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Head restraint systems specifically engineered to reduce the impact of whiplash injury in the event of a rear-end collision were introduced in the late 1990s with the aim of reducing whiplash injury risk that went 'beyond simple geometric improvements' to head restraints. Whilst studies have shown that whiplash-reducing head restraint systems are highly effective in reducing whiplash injury, these were based on a limited range of systems including Toyota's Whiplash Injury Lessening (WIL) seating system, Volvo's Whiplash Injury Prevention System (WHIPS) and the Saab Active Head Restraint (SAHR) and have generally focussed on Swedish crash and insurance data. However, there has been no broad real-world crash-based evaluation of the effectiveness of whiplash-reducing head restraint systems currently present in the vehicle fleet that validates the results of these studies in other populations. The objective of this study was to undertake a retrospective evaluation of vehicle whiplash-reducing head restraint systems to prevent whiplash injury using real-world crash data linked to insurance claims data in Victoria, Australia. It was found that whiplash-reducing head restraint systems are associated with a statistically significant reduction in the odds of driver and front seat passenger whiplash injury in a vehicle struck in a rear-end collision of 11.6 % (95 % CI 0.20 %, 21.6 %). The results indicate that whiplash-reducing head restraint systems are an effective technology for reducing the risk of whiplash injury to drivers and front seat passengers in a vehicle struck in a rear-end collision. Considering that around a quarter of all casualty crashes involving passenger and light commercial vehicles are rear-end, the fitment of whiplash-reducing head restraint systems to all vehicles as a standard safety feature would likely see a significant reduction in the incidence of whiplash injury.

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

Synopsis Head and spinal injuries commonly occur during motor vehicle crashes (MVCs). The goal of this clinical commentary is to discuss real-life versus simulated MVCs and to present clinical, biomechanical, and epidemiological evidence of MVC-related injury mechanisms. It will also address how this knowledge may guide and inform the design of injury mitigation devices and assist in clinical decision making. Evidence indicates that there exists no universal injury tolerance applicable to the entire population of the occupants of MVCs. Injuries sustained by occupants depend on a number of factors, including occupant characteristics (age, height, weight, sex, bone mineral density, and pre-existing medical and musculoskeletal conditions), pre-MVC factors (awareness of the impending crash, occupant position, usage of and position of the seatbelt and head restraint, and vehicle specifications), and MVC-related factors (crash orientation, vehicle dynamics, type of active or passive safety systems, and occupant kinematic response). Injuries resulting from an MVC occur due to blunt impact and/or inertial loading. An S-shaped curvature of the cervical spine and associated injurious strains have been documented during rear-, frontal-, and side-impact MVCs. Data on the injury mechanism and the quantification of spinal instability guide and inform the emergent and subsequent conservative or surgical care. Such care may require determining optimal patient positioning during transport, which injuries may be treated conservatively, whether reduction should be performed, optimal patient positioning intraoperatively, and whether bracing should be worn prior to and/or following surgery. The continued improvement of traditional injury mitigation systems, such as seats, seatbelts, airbags, and head restraints, together with research of newer collision-avoidance technologies, will lead to safer motor vehicles and ultimately more effective injury management strategies. J Orthop Sports Phys Ther 2016;46(10):826-833. Epub 3 Sep 2016. doi:10.2519/jospt.2016.6716.

Purpose: Small animal immobilization devices facilitate positioning of animals for reproducible imaging and accurate focal radiation therapy. In this study, the authors demonstrate the use of three-dimensional (3D) printing technology to fabricate a custom-designed mouse head restraint. The authors evaluate the accuracy of this device for the purpose of mouse brain irradiation. Methods: A mouse head holder was designed for a microCT couch using cad software and printed in an acrylic based material. Ten mice received half-brain radiation while positioned in the 3D-printed head holder. Animal placement was achieved using on-board image guidance and computerized asymmetric collimators. To evaluate the precision of beam localization for half-brain irradiation, mice were sacrificed approximately 30 min after treatment and brain sections were stained for γ-H2AX, a marker for DNA breaks. The distance and angle of the γ-H2AX radiation beam border to longitudinal fissure were measured on histological samples. Animals were monitored for any possible trauma from the device. Results: Visualization of the radiation beam on ex vivo brain sections with γ-H2AX immunohistochemical staining showed a sharp radiation field within the tissue. Measurements showed a mean irradiation targeting error of 0.14 ± 0.09 mm (standard deviation). Rotation between the beam axis and mouse head was 1.2° ± 1.0° (standard deviation). The immobilization device was easily adjusted to accommodate different sizes of mice. No signs of trauma to the mice were observed from the use of tooth block and ear bars. Conclusions: The authors designed and built a novel 3D-printed mouse head holder with many desired features for accurate and reproducible radiation targeting. The 3D printing technology was found to be practical and economical for producing a small animal imaging and radiation restraint device and allows for customization for study specific needs.

Background The success of many neuroscientific studies depends upon adequate head fixation of awake, behaving animals. Typically, this is achieved by surgically affixing a head-restraint prosthesis to the skull. New method Here we report the use of thermoplastic masks to non-invasively restrain monkeys’ heads. Mesh thermoplastic sheets become pliable when heated and can then be molded to an individual monkey's head. After cooling, the custom mask retains this shape indefinitely for day-to-day use. Results We successfully trained rhesus macaques (Macaca mulatta) to perform cognitive tasks while wearing thermoplastic masks. Using these masks, we achieved a level of head stability sufficient for high-resolution eye-tracking and intracranial electrophysiology. Comparison with existing method Compared with traditional head-posts, we find that thermoplastic masks perform at least as well during infrared eye-tracking and single-neuron recordings, allow for clearer magnetic resonance image acquisition, enable freer placement of a transcranial magnetic stimulation coil, and impose lower financial and time costs on the lab. Conclusions We conclude that thermoplastic masks are a viable non-invasive form of primate head restraint that enable a wide range of neuroscientific experiments.

