Biomechanics and Biotransport Commons^™

Understanding The Role Of Ligamentous Constraint In Trapeziometacarpal Pathomechanics, Lizzie Walker

All Dissertations

The trapeziometacarpal (TMC) joint is the most common site for osteoarthritis (OA) in the upper limb. This joint is characterized by its wide range of motion and limited bony stability, making it susceptible to OA. The TMC joint relies mostly on ligaments and muscles for its static and dynamic stability, respectively. While importance of both volar and dorsal capsular TMC stabilizers has been demonstrated, the role of TMC ligamentous tissues in the development of thumb basal joint OA remains unclear.

The goal of this work was to identify morphometric and mechanical changes in key TMC ligament stabilizers, including the volar …

Applying Residence Time Distribution Theory To Coronary Thermodilution Curves., Jacob Michael Miller

Electronic Theses and Dissertations

Cardiovascular diseases remain the leading cause of death worldwide and coronary microvascular dysfunction is one cardiovascular disease which is particularly challenging to diagnose and treat. Coronary thermodilution is a widely used, invasive procedure to evaluate microvascular function by generating physiological indices such as coronary flow reserve and the index of microvascular resistance. Although commonly cited as an indicator dilution method in the cardiovascular literature, current coronary thermodilution techniques lack rigorous application of the accompanying mathematical framework, thereby leaving potentially valuable diagnostic information unexploited. This study bridges that gap by demonstrating the equivalence between indicator-dilution theory and residence time distribution theory …

Biomechanical Assessment Of Fracture Risk In Young Children With Healthy Bone And Osteogenesis Imperfecta., Keyonna Mckinsey

Electronic Theses and Dissertations

Osteogenesis imperfecta (OI) is a group of genetic bone disorders that can range from a mild increase in fractures in one’s lifetime to perinatally lethal. Biomechanical assessment via finite element analysis (FEA) can be used to provide subject specific evaluation of fracture risk and thus aid in furthering understanding of likelihood of fracture due to loading associated with common daily activities. Thus, the purpose of this dissertation research was to characterize the risk of femur fracture in young children with OI compared to that of healthy children when exposed to loading associated with common activities, specifically gait. To accomplish this, …

Providing A Solution For Active-Duty Servicewomen Facing Chronic Musculoskeletal Injuries Due To Improper Gear Fit, Celia Watson, Denver Tidwell, Hadi Obaji

Honors Theses

As senior biomedical engineering students at the University of Mississippi, we began our academic year brainstorming unmet clinical needs in healthcare intending to provide an innovative solution. After conducting personal inventories, determining a mission, and evaluating internal and external factors, we established acceptance criteria for our strategic focus and clarified our needs statement: develop a prophylactic device for chronic musculoskeletal injuries (MSKIs) in active-duty servicewomen (ADSW). The average female soldier is at a disadvantage compared to her male counterpart due to anthropometric and physiological differences between men and women in most aspects of physical performance (Epstein et al. 2673). These …

Advancing Tka Biomechanics: From Joint Simulator To Boundary Condition Development, Yashar Ali Behnam

Electronic Theses and Dissertations

This dissertation addresses four specific aims that collectively attempted to advance the experimental and computational analysis of total knee arthroplasty (TKA) components. The first study focused on the development of a novel whole knee joint simulator capable of simultaneous tibiofemoral and patellofemoral knee loading. This simulator employs custom fixturing to facilitate dynamic, unconstrained, muscle-driven PF articulation alongside controlled TF contact mechanics. Validation against experimental measurements showed strong agreement, demonstrating the simulator's potential as a valuable tool for future TKA design and surgical technique investigations.

The second study verified implant-specific physiological boundary conditions which accurately simulate activities of daily living using …

Muscle Force Analysis In Patients With Forefoot Amputees And Healthy Subjects During Walking, Anthony Melgar, Dumitru Caruntu, Javier La Fontaine, Luis Venegas, Hafizur Rahman

Research Symposium

Forefoot amputation, a type of partial foot amputation, involves the surgical disarticulation of either the interphalangeal or metatarsophalangeal joints. This procedure not only removes critical joint structures but also alters the positioning of associated muscles. Forefoot amputations significantly affect gait patterns and redistribute plantar pressure maps across the plantar surface of the foot. The phalanges are crucial in absorbing and redistributing plantar pressure during the gait cycle. The absence of phalanges and the loss of metatarsophalangeal joints alter the normal pressure distribution maps, possibly shifting peak pressure from one local foot region to another region of the foot. This research …

Your Foot Is Not A Brick: Using A Multi-Segment Foot Model To Explore The Actions Of The Ankle-Foot Complex During Uneven Terrain Gait., Tayler Jon Hoekstra

Dissertations and Theses

The field of biomechanics has seen continued development of models to be used and circumstances to be considered. An increasing number of more complex models for the foot known as multi-segment foot models (MSFMs) have created opportunities to better understand the compensatory motion of this vital portion of human anatomy. This research seeks to utilize one such MSFM model to increase understanding in how human ambulation changes in uneven terrain environments. Unique inner-foot joints defined by the Rizzoli foot model (RFM) were measured for and compared for subjects traversing both even and uneven terrain to quantify joints that experienced significant …

Intervertebral Lateral Bending Moment Differences In The Lumbar Spine Of Baseball Pitchers Across Throwing Velocities, Justin Humenay

Theses and Dissertations

Introduction Baseball pitching imposes substantial mechanical demands on the lumbar spine, a crucial link in the kinetic chain responsible for transferring energy from the lower body to the upper extremity. While increased pitch velocity is associated with greater trunk forces the specific intervertebral loading patterns during high-velocity pitching remain unclear. This study investigates differences in lateral bending moments across lumbar spinal segments between collegiate pitchers throwing at high versus low velocities.

