Clinical Significance of the Seat Belt Sign as Evidence of a Compromised Occupant-Seat Belt Relationship.

BACKGROUND: Seat belt marks are seen frequently on occupants after motor vehicle accidents. Over the years, the clinical significance of these marks has changed as restraint systems have evolved. With modern restraint systems, signs of a compromised occupant-restraint relationship are an important and easily identified bedside finding. OBJECTIVES: We sought to learn to recognize seat belt marks that demonstrate an abnormal occupant-restraint system relationship and to cultivate an understanding of significant soft tissue biomechanical loading associated with marks caused by a compromised occupant-restraint relationship. DISCUSSION: A review of case studies from the literature combined with forensic work demonstrate a strong correlation between significant injury and improper seatbelt use. When evidence of a compromised occupant-restraint relationship exists, incorporating computed tomography angiography and observation may be clinically indicated. CONCLUSION: The recognition of seat belt marks made by a compromised occupant-restraint relationship is an important finding that allows risk stratification of the patient at the bedside. Further investigation with a prospective trial at a trauma center is warranted.

Are parents following the recommendations for keeping children younger than 2 years rear facing during motor vehicle travel?

PURPOSE: Between 2007 and 2012 there have been several recommendations that infants and toddlers ride in a car safety seat (CSS) rear facing until 2 years of age. This study reports the effect of these recommendations on the observed direction of travel for infants and toddlers transported in motor vehicles between 2007 and 2012. METHODS: This is an observational, cross-sectional survey of drivers transporting children collected at 25 convenience locations selected in Indiana during summer 2007 through 2012. Observations were conducted by Certified Child Passenger Safety Technicians. As drivers completed a written survey, the Certified Child Passenger Safety Technician recorded the vehicle seating location, type of restraint, CSS direction and use of the CSS harness or safety belt as appropriate, and demographic data. The infant and toddler's age and weight were collected. Data from 2007 through 2012 for ages birth through 23 months were compared in order to determine if recommendations impacted observed direction of travel. RESULTS: During the study period, the percent of infants and toddlers (birth through 23 months) observed rear facing in a motor vehicle varied from 44.2% (2007) to 59.1% (2012). For infants (birth through 11 months) observed rear facing, it was 85.1% (2009) to 91.6% (2012). The percent of toddlers (12 months through 23 months) observed rear facing ranged from 3.3% (2008) to 18.2% (2012). CONCLUSIONS: During the study period, the proportion of toddlers rear facing increased approximately 15% (p=0.03). Counselling by primary care providers should continue and be strengthened to increase parent and caregiver awareness of the latest child passenger safety recommendations.

Relationship Between Restraint System Use and Brachial Plexus Injuries in Motor Vehicle Accidents: A Case-Control Study from the National Trauma Databank.

INTRODUCTION: High-speed motor vehicle accidents (MVAs) are an important cause of brachial plexus injury (BPI). Some case reports have demonstrated shoulder seat belt use resulting in traction injuries to the brachial plexus. We used a national trauma registry to determine the association between seat belt use and brachial plexus injury in MVAs. METHODS: The authors queried the National Trauma Databank between 2016 and 2017 for patients with a hospital admission following an MVA. Cases with BPI were identified using International Classification of Diseases, Tenth Edition, Clinical Modification, diagnosis codes. Case-control matching by age and sex was performed to identify 2 non-BPI controls for every case of BPI. Multivariable conditional logistic regression adjusting for body mass index, alcohol use, and drug use was then performed to determine the adjusted association between safety equipment use (seat belt use and airbag deployment) and BPI. RESULTS: A total of 526,007 cases of MVAs were identified, of which 704 (0.13%) sustained a BPI. The incidences of BPI in patients were the following without any protective device (0.16%), with airbag deployment alone (0.08%), with seat belt use alone (0.08%), and with combined airbag deployment and seat belt use (0.07%). Following 1:2 case-control matching by age and sex and multivariable conditional logistic regression, seat belt use (odds ratio [OR] 0.55; 95% confidence interval [CI] 0.42-0.71; P < 0.001) and airbag deployment (OR 0.52; 95% CI 0.33-0.82; P = 0.004) were found to be associated with decreased odds for BPI, with the least odds observed with combined seat belt use and airbag deployment (OR 0.49; 95% CI 0.33-0.74; P = 0.001). CONCLUSIONS: Despite anecdotal evidence suggesting increased likelihood of BPI with shoulder seat belt use, case-control analysis from a national trauma registry demonstrated that both seat belt use and airbag deployment are associated with lower odds of sustaining BPIs in MVAs, with the greatest protective effect observed with combined use. Future studies adjusting for rider location (passenger vs. driver) and other potential confounders such as make, type and speed of vehicle may help further characterize this association.