Currently, proper vehicle head restraint (HR) positioning requires manual adjustment and knowledge on the part of the occupant. By removing the requirement for manual adjustment, an HR positioning system that autonomously moves and adapts the HR position properly to any seated occupant could serve to reduce the social and personal costs of whiplash injuries, as compared with existing manual systems. To achieve this, quantification of the occupant's head position relative to the HR is required. In a previous paper, a rectangular capacitive proximity-sensing array for the purpose of occupant head position quantification was studied. Here, a range-maximized sensor was first designed to reduce electrostatic and environmental disturbances. To achieve this, numerical modeling and laboratory experiments were conducted, and then, a design process for an interdigitated comb-shaped sensor geometry was proposed to maximize the sensing range of the sensor. The effects of temperature and humidity on the sensor were also evaluated and compensated. A novel capacitive proximity-sensing array was then designed, which had the minimum number of the aforementioned comb-shaped sensors necessary for accurately estimating the 3-D position of an occupant's head in near real time. This estimation was carried out using a nonparametric neural network. The above capacitive array was then integrated and fully contained in a customized HR as part of a vehicle seat safety system. The system was tested and demonstrated that such a head position sensing methodology would be capable of autonomously positioning an HR to meet the guidelines of the Insurance Institute for Highway Safety (IIHS).

Pro-active head restraint is a new automotive safety device with both active safety and passive safety characteristics. It can make a pre-estimation of the occurrence possibility of rear-end collision. Thus, the whiplash injury can be effectively reduced or even prevented. One of the key elements in rear-end collision avoidance system is to establish an effective safety distance mathematical model. Based on the running state of front car, the related calculation models of safety distance are established by means of dynamical and kinematical analysis of vehicle braking process and following process. Taken randomness and dynamic characteristics of parameters into consideration, the fuzzy relations between these parameters should be validated by means of fuzzy theory. Thus, it may accord with the actual driving conditions. By using the MATLAB software, the study shows that safety distance model and the methods used to determine parameters are reasonable, and the false alarm can be effectively minimized.

Pro-active head restraint is a new automotive safety device. It can make a pre-estimation of the occurrence possibility of rear-end collision. Thus, the whiplash injury can be effectively reduced or even prevented. One of the key elements in rear-end collision avoidance system is to establish an effective safety distance mathematical model. Based on the running state of front car, the related calculation models of safety distance are established by means of dynamical and kinematical analysis of vehicle braking process and following process. Taken randomness of parameters into consideration, the fuzzy relations between these parameters should be validated by means of fuzzy theory. By using the MATLAB software, the study shows that safety distance model and the methods used to determine parameters are reasonable, and the false alarm can be effectively minimized.

Starting in 1997, General Motors (GM) introduced high retention seats in new model vehicles to improve rear impact safety. The seat allowed the occupant to pocket into the seatback and had increased strength and improved head restraint coverage. The initial 4-year safety trends were evaluated using the 1991-2000 Fatality Analysis Reporting System (FARS). The reduction in odds of fatal injury was 30.4% (95% confidence interval [CI], 0.9-51.1, P.05). This study updates the earlier one by adding 8 years of FARS data.The 2001-2008 FARS was analyzed for rear impacts of 1992 to 2008 model year GM vehicles that transitioned to high retention seats. The number of fatal and nonfatal injuries to drivers and right-front passengers was determined in vehicles with baseline (earlier designs) and high retention seats. The odds ratio for fatal injury and the change in fatality risk were determined with ±95% confidence intervals, z-statistic, and significance level. The data were further subdivided by passenger car, light truck (truck, SUV, and van) and driver-only crashes.Based on 9,570 drivers and right-front passengers in fatal rear impacts in 1991-2008 FARS data, the fatality risk was 16.6% (95% CI, 15.1-18.3) in vehicles with high retention seats and 27.1% (95% CI, 26.1-28.1) in vehicles with baseline seats. The reduction in odds for fatal injury was 46.3% (95% CI, 39.3-52.4) with high retention seats and it was statistically significant with z = 9.982, P.0001. The reduction in odds for fatal injury was similar for occupants in passenger cars at 45.4% (95% CI, 35.4-53.8) and light trucks, SUVs, and vans at 45.0% (95% CI, 28.8-57.5) using 2001-2008 FARS; however, the fatality risk was higher in passenger cars, at 23.1% (95% CI, 20.6-25.7), than in light trucks, SUVs, and vans, at 8.7% (95% CI, 7.0-10.7).Vehicles with high retention seats significantly reduced the odds for fatal injury by 46.3% (95% CI, 39.3-52.4, P.0001) in rear impacts compared to vehicles with earlier seat designs. The new generation of yielding seats has significantly improved occupant safety in rear impacts.

Introduction: Our recent report of ocular tremor in Parkinson’s disease (PD) has raised considerable controversy as to the origin of the tremor. Using an infrared based eye tracker and a magnetic head tracker, we reported that ocular tremor was recordable in PD subjects with no apparent head tremor. However, other investigators suggest that the ocular tremor may represent either transmitted appendicular tremor or subclinical head tremor inducing the vestibulo-ocular reflex (VOR). The present study aimed to further investigate the origin of ocular tremor in PD. Methods: Eye movements were recorded in 8 PD subjects both head free, and with full head restraint by means of a head holding device and a dental impression bite plate. Head movements were recorded independently using both a high sensitivity tri-axial accelerometer and a magnetic tracking system, each synchronized to the eye tracker. Results: Ocular tremor was observed in all 8 PD subjects and was not influenced by head free and head fixed conditions. Both magnetic tracking and accelerometer recordings supported that the ocular tremor was fully independent of head position. Conclusion: The present study findings support our initial findings that ocular tremor is a fundamental feature of PD unrelated to head movements. Although the utility of ocular tremor for diagnostic purposes requires validation, current findings in large cohorts of PD subjects suggest its potential as a reliable clinical biomarker. Published by Elsevier Ltd.

