Effects of the Variation in Brain Tissue Mechanical Properties on the Intracranial Response of a 6-Year-Old Child

Brain tissue mechanical properties are of importance to investigate child head injury using finite element (FE) method. However, these properties used in child head FE model normally vary in a large range in published literatures because of the insufficient child cadaver experiments. In this work, a head FE model with detailed anatomical structures is developed from the computed tomography (CT) data of a 6-year-old healthy child head. The effects of brain tissue mechanical properties on traumatic brain response are also analyzed by reconstruction of a head impact on engine hood according to Euro-NCAP testing regulation using FE method. The result showed that the variations of brain tissue mechanical parameters in linear viscoelastic constitutive model had different influences on the intracranial response. Furthermore, the opposite trend was obtained in the predicted shear stress and shear strain of brain tissues caused by the variations of mentioned parameters

Severe head injuries in children

The aim of this dissertation is to review the current literature on severe head injuries in children, with particular respect to epidemiology, clinical features and investigation, pathophysiology, management and outcome. In addition a retrospective study was carried out on severe head injuries at Red Cross War Memorial Children's Hospital. Finally, the findings of this study are discussed in the light of the experience of other neurosurgical and trauma centres. In this way similarities as well as features peculiar to our setting can be identified with the aim of improving the understanding and management of severe head injuries in children in the Western Cape

Computational simulation of skull fracture patterns in pediatric subjects using a porcine model

In cases of suspected child abuse with skeletal trauma, it is often the role of the injury biomechanist, forensic pathologist, clinical radiologist, and forensic anthropologist to determine the mechanism of injury when the child victims cannot speak for themselves. This is a challenging task, especially for the head, as comprehensive biomechanical data on skull fracture in infants and children do not currently exist, and frequently the determination regarding cause of injury is based on anecdotal evidence from the medical literature and unsubstantiated eyewitness accounts. The current process may result in unreliable autopsy interpretation and miscarriages of justice due to a lack of scientific verification in expert witness testimony. A method to examine the mechanisms of skeletal trauma, specifically skull fracture, in children would be beneficial in providing a solid biomechanical foundation to the forensic investigators in these child abuse cases. Finite element (FE) computational modeling techniques can be used to simulate failure of materials, including biological materials such as bone. However the efficacy of these methods has not been thoroughly tested against a well-defined experimental dataset, particularly for the pediatric population. The specific aims of this study were: (1)To determine appropriate constitutive laws and material properties for the piglet skull and suture, (2) To predict skull fracture patterns in a piglet model using FE methods, and (3) To analyze the sensitivity and robustness of these FE techniques for reliable biomechanical and forensic analysis. Results highlight the ability of macro-scale blunt impact computational models to predict fracture initiation sites and the role of computational models in guiding future experimental work

A comparison in a youth population between those with and without a history of concussion using biomechanical reconstruction

OBJECTIVE: Concussion is a common topic of research as a result of the short- and long-term effects it can have on the affected individual. Of particular interest is whether previous concussions can lead to a biomechanical susceptibility, or vulnerability, to incurring further head injuries, particularly for youth populations. The purpose of this research was to compare the impact biomechanics of a concussive event in terms of acceleration and brain strains of 2 groups of youths: those who had incurred a previous concussion and those who had not. It was hypothesized that the youths with a history of concussion would have lower-magnitude biomechanical impact measures than those who had never suffered a previous concussion. METHODS: Youths who had suffered a concussion were recruited from emergency departments across Canada. This pool of patients was then separated into 2 categories based on their history of concussion: those who had incurred 1 or more previous concussions, and those who had never suffered a concussion. The impact event that resulted in the brain injury was reconstructed biomechanically using computational, physical, and finite element modeling techniques. The output of the events was measured in biomechanical parameters such as energy, force, acceleration, and brain tissue strain to determine if those patients who had a previous concussion sustained a brain injury at lower magnitudes than those who had no previously reported concussion. RESULTS: The results demonstrated that there was no biomechanical variable that could distinguish between the concussion groups with a history of concussion versus no history of concussion. CONCLUSIONS: The results suggest that there is no measureable biomechanical vulnerability to head impact related to a history of concussions in this youth population. This may be a reflection of the long time between the previous concussion and the one reconstructed in the laboratory, where such a long period has been associated with recovery from injury

Biomechanics and injury assessment of household falls in children : clinical, anthropomorphic surrogate, and computer simulation studies.