Managing non-response rates for the National Child Safety Seat Survey in Canada.

BACKGROUND: Canada has a Road Safety Vision of having the safest roads in the world, yet vehicle crashes have remained the leading cause of death of Canadian children for a number of years. OBJECTIVES: Determine the influence of high rates of non-participation on the estimates for correct use of safety seats for child occupants in vehicles. Examine the impact of three different criteria for determining correct safety seat use on the estimates of correct use of safety seats for children in Canada. METHODS: A national child seat safety survey was conducted in 200 randomly selected sites across Canada that included both naturalistic observation of child seat safety use at intersections and a detailed vehicle inspection in nearby parking lots. Non-participation in the detailed parking lot study was high. This study reports on statistical methods for managing high rates of non-response and compared estimates of correct use using three different criteria. RESULTS AND CONCLUSIONS: Results revealed that high non-participation rates introduced bias into the raw estimates of correct safety seat use. Correct use estimates also varied substantially depending on which criterion (more stringent or less stringent) for correct use was applied in the analysis. When child age was the only criterion for correct use, estimates were higher than when more stringent criteria of child height and weight were applied to estimate rates of correct use. This study identifies the importance of managing high rates of non-response in safety seat observation studies using statistical techniques. Stringent criteria for correct use may provide more accurate estimates of the correct use of safety seats. Studies of child seat use in vehicles (using voluntary participation) may benefit from the use of naturalistic observation to capture non-participants' use of child occupant restraints, as it may more accurately estimate the rates of correct use in populations.

Factors predicting incorrect use of restraints by children travelling in cars: a cluster randomised observational study.

BACKGROUND: The benefits of correctly using size-appropriate restraints for children travelling in cars are well established, and considerable research has focused on the determinants of appropriate restraint choice. There are few studies of the factors associated with incorrect use. Objective To determine predictors of incorrect restraint use by child occupants and how these differ from inappropriate use. METHODS: A stratified multistage cluster sample of child occupants aged 0-10 years in New South Wales, Australia was used. Observation of restraint type and inspection of correctness of use was performed on arrival at schools, childcare centres, and child health clinics. An interview was conducted with the driver. Logistic regression was performed to estimate the effects of parental, family, and other characteristics on the likelihood of moderate or serious incorrect restraint use for restraint classes (rear/forward facing, booster, and seatbelt). RESULTS: Significant factors varied depending on age and restraint class. Older child restraint users (OR per year of age 0.27, 95% CI 0.07 to 0.98) and seatbelt users (OR per year of age 0.54, 95% CI 0.45 to 0.64) were less likely to be incorrectly using their restraints than younger users. Child restraint and booster users from non-English speaking families were more likely to be incorrectly using their restraints. Having more children in the car appeared to reduce incorrect use for booster (OR 0.18, 95% CI 0.06 to 0.57) and seatbelt users (OR 0.39, 95% CI 0.16 to 0.93). CONCLUSIONS: There is a need to reduce incorrect restraint use by both education and improved restraint design. Education aimed at reducing incorrect use may need to be targeted differently to appropriate use programmes, as the predictive factors differ.

Effects of seat belts worn by pregnant drivers during low-impact collisions.

OBJECTIVE: The aim of this study was to understand the injury mechanisms of pregnant drivers and associated fetal outcomes. STUDY DESIGN: Frontal and rear impact tests using a dummy representing the anthropometry of a pregnant woman were conducted. RESULTS: In frontal impact tests without a seat belt, abdominal pressure peaked at the point where the dummy contacted the steering wheel. Rear impact tests without a seat belt showed that the dummy moved forward because of rebound and contacted the steering wheel, which was avoided when a seat belt was worn. CONCLUSION: Wearing a seat belt reduces abdominal pressure or prevents contact with the steering wheel during collisions.

Transporting Children With Special Health Care Needs.

Children with special health care needs should have access to proper resources for safe transportation as do typical children. This policy statement reviews important considerations for transporting children with special health care needs and provides current guidance for the protection of children with specific health care needs, including those with airway obstruction, orthopedic conditions or procedures, developmental delays, muscle tone abnormalities, challenging behaviors, and gastrointestinal disorders.

Transportation of Older Adults: Common Behaviors Interfering With Safety.

