Biomechanics Commons^™

The Effect Of Repetitive Sub-Concussive Head Impacts In A Rodent Model And Its Implication In Contact Sports, Jay Venkatraman

Wayne State University Dissertations

Traumatic Brain Injury (TBI) is the damage caused to the brain by an external force causing rapid acceleration and deceleration of the brain, and a sub-concussive impact is defined as a bump, blow or jolt to the head not resulting in any apparent symptoms. Within the United States, around 1.7 million people suffer from TBI, of which sports-related injuries are the cause for one-third of the head injuries. It is estimated that approximately 20% of professional boxers experience at least one incidence of concussion or knockout in their careers and 40% of retired boxers suffer from lasting effects ranging from …

Comparison Of The Dynamic Response And Fracture Characteristics Of Female And Male Lumbar Spine And Pelvis In Underbody Blast Loading, Hollie Ann Pietsch

Wayne State University Dissertations

Underbody blast (UBB) attacks on US Military vehicles in the recent conflicts resulted in debilitating injuries to mounted Warfighters. Biomechanical research studies in the last decade aimed to understand UBB related injuries to guide protective technology designs for military ground vehicles. The design of protective seats is driven by injuries to the pelvis and lumbar spine, which are aligned with the vertical direction of UBB loading. When the US Military began to open many combat roles to female soldiers in 2016, a need arose to understand the impact of survivability and protection for the female Warfighter population as well. Although …

Investigation Of Biomechanical Thresholds Of Mild To Severe Brain Injury Using An Anisotropic Visco-Hyperelastic Finite Element Head Model: Model Development And Simulation Of Impact Injury And Blast Injury, Ding Lyu

Wayne State University Dissertations

Traumatic Brain Injury (TBI) is a significant cause of death and disability in the United States, with approximately 2.5 million emergency department visits, 288,000 hospitalizations, and 56,800 deaths reported to be related to TBI. The majority of TBIs are caused by blunt impacts resulting from falls and motor vehicle crashes. The head injury criterion is the only standard used to assess the safety related to vehicles, personal protective gear, and sports equipment. A new brain injury criterion assessing rotation velocity effect was recently proposed by the US government. Unfortunately, it derivation from animal data scaled to a computer model of …

Development Of Rat Head Finite Element Model And Tissue Level Biomechanical Threshold For Traumatic Axonal Injury, Runzhou Zhou

Wayne State University Dissertations

Traumatic brain injury (TBI) is caused by local tissue deformation at the time of trauma, leading to neurological dysfunction. In the United States alone, 2.87 million people sustain a TBI each year, of which one-fifth results in death. Traumatic axonal injury (TAI) is a well-recognized consequence of every fatal head injury and more than 85% of vehicular crash-related blunt head injuries. The most common and important pathologic feature of TBIs are multifocal changes to axons in the white matter produced by rapid head acceleration/deceleration during a traumatic event with consequent local shear/tension on neural tissue and axons contributing to secondary …

Optimization Of Underbody Blast Energy-Attenuating Seat Mechanisms Using Modified Madymo Hybrid Iii And Human Body Models, Kelly Erin Bryan Bosch

Wayne State University Dissertations

Energy attenuating (EA) blast seats, although not new to the market, have not been fully characterized with respect to energy attenuation capability and the resulting effects on occupant protection. EA seats utilize stroking mechanisms to absorb energy and reduce the vertical forces imparted on the occupant’s pelvis and lower spine complex. Although a variety of EA seats are available on the market, the fundamental question behind how to optimize the force and deflection rates of the EA mechanisms to effectively reduce occupant injury has not yet been answered. Using modeling and simulation techniques, this research developed a tool to determine …

Engineering Hyaluronic Acid Carbon Nanotube Nanofibers: A Peripheral Nerve Interface To Electrically Stimulate Regeneration, Elisabeth M. Steel

Wayne State University Dissertations

Peripheral nerve injuries annually affect hundreds of thousands of people globally. Current treatments like the gold standard autograft and commercially available nerve guide conduits (NGC) are insufficient to repair long gap peripheral nerve injuries. NGCs can aid recovery but lack key microenvironment cues that promote nerve regeneration. We hypothesized that providing topographical, mechanical, and electrical guidance cues through a nanofibrous composite biopolymer would result in improved neuron growth metrics using an in vitro model. We embedded hydrophilic carbon nanotubes (CNT) within hyaluronic acid (HA) nanofibers by electrospinning. The aims of this study were (1) to define the topographical, nanomechanical, and …