Pediatric short-distance falls, especially from beds or other furniture, are common false histories given by caretakers to cover up abusive trauma. However, short-distance falls are also a common occurrence in young children. Knowledge of the types and severity of injuries that can result from these short falls can aid clinicians in distinguishing between inflicted and non-inflicted injuries. Early detection of abuse may lead to prevention of further escalating injuries and, in some cases, prevent the death of the child. The purpose of this study was to describe relationships between biomechanical measures and injury potential in short-distance household falls. This study involved three components: case-based biomechanical fall assessments, fall simulations using an anthropomorphic test device (ATD), and development/validation of a computer simulation model used to investigate sensitivity of injury outcome measures to fall environment and child surrogate parameters. Overall, the risk of severe or life-threatening injury in short-distance household falls is low. Fractures of the skull and extremities commonly result from these falls (21.5% of falls resulting in Emergency Department visits). 2 of 79 fall cases involved small, contact-type subdural hematomas. These subjects both had unique fall dynamics that contributed to their injuries. Results of ATD experiments supported those from the clinical portion of the study with the exception of neck injury potential. Future studies are needed to both improve ATD neck biofidelity and determine more accurate pediatric neck injury thresholds. Fall environment parameters (fall height and impact surface type) have been shown previously to influence injury potential, but this is the first study to investigate the influence of child or surrogate parameters (body mass index, overall mass, head stiffness, and neck properties) on injury potential. Additionally, through a parametric sensitivity analysis, it was found that fall environment and surrogate parameters that altered fall dynamics had the greatest influence on injury potential. These results highlight the need for obtaining detailed case histories when making injury assessments that include not only environment and child factors, but descriptions of the fall dynamics and orientation of the child upon impact with the ground

Injury and Skeletal Biomechanics

This book covers many aspects of Injury and Skeletal Biomechanics. As the title represents, the aspects of force, motion, kinetics, kinematics, deformation, stress and strain are examined in a range of topics such as human muscles and skeleton, gait, injury and risk assessment under given situations. Topics range from image processing to articular cartilage biomechanical behavior, gait behavior under different scenarios, and training, to musculoskeletal and injury biomechanics modeling and risk assessment to motion preservation. This book, together with "Human Musculoskeletal Biomechanics", is available for free download to students and instructors who may find it suitable to develop new graduate level courses and undergraduate teaching in biomechanics

Accid Anal Prev

Falls are a major cause of traumatic head injury in children. Understanding head kinematics during low height falls is essential for evaluating injury risk and designing mitigating strategies. Typically, these measurements are made with commercial anthropomorphic infant surrogates, but these surrogates are designed based on adult biomechanical data. In this study, we improve upon the state-of-the-art anthropomorphic testing devices by incorporating new infant cadaver neck bending and tensile data. We then measure head kinematics following head-first falls onto 4 impact surfaces from 3 fall heights with occipital and parietal head impact locations. The biofidelic skull compliance and neck properties of the improved infant surrogate significantly influenced the measured kinematic loads, decreasing the measured impact force and peak angular accelerations, lowering the expected injury risk. Occipital and parietal impacts exhibited distinct kinematic responses in primary head rotation direction and the magnitude of the rotational velocities and accelerations, with larger angular velocities as the head rebounded after occipital impacts. Further evaluations of injury risk due to short falls should take into account the impact surface and head impact location, in addition to the fall height.R01 CE001445/CE/NCIPC CDC HHS/United StatesR01 NS039679/NS/NINDS NIH HHS/United StatesR01NS039679/NS/NINDS NIH HHS/United StatesR49CE000411/CE/NCIPC CDC HHS/United States2016-09-01T00:00:00Z26072183PMC451518