There is a dearth of evidence on safely transporting frail older adults in the community. Therefore, the purpose of the current study was to gain a better understanding of behavioral expression exhibited by older adults during van transportation and to learn what actions van assistants and van drivers take to prevent or address behavioral expressions, which can create potential challenges to safe transportation. A qualitative descriptive approach was used and included four focus groups of van assistants and van drivers (N = 32) at one urban Program of All-Inclusive Care for the Elderly (PACE), which routinely transports approximately 90% of enrollees to and from the PACE center. Conventional content analysis was used to analyze the data. Four themes emerged. The first two themes were common behaviors: Removing Seat Belts and Verbal Behaviors. The remaining two themes addressed unusual behaviors that left lasting impressions: Physical Aggression and Conflict Between Passengers. Van assistants and van drivers used redirection and reassurance as preventive interventions to keep everyone safe. Transportation of PACE enrollees requires well-trained and astute van assistants and van drivers skilled with preventing and diffusing potentially unsafe behaviors. [Res Gerontol Nurs. 2019; 12(4):184-192.].

Using head-on collisions to compare risk of driver death by frontal air bag generation: a matched-pair cohort study.

US air bag regulations were changed in 1997 to allow tests of unbelted male dummies in vehicles mounted and accelerated on sleds, resulting in longer crash pulses than rigid-barrier crashes. This change facilitated depowering of frontal air bags and was intended to reduce air bag-induced deaths. Controversy ensued as to whether sled-certified air bags could increase adult fatality risk. A matched-pair cohort study of two-vehicle, head-on, fatal collisions between drivers involving first-generation versus sled-certified air bags during 1998-2005 was conducted by using Fatality Analysis Reporting System data. Sled certification was ascertained from public information and a survey of automakers. Conditional Poisson regression for matched-pair cohorts was used to estimate risk ratios adjusted for age, seat belt status, vehicle type, passenger car size, and model year for driver deaths in vehicles with sled-certified air bags versus first-generation air bags. For all passenger-vehicle pairs, the adjusted risk ratio was 0.87 (95% confidence interval: 0.77, 0.98). In head-on collisions involving only passenger cars, the adjusted risk ratio was 1.04 (95% confidence interval: 0.85, 1.29). Increased fatality risk for drivers with sled-certified air bags was not observed. A borderline significant interaction between vehicle type and air bag generation suggested that sled-certified air bags may have reduced the risk of dying in head-on collisions among drivers of pickup trucks.

The safest seat: effect of seating position on occupant mortality.

INTRODUCTION: This study investigated the survival rates of occupants of passenger cars involved in a fatal crash between 2000 and 2003. METHODS: The information from every fatal crash in the United States between 2000 and 2003 was analyzed. Variables such as seat position, point of impact, rollover, restraint use, vehicle type, vehicle weight, occupant age, and injury severity were extracted from the Fatality Analysis Reporting System (FARS). Univariate and a full logistic multivariate model analyses were performed. RESULTS: The data show that the rear middle seat is safer than any other occupant position when involved in a fatal crash. Overall, the rear (2(nd) row) seating positions have a 29.1% (Univariate Analysis, p<.0001, OR 1.29, 95% CI 1.22 - 1.37) increased odds of survival over the first row seating positions and the rear middle seat has a 25% (Univariate Analysis, p<.0001, OR 1.25, 95% CI 1.17 - 1.34) increased odds of survival over the other rear seat positions. After correcting for potential confounders, occupants of the rear middle seat have a 13% (Logistic Regression, p<.001, 95% CI 1.02 - 1.26) increased chance of survival when involved in a crash with a fatality than occupants in other rear seats. CONCLUSION: This study has shown that the safest position for any occupant involved in a motor-vehicle crash is the rear middle seat. IMPACT ON INDUSTRY: The results of this research may impact how automobile manufacturers look at future rear middle seat designs. If the rear seat was to be designed exactly like its outboard counterparts (headrest, armrests, lap and shoulder belt, etc.) people may choose to sit on it more often rather than waiting to use it out of necessity due to multiple rear seat occupants.

Occupant restraint preferences of individuals traveling in motor vehicles while seated in their wheelchairs.

A survey among 127 wheelchair users was conducted to characterize wheelchair occupant restraint usage patterns, restraint deficiencies, user characteristics, and essential wheelchair occupant restraint design parameters for when individuals travel in motor vehicles while seated in their wheelchairs. Survey respondents value independent travel and seem generally interested in the use of an occupant restraint system that is attached to the wheelchair frame and that can be used independently by the wheelchair user without caregiver or vehicle driver assistance. Results of the survey further indicate that despite the relatively high percentage of respondents who are attempting to travel safely (78.8%), almost half of these wheelchair users have experienced injury or compromised wheelchair balance while traveling in motor vehicles.