An Investigation Of The Mechanism Of Traumatic Brain Injury Caused By Blast In The Open Field, Ke Feng

Wayne State University Dissertations

Blast-induced traumatic brain injury (bTBI) is a signature wound of modern warfare. The current incomplete understanding of its injury mechanism impedes the development of strategies for effective protection of bTBI. Despite a considerable amount of experimental animal studies focused on the evaluation of brain neurotrauma caused by blast exposure, there is very limited knowledge on the biomechanical responses of the gyrenecephalic brain subjected to primary free-field blast waves imposed in vivo, and the correlation analysis between the biomechanical responses and its injury outcomes. Such information is crucial to the development of injury criteria of bTBI.

This study aims to evaluate …

Biomechanics Of Concussion: The Importance Of Neck Tension, Ron Jadischke

Wayne State University Dissertations

Linear and angular velocity and acceleration of the head are typically correlated to concussion. Despite improvements in helmet performance to reduce accelerations, a corresponding reduction in the incidence of concussion has not occurred (National Football League [NFL] 1996 – present).

There is compelling research that forces on and deformation to the brain stem are related to concussion. The brain stem is the center of control for respiration, blood pressure and heart rate and is the root of most cranial nerves. Injury to the brain stem is consistent with most symptoms of concussion reported in the National Football League and the …

Biofidelity Assessment Of 6-Year-Old Anthropometric Test Devices (Atds) And Scaling Laws In Lateral Impact, Jennifer Yaek

Wayne State University Dissertations

There is a clear need to further develop the design and biofidelity of the 6-Year-Old ATDs for future child safety research and child occupant protection in side impacts. Due to the scarcity of pediatric PMHS impact testing, specifically in the lateral direction, alternative means of obtaining relevant data for pediatric models need to be considered.

In this first portion of this study, assessment of the mechanical behavior and biofidelity of existing 6-Year-Old ATDs in lateral impact were performed. None of the three 6-year-old ATDs (HIII, Q6, and Q6s) tested were found to be considered good tools for assessing side impact …

Development Of A Finite Element Pelvis And Lower Extremity Model With Growth Plates For Pediatric Pedestrian Protection, Ming Shen

Wayne State University Dissertations

Finite element (FE) model is a useful tool frequently used for investigating the injury mechanisms and designing protection countermeasures. At present, no 10 years old (YO) pedestrian FE model has been developed from appropriate anthropometries and validated against limitedly available impact response data. A 10 YO child FE pelvis and lower extremities (PLEX) model was established to fill the gap of lacking such models in this age group. The baseline model was validated against available pediatric postmortem human subjects (PMHS) test data and additional scaled adult data, then the PLEX model was integrated to build a whole-body FE model representing …

Identifying The Function Of The Calpain Small Subunit In The Mechanics Of Cell Migration, Bingqing Hao

Wayne State University Dissertations

Cell migration plays a vital role in many physiological events including: morphogenesis, wound healing, and immune response. Dysfunctional cell migration results in multiple disease states including chronic inflammation, vascular disease, and tumor metastasis, to name a few. Progress in understanding the mechanism of cell migration had been slow until the turn of the century when rapid technological advances in microscopy and omics burst to the forefront. These advances led to the realization that physical factors (dimensions, fluid shear stress, hydrostatic pressure, compression stress, environmental stiffness, and topography) have profound effects on cell migration. This study of cell mechanics has expanded …

Development Of An Elderly Female Torso Finite Element Model For Restraint System Research And Development Applications, Anil Kalra Kalra

Wayne State University Dissertations

Elderly females are found to be one of the most vulnerable segments of population during motor vehicle crashes and their population is increasing in the coming decades. Current design of restraint systems as well as other passive safety measures are designed based on anthropomorphic details of younger population. Developing another dummy representing elderly female population is a costly effort, while a finite element (FE) model of elderly female with similar anthropomorphic details and age- and gender-specific material properties can be a better alternative solution. The current research focuses on the development of a FE model of an elderly female torso, …

An Investigation Of The Relationship Between Axonal Injury, Biomarker Expression And Mechanical Response In A Rodent Head Impact Acceleration Model, Yan Li

Wayne State University Dissertations

In the United States 1.4 million people sustain traumatic brain injury (TBI) each year, resulting in 235,000 hospitalizations and 50,000 fatalities annually. Traumatic axonal injury (TAI) is a serious outcome of TBI that accounts for 40-50% of hospitalizations due to head injury and one third of the mortality due to TBI, and it is difficult to diagnose and evaluate. The purpose of this dissertation is to determine mechanical injury predictors for TAI and identify potential biomarkers to evaluate TAI.

