Engineering Commons^™

Atv Dynamics And Pediatric Rider Safety, James T. Auxier Ii

Theses and Dissertations--Biomedical Engineering

It has been observed through numerous academic and governmental agency studies that pediatric all-terrain vehicle ridership carries significant risk of injury and death. While no doubt valuable to safety, the post-hoc approach employed in these studies does little to explain the why and how behind the risk factors. Furthermore, there has been no prolonged, widespread, organized, and concerted effort to reconstruct and catalog the details and causes of the large (20,000+) number of ATV-related injuries that occur each year as has been done for road-based motor vehicle accidents. This dissertation takes the opposite approach from a meta-analysis and instead examines …

Automated And Standardized Tools For Realistic, Generic Musculoskeletal Model Development, Trevor Rees Moon

Graduate Theses, Dissertations, and Problem Reports

Human movement is an instinctive yet challenging task that involves complex interactions between the neuromusculoskeletal system and its interaction with the surrounding environment. One key obstacle in the understanding of human locomotion is the availability and validity of experimental data or computational models. Corresponding measurements describing the relationships of the nervous and musculoskeletal systems and their dynamics are highly variable. Likewise, computational models and musculoskeletal models in particular are vitally dependent on these measurements to define model behavior and mechanics. These measurements are often sparse and disparate due to unsystematic data collection containing variable methodologies and reporting conventions. To date, …

Cnn-Based Estimation Of Sagittal Plane Walking And Running Biomechanics From Measured And Simulated Inertial Sensor Data, Eva Dorschky, Marlies Nitschke, Christine F. Martindale, Antonie J. Van Den Bogert, Anne D. Koelewijn, Bjoern M. Eskofier

Mechanical Engineering Faculty Publications

Machine learning is a promising approach to evaluate human movement based on wearable sensor data. A representative dataset for training data-driven models is crucial to ensure that the model generalizes well to unseen data. However, the acquisition of sufficient data is time-consuming and often infeasible. We present a method to create realistic inertial sensor data with corresponding biomechanical variables by 2D walking and running simulations. We augmented a measured inertial sensor dataset with simulated data for the training of convolutional neural networks to estimate sagittal plane joint angles, joint moments, and ground reaction forces (GRFs) of walking and running. When …

Effects On Initial Fixation Of Cementless Tibial Trays In Total Knee Arthroplasty, Brooke Fritts Thompson

Electronic Theses and Dissertations

Bone mineral density (BMD), among other factors, largely effect the initial stability of the cementless tibial tray component in a total knee replacement (TKR), where increased motion at the tray-bone interface hinders bony ingrowth. With a lack of bony ingrowth, the cementless implant will not experience long-term success. Understanding which factors influence initial stability yields insight into surgical technique considerations and help inform a surgeon’s implant choice. The objective of this study was to evaluate factors influencing the initial stability of cementless tibial trays using a 6-degree of freedom (6-DOF) robotic joint simulator, the AMTI VIVO, and combined loading scenarios …

Tracking Center Of Mass With Limited Inertial Measurement Units, Connor Nathaniel Morrow

Dissertations and Theses

Wearable motion tracking systems pose an opportunity to study and correct human balance and posture during movement. Currently, these observations are either being conducted in laboratories with the use of camera systems and markers placed on the body, or through the use of suits containing large numbers (15-20) of inertial measurement units. However, to aid with rehabilitation of individuals with impaired balance, there needs to be an option to collect these observations outside of clinics and without incurring much cost from the user. I have focused on three inertial measurement units, one placed on each shank and one placed on …

Simulated Tremor Propagation In The Upper Limb: From Muscle Activity To Joint Displacement, Thomas Corie, Steven Knight Charles

Faculty Publications

Although tremor is the most common movement disorder, there are few non-invasive treatment options. Creating effective tremor suppression devices requires a knowledge of where tremor originates mechanically (which muscles) and how it propagates through the limb (to which degrees of freedom, DOF).

To simulate tremor propagation, we created a simple model of the upper limb, with tremorogenic activity in the 15 major superficial muscles as inputs and tremulous joint displacement in the 7 major DOF as outputs. The model approximated the muscle excitation-contraction dynamics, musculoskeletal geometry, and mechanical impedance of the limb.