[Seatbelts on school buses: are they safe for our children?].

In Israel, 280,000 pupils travel daily to school and back home by means of school transportation. In an effort to increase school transportation safety, the installation of lap belts in school transportation vehicles is required since September 1, 2006. In Israel, laws are often passed with good intentions, but frequently without exploring the potential outcomes. Traffic regulation 364a states that "lap belts or other seatbelts" are required in all vehicles used for school transportation. The objective of this study is to review the world-wide literature regarding seatbelts on school buses with an emphasis to identify the risks associated with lap restraints. Over 50 studies, articles and position papers referring to the efficacy of seatbelts, with an emphasis on school transportation, were reviewed. According to the literature, this new traffic regulation could produce more devastating outcomes than previously. Seatbelts were designed to prevent passenger injuries during a motor vehicle crash. Researchers have not proven efficacy of seatbelts in school buses. Lap-only belts have shown to increase the risk of severe injury among children, even in mild crashes. Since young children are not adequately developed to take the force of a lap-only restraint, these belts have been associated with internal injuries, lumbar fracture-dislocations, abdominal contusions and head injuries. The National Highway Traffic Safety Administration (NHTSA) in the USA has reported that lap belts are not effective in preventing injury among children traveling by bus. Children have a two to three fold risk of severe injury when using lap only restraints. On the contrary, lap-shoulder belts may reduce the risk of abdominal injuries by up to 50% relative to lap-only belts. In conclusion, policy makers aimed to implement regulations which will reduce injuries and fatalities. However, neglecting to carry out an in-depth professional review has brought about a regulation requiring lap belts in school buses; a decision which, according to international research studies, can potentially increase the injury risks among pupils.

Assessing tether anchor labeling and usability in pickup trucks.

OBJECTIVE: The objective of this study was to investigate vehicle factors associated with child restraint tether use and misuse in pickup trucks and evaluate 4 labeling interventions designed to educate consumers on proper tether use. METHODS: Volunteer testing was performed with 24 subjects and 4 different pickup trucks. Each subject performed 8 child restraint installations among the 4 pickups using 2 forward-facing restraints: a Britax Marathon G4.1 and an Evenflo Triumph. Vehicles were selected to represent 4 different implementations of tether anchors among pickups: plastic loop routers (Chevrolet Silverado), webbing routers (Ram), back wall anchors (Nissan Frontier), and webbing routers plus metal anchors (Toyota Tundra). Interventions included a diagram label, Quick Response (QR) Code linked to video instruction, coordinating text label, and contrasting text tag. RESULTS: Subjects used the child restraint tether in 93% of trials. However, tether use was completely correct in only 9% of trials. An installation was considered functional if the subject attached the tether to a tether anchor and had a tight installation (ignoring routing and head restraint position); 28% of subjects achieved a functional installation. The most common installation error was attaching the tether hook to the anchor/router directly behind the child restraint (near the top of the seatback) rather than placing the tether through the router and attaching it to the anchor in the adjacent seating position. The Nissan Frontier, with the anchor located on the back wall of the cab, had the highest rate of correct installations but also had the highest rate of attaching the tether to components other than the tether anchor (seat adjustor, child restraint storage hook, around head restraint). None of the labeling interventions had a significant effect on correct installation; not a single subject scanned the QR Code to access the video instruction. Subjects with the most successful installations spent extensive time reviewing the vehicle manuals. CONCLUSION: Current implementations of tether anchors among pickup trucks are not intuitive for child restraint installations, and alternate designs should be explored. Several different labeling interventions were ineffective at achieving correct tether use in pickup trucks.

Analysis of mechanics of side impact test defined in UN/ECE Regulation 129.

OBJECTIVE: This article discusses differences between a side impact procedure described in United Nations/Economic Commission for Europe (UN/ECE) Regulation 129 and scenarios observed in real-world cases. METHODS: Numerical simulations of side impact tests utilizing different boundary conditions are used to compare the severity of the Regulation 129 test and the other tests with different kinematics of child restraint systems (CRSs). In the simulations, the authors use a validated finite element (FE) model of real-world CRSs together with a fully deformable numerical model of the Q3 anthropomorphic test device (ATD) by Humanetics Innovative Solution, Inc. RESULTS: The comparison of 5 selected cases is based on the head injury criterion (HIC) index. Numerical investigations reveal that the presence of oblique velocity components or the way in which the CRS is mounted to the test bench seat fixture is among the significant factors influencing ATD kinematics. The results of analyses show that the side impact test procedure is very sensitive to these parameters. A side impact setup defined in Regulation 129 may minimize the effects of the impact. CONCLUSIONS: It is demonstrated that an artificial anchorage in the Regulation 129 test does not account for a rotation of the CRS, which should appear in the case of a realistic anchorage. Therefore, the adopted procedure generates the smallest HIC value, which is at the level of the far-side impact scenario where there are no obstacles. It is also shown that the presence of nonlateral acceleration components challenges the quality of a CRS and its headrest much more than a pure lateral setup.