Methods Twenty right-handed collegiate pitchers were divided into two groups: high-velocity (n = 10, 90.3 ± 1.6 mph) and low-velocity (n = 10, 81.6 ± 1.1 mph). Motion capture …

Traction Force Microscopy Using An Epifluorescence Microscope: Experimental Considerations And Caveats, Zaria Booth, Mazen Mezher, Rudra Patel, Venkat Maruthamuthu

Mechanical & Aerospace Engineering Faculty Publications

Forces exerted by cells due to their internal contractility play fundamental roles in a host of processes, including adhesion, migration, survival and differentiation. Traction force microscopy (TFM) enables the determination of forces exerted by cells or cell collectives on their environment, which is typically taken to be an extra-cellular matrix (ECM)-coated substrate. Sample preparation for TFM involves the plating of cells onto an environment embedded with fiducial markers. The imaging of these fiducial markers in the presence and absence of the cells then enables calculation of the displacement of localized regions of the environment, and, consequently, the spatial distribution of …

Strength Imbalances And Shoulder Pain In Manual Wheelchair Users Stratified By Age Of Spinal Cord Injury/Disorder (Sci/D) Onset, Ashlyn M. Jones

Theses and Dissertations

Introduction The majority of manual wheelchair users (MWUs) with spinal cord injury or disorder (SCI/D) develop shoulder pain. In adults with SCI/D, there is evidence that upper limb strength imbalances are associated with shoulder pain. However, strength imbalances may indicate protective compensatory strategies, and other factors may be important contributors to pain. Currently, personalized prevention and management of pain is limited, little is known about joint strength imbalances and pain in children who use manual wheelchairs, and the effect of the age of SCI/D onset is poorly understood. The purpose of this study was to assess the effect of age …

The Design Of A Bioinspired Impact Mitigation System Towards The Prevention Of Brain Injuries, Bryce H. Reimer

Master’s Theses

Traumatic brain injuries (TBIs), including concussions and chronic traumatic encephalopathy (CTE), remain a major concern across contact sports, military operations, and transportation. Despite advancements in protective equipment, current strategies often fall short in preventing the mechanical conditions that contribute to long-term neurological damage. This thesis presents the design and validation of a bioinspired impact mitigation system modeled after bighorn sheep horn structures, which have evolved to endure high-energy collisions without apparent brain injury.

Using biomimetic principles, the research integrates experimental and computational methods to evaluate how horn-like geometries reduce impact-induced accelerations. A custom drop tower was built to test dynamic …

Effects Of Changes In Strouhal And Reynolds Numbers On Beetle Wing Aerodynamics, Keith L. Thiha

Honors Undergraduate Theses

Insect flight has long been a subject of interest across the scientific community, largely due to the exceptional aerodynamic performance insects demonstrate relative to their size. Insects tend to have very high aerodynamic performance characteristics like thrust and lift generation compared to their size. This has many potential applications in improving aircraft performance, however the flow phenomena concerning insect wing aerodynamics is still an area of ongoing research. This study aims to investigate how variations in key nondimensional flow parameters—specifically the Reynolds number and Strouhal number—affect the aerodynamic performance of beetle wings. Strouhal numbers ranging from 0.2 to 0.6 were …

Direct Numerical Simulation Of Pulsating Flow In Curved Pipes: Insights Into Aortic Dissection In Humans, Gokul Anugrah Gopakumar

Theses and Dissertations--Mechanical and Aerospace Engineering

This dissertation investigates the hemodynamics of pulsating blood flow in curved vessels through direct numerical simulations (DNS), with the overarching aim of uncovering fluid dynamic mechanisms linked to the onset and progression of aortic dissection in humans. The work is structured in two parts: (i) fundamental studies in idealized geometries and (ii) preliminary investigations in patient-specific anatomies. In the first part, curved pipe models representing the aortic arch are used to isolate the effects of pulsation frequency, amplitude ratio, and curvature ratio on transitional and turbulent flow dynamics. The simulations reveal that curvature-driven centrifugal forces shift the peak velocity toward …

Development And Validation Of A Subject-Specific Integrated Finite Element Musculoskeletal Model Of Human Trunk With Ergonomic And Clinical Applications, Farshid Ghezelbash, Amir Hossein Eskandari, Amir Jafari Bidhendi, Aboulfazl Shirazi-Adl, Christian Lariviere

