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Injury to the far side occupant has been demonstrated as a significant portion of the total trauma in side impacts. The objective of the study was to determine the response of PMHS in far side impact configurations, with and without generic countermeasures, and compare responses to the WorldSID and THOR dummies. A far side impact buck was designed for a sled test system that included a center console and three-point belt system. The buck allowed for additional options of generic countermeasures including shoulder or thorax plates or an inboard shoulder belt. The entire buck could be mounted on the sled in either a 90-degree (3-o'clock PDOF) or a 60-degree (2-o'clock PDOF) orientation. A total of 18 tests on six PMHS were done to characterize the far side impact environment at both low (11 km/h) and high (30 km/h) velocities. WorldSID and THOR-NT tests were completed in the same configurations to conduct matched-pair comparisons.

With the widespread use of supplemental restraint systems (airbags), occasional rare injuries have occurred because of the force associated with these systems upon deployment. Recent case studies have demonstrated forearm fractures associated with airbag deployment. The present study was conducted to determine the tolerance of the human forearm under a dynamic bending mode. A total of 30 human cadaver forearm specimens were tested using three-point bending protocol to failure at 3.3 m/s and 7.6 m/s velocities. Results indicated significantly (p < 0.01) greater biomechanical parameters associated with males compared to females. The bending tolerance of the human forearm, however, was found to be most highly correlated to bone mineral density, bone area, and forearm mass. Thus, any occupant with lower bone mineral density and lower forearm geometry/mass is at higher risk. The mean failure bending moment for all specimens was 94 Nm.

Inertial loading of the head-neck complex occurs in rear impacts wherein the head and neck of the occupant are initially subjected to rearward forces. Epidemiological evidence exists to demonstrate the significance and societal impact of these injuries [4]. From a clinical perspective, trauma secondary to inertial loads belongs to the lower end of the Abbreviated Injury Scale, and no specific diagnostic techniques are available to quantitatively document the injury. Furthermore, identification of the mechanisms of injury and derivation of injury thresholds are limited. In fact, there is a paucity of literature focusing on the reproduction of rear impact-induced neck injuries due to a single-event rear impact. Because the impact acceleration is transmitted to the head from the torso via the cervical column, the components of the human neck play a role in the mechanics of trauma.

Spinal trauma produced from motor vehicle accidents, diving accidents, or falls occur at high rates of loading. This study was undertaken to reproduce clinically relevant cervical spine injuries under controlled conditions. Six isolated head - T2 human cadaveric preparations were tested using an electrohydraulic piston actuator at loading rates from 295 to 813 cm/sec. The Hybrid III head-neck was tested similarly at rates from 401 to 683 cm/sec. The input forces for specimen tests were of higher magnitude and shorter duration than the distally measured forces. In contrast, the Hybrid III head-neck revealed similar magnitude and duration force traces from input to output. The specimen preparations were analyzed kinematically at 1200 frames/sec with 20 to 30 retroreflective targets fixed to each level of the cervical spine. With this technique it is possible to temporally follow cervical damage as a function of applied force.

Head injury is a serious threat to lives of people working around farm machinery. The consequence of head injuries are costly, paralytic, and often fatal. Clinical and biomechanical data on head injuries are reviewed and their application in the analysis of head injury risk associated with farm tractor discussed. A significant proportion of tractor-related injuries and deaths to adults, as well as children, is due directly or indirectly to head injury. An improved injury reporting program and biomechanical studies of human response to tractor rollover, runover, and falls, are needed to understand mechanisms of the associated head injury.

Sixty-three simulated frontal impacts using cadaveric specimens were performed to examine and quantify the performance of various contemporary automotive restraint systems. Test specimens were instrumented with accelerometers and chest bands to characterize their mechanical responses during the impact. The resulting thoracic injury severity was determined using detailed autopsy and was classified using the Abbreviated Injury Scale. The ability of various mechanical parameters and combinations of parameters to assess the observed injury severities was examined and resulted in the observation that belt restraint systems generally had higher injury rates than air bag restraint systems for the same level of mechanical responses. To provide better injury evaluations from observed mechanical parameters without prior knowledge of what restraint system was being used, a dichotomous process was developed.

Axial loading of the calcaneus-talus-tibia complex is an important injury mechanism for moderate and severe vehicular foot-ankle trauma. To develop a more definitive and quantitative relationship between biomechanical parameters such as specimen age, axial force, and injury, dynamic axial impact tests to isolated lower legs were conducted at the Medical College of Wisconsin (MCW). Twenty-six intact adult lower legs excised from unembalmed human cadavers were tested under dynamic loading using a mini-sled pendulum device. The specimens were prepared, pretest radiographs were taken, and input impact and output forces together with the pathology were obtained using load cell data. Input impact forces always exceeded the forces recorded at the distal end of the preparation. The fracture forces ranged from 4.3 to 11.4 kN.