In this dissertation, a modified Marmarou impact acceleration injury model was developed to allow the monitoring of velocity of the impactor …

The Relationship Between Axonal Injury, Biomarker Expression And Mechanical Response In A Rodent Head Impact Acceleration Model, Yan Li

Wayne State University Dissertations

In the United States 1.4 million people sustain traumatic brain injury (TBI) each year, resulting in 235,000 hospitalizations and 50,000 fatalities annually. Traumatic axonal injury (TAI) is a serious outcome of TBI that accounts for 40-50% of hospitalizations due to head injury and one third of the mortality due to TBI, and it is difficult to diagnose and evaluate. The purpose of this dissertation is to determine mechanical injury predictors for TAI and identify potential biomarkers to evaluate TAI.

In this dissertation, a modified Marmarou impact acceleration injury model was developed to allow the monitoring of velocity of the impactor …

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

Wayne State University Dissertations

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's 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's 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 …

Biophysical And Biochemical Factors In The Cellular Microenvironment; Effects On Cell Migration And Invasion, Shalini Menon

Wayne State University Dissertations

Cellular migration is a vital process central to many physiological events including development, immune surveillance and wound healing. However, migration and invasion are not unique to normal physiology, they are also key determinants in the progression of disease states such as cancer. Given the significance of migration it is important that we understand how the process is regulated intracellularly and the various stimuli that can promote it. Even though the role of biochemical factors in mediating migration has been studied extensively, the role of biophysical factors in modulating migration and invasion is less appreciation. The biochemical and biophysical components of …

Finite Element Reconstruction Of Real World Aortic Injury In Near-Side Lateral Automotive Crashes With Conceptual Countermeasures, Aditya Neelakanta Belwadi

Wayne State University Dissertations

Traumatic rupture of the aorta (TRA) remains the second most common cause of death associated with motor vehicle crashes after brain injury. On an average, nearly 8,000 people die annually in the United States due to blunt injury to the aorta. It is observed that more than 80% of occupants who suffer an aortic injury die at the scene due to exsanguination into the chest. With the advent of more accurate and established human body finite element (FE) models, FE crash reconstruction methods may become a valuable tool when assessing crash scenarios and occupant injury mechanisms.

The current study is …

A Multi-Species Analysis Of Biomechanical Responses Of The Head To A Shock Wave, Richard Bolander

Wayne State University Dissertations

Shock wave induced brain injury remains a field of research that has great consequences for the rehabilitation of soldiers and civilians that are exposed to an explosion. As such, for the research to be successful in developing strategies to mitigate the effects of these injuries, appropriate research methods need to be developed. Animal models are currently employed to understand the brain's response to a shock wave exposure. Unfortunately no criteria have been established that indicates in what way the mechanical inputs that the cells in an animal's brain are subjected to are similar to a human. The purpose of this …

Computational Simulation Of Skull Fracture Patterns In Pediatric Subjects Using A Porcine Model, Christina Devito Wagner

Wayne State University Dissertations

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 …

Development Of Lower Extremity Injury Criteria And Biomechanical Surrogate To Evaluate Military Vehicle Occupant Injury During An Explosive Blast Event, Brian J. Mckay

Wayne State University Dissertations

Anti-vehicular (AV) landmines and improvised explosive devices (IED) have accounted for more than half of the United States military hostile casualties and wounded in Operation Iraqi Freedom (OIF). The lower extremity is the predominantly injured body region following an AV mine or IED blast accounting for 26 percent of all combat injuries in OIF (Owens et al., 2007). Detonations occurring under the vehicle transmit high amplitude and short duration axial loads onto the foot-ankle-tibia region of the occupant causing injuries to the lower leg. The current effort was initiated to develop lower extremity injury criteria and biofidelic biomechanical surrogate to …