This article is devoted to the urgent, presently, problem that is to ensure the best level of the passive safety of car seats with active head restraints, as well as to assess the effectiveness of such constructional designs. This is an impact-related task, to be, as a consequence, essentially nonlinear with large deformations, strains and accelerations.To solve this problem finite element models of three types of seat designs with active head restraints have been developed. When creating the simulation FEM a number of CAD (Computer Aided Design)/CAE (Computer Aided Engineering) software was used.This work was performed within the framework of the developed technique, which allows an efficient creation of the car seat designs with passive and active head restraints that meet requirements of the passive safety.The results of calculations and experiments allowed us to find that the active head restraint significantly reduced a NIC (Neck Injury Criterion) value, namely up to 36.92 (4%) when using the active headrest with articulated tilting couch, 29.23 (per 24%) when using the active headrest with sliding pad, and 26.15 (31%) when using the active head restraint, which is provided with an airbag. We have also managed to achieve significantly reduced head acceleration under impact.It was found that FEM seats with active head restraint, which is provided with an airbag, are the most secure because of the least NIC value under the impact (26.15).Presented in the article materials are used in teaching students at the department “Wheeled vehicles” of scientific and educational complex "Special engineering" in BMSTU.

In performing calculations to evaluate passive safety of car seats by computer modelling methods it is desirable to use the final element models (FEM) thereby providing the greatest accuracy of calculation results. Besides, it is expedient to use FEM, which can be calculated by computer for a small period of time to give preliminary results for short terms.The paper describes the features to evaluate a passive safety, which is ensured by the developed KEM of seats with passive head restraints according to requirements of the EURO NCAP.Besides, accuracy of calculated results that is provided by the developed KEM was evaluated. Accuracy evaluation was accomplished in relation to the results obtained the by specialists of the organization conducting similar researches (LSTC).This work was performed within the framework of a technique, which allows us to develop effectively the car seat designs both with passive, and active head restraints, meeting requirements for passive safety.By results of made calculations and experiments it was found that when evaluating by the EURO NCAP technique the "rough" KEM (the 1st and 2nd levels) can be considered as rational ones (in terms of labour costs for its creation and problem solving as well as by result errors) and it is expedient to use them for preliminary and multivariate calculations. Detailed models (the 3rd level) provide the greatest accuracy (the greatest accuracy is reached with the evaluated impact of 16km/h speed under the loading conditions "moderate impact". A relative error of full head acceleration is of 12%).In evaluation by EURO NCAP using NIC criterion a conclusion can be drawn that the seat models of the 2nd level (467 936 KE) and the 3rd level (1 255 358 KE) meet the passive safety requirements according to EURO NCAP requirements under "light", "moderate", and "heavy" impacts.In evaluation by EURO NCAP for preliminary and multivariate calculations a model of the middle level (consisting of 467 936 KE) can be used. The relative error (loading according to figure 6, "moderate" impact) of the full head acceleration makes 22%. By the values of labour costs for its creation and task solution and by errors of results such models can be considered to be rational.The materials presented in paper are used to teach students at the Department of Wheel Vehicles of the Scientific and Educational Complex "Special Mechanical Engineering" at Bauman Moscow State Technical University.

A three-dimensional multi-body model of the 50th percentile male human and discretized neck was built to evaluate the effect of active head restraint on cervical vertebrae injuries lessening in vehicle rear impact. The discretized neck includes of cervical spine vertebrae, intervertebral discs, ligaments, and muscles. The BioRID-II adult male dummy restrained using safety belt was seated on a sled, whose longitudinal velocity measured from rear impact FEM simulation was applied to simulate the relative motion of the head and neck. According to the interspinous ligament loads and the ligamenta flava loads of the cervical spine, an active head restraint and an impact absorber were designed to lessening the neck injuries in vehicle rear end collisions.

Neuroreceptor imaging in the nonhuman primate (NHP) is valuable for translational research approaches in humans. However, most NHP studies are conducted under anesthesia, which affects the interpretability of receptor binding measures. The aims of this study were to develop awake NHP imaging with minimal head restraint and to compare in vivo binding of the γ-aminobutyric acid type A (GABAA)-benzodiazepine radiotracer (11)C-flumazenil under anesthetized and awake conditions. We hypothesized that (11)C-flumazenil binding potential (BPND) would be higher in isoflurane-anesthetized monkeys.The small animal PET scanner was fitted to a mechanical device that raised and tilted the scanner 45° while the awake NHP was tilted back 35° in a custom chair for optimal brain positioning, which required acclimation of the animals to the chair, touch-screen tasks, intravenous catheter insertion, and tilting. For PET studies, the bolus-plus-constant infusion method was used for (11)C-flumazenil administration. Two rhesus monkeys were scanned under the awake (n = 6 scans) and isoflurane-anesthetized (n = 4 scans) conditions. An infrared camera was used to track head motion during PET scans. Under the awake condition, emission and head motion-tracking data were acquired for 40-75 min after injection. Anesthetized monkeys were scanned for 90 min. Cortisol measurements were acquired during awake and anesthetized scans. Equilibrium analysis was used for both the anesthetized (n = 4) and the awake (n = 5) datasets to compute mean BPND images in NHP template space, using the pons as a reference region. The percentage change per minute in radioactivity concentration was calculated in high- and low-binding regions to assess the quality of equilibrium.The monkeys acclimated to procedures in the NHP chair necessary to perform awake PET imaging. Image quality was comparable between awake and anesthetized conditions. The relationship between awake and anesthetized values was BPND (awake) = 0.94 BPND (anesthetized) + 0.36 (r(2) = 0.95). Cortisol levels were significantly higher under the awake condition (P0.05).We successfully performed awake NHP imaging with minimal head restraint. There was close agreement in (11)C-flumazenil BPND values between awake and anesthetized conditions.