The patho-anatomic alterations due to vertical loading of the human cervical column were documented and correlated with biomechanical kinematic data. Seven fresh human cadaveric head-neck complexes were prepared, and six-axis load cells were placed at the proximal and distal ends of the specimens to document the gross biomechanical response. Retroreflective markers were placed on bony landmarks of vertebral bodies, articular facets, and spinous processes along the entire cervical column. Targets were also placed on the occiput and arch of C1. The localized movements of these markers were recorded using a video analyzer during the entire loading cycle. Pre-test two-dimensional, and three-dimensional computerized tomography (CT), and plane radiographs were taken. The specimens were loaded to failure using an electrohydraulic testing device at a rate of 2 mm/s.

In the present investigation a tractor wheel runover accident was simulated to obtain biomechanical information relating to mechanism of injury. Twelve cadaver porcine specimens were runover with the right front wheel of a tractor. Specimens were placed on a six-axis force plate and thorax contours were recorded temporally. Results indicated up to 68% compression of the chest occurred during the runover event. The shear force in the direction of travel was a significant factor in the type of fractures that occurred to the rib cage. Pathology determined from x-ray revealed multiple fractures per rib in the area directly below the path of the tire. Autopsy evaluation revealed soft tissue contusion on the left side in the area of wheel path. There was often extra blood in the pericardial space and examination of the brain showed petechial hemorrhaging subdurally.

Engineering efforts directed at better occupant safety require a thorough understanding of available epidemiologic data. Epidemiologic studies using clinical as well as accident information facilitates the prioritization of biomechanics research so that controlled laboratory experimentation and/or analytical models can be advanced. This information has also value in dictating levels and types of injury that are critical to the development of anthropomorphic test devices used in crash environments. In this paper, motor vehicle accident related (excluding pedestrians, bicyclists, and motorcyclists) epidemiologic data were obtained from clinical and computerized accident (National Accident Sampling System-NASS) files. Clinical data were gathered from patients admitted to the Medical College of Wisconsin Affiliated Hospitals, and fatalities occurring in Milwaukee County, State of Wisconsin. NASS database with specific focus on spinal injuries of motor vehicle occupants was also used.

This study was conducted to collect data and gain insights relative to the mechanisms and factors involved in hip injuries during frontal crashes and to study the tolerance of hip injuries from this type of loading. Unembalmed human cadavers were seated on a standard automotive seat (reinforced) and subjected to knee impact test to each lower extremity. Varying combinations of flexion and adduction/abduction were used for initial alignment conditions and pre-positioning. Accelerometers were fixed to the iliac wings and twelfth thoracic vertebral spinous process. A 23.4-kg padded pendulum impacted the knee at velocities ranging from 4.3 to 7.6 m/s. The impacting direction was along the anteroposterior axis, i.e., the global X-axis, in the body-fixed coordinate system. A load cell on the front of the pendulum recorded the impact force. Peak impact forces ranged from 2,450 to 10,950 N. The rate of loading ranged from 123 to 7,664 N/msec. The impulse values ranged from 12.4 to 31.9 Nsec.

Recent epidemiology studies have reported increase in lumbar spine injuries in frontal crashes. Whole human body finite element models (FEHBM) are frequently used to delineate mechanisms of such injuries. However, the accuracy of these models in mimicking the response of human spine relies on the characterization data of the spine model. The current study set out to generate characterization data that can be input to FEHBM lumbar spine, to obtain biofidelic responses from the models. Twenty-five lumbar functional spinal units were tested under compressive loading. A hydraulic testing machine was used to load the superior ends of the specimens. A 75N load was placed on the superior PMMA to remove the laxity in the joint and mimic the physiological load. There were three loading sequences, namely, preconditioning, 0.5 m/s (non-injurious) and 1.0 m/s (failure). Forces and displacements were collected using six-axis load cell and VICON targets.

Lower extremity injuries caused by floor plate impacts through the axis of the lower leg are a major source of injury and disability for civilian and military vehicle occupants. A collection of PMHS pendulum impacts was revisited to obtain data for paired booted/unbooted test on the same leg. Five sets of paired pendulum impacts (10 experiments in total) were found using four lower legs from two PMHS. The PMHS size and age was representative of an average young adult male. In these tests, a PMHS leg was impacted by a 3.4 or 5.8 kg pendulum with an initial velocity of 5, 7, or 10 m/s (42-288 J). A matching LS-DYNA finite element model was developed to replicate the experiments and provide additional energy, strain, and stress data. Simulation results matched the PMHS data using peak values and CORA curve correlations. Experimental forces ranged between 1.9 and 12.1 kN experimentally and 2.0 and 11.7 kN in simulation.