Études primaires

Biomechanical modeling of the human trunk is crucial for understanding spinal mechanics and its role in ergonomics and clinical interventions. Traditional models have been limited by only considering the passive structures of the spine in finite element (FE) models or incorporating active muscular components in multi-body musculoskeletal (MS) models with an oversimplified spine. To address those limitations, we developed a subject-specific coupled FE-MS model of the trunk and explored its applications in ergonomics and surgical interventions. A parametric detailed FE model was constructed, integrated with a muscle architecture, and individualized based on existing datasets. Our comprehensive validation encompassed tissue-level responses, …

Measuring Achilles Tendon Stiffness And Kinetics In-Vivo, Chloe L. Pinkston

Honors Undergraduate Theses

This study aims to measure the gastrocnemii Achilles subtendon passive stiffness and energy storage during walking. Stiffness was first determined using a noninvasive method that combines ultrasound, motion capture, musculoskeletal modeling, and a force transducer. Eight healthy participants were tested using this method to obtain the passive force-displacement relationship of the Achilles tendon at two different knee angles to calculate stiffness of the gastrocnemii subtendon. A gait analysis session was then performed using ultrasound, motion capture, and an instrumented treadmill at self-selected slow, normal, and fast walking speeds, using stiffness to calculate the subtendon’s force and energy storage. Gastrocnemii Achilles …

Integrated Compliant Structure For A Hand Exoskeleton, Tristan R. Koopman

Honors Undergraduate Theses

This thesis presents the design and prototyping of a wearable hand exoskeleton that integrates a flexible structural framework to assist with hand movement while maintaining comfort and anatomical conformity. The goal was to create a device that supports tendon-driven actuation through a compliant structure, combining elements of rigidity and flexibility to match the natural geometry and motion of the human hand. Traditional hand exoskeletons often trade off motion for structure or vice versa. This project aims to bridge that gap with a hybrid compliant design that balances flexibility and support. The design process followed an iterative approach involving rapid prototyping …

Generation And Characterization Of Human Blood-Brain Barrier Models For Investigating Neuropsychiatric Disorders And Tumor Metastasis, Yunfei Li

Dissertations and Theses

The blood–brain barrier (BBB) is important in the normal function of the central nervous system (CNS). An altered BBB has been described in various neuropsychiatric disorders. The brain-specific microvascular endothelial cell (BMEC) is an essential structural component of the BBB. To test if integrity of the BBB formed by BMECs is compromised in 22q11.2 deletion syndrome (also called DiGeorge syndrome), which is one of the validated genetic risk factors for schizophrenia, a 2D iBBB (induced BBB) on a Transwell filter was generated from human microvascular endothelial cells (HBMECs) derived from the induced pluripotent stem cells (iPSCs) out of patients with …

Form And Function In Mobulids: A Comparative Analysis Of Filter Morphology With Bioinspiration Applications, J. B. Teeple, S. R. Kahane-Rapport, K. E. Cohen, L. Hamann, J. A. Strother, E. W. M. Paig-Tran

Biological Sciences Faculty Publications

Mobulas (manta and devil rays) are large-scale ram filter feeders that separate planktonic food particles from large volumes of water with minimal clogging. This contrasts with most human-made filters that can suffer from problematic clogging requiring additional mechanisms for clearing blocked surfaces and maintaining performance. Prior studies have shown that mobulas employ a unique mechanism referred to as ricochet separation to filter feed, whereby captive vortices in filter pores cause particles to bounce off the filter surfaces and away from the filter pores. This mechanism enables the filtration of particles smaller than the pore size and reduced clogging. However, few …

Microwell Fabrication For Impedance And Ac Measurements Of Isolated Ventricular Cardiomyocytes, Fallon Wenck

Multidisciplinary Studies Theses and Dissertations

Electrophysiological behavior of human hearts have been extensively studied for hundreds of years. Even with elucidation of not just biological function, but also time and frequency-dependent current flow, the sheer intricacy of in vivo cardiac tissue function remains somewhat enigmatic. All while heart disease has been the leading cause of death in the United States for over a century, with its rates of occurrence still increasing annually [1]. Thus, new research techniques and tools to quantify cardiac function are still being pursued at smaller and smaller scales to decrease research/innovation time, cost, and diagnostic ambiguity. In fact, it remains incredibly …

Measuring Gait Of Total Knee Arthroplasty Patients Pre-Op And Post-Op Using A Smartphone, Celeste A. Thai

Master's Theses

Motion capture technology is a tool often used in orthopedic applications, including measuring gait dysfunctions. However, gait analysis research focused on total knee arthroplasty (TKA) patients is limited, especially using motion capture systems. This may be due to a multitude of factors, such as inaccessibility to gait labs to the general public, difficulty of travel post-surgery, and overall costs of care and maintenance of motion lab equipment. New emerging novel methods use wearable devices such as smartphones and inertial measurement devices (IMUs) to perform gait assessment and are becoming favorable due to their increasingly ubiquitous nature. One such method using …