From our simulations, we determined fundamental principles for …

How Infant Positioning Impacts Hip Motion And The Associated Implications For Babies With Hip Dysplasia, Lauren Buchele

Biomedical Engineering Undergraduate Honors Theses

Developmental dysplasia of the hip (DDH) refers to a group of disorders, ranging from slight instability (Grades 1-3) to a severe dislocation (Grade 4) of the femoral head from the acetabulum [1]. In order to treat DDH in infants, a reduction procedure and the use of a lower body harness to secure the hip joint as the bones and ligaments re-form properly is typically prescribed. The Pavlik Harness is currently the “gold-standard” orthopedic device used to place hips in proper positioning. However, little research has been reported on the biomechanical affects during use of these device types.

Although the Pavlik …

Biomechanics Of Lower Limb During The Golf Swing Using Opensim Modeling, Andrew B. Butler

Theses and Dissertations

The purpose of this research is to investigate the biomechanics of the lower-limb using an inverse dynamics model. Experimental data, recorded by an integrated Motion Analysis – Force Plate System in the UTRGV Biomechanics Laboratory, is used to determine ground reaction forces and marker trajectories. OpenSim, a graphical musculoskeletal and computational platform, is used to model the body in three dimensions. The human body is modeled as a 12-segment linkage, consisting of 23 degrees-of-freedom and 92 muscles. The experimental data for the Biomechanics Laboratory is imported in OpenSim. Then, joint angles, generalized coordinates & accelerations of lower-limb segments, muscle forces, …

Use Of Flexible Sensor To Characterize Biomechanics Of Canine Skin, Austin Downey, Jin Yan, Eric M. Zellner, Karl H. Kraus, Iris V. Rivero, Simon Laflamme

Faculty Publications

Background Suture materials and techniques are frequently evaluated in ex vivo studies by comparing tensile strengths. However, the direct measurement techniques to obtain the tensile forces in canine skin are not available, and, therefore, the conditions suture lines undergo is unknown. A soft elastomeric capacitor is used to monitor deformation in the skin over time by sensing strain. This sensor was applied to a sample of canine skin to evaluate its capacity to sense strain in the sample while loaded in a dynamic material testing machine. The measured strain of the sensor was compared with the strain measured by the …

Analyzing Moment Arm Profiles In A Full-Muscle Rat Hindlimb Model, Fletcher Young, Christian Rode, Alexander Hunt, Roger Quinn

Mechanical and Materials Engineering Faculty Publications and Presentations

Understanding the kinematics of a hindlimb model is a fundamental aspect of modeling coordinated locomotion. This work describes the development process of a rat hindlimb model that contains a complete muscular system and incorporates physiological walking data to examine realistic muscle movements during a step cycle. Moment arm profiles for selected muscles are analyzed and presented as the first steps to calculating torque generation at hindlimb joints. A technique for calculating muscle moment arms from muscle attachment points in a three-dimensional (3D) space has been established. This model accounts for the configuration of adjacent joints, a critical aspect of biarticular …

A Reticulation Of Skin-Applied Strain Sensors For Motion Capture, Christopher A. Schroeck

ETD Archive

The purpose of this research is to develop a system of motion capture based on skin-applied strain sensors. These elastic sensors are of interest because they can be applied to the body without restricting motion and are well suited to operate in more practical environments, such as sports fields, gymnasiums, and outdoor areas. This combination is currently not available in the field of motion capture. The current issues with strain sensor motion capture technology is the accurate is not sufficient for motion analysis and axial rotation monitoring of joints is not available. This project will build and test a sensor …

Hip And Knee Biomechanics For Transtibial Amputees In Gait, Cycling, And Elliptical Training, Greg Orekhov

Master's Theses

Transtibial amputees are at increased risk of contralateral hip and knee joint osteoarthritis, likely due to abnormal biomechanics. Biomechanical challenges exist for transtibial amputees in gait and cycling; particularly, asymmetry in ground/pedal reaction forces and joint kinetics is well documented and state-of-the-art passive and powered prostheses do not fully restore natural biomechanics. Elliptical training has not been studied as a potential exercise for rehabilitation, nor have any studies been published that compare joint kinematics and kinetics and ground/pedal reaction forces for the same group of transtibial amputees in gait, cycling, and elliptical training. The hypothesis was that hip and knee …