EEG recordings made during concurrent fMRI are confounded by the pulse artefact (PA), which although smaller than the gradient artefact is often more problematic because of its variability over multiple cardiac cycles. A better understanding of the PA is needed in order to generate improved methods for reducing its effect in EEG–fMRI experiments. Here we performed a study aimed at identifying the relative contributions of three putative sources of the PA (cardiac-pulse-driven head rotation, the Hall effect due to pulsatile blood flow and pulse-driven expansion of the scalp) to its amplitude and variability. EEG recordings were made from 6 subjects lying in a 3 T scanner. Accelerometers were fixed on the forehead and temple to monitor head motion. A bite-bar and vacuum cushion were used to restrain the head, thus greatly attenuating the contribution of cardiac-driven head rotation to the PA, while an insulating layer placed between the head and the EEG electrodes was used to eliminate the Hall voltage contribution. Using the root mean square (RMS) amplitude of the PA averaged over leads and time as a measure of the PA amplitude, we found that head restraint and insulating layer reduced the PA by 61% and 42%, respectively, when compared with the PA induced with the subject relaxed, indicating that cardiac-pulse-driven head rotation is the dominant source of the PA. With both the insulating layer and head restraint in place, the PA was reduced in RMS amplitude by 78% compared with the relaxed condition, the remaining PA contribution resulting from scalp expansion or residual head motion. The variance of the PA across cardiac cycles was more strongly reduced by the insulating layer than the head restraint, indicating that the flow-induced Hall voltage makes a larger contribution than pulse-driven head rotation to the variability of the PA., Highlights ► We experimentally isolate the putative sources of the pulse artefact (PA) in humans. ► Head rotation is the dominant source its removal produces a 61% reduction of the PA. ► Removing Hall effect produces a considerable, 42%, reduction in PA. ► Hall effect produces largest contribution to PA variance across cardiac cycles.

Background We investigated the origin of a recently reported ocular microtremor in patients with Parkinson's disease (PD). Methods Eye movements were recorded in 2 unselected patients with PD. Two recording techniques were used to control for artifacts: infrared video-oculography and infrared scleral reflection techniques. Head movements were also recorded with 2 different accelerometers. Results We recorded ocular oscillations in both patients (microtremor). Ocular tremor was accompanied by a recordable (but clinically nonvisible) head tremor of equal fundamental frequency and high coherence with both the eye oscillation and a recordable limb tremor. The eye movements were in the opposite direction to the head oscillation (ie, compensatory) and were suppressed by head restraint. There was no subjective oscillopsia, nor ocular tremor on fundoscopy. Conclusions The “ocular tremor” observed in patients with PD disease is a compensatory eye movement secondary to transmitted head tremor, in agreement with clinical wisdom that these patients do not report oscillopsia. © 2013 Movement Disorder Society

Objective: Whiplash-associated disorder (WAD), commonly denoted whiplash injury, is a worldwide problem. These injuries occur at relatively low changes of velocity (typically Methods: The seated positions of drivers in stationary conditions have been investigated in a total of 76 volunteers (34 females, 42 males) who participated in the study. Inclusion criteria incorporated driving a Saab 9–3 on a regularly basis. Results: The majority of the volunteers (89%) adjusted the head restraint to any of the 3 uppermost positions and as many as 59% in the top position. The average vertical distance between the top of the head and the top of the head restraint (offset) increase linearly with increasing statures, from an average of −26 mm (head below the head restraint) for small females to an average of 82 mm (head above the head restraint) for large males. On average, the offset was 23 mm for females, which is within a satisfactory range and in accordance with recommendations; the corresponding value for males was 72 mm. The backset tended to be shorter among female volunteers (on average 27 mm) compared to the male volunteers (on average 44 mm). Moreover, the backset tended to increase with increasing statures. Conclusions: Incorrect adjustment of the head restraint cannot explain the large differences found between the sexes in the effectiveness of the SAHR system.

High resolution, in vivo optical imaging of the mouse brain over time often requires anesthesia, which necessitates maintaining the animal's body temperature and level of anesthesia, as well as securing the head in an optimal, stable position. Controlling each parameter usually requires using multiple systems. Assembling multiple components into the small space on a standard microscope stage can be difficult and some commercially available parts simply do not fit. Furthermore, it is time-consuming to position an animal in the identical position over multiple imaging sessions for longitudinal studies. This is especially true when using an implanted gradient index (GRIN) lens for deep brain imaging. The multiphoton laser beam must be parallel with the shaft of the lens because even a slight tilt of the lens can degrade image quality. In response to these challenges, we have designed a compact, integrated in vivo imaging support system to overcome the problems created by using separate systems during optical imaging in mice. It is a single platform that provides (1) sturdy head fixation, (2) an integrated gas anesthesia mask, and (3) safe warm water heating. This THREE-IN-ONE (TRIO) Platform has a small footprint and a low profile that positions a mouse’s head only 20 mm above the microscope stage. This height is about one half to one third the height of most commercially available immobilization devices. We have successfully employed this system, using isoflurane in over 40 imaging sessions with an average of 2 h per session with no leaks or other malfunctions. Due to its smaller size, the TRIO Platform can be used with a wider range of upright microscopes and stages. Most of the components were designed in SOLIDWORKS® and fabricated using a 3D printer. This additive manufacturing approach also readily permits size modifications for creating systems for other small animals.