Cervical spine injuries can occur in military scenarios from events such as underbody blast events. Such scenarios impart inferior-to-superior loads to the spine. The objective of this study is to develop human injury risk curves (IRCs) under this loading mode using Post Mortem Human Surrogates (PMHS). Twenty-five PMHS head-neck complexes were obtained, screened for pre-existing trauma, bone densities were determined, pre-tests radiological images were taken, fixed in polymethylmethacrylate at the T2-T3 level, a load cell was attached to the distal end of the preparation, positioned end on custom vertical accelerator device based on the military-seating posture, donned with a combat helmet, and impacted at the base. Posttest images were obtained, and gross dissection was done to confirm injuries to all specimens. Axial and resultant forces at the cervico-thoracic joint was used to develop the IRCs using survival analysis.

During certain events such as underbody blasts due to improvised explosive devices, occupants in military vehicles are exposed to inferior-to-superior loading from the pelvis. Injuries to the pelvis-sacrum-lumbar spine complex have been reported from these events. The mechanism of load transmission and potential variables defining the migration of injuries between pelvis and or spinal structures are not defined. This study applied inferior-to-superior impacts to the tuberosities of the ischium of supine-positioned five post mortem human subjects (PMHS) using different acceleration profiles, defined using shape, magnitude and duration parameters. Seventeen tests were conducted. Overlay temporal plots were presented for normalized (impulse momentum approach) forces and accelerations of the sacrum and spine.

A series of twenty-nine tests was completed by conducting static deployment of side airbag systems to an out-of-position Hybrid III three-year-old dummy. Mock-ups (bucks) of vehicle occupant compartments were constructed. The dummy was placed in one of four possible positions for both door- and seat-mounted side airbag systems. When data from each type of position test were combined for the various injury parameters it was noted that the head injury criteria (HIC) were maximized for head and neck tests, and the chest injury parameters were maximized for the chest tests. For the neck injury parameters, however, all of the test positions produced high values for at least one of the parameters. The study concluded the following. Static out-of- position child dummy side airbag testing is one possible method to evaluate the potential for injury for worst-case scenarios. The outcome of these tests are sensitive to preposition and various measurements should be made to reproduce the tests.

Injury to the far side occupant has been demonstrated as a significant portion of the total trauma in side impacts. The objective of the study was to determine the response of PMHS in far side impact configurations, with and without generic countermeasures, and compare responses to the WorldSID and THOR dummies. A far side impact buck was designed for a sled test system that included a center console and three-point belt system. The buck allowed for additional options of generic countermeasures including shoulder or thorax plates or an inboard shoulder belt. The entire buck could be mounted on the sled in either a 90-degree (3-o'clock PDOF) or a 60-degree (2-o'clock PDOF) orientation. A total of 18 tests on six PMHS were done to characterize the far side impact environment at both low (11 km/h) and high (30 km/h) velocities. WorldSID and THOR-NT tests were completed in the same configurations to conduct matched-pair comparisons.

It is well known that rotational loading is responsible for a spectrum of diffuse brain injuries spanning from concussion to diffuse axonal trauma. Many experimental studies have been performed to understand the pathological and biomechanical factors associated with diffuse brain injuries. Finite element models have also been developed to correlate experimental findings with intrinsic variables such as strain. However, a paucity of studies exists examining the combined role of the strain-time parameter. Consequently, using the principles of finite element analysis, the present study introduced the concept of sustained maximum principal strain (SMPS) criterion and explored its potential applicability to diffuse brain injury. An algorithm was developed to determine if the principal strain in a finite element of the brain exceeded a specified magnitude over a specific time interval.

The objective of the present study was to determine the thorax and abdomen deflections sustained by post mortem human surrogate (PMHS) in oblique side impact sled tests and compare the responses and injuries with pure lateral tests. Oblique impact tests were conducted using modular and non-modular load-wall designs, with the former capable of accommodating varying anthropometry. Tests were conducted at 6.7 m/s velocity. Deflection responses from chestbands were analyzed from 15 PMHS tests: five each from modular load-wall oblique, non-modular load-wall oblique and non-modular load-wall pure lateral impacts. The thorax and abdomen peak deflections were greater in non-modular load-wall oblique than pure lateral tests. Peak abdomen deflections were statistically significantly different while the upper thorax deflections demonstrated a trend towards significance.

The objective of the present exploratory study is to understand occupant responses in oblique and side-facing seats in the aviation environment, which are increasingly installed in modern aircrafts. Sled tests were conducted using intact Post Mortem Human Surrogates (PMHS) seated in custom seats approximating standard aircraft geometry. End conditions were selected to represent candidate aviation seat and restraint configurations. Three-dimensional head center-of-gravity linear accelerations, head angular velocities, and linear accelerations of the T1, T6, and T12 spinous processes, and sacrum were obtained. Three-dimensional kinematics relative to the seat were obtained from retroreflective targets attached to the head, T1, T6, T12, and sacrum. All specimens sustained spinal injuries, although variations existed by vertebral level.