Opensim Versus Human Body Model: A Comparison Study For The Lower Limbs During Gait, Antoine Falisse, Sam Van Rossom, Johannes Gijsbers, Frans Steenbrink, Ben J. Van Basten, Ilse Jonkers, Antonie J. Van Den Bogert, Friedl De Groote

Mechanical Engineering Faculty Publications

Musculoskeletal modeling and simulations have become popular tools for analyzing human movements. However, end users are often not aware of underlying modeling and computational assumptions. This study investigates how these assumptions affect biomechanical gait analysis outcomes performed with Human Body Model and the OpenSim gait2392 model. The authors compared joint kinematics, kinetics, and muscle forces resulting from processing data from 7 healthy adults with both models. Although outcome variables had similar patterns, there were statistically significant differences in joint kinematics (maximal difference: 9.8 degrees {[}1.5 degrees] in sagittal plane hip rotation), kinetics (maximal difference: 0.36 {[}0.10] N.m/kg in sagittal plane …

Subject-Specific Finite Element Predictions Of Knee Cartilage Pressure And Investigation Of Cartilage Material Models, Michael G. Rumery

Master's Theses

An estimated 27 million Americans suffer from osteoarthritis (OA). Symptomatic OA is often treated with total knee replacement, a procedure which is expected to increase in number by 673% from 2005 to 2030, and costs to perform total knee replacement surgeries exceeded $11 billion in 2005. Subject-specific modeling and finite element (FE) predictions are state-of-the-art computational methods for anatomically accurate predictions of joint tissue loads in surgical-planning and rehabilitation. Knee joint FE models have been used to predict in-vivo joint kinematics, loads, stresses and strains, and joint contact area and pressure. Abnormal cartilage contact pressure is considered a risk factor …

Microenvironment Regulates Fusion Of Breast Cancer Cells, Peiran Zhu

Masters Theses

Fusion of cancer cells has been observed in tumors for more than a century and is thought to contribute to tumor development and drug resistance. The low frequency of cell fusion events and the instability of fused cells have hindered our ability to understand the molecular mechanisms that govern cell fusion. We have developed a patterned gel system that can isolate cell fusion events and we demonstrate that several breast cancer cell lines can fuse into multinucleated giant cells in vitro, and the initiation and longevity of fused cells can be regulated solely by biophysical factors. Dynamically tuning the adhesive …

Knee Angles And Axes Crosstalk Correction In Gait, Cycling, And Elliptical Training Exercises, Jordan M. Skaro

Master's Theses

When conducting motion analysis using 3-dimensional motion capture technology, errors in marker placement on the knee results in a widely observed phenomenon known as “crosstalk” [1-18] in calculated knee joint angles (i.e., flexion-extension (FE), adduction-abduction (AA), internal-external rotation (IE)). Principal Component Analysis (PCA) has recently been proposed as a post hoc method to reduce crosstalk errors and operates by minimizing the correlation between the knee angles [1, 2]. However, recent studies that have used PCA have neither considered exercises, such as cycling (C) and elliptical training (E), other than gait (G) nor estimated the corrected knee axes following PCA correction. …

Neuromuscular Reflex Control For Prostheses And Exoskeletons, Sandra K. Hnat

ETD Archive

Recent powered lower-limb prosthetic and orthotic (P/O) devices aim to restore legged mobility for persons with an amputation or spinal cord injury. Though various control strategies have been proposed for these devices, specifically finite-state impedance controllers, natural gait mechanics are not usually achieved. The goal of this project was to invent a biologically-inspired controller for powered P/O devices. We hypothesize that a more muscle-like actuation system, including spinal reflexes and vestibular feedback, can achieve able-bodied walking and also respond to outside perturbations. The outputs of the Virtual Muscle Reflex (VMR) controller are joint torque commands, sent to the electric motors …

Predictive Simulations Of Gait And Their Application In Prosthesis Design, Anne D. Koelewijin

ETD Archive

Predictive simulations predict human gait by solving a trajectory optimization problem by minimizing energy expenditure. These simulations could predict the effect of a prosthesis on gait before its use. This dissertation has four aims, to show the application of predictive simulations in prosthesis design and to improve the quality of predictive simulations. Aim 1 was to explain joint moment asymmetry in the knee and hip in gait of persons with a transtibial amputation (TTA gait). Predictive simulations showed that an asymmetric gait required less effort. However, a small effort increase yielded a gait with increased joint moment symmetry and reduced …