Objectives: The Insurance Institute for Highway Safety (IIHS) rates front seat/head restraint designs using a combination of static and dynamic measurements following RCAR-IIWPG procedures. The purpose of this study was to determine whether vehicles with better IIHS-rated seats/head restraints had lower injury risk in rear-end collisions and how the effect of better rated seats interacted with driver gender and age. Methods: The presence of an associated insurance injury claim was determined for rear-impact crashes using 2001–2014 model year cars and SUVs. Logistic regression was used to compare injury risk for vehicles with good, acceptable, and marginal IIHS-rated seats/head restraints with poor-rated seats/head restraints. Analyses were run by gender and driver age and also by the rate of more severe injury claims. Results: Injury rates were 11.2% lower for vehicles with seats/head restraints rated good compared to vehicles with seats/head restraints rated poor. The percentage reduction for good- versus poor-rated seats was greater for females (12.7%) than males (8.9%). Comparing good- with poor-rated seats, driver ages 15–24 had the largest reduction at 19.8%, followed by 10.7% for driver ages 45–64 and 10.4% for driver ages 25–44. Conclusions: Seats/head restraints with better IIHS ratings are associated with lower injury rates in rear-impact collisions than seats rated poor. The reductions in injury rates were strongest for females and for young-to–middle-age drivers. The strong reductions in injury rates for these groups are encouraging given their high initial injury rates.

Objective: This study investigated overall performance of an energy-absorbing sliding seat concept for whiplash neck injury prevention. The sliding seat allows its seat pan to slide backward for some distance under certain restraint force to absorb crash energy in rear impacts. Methods: A numerical model that consisted of vehicle interior, seat, seat belt, and BioRID II dummy was built in MADYMO to evaluate whiplash neck injury in rear impact. A parametric study of the effects of sliding seat parameters, including position and cushion stiffness of head restraint, seatback cushion stiffness, recliner characteristics, and especially sliding energy-absorbing (EA) restraint force, on neck injury criteria was conducted in order to compare the effectiveness of the sliding seat concept with that of other existing anti-whiplash mechanisms. Optimal sliding seat design configurations in rear crashes of different severities were obtained. A sliding seat prototype with bending of a steel strip as an EA mechanism was fabricated and tested in a sled test environment to validate the concept. The performance of the sliding seat under frontal and rollover impacts was checked to make sure the sliding mechanism did not result in any negative effects. Results: The protective effect of the sliding seat with EA restraint force is comparable to that of head restraint–based and recliner stiffness–based anti-whiplash mechanisms. EA restraint force levels of 3 kN in rear impacts of low and medium severities and 6 kN in impacts of high severity were obtained from optimization. In frontal collision and rollover, compared to the nonsliding seat, the sliding seat does not result in any negative effects on occupant protection. The sled test results of the sliding seat prototype have shown the effectiveness of the concept for reducing neck injury risks. Conclusion: As a countermeasure, the sliding seat with appropriate restraint forces can significantly reduce whiplash neck injury risk in rear impacts of low, medium, and high severities with no negative effects on other crash load cases.

A correctly positioned vehicle head restraint (HR) can reduce whiplash injury risk in collisions, however, HRs are often sub-optimally positioned. The primary aim of this study was to investigate vehicle HR position and driver knowledge of correct HR positioning in an Irish population. Secondary aims were to investigate the associations with driver age, gender and vehicle age. Data collection involved HR measurement and a driver questionnaire (n = 110). Just 27% of drivers had optimal HR positioning, while 30% had poor or marginal positioning. Newer vehicles (

The authors sought to evaluate the relative importance of locomotor control and postural control in the perception of affordances. While seated in a stationary wheelchair, participants made a series of judgments about the minimum lintel height under which they could roll in the wheelchair. Prior to making judgments, participants were given brief (∼2 min) experience with wheelchair locomotion. They expected that this practice would influence the accuracy of subsequent affordance judgments. During practice, participants moved under their own power (using their hands on the wheels) or with an experimenter pushing the wheelchair. Also during wheelchair locomotion the participant's head was restrained, or was not. Results revealed that head restraint during the practice session had no effect on the accuracy of subsequent judgments. By contrast, the judgments of participants who controlled locomotion during practice were significantly more accurate than the judgments of participants who had not controlled their locomotion during practice.

Previous research indicates that most vehicle occupants are unaware that a correctly adjusted, well-designed vehicular head restraint provides substantial protection against whiplash injuries. This study examined whether a brief educational intervention could improve awareness regarding whiplash injuries and prevention strategies among a cohort of vehicle fleet managers.A brief written survey was administered prior to, and approximately 1 h after a 30-min presentation on whiplash injury and prevention measures, which was delivered at a regional fleet manager meeting held in British Columbia, Canada (n = 27 respondents).Respondents had low baseline knowledge levels regarding the causes, consequences, and prevention of whiplash. Following the presentation, however, respondents improved awareness in all of these domains and, most important, reported an increased motivation to implement changes based on this newly acquired knowledge.These results indicate that improved education practices and social marketing tools are potentially valuable to increase awareness among relevant stakeholders.

Seat is a main part of vehicle to contact with occupant in rear impact and chiefly concern with the severity of neck injuries. Therefore, improvement in seat design can effectively reduce the neck injuries of occupant. For designing an effective vehicle seat to protect occupant, this study develops the numerical model of sled test by using MADYMO software and discusses the relevance between the seat parameters and occupant’s neck based on the validated numerical model. The seat parameters include the stiffness of seat angle device, seat friction and angle of head restraint. The discussion of influencing factors of seat can be referred for designing a safety seat. The occupant neck then can be protected in rear impact accidents.

