Methods: In total, 20 frontal sled tests were conducted using a custom sled buck that was reconfigurable to represent both the driver and passenger compartments of a light tactical military vehicle. Tests were performed at a delta-V of 30 mph and a peak acceleration of 25 g. The sled tests used the Hybrid III 5th percentile female, 50th percentile male, and 95th percentile male ATDs outfitted with standard combat boots and advanced combat helmets. In some tests, the ATDs were outfitted with additional military gear, which included an improved outer tactical vest (IOTV), IOTV and squad automatic weapon (SAW) gunner with a tactical assault panel (TAP), or IOTV and rifleman with TAP. ATD kinematics and injury outcomes were determined for each test.
Results: Maximum excursions were generally greater in the 95th percentile male compared to the 50th percentile male ATD and in ATDs wearing TAP compared to ATDs without TAP. Pretensioners and load limiters were effective in decreasing excursions and injury measures, even when the ATD was outfitted in military gear.
Conclusions: ATD injury response and kinematics are influenced by the size of the ATD, military gear, and restraint system. This study has provided important data for validating FE models of military occupants, which can be used for design optimization of military vehicle restraint systems. 相似文献
Methods: This is an analysis of data from a cross sectional observation study of child restraint use in New South Wales. Logistic regression was used to model the relationship between parent-reported comfort and restraint misuse and age-appropriate restraint choice.
Results: There was no significant relationship between either parent-reported comfort and restraint misuse or parent-reported comfort and age-appropriate restraint choice.
Conclusions: Parent perceptions of comfort of children in child restraints do not appear to be associated with incorrect child restraint use or age appropriate restraint choice. It is possible that the actual comfort of the child may be related to incorrect use but this remains to be tested. Further investigation of the relationship between parent-perceived comfort and the actual comfort of the child, as well as the impact of child comfort on optimal child restraint use is warranted. 相似文献
Objective
To assess the effect of the newly enacted child passenger safety law, Wisconsin Act 106, on self-report of proper restraint usage of children in Milwaukee's central city population.Method
A prospective, non-randomized study design was used. The settings used were (a) a pediatric urban health center, and (b) two Women, Infants and Children offices in Milwaukee, Wisconsin. Participants included 11,566 surveys collected over 18 months that spanned the pre-legislation and post-legislation time periods from February 2006 through August 2008.Results
The study set out to assess appropriate child passenger restraint. The results showed that the changes in adjusted proper restraint usage rates for infants between the pre-law, grace period, and post-fine periods were 94%, 94%, and 94% respectively. For children 1-3 years old, the adjusted proper usage rates were 65%, 63%, and 59%, respectively. And for children 4-7 years old, the rates were 43%, 44% and 42%, respectively. There was a significant increase in premature booster seat use in children who should have been restrained in a rear- or forward-facing car seat (10% pre-law, 12% grace period, 20% post-fine; p < 0.0005). There was no statistically significant change over time in unrestrained children (2.1%, 1.7%, 1.7%, p = 0.7, respectively).Conclusions
The passage of a strengthened child passenger safety law with fines did not significantly improve appropriate restraint use for 0-7 year olds, and appropriate use in 1-7 year olds remained suboptimal with a majority of urban children inappropriately restrained. Although the number of unrestrained children decreased, we identified an unintended consequence of the legislation - a significant increase in the rate of premature belt-positioning booster seat use among poor, urban children.Impact on Industry
The design of child restraint systems maximizes protection of the child. Increasing reports of misuse is a call to those who manufacture these child passenger restraints to improve advertising and marketing to the correct age group, ease of installation, and mechanisms to prevent incorrect safety strap and harness placement. To ensure accurate and consistent use on every trip, car seat manufacturers must ensure that best practice recommendations for use as well as age, weight, and height be clearly specified on each child restraint. The authors support the United States Department of Transportation's new consumer program that will assist caregivers in identifying the child seat that will fit in their vehicle. In addition, due to the increase in premature graduation of children into belt-positioning booster seats noted as a result of legislation, promoting and marketing booster seat use for children less than 40 pounds should not be accepted. Child passenger safety technicians must continue to promote best practice recommendations for child passenger restraint use and encourage other community leaders to do the same. 相似文献Methods: The seats were fixed in a sled buck subjected to a 40.2 km/h (25 mph) rear sled test. The pulse was a 15 g double-peak acceleration with 150 ms duration. The 50th percentile Hybrid III was lap–shoulder belted in the FMVSS 208 design position. The testing included 11 <2000 MY, 8 ≥2000 MY, and 7 ABTS seats. The dummy was fully instrumented, including head accelerations, upper and lower neck 6-axis load cells, chest acceleration, thoracic and lumbar spine load cells, and pelvis accelerations. The peak responses were normalized by injury assessment reference values (IARVs) to assess injury risks. Statistical analysis was conducted using Student's t test. High-speed video documented occupant kinematics.
Results: Biomechanical responses were lower with modern (≥2000 MY) seats than older (<2000 MY) designs. The lower neck extension moment was 32.5 ± 9.7% of IARV in modern seats compared to 62.8 ± 31.6% in older seats (P =.01). Overall, there was a 34% reduction in the comparable biomechanical responses with modern seats. Biomechanical responses were lower with modern seats than ABTS seats. The lower neck extension moment was 41.4 ± 7.8% with all MY ABTS seats compared to 32.5 ± 9.7% in modern seats (P =.07). Overall, the ABTS seats had 13% higher biomechanical responses than the modern seats.
Conclusions: Modern (≥2000 MY) design seats have lower biomechanical responses in 40.2 km/h rear sled tests than older (<2000 MY) designs and ABTS designs. The improved performance is consistent with an increase in seat strength combined with improved occupant kinematics through pocketing of the occupant into the seatback, higher and more forward head restraint, and other design changes. The methods and data presented here provide a basis for standardized testing of seats. However, a complete understanding of seat safety requires consideration of out-of-position (OOP) occupants in high-speed impacts and consideration of the much more common, low-speed rear impacts. 相似文献
Methods: Injury distributions were examined by occupant age and vehicle model year (stratified at pre- and post-2009). Logistic regression models were developed to examine the effects of various factors on injury risk (by body region), controlling for delta-V, sex, age, height, body mass index (BMI), vehicle model year (again stratified at 2009).
Results: Among other observations, these analyses indicate that newer model year vehicles (model year [MY] 2009 and later) carry less risk of Abbreviated Injury Scale (AIS) 2+ and AIS 3+ injury compared to older model year vehicles, with odds ratios of 0.69 (AIS 2+) and 0.45 (AIS 3+). The largest reductions in risk between newer model year vehicles and older model year vehicles occur in the lower extremities and in the risk of skull fracture. There is no statistically significant change in risk of AIS 3+ rib fracture or sternum injury between model year categories. Females are at greater risk of AIS 2+ and AIS 3+ injury compared to males, with increased risk across most injury types.
Conclusions: For belted occupants in frontal collisions, substantial reductions in injury risk have been realized in many body regions in recent years. Risk reduction in the thorax has lagged other body regions, resulting in increasing prevalence among skeletal injuries in newer model year vehicles (especially in the elderly). Injuries also remain common in the arm and hand/wrist for all age ranges studied. These results provide insight into where advances in the field have made gains in occupant protection and what injury types remain to be addressed. 相似文献