Design And Analysis Of A 3d-Printed, Thermoplastic Elastomer (Tpe) Spring Element For Use In Corrective Hand Orthotics, Kevin Thomas Richardson

Theses and Dissertations--Mechanical Engineering

This thesis proposes an algorithm that determine the geometry of 3D-printed, custom-designed spring element bands made of thermoplastic elastomer (TPE) for use in a wearable orthotic device to aid in the physical therapy of a human hand exhibiting spasticity after stroke. Each finger of the hand is modeled as a mechanical system consisting of a triple-rod pendulum with nonlinear stiffness at each joint and forces applied at the attachment point of each flexor muscle. The system is assumed quasi-static, which leads to a torque balance between the flexor tendons in the hand, joint stiffness and the design force applied to …

Characterizing Anisotropy In Fibrous Soft Materials By Mr Elastography Of Slow And Fast Shear Waves, John Larson Schmidt

McKelvey School of Engineering Theses & Dissertations

The general objective of this work was to develop experimental methods based on magnetic resonance elastography (MRE) to characterize fibrous soft materials. Mathematical models of tissue biomechanics capable of predicting injury, such as traumatic brain injury (TBI), are of great interest and potential. However, the accuracy of predictions from such models depends on accuracy of the underlying material parameters. This dissertation describes work toward three aims. First, experimental methods were designed to characterize fibrous materials based on a transversely isotropic material model. Second, these methods are applied to characterize the anisotropic properties of white matter brain tissue ex vivo. Third, …

Rehabilitating Asymmetric Gait Using Asymmetry, Tyagi Ramakrishnan

USF Tampa Graduate Theses and Dissertations

Human gait is a complex process that involves the coordination of the central nervous and muscular systems. A disruption to the either system results in the impairment of a person’s ability to walk. Impairments can be caused by neurological disorders such as stroke and physical conditions like amputation. There is not a standardized method to quantitatively assess the gait asymmetry of affected subjects. The purpose of this research is to understand the fundamental aspects of asymmetrical effects on the human body and improve rehabilitation techniques and devices. This research takes an interdisciplinary approach to address the limitations with current rehabilitation …

Biomechanical Testing Of An Exercise For Strengthening The Proximal Femur., Alyssa Osbourne

Electronic Theses and Dissertations

Based on the principles of cutting edge bone remodeling research, a unique therapeutic exercise device was designed specifically to improve bone quality at the most critical location of the proximal femur prone to fracture: the superior-lateral femoral neck where the fracture first initiates during a fall. The exercise/device is intended to work by inducing enough strain in the bone to stimulate the body’s natural bone remodeling mechanisms to increase bone density in the proximal femur and consequently prevent a fracture from arising if a fall to the side does occur.

In order to test the proposed exercise, experiments simulating the …

Kinematics Of The Lower Extremities During Fundamental Martial Arts Tricking Techniques, Kevin P. Grassie

Honors Scholar Theses

Martial Arts Tricking (MAT) is a relatively new sport that combines martial arts, gymnastics, acrobatics, and breakdancing for the purposes of creating aesthetic and impressive combinations of kicks, flips and twists. It has been growing exponentially through social media and the overall athletic and entertainment communities. The sport is very unique in that the movements, with their blended influences, provide novel ways for athletes to generate and utilize their momentum in a creative way. The results often include off-axis flips and twists, single-leg landings, and complicated yet fluid techniques that easily chain together.

Due to the sport only being a …

Design And Control Of A Powered Rowing Machine With Programmable Impedance, Jose Humberto De La Casas Zolezzi

ETD Archive

Due to the rise of obesity, diabetes and cardiovascular disease, research in human performance and physical activity has received increased attention. Rowing machines are used for performance improvements through concentric exercises, however a combination of concentric and eccentric actions is known to improve the effectiveness of training. In this work, a conventional rowing machine was modified to include an electric motor and a robust impedance control system, enabling programmable impedance with concentric and eccentric capabilities. Eccentric exercises are known to contribute significantly to the efficacy of training and to diminish the detrimental effects of humans operating in microgravity for long …

Piv Analysis Of Wake Structure Of Real Elephant Seal Whiskers, Joseph Antun Bunjevac