In order to solve the problem that the performance of anti-whiplash seat did not satisfy the requirements of score, the seat is analyzed for the structure and simulation. It is found that there are several main factors which have great influence on it such as Head Restraint geometry position, Head Restraint and seat back stiffness, seat bracket stiffness and so on. With optimized and adjusted correlative parameter, the seat exerts itself completely with excellent performance of anti-whiplash and this performance of car will also meet target request.

Chronic radicular symptoms have been documented in whiplash patients, potentially caused by cervical neural tissue compression during an automobile rear crash. Our goals were to determine neural space narrowing of the lower cervical spine during simulated rear crashes with whiplash protection system (WHIPS) and active head restraint (AHR) and to compare these data to those obtained with no head restraint (NHR). We extrapolated our results to determine the potential for cord, ganglion, and nerve root compression.Our model, consisting of a human neck specimen within a BioRID II crash dummy, was subjected to simulated rear crashes in a WHIPS seat (n = 6, peak 12.0 g and ΔV 11.4 kph) or AHR seat and subsequently with NHR (n = 6, peak 11.0 g and ΔV 10.2 kph with AHR; peak 11.5 g and ΔV 10.7 kph with NHR). Cervical canal and foraminal narrowing were computed and average peak values statistically compared (P0.05) between WHIPS, AHR, and NHR.Average peak canal and foramen narrowing could not be statistically differentiated between WHIPS, AHR, or NHR. Peak narrowing with WHIPS or AHR was 2.7 mm for canal diameter and 1.6 mm, 2.7 mm, and 5.9 mm(2) for foraminal width, height and area, respectively.While lower cervical spine cord compression during a rear crash is unlikely in those with normal canal diameters, our results demonstrated foraminal kinematics sufficient to compress spinal ganglia and nerve roots. Future anti-whiplash systems designed to reduce cervical neural space narrowing may lead to reduced radicular symptoms in whiplash patients.

This study presents car seat concepts which are designed to mitigate whiplash injuries through coordinated motion of seat components for a wide range of crash severities. In order to evaluate the effectiveness of the proposed car seat concepts, computational multibody models of a generic car seat and a biofidelic 50th-percentile male human model for rear impact are developed. A number of car seat concepts are shown to reduce the risk of whiplash injuries by utilizing head restraint support and energy-absorbing features, which remain reusable after impact.

Although several previous studies have evaluated horizontal head restraint backset distances, few studies have evaluated them during driving. The purpose of this study was to measure this backset during routine automobile driving and to specifically evaluate the backset during individual driving tasks such as turning, stopping, starting, and lane changes.Fourteen subjects drove around a specified route through the city of Guelph, Ontario, Canada, that included residential, thruway, and highway driving; additional minor driving tasks, such as lane changes, were evaluated. The distance of head restraint to posterior aspect of the head was measured continuously throughout the drive using an ultrasonic measurement system. The timing of specific tasks was documented using a video camera.The average head-to-restraint distance throughout the driving route was 78.1 mm (standard deviation [SD] 24.8 mm); this distance did not vary significantly between the global measures during various driving areas (residential, thruway, and highway). We observed that the head restraint backsets during right turns (93.6 mm; SD 34.8 mm) were significantly larger compared to the other driving tasks (p.001). The 7 males and 7 females showed similar backset distances: 84.52 mm (SD 12.08) and 71.68 mm (SD 5.53), respectively (p = .0785).We observed that most subjects maintain a relatively consistent head-to-restraint distance throughout their driving route; 2 subjects adopted very large head restraint backset distances throughout their drive and 2 others adopted very small head restraint backset distances-this appears to reflect driver posture. Twelve of 14 subjects had average backset distances that exceed the National Highway Traffic Safety Administration and the Federal Motor Vehicle Safety Standard guidelines, indicating that most drivers may be at risk for whiplash-like disorders if exposed to a rear impact while driving. Of the monitored driving tasks, turning, especially right turns, caused drivers to increase their head-to-restraint backset distance.

designed a equipment for testing the strength of seats and head restraints, the equipment can testing the seats and head restraints with the standard of GB 11550-1995 5.2. The equipment was composed of one upper cylinder elevating system, a beam elevating system, two load cylinders and a hydraulic station. In addition to designed the principle of the hydraulic system.

Introduction: CarFit is a community-based educational programme developed to address driver-vehicle fit and vehicle safety feature use among older drivers in the United States. The purpose of this study was to evaluate the usefulness and impact of the CarFit programme. Method: Four separate CarFit events were conducted using the standardised 12-point checklist, after which participants were provided with a questionnaire to complete and return. Results: The results revealed that 95% of the 54 participants felt that CarFit was somewhat or very useful. Information about the programme reached beyond the study participants because 74% discussed the programme with others and 96% were somewhat or very likely to recommend CarFit. Feelings of programme usefulness were associated positively with the likelihood of recommending CarFit (χ2(6) = 32.502, pConclusion: The results suggest that an interactive community education programme such as CarFit can change the safety behaviours of older drivers. The potential for increased societal impact exists due to the significant sharing of information by CarFit participants.

To reduce whiplash injury risk in low-speed rear-impact accidents, a sliding mechanism of vehicle seat with crash energy-absorption (EA) function is proposed and analysed in this study. It can reduce relative motion between occupant head and torso under rear impact and lower values of neck injury related parameters such as neck injury criterion (NIC), neck displacement criterion (NDC) and neck forces and moment. A number of parameters of seat structure and countermeasures have great influence on occupant head–neck responses in rear impacts. They include head restraint position, seat recliner characteristic and seatback cushion stiffness, as well as the newly proposed seat sliding characteristic. A numerical model that includes a seat and a BIORID II dummy is used in a parametric study to evaluate effects of whiplash injury risk reduction. The analysis results show that proper combinations of the values of these parameters can mitigate the whiplash injuries and they form the basis of the existing counterme...