Hard hitting facts on childhood head trauma: an epidemiological analysis

Background: According to the World Health Organization (WHO), Traumatic Brain Injury (TBI) will become the third largest cause of global disease by the year 2020. Despite its astonishing numbers, TBI remains a silent or even forgotten epidemic with significant paucity in epidemiological data. TBI in developing countries represents a disproportionate burden of disease and data are lacking regarding the unique demographics in South Africa to design and implement focused prevention programmes. A valuable tool to assess the severity of TBI is the use of Computer tomography (CT). CT also is the main imaging modality to provide rapid identification and information for the management of children with TBI. CT scanning utilises ionising radiation and as an imaging modality poses risk to the patient. In order to guide decision protocol/algorithm, various Clinical Decision Rules (CDRs) have been established in High Income Countries. These protocols, including the need for CT scan might differ in a Medium/Low Income setting. Methodology: This is a prospective, single centre cohort study. Data were collected over an 18-month period (1 August 2015 - 31 January 2017). Children under the age of 13 years (n=3007) presenting to RCWCH after sustaining a head injury were included. Various epidemiological data were collected. A Road Safety Questionnaire was also used to evaluate safety knowledge of health care workers. Three different CDRs were compared to the standard of practice in RCWCH. A final analysis of demographics, mechanism of injury, radiology outcome, safety analysis and evaluation of a comparison of local protocol compared to the other CDRs was performed using descriptive statistics. Results: The mean age of paediatric patients presenting after a head injury was 4.6 years. There was a significant male predominance (66%) and almost two thirds of all children were of pre-school age. Falls (53%; n=1601) represented the most common mechanism of injury across all age groups, followed by road traffic related injuries (RTI) (29%; n=864), struck by or against an object (9%; n=279) and injuries as a result of interpersonal violence (8%; n=230). Within the subset of RTI (n=864) only 6 passengers were appropriately restrained, with 142 unrestrained and 56 passengers transported on the back of a goods vehicle. In the under 3-yearold age group, only 1 patient was appropriately transported in a car seat, with 51 unrestrained and 6 transported on the back of a goods vehicle. Pedestrian related injuries were by far the largest group of RTI (70%) with 50% of these under the age of 5 years. Intentional injuries inflicted by an adult were most common (34%) in the pre-verbal (under 2 years old) group. Interpersonal violence among minors (assault with a brick or stone) constituted 52% of intentional injuries. Eight firearm related injuries were recorded. Appliances and iron gates that were not correctly installed were additional causes of injury. CT scans were obtained according to the RCWCH protocol in 59% of cases and 34% showed an abnormal result. The sensitivity (98%) and specificity (93%) while using the standard of practice protocol was better than the 3 CDRs developed in High Income Countries. Analysing our Road Safety Questionnaire there appears great room for improvement regarding awareness of road safety guidelines and legislation. Conclusion: The performance of the current RCWCH CT scan protocol appears appropriate in our setting although there is some room for improvement using the strengths of the other CDRs. Valuable insight regarding the epidemiology of TBI in our setting has been highlighted. Of specific importance is the large proportion of very young children at risk of injury by all mechanisms of injury, particularly pedestrian-related injuries, unrestrained passengers and interpersonal violence among minors. Important gaps in knowledge about current recommendations for road safety were identified by the questionnaire. As long as these issues are not appropriately addressed through enhanced injury prevention programmes, children will continue to carry the heavy burden of TBI morbidity and mortality

Pedestrian Head Protection During Car To Pedestrian Accidents: In The Event Of Primary Impact With Vehicle And Secondary Impact With Ground

Current regulations for assessing pedestrian safety use a simplified test setup that ignores many real-world factors. In particular, the level of protection is assessed using a free-motion headform impacting the vehicle\u27s hood at a fixed angle. As such, this test setup does not capture the effect due to the vehicle front-end profile, nor does it comprehend injury due to a possible secondary impact of the pedestrian\u27s head with ground. This thesis aims to numerically simulate vehicle to pedestrian crashes to develop knowledge that may suggest ways to improve safety above and beyond the regulatory tests. Inputs to the simulations include the vehicle front-end profile, impact speed, and pedestrian size. Outputs include the angle of primary head impact to the hood, the extent of head injury (HIC), and whether or not there is a secondary head impact with the ground. One key finding is that head impact angles, and hence head injury measures, vary greatly due to changes in vehicle front-end profile. This suggests that the current test setup for assessing pedestrian head impact, which assumes a fixed head-impact angle, could be improved to better capture the kinematics of real-world pedestrian crash events. One improvement could be the use of a full scale pedestrian dummy or human body model rather than a free motion headform. A second finding is that severity of head injury is much greater in a secondary head impact with ground than in the primary impact with the hood. Moreover, it is possible to avoid the secondary head impact with ground by careful designing of vehicle front-end profile. More research needs to be carried out to prove that concepts developed through numerical simulations also works in physical tests