ETD Archive

Seals are able to accurately detect minute disturbances in the ambient flow
environment using their whiskers, which is attributed to the exceptional capability of
their whiskers to suppress vortex-induced vibrations in the wake. To explore potential applications for designing smart flow devices, such as high-sensitivity underwater
flow sensors and drag reduction components, researchers have studied how the role
of some key parameters of whisker-like morphology affect the wake structure. Due to
the naturally presented variation in size and curvature along the length of whiskers,
it is not well understood how a real whisker changes the surrounding flow and the
vortex …

Disturbed Cyclical Stretch Of Endothelial Cells Promotes Nuclear Expression Of The Pro-Atherogenic Transcription Factor Nf-Kb, Ryan M. Pedrigi, Konstantinos I. Papadimitriou, Avinash Kondiboyina, Sukhjinder Sidhu, James Chau, Miten B. Patel, Daniel C. Baeriswyl, Emmanuel M. Drakakis, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

Exposure of endothelial cells to low and multidirectional blood flow is known to promote a pro-atherogenic phenotype. The mechanics of the vessel wall is another important mechano-stimulus within the endothelial cell environment, but no study has examined whether changes in the magnitude and direction of cell stretch can be pro-atherogenic. Herein, we developed a custom cell stretching device to replicate the in vivo stretch environment of the endothelial cell and examined whether low and multidirectional stretch promote nuclear translocation of NF-kB. A fluid–structure interaction model of the device demonstrated a nearly uniform strain within the region of cell attachment and …

The Effects Of Obesity On Resultant Knee Joint Loads For Gait And Cycling, Juan Gutierrez-Franco

Master's Theses

Osteoarthritis (OA) is a degenerative disease of cartilage and bone tissue and the most common form of arthritis, accounting for US$ 10.5 billion in hospital charges in 2006. Obesity (OB) has been linked to increased risk of developing knee OA due to increased knee joint loads and varus-valgus misalignment. Walking is recommended as a weight-loss activity but it may increase risk of knee OA as OB gait increases knee loads. Cycling has been proposed as an alternative weight-loss measure, however, lack of studies comparing normal weight (NW) and OB subjects in cycling and gait hinder identification of exercises that may …

Walking Simulator Mechanism, Titus Lungu, Igor Tachynskyy, Omri Tayyara

The Downtown Review

This paper presents the design, simulation, and kinematic evaluation of a mechanism aimed at simulating both the motion and ground reaction forces produced by a human foot while walking. Such a mechanism can be used to test the durability of shoes through life cycle analysis. In attempting to mimic the physical motion of the human foot as closely as possible, the forces experienced by the human foot were also accurately replicated through the incorporation of a non-stationary testing platform. As is shown in the paper, this testing environment allows for simple adjustments to be made in order to simulate different …

Influence Of Shear Stress Magnitude And Direction On Atherosclerotic Plaque Composition, Ryan M. Pedrigi, Vikram V. Mehta, Sandra M. Bovens, Zahra Mohri, Christian Bo Poulsen, Willy Gsell, Jordi L. Tremoleda, Leila Towhidi, Ranil De Silva, Enrico Petretto, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

The precise flow characteristics that promote different atherosclerotic plaque types remain unclear. We previously developed a blood flow-modifying cuff for ApoE^−/− mice that induces the development of advanced plaques with vulnerable and stable features upstream and downstream of the cuff, respectively. Herein, we sought to test the hypothesis that changes in flow magnitude promote formation of the upstream (vulnerable) plaque, whereas altered flow direction is important for development of the downstream (stable) plaque. We instrumented ApoE^−/− mice (n=7) with a cuff around the left carotid artery and imaged them with micro-CT (39.6 μm resolution) eight to nine weeks …

Biomechanical Investigation Of Elite Place-Kicking, Chase M. Pfeifer

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Many studies aim to understand the fundamentals of kicking commonly displayed by soccer players [4,6,10,16,17,18,24,25,28,29,30,34,36,38,40]. Of those studies, most are limited to a two-dimensional (2D) analysis using high-speed cameras for position tracking or utilizing electromyography to observe the activity of select muscles [4,6,18,25,29,36]. The few studies that investigate kicking using a three-dimensional (3D) model are limited in their position tracking capabilities and focus mainly on joint flexion potentials and foot speed.

This dissertation is a comprehensive biomechanical analysis (kinematic and EMG) of the field-goal place-kicking techniques of four elite kickers in American football. Data were compared and contrasted with ball …