This paper evaluates the consequences of the impact of an unrestrained object against the head of vehicle occupant during a frontal crash by means of a computational head–neck biomechanical model. The correct positioning of head restraints can partially protect the rear side of the head, but there is still a significant probability of being injured. However, because head restraints are typically not properly adjusted as whiplash studies have shown, the probability of being impacted by an unrestrained object during a frontal crash is noticeably high and hence the risk of being injured is also high. In this work, head injury risk is evaluated through the Head Injury Criterion (HIC), by simulating a complete head–neck biomechanical model with realistic motion under frontal crash condition. The model developed includes all cervical vertebrae, intervertebral discs, ligaments and muscles. The model was validated against experimental data. Results have shown that the risk of severe head injury in frontal collisi...

Domestic automobile insurance claims were investigated to correlate the driver neck injury risk with the safety rating of the head restraint, the severity of vehicle damage, and other human factors. The results of our statistical analysis reveal that the risk of neck injury for the driver is significantly different for vehicle size, use, driver gender, driver age, impact direction, accident location, and safety rating of head restraint, depending on vehicle the damage level which is assumed to imply impact severity during a rear-end crash accident. One of the unique findings from domestic insurance claims from low-speed rear-end crash accidents is the frequent reports of lower back injury together with whiplash. Thus, the risk of lower back discomfort is also included in this statistical analysis.

This paper presents the validation of a 50th-percentile male multi-body human model specifically developed for rear-impact simulation. The aim is to develop a biofidelic model with the simplest architecture that can simulate the interaction of the human body with the seat during rear impact. The model was validated using the head-and-neck and torso responses of seven volunteers from the Japanese Automobile Research Institute sled tests, which were performed at an impact speed of 8km/h with a rigid seat and without head restraint and seat belt. The results indicate that the human-body model can effectively mimic the rear-impact response of a 50th-percentile male with a good level of accuracy and has the potential to predict whiplash injury.

Soft tissue neck injury (STNI) is thought to be related to automotive seat characteristics, and it is important to know how the stiffness of the seatback and head restraint foam affect the occupant’s motions in low speed rear impacts. The combined MADYMO(MAthematical DYnamic MOdel, TNO) 50th percentile facet male human body model with a detailed neck model was selected for this analysis. In order to determine the relationship between the occupant’s motions and seatback and head restraint foam stiffnesses, 40% offset rear impact simulations were performed by changing the stiffness of seatback and head restraint. Simulated results show that the maximum acceleration of head and trunk would tend to increase with those stiffnesses. Increased stiffness of the seatback and head restraint resulted in increased ligament and disc forces. On the other hand a proper combination of seatback and head restraint stiffness can reduce a possible neck injury. It is clear that an appropriate combination of stiffnesses between seatback and head restraint allows to minimize a neck injury.

Objectives: Whiplash injuries from vehicle collisions are common and costly. These injuries most frequently occur as a result of a rear impact and, compared to males, females have up to twice the risk of whiplash-associated disorders (WAD) resulting from vehicle crashes. The present study focuses on the differences in the dynamic response corridors of males and females in low-severity rear impacts. Methods: In this study, analysis of data fromvolunteer tests of females frompreviously published data has been performed. Corridors for the average female response were generated based on 12 volunteers exposed to a change of velocity of 4 km/h and 9 volunteers exposed to a change of velocity of 8 km/h. These corridors were compared to corridors for the average male response that were previously generated based on 11 male volunteers exposed to the same test conditions. Results: Comparison between the male and female data showed that the maximum x-acceleration of the head for the females occurred on average 10 ms earlier and was 29% higher during the 4 km/h test and 12 ms earlier and 9% higher during the 8 km/h test. Head-to-head restraint contact for the females occurred 14 ms earlier at 4 km/h and 11 ms earlier at 8 km/h compared to the males. For the same initial head-to-head restraint distance, head restraint contact occurred 11 and 7 ms earlier for the females than the males at 4 and 8 km/h, respectively. Furthermore, the calculated Neck Injury Criteria (NIC) values were similar for males and females at 4 km/h, whereas they were lower for females compared to the males at 8 km/h (3.2 and 4.0 m2/s2, respectively). Conclusions: The results of this study highlight the need to further investigate the differences in dynamic responses between males and females at low-severity impacts. Such data are fundamental for the development of future computer models and dummies for crash safety assessment. These models can be used not only as a tool in the design and development process of protective systems but also in the process of further evaluation and development of injury criteria.

This study presents an investigation of anti-whiplash features that can be implemented in a car seat to reduce whiplash injuries in the case of a rear impact. The main emphasis is on achieving a seat design with good energy absorption properties.A biofidelic 50th percentile male multi-body human model for rear impact is developed to evaluate the performance of car seat design concepts. The model is validated using the responses of 7 volunteers from the Japanese Automobile Research Institute (JARI) sled tests, which were performed at an impact speed of 8 kph with a rigid seat and without head restraint and seatbelt. A generic multi-body car seat model is also developed to implement various seatback and recliner properties, anti-whiplash devices, and head restraints. Using the same driving posture and the rigid seat in the JARI sled tests as the basic configuration, several anti-whiplash seats are designed to allow different types of motion for the seatback and seat-pan.The anti-whiplash car seat design concepts limit neck internal motion successfully until the head-to-head restraint contact occurs and they exhibit low NIC(max) values (7 m(2)/s(2) on average). They are also effective in reducing neck compression forces and T1 forward accelerations. In principle, these car seat design concepts employ controlled recliner rotation and seat-pan displacement to limit the formation of S-shape. This is accomplished by using anti-whiplash devices that absorb the crash energy in such a way that an optimum protection is provided at different severities.The results indicate that the energy absorbing car seat design concepts all demonstrate good whiplash-reducing performances at the IIWPG standard pulse. Especially in higher severity rear impacts, two of the car seat design concepts reduce the ramping of the occupant considerably.

