First Entries into Trampoline Dismount Foam Pits: Considerations for Trampoline Park Safety

Serious cervical spine injuries have been documented from falls into foam pits at trampoline parks. To address the lack of evidence on how foam pits should be designed for mitigating neck injury risk, this study aimed to quantify neck loads during head-first entry into varying foam pit designs. An instrumented Hybrid III anthropomorphic test device was dropped head-first from a height of up to 1.5 m into three differently constructed foam pits, each using a different mechanism to prevent direct contact between the falling person and the floor (foam slab, trampoline or net bed). Measured neck loads were compared to published injury reference values. In the simplest, foam-only pit design, increasing foam depth tended to reduce peak compressive force. At least one injury assessment reference metric was exceeded in all pit conditions tested for 1.5 m falls, most commonly the time-dependent neck compression criterion. The results highlight the importance of adequate foam depth in combination with appropriate pit design in minimizing injury risk. The risk of cervical spine injury may not be reduced sufficiently with current foam pit designs.

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

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;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 NCAP by 124% and 9%, respectively，increasing the risk of slight neck injury. Neck Protection Criteria (N&lt;sub&gt;km&lt;/sub&gt;), NIC, cervical spine stress, and spinal cord stress from 120° sitting posture decreased by 23%, 42%, 56.9%, and 41.1%, respectively, compared with those parameters from the child standard sitting posture (105°). However, the Fx value from 120° sitting posture exceeded the higher limit by 101%; a slight risk of neck injury thus still exists. These assessment parameters from 135° sitting posture decreased by 60%, 50%, 77.6% and 43.6%, respectively, and the parameters were all lower than the higher limit of Euro NCAP. In addition, the maximum von Mises stress was mainly concentrated at the contact position between atlas and axial odontoid (105° and 120° postures) and the posterior arch of atlas with axial odontoid (135° postures). In conclusion, the risk of whiplash injury decreased with the increase of upper torso angle.&lt;/div&gt;&lt;/div&gt;