Effectiveness of child safety seats vs safety belts for children aged 2 to 3 years.

OBJECTIVE: To compare the effectiveness of child safety seats and lap-shoulder belts in rear passenger vehicle seats for 2- to 3-year-old crash survivors. DESIGN: Cohort study. SETTING: The January 1, 1998, to December 31, 2004, US data on a nationally representative sample of crashes that resulted in at least 1 vehicle being towed away. PARTICIPANTS: Toddlers who were sitting in rear vehicle seats and using lap-shoulder belts or child seats when involved in highway crashes. INTERVENTION: Child safety seat vs safety belt. OUTCOME MEASURE: Presence of any injury after a crash. RESULTS: The adjusted odds of injury were 81.8% lower (95% confidence interval, 58.3%-92.1% lower) for toddlers in child seats than belted toddlers. CONCLUSIONS: Child safety seats seem to be more effective rear seat restraints than lap-shoulder safety belts for children aged 2 to 3 years. Laws requiring that children younger than 4 years travel in child safety seats have a sound basis and should remain in force.

Premature graduation of children in child restraint systems: an observational study.

This study investigated the use and misuse of child restraint systems (CRS) in Flanders (Belgium). Observations were conducted at a random sample of primary school and recreation areas. In total 1376 children were observed. A logistic regression model was constructed in order to determine the variables involved. The parameter-estimates of this model have shown that children are more often restrained when the driver buckles up, the ride takes less than 1h, the children are younger, the children sit in the front seat of the car, a recreational area is the destination of the trip and there are less than five children in the car. Also premature graduation to CRS was analysed. More than half of the children are not appropriately restrained, according to their age, weight or height. Improper shoulder belt use (putting the shoulder belt behind the back or under the arm) was observed in 8.99% of the children being restrained with high back booster seats, in 32.73% of the children being restrained with backless booster seats and finally in 19.07% of the children being restrained with seat belts. The risk of incorrectly using the shoulder belt increases when children are prematurely graduated in a CRS. The results are discussed in the light of other studies on this matter.

Field use patterns and performance of child restraints secured by lower anchors and tethers for children (LATCH).

A revised attachment system for child restraint systems (CRS), Lower Anchors and Tethers for Children (LATCH), was introduced to address issues of misuse of attachment of the CRS to the vehicle. This study provides the first real-world experience of this new restraint system. Relevant cases were selected from the partners for child passenger safety (PCPS) child-specific crash surveillance system based in the United States. Vehicles qualifying for the PCPS study were those model year 1990 or newer involved in a crash with at least one passenger

Performance of booster seats in side impacts: effect of adjacent passengers and ISOfix attachment.

This study examined the performance of a booster seat in different seating configurations in side-impact hyGe sled tests (crash severity 30 km/h) with two attachment systems: a standard seatbelt and ISOfix (rigid). The objectives of the study were twofold: (i) to identify the relative benefits of ISOfix attachment compared with seatbelt attachment of a near-side booster seat in a 3-abreast seating configuration with adjacent occupants in child restraints (CRS); and (ii) to examine the effects of 3-abreast seating configurations compared with no adjacent passengers on booster seat crash protection characteristics. Overall, the findings confirmed the superior performance of the rigid anchorages in reducing lateral motion of the booster as well as the two adjacent CRS. However, the expected benefits of the rigid attachment in reducing head accelerations were not uniformly observed across the three occupants/seating positions and also appeared to be influenced by seating configuration (3-abreast versus no adjacent occupant). Further research is warranted to explore the applicability of the findings for different CRS types and seating configurations.

Misuse of child restraint systems in crash situations - danger and possible consequences.

Based on real-world crash data and recent field studies, an ad-hoc group was set up in order to have a better comprehension of the effects of misuse of Child Restraint Systems (CRS) on child protection. A testing programme of 60 single misuse situations was conducted. Test results confirmed that, in frontal impact, children have higher risk of being injured on a number of different body regions when CRS's are misused. This work provides material for educational and training purposes to help parents understand that child restraints need to be correctly fitted in order to provide the level of protection they are designed for.