The objective of the study was to compare stature, weight and backset (the horizontal distance (x) between the back of the occupant's head and the front of the seam on top of the head restraint) of the Biofidelic Rear Impact Dummy (BioRID II) to the same variables on seated volunteers in a car. The following methods were used. Data were collected from 154 randomly selected Swedish individuals (78 males and 76 females). The volunteers and the BioRID II were examined in a Volvo V70 car, year model 2003, in three positions: driver (hands on steering wheel), front passenger (hands in lap) and rear passenger. The study results were as follows: the BioRID II was found to correspond approximately to a 35th-45th percentile male in stature (-2 cm), a 35th percentile male in weight (-7 kg), a 96th percentile female in stature (+11 cm) and a 69th percentile female in weight (+8 kg). The BioRID II was designed to represent a male driver. The BioRID II backset corresponded well with the average of the male drivers of its stature. Larger deviations in backset were found for other volunteer sizes and other seating positions. The average backsets were 26 mm for females and 63 mm for males in the front seat positions. The volunteers had larger backset in the driver position (60 mm) than in the front passenger position (29 mm). Smaller differences in backset were seen between the BioRID II and the volunteers in the rear passenger position. This study provides data regarding the occupant size coverage of BioRID II, and unique data regarding backset, of different occupant positions in the car; driver with hands on steering wheel, and front and rear passengers with hands in lap, for female and male in relation to the BioRID II dummy.

Electrical stimuli are used increasingly to confine cattle, whether through conventional electric fencing or the development of ‘virtual’ fencing systems. Two experiments were conducted to assess behavioural, heart rate and stress hormone responses of cattle to electrical stimuli typically used in such confinement applications. In the first experiment, 30 steers (18-months old; n = 10 per treatment) were held in a handling crush for 15 min after receiving one of the following treatments: nothing (control); delivery of three shocks at 2 s intervals (600 V, 250 mW); and restraint in a head bail for 3 min. Plasma cortisol and β-endorphin concentrations were measured at 0, 5, 10, 15 min, 1, 2, 3, and 4 h. In a second experiment, heart rate and behaviour were measured in 17 heifers (18 months of age) subjected to one of the following treatments whilst held in a crush for 10 min: nothing (control; n = 5); delivery of three shocks at 2 s intervals (600 V, 250 mW; n = 6); and restraint in a head bail for 3 min ( n = 6). Cortisol and β-endorphin concentrations did not differ between treatments ( P > 0.05). Whilst animals were receiving the treatments, heart rate was lower when head restrained compared with shock or control treatments ( P = 0.009) and did not differ between control and electric shock treatments ( P = 0.35). Upon release from the crush, heart rate was higher in shock and head restrained treatments than the control treatment ( P = 0.005). Animals receiving the electric shock treatment tossed their heads more frequently whilst in the crush than control animals ( P = 0.012) but did not differ from the other treatments in the number of vocalisations, tail swishes, steps back and forward, head tilts and head turns. There was a significant effect of treatment on flight time ( P = 0.005); animals receiving the electric shocks were faster to leave the crush than control animals ( P = 0.005) and there was no difference between head restraint and shock treatment ( P = 0.86). In 10 min following release from the crush, there was no treatment difference in the time to start feeding. This study suggests that the stress response of cattle to low energy electric shocks is minimal and is similar to that induced by restraint in a crush.

The objective of this study was to investigate the influence of anthropometric data on the kinematics of the cervical spine and the risk factors for sustaining a neck injury during rear-end collisions occurring in a sled test. A rear-end collision with a velocity change (ΔV) of 6.3 km/h was simulated in a sled test with eight healthy female subjects. The study analysed the association of anthropometric data with the initial distance between the head and the head restraint, defined kinematic characteristics, the neck injury criterion (NIC) and the neck injury criterion minor (NICmin). The head circumference is negatively associated (r = −0.598) with the initial distance between the head and the head restraint, the maximal head extension (r = −0.687) and the maximal dorsal angular head acceleration (r = −0.633). The body weight (r = 0.800), body height (r = 0.949) and thorax circumference (r = 0.632) are positively associated with the maximal ventral head translation. The neck length correlates positively with the NIC (r = 0.826) and negatively with the NICmin (r = −0.797). Anthropometric factors influence the kinematics of the cervical spine and the risk of injury. A high risk of injury may be assumed for individuals with a small head circumference, long neck, tall body height and high body weight.

This article presents a simple, but yet quantitative model of vehicle and occupant movement in moderate-speed, in-line collisions. The modelling is based upon established and validated representations of force-deflection relations during frontal/rear-end collisions. The developed model is applicable with head-on, rear-end, and fixed structure collisions. The modelling results show that the vehicle and occupant movement during collision is well described by sinusoidal and linear functions. The model shows that in the beginning stages of an accident, the occupant movement relative to the vehicle is proportional to the cube of the accident time. Thus, the occupant movement in the vehicle is initially slow but then rapidly increasing. Thus, from the perspective of safety, the beginning stages of an accident provide the greatest opportunity for implementation/deployment of air bags, pretensioners, and adaptive head restraint systems.