Comparison of thoracolumbar spine kinematics and injuries in reclined frontal impact sled tests between mid-size adult female and male PMHS.

Disparities in injury tolerance and kinematic response remain understudied despite field data highlighting sex-based differences in injury risk. Furthermore, the automotive industry anticipates occupants will prefer reclined seating in highly automated vehicles. This study aimed to compare thoracolumbar spine kinematics and injuries between mid-size female and male post-mortem human subjects (PMHS) in reclined frontal impacts. Seven adult PMHS (three female, four male) were tested in reclined (50°) 50 km/h frontal impacts. The PMHS were seated on a semi-rigid seat and restrained by a prototype three-point seat belt system designed to mitigate submarining. The 3-D motions of five vertebrae and the pelvis were measured by an optical motion tracking system. Pressure transducers were inserted into intervertebral discs at three locations along the lumbar spine to track timing of lumbar vertebra fractures. Due to variations in the geometry of the pelvis and soft tissue surrounding the pelvis compared to the male subjects, the female subjects could not be positioned in the seat the same as the males, and, as a result, the females and their belt anchors needed to be translated forward in the seat to maintain similar belt geometry relative to the males. The females exhibited similar pre-test spinal curvatures and kinematics to the males. An L1 fracture was observed in one of three female subjects and two of four male subjects, and timing of these fractures were both similar (61 âˆ¼ 65 ms) and close to the time of peak downward seat force. Generally, the female and male subjects exhibited similar kinematic and injury responses in this reclined frontal impact sled test condition.

Development of an Injury Risk Function for the Anterior Pelvis Under Frontal Lap Belt Loading Conditions.

Iliac wing fractures due to lap belt loading have been identified in laboratory tests for almost 50 years and an analysis of recent data suggests these injuries are also occurring in the field. With the introduction of highly autonomous vehicles on the horizon, vehicle manufacturers are exploring open cabin concepts that permit reclined postures and separation of the occupant from the knee bolster and instrument panel. This will result in greater reliance on the lap belt and lap belt/pelvis loading to restrain occupants. No injury criteria exist for iliac wing fractures resulting from lap belt loading like that seen in frontal crash conditions. This study tested the tolerance of isolated iliac wings in a controlled lap belt-like loading environment while incorporating the effect of loading angle after analyzing lap belt loading experiments from a previous study. Twenty-two iliac wings were tested; nineteen of them sustained fracture (exact), but the loading input was insufficient to cause fracture in the other three (right censored). The fracture tolerance of the tested specimens ranged widely (1463-8895 N) and averaged 4091 N (SD 2381 N). Injury risk functions were created by fitting Weibull survival models to data that integrated censored and exact failure observations.

Characterization of fatal injuries in oil and gas industry-related helicopter accidents in the Gulf of Mexico, 2004-2014.

BACKGROUND: Transportation events are the most common cause of offshore fatalities in the oil and gas industry, of which helicopter accidents comprise the majority. Little is known about injury distributions in civilian helicopter crashes, and knowledge of injury distributions could focus research and recommendations for enhanced injury prevention and post-crash survival. This study describes the distribution of injuries among fatalities in Gulf of Mexico oil and gas industry-related helicopter accidents, provides a detailed injury classification to identify potential areas of enhanced safety design, and describes relevant safety features for mitigation of common injuries. METHODS: Decedents of accidents during 2004-2014 were identified, and autopsy reports were requested from responsible jurisdictions. Documented injuries were coded using the Abbreviated Injury Scale (AIS), and frequency and proportion of injuries by AIS body region and severity were calculated. Injuries were categorized into detailed body regions to target areas for prevention. RESULTS: A total of 35 autopsies were coded, with 568 injuries documented. Of these, 23.4% were lower extremity, 22.0% were thorax, 13.6% were upper extremity, and 13.4% were face injuries. Minor injuries were most prevalent in the face, neck, upper and lower extremities, and abdomen. Serious or worse injuries were most prevalent in the thorax (53.6%), spine (50.0%), head (41.7%), and external/other regions (75.0%). The most frequent injuries by detailed body regions were thoracic organ (23.0%), thoracic skeletal (13.3%), abdominal organ (9.6%), and leg injuries (7.4%). Drowning occurred in 13 (37.1%) of victims, and drowning victims had a higher proportion of moderate brain injuries (7.8%) and lower number of documented injuries (3.8) compared with non-drowning victims (2.9 and 9.4%, respectively). CONCLUSIONS: Knowledge of injury distributions focuses and prioritizes the need for additional safety features not routinely used in helicopters. The most frequent injuries occurred in the thorax and lower extremity regions. Future research requires improved and expanded data, including collection of detailed data to allow characterization of both injury mechanism and distribution. Improved safety systems including airbags and helmets should be implemented and evaluated for their impact on injuries and fatalities.

Biomechanics of the Human Brain during Dynamic Rotation of the Head.

Traumatic brain injuries (TBI) are a substantial societal burden. The development of better technologies and systems to prevent and/or mitigate the severity of brain injury requires an improved understanding of the mechanisms of brain injury, and more specifically, how head impact exposure relates to brain deformation. Biomechanical investigations have used computational models to identify these relations, but more experimental brain deformation data are needed to validate these models and support their conclusions. The objective of this study was to generate a dataset describing in situ human brain motion under rotational loading at impact conditions considered injurious. Six head-neck human post-mortem specimens, unembalmed and never frozen, were instrumented with 24 sonomicrometry crystals embedded throughout the parenchyma that can directly measure dynamic brain motion. Dynamic brain displacement, relative to the skull, was measured for each specimen with four loading severities in the three directions of controlled rotation, for a total of 12 tests per specimen. All testing was completed 42-72 h post-mortem for each specimen. The final dataset contains approximately 5,000 individual point displacement time-histories that can be used to validate computational brain models. Brain motion was direction-dependent, with axial rotation resulting in the largest magnitude of displacement. Displacements were largest in the mid-cerebrum, and the inferior regions of the brain-the cerebellum and brainstem-experienced relatively lower peak displacements. Brain motion was also found to be positively correlated to peak angular velocity, and negatively correlated with angular velocity duration, a finding that has implications related to brain injury risk-assessment methods. This dataset of dynamic human brain motion will form the foundation for the continued development and refinement of computational models of the human brain for predicting TBI.