Life Sciences Commons^™

Defining The Role Of Elastic Fibers In Tendon Mechanics, Jeremy D. Eekhoff

McKelvey School of Engineering Theses & Dissertations

Tendons serve as a linking component of the musculoskeletal system by transferring forces between muscle and bone. As such, the structural proteins of the tendon extracellular matrix are of vital importance for the tissue to function properly and maintain its mechanical integrity. Collagen is the principal constituent of tendon and makes up its aligned hierarchical organization. Other structural proteins, such as elastin, are in comparison understudied and not well understood in relation to tendon function. Elastin, the main component of elastic fibers, has unique mechanical properties including high extensibility, fatigue resistance, and elasticity; these properties are important for elastin-rich tissues …

Effects Of Seat And Axle Position On Pain, Pathology, And Independence In Pediatric Manual Wheelchair Users With Spinal Cord Injury, Hannah Frank

Theses and Dissertations

Manual wheelchair (MWC) users with spinal cord injury (SCI) rely heavily on their upperextremities to complete daily occupations. Due to repetitive shoulder use during wheelchair mobility and propulsion, MWC users are at greater risk of shoulder pain and shoulder pathology, and thus decreased independence, and lower quality of life. The relative fit of the wheelchair and its parameters are critical and can further impact the user’s propulsion biomechanics. Parameters such as seat angle and axle position may put the user in detrimental shoulder positions for longer periods of time, impacting health outcomes even more. Although the effects of wheelchair setup …

Mental Fatigue On Landing Performance, Madison Marie Gaffney

Dissertations and Theses

Mental fatigue has been shown to impair physical performance, especially for endurance-based sports. However, little research has been done regarding the impacts of mental fatigue on shorter maximal effort movements during a common sport related activity such as the depth jump. The purpose of this study was to investigate the effects of mental fatigue on short maximal performance efforts and predisposing biomechanical variables for non-contact ACL tears during depth-jumps in 18 Division I female soccer players. Each participant completed five depth jumps, followed by a 30-minute Stroop task to induce mental fatigue, and then completed five more depth jumps. Multiple …

An Investigation Of Upper Extremity Motor Impairments In Children Diagnosed With Autism Spectrum Disorder: Motor Planning Vs Motor Execution, Patrick Anthony Cereceres

Open Access Theses & Dissertations

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder typically diagnosedwhen a child displays social and communication impairments, repetitive behaviors, and rhythmic movements like hand flapping. This disorder is unique because of the high variability of symptoms displayed between each individual who is diagnosed. Because of this, no neurological or physiological test exists to diagnose a child with ASD. Current diagnostic tests are various forms of interviews or observations which an experienced clinician must administer. While these tests have been instrumental in diagnosing children with ASD, many go undiagnosed, which can be detrimental as they transition into adulthood. Current literature indicates …

Central Sensitization, Muscle Function, And Knee Kinematics In Females With Patellofemoral Pain, Kemery Jean Sigmund

Theses and Dissertations

Context: Females with patellofemoral pain (PFP) are at higher risk, have higher rates, and experience worse long-term outcomes than males. Structural and functional changes have been observed in pain networks and neuromuscular systems in individuals with PFP. Central sensitization describes dysfunctional pain modulation which could lead to altered neuromuscular control. Evidence examining relationships between central sensitization and muscle function in PFP is lacking.

Objective: The purpose of this study is to determine whether females with PFP exhibit signs of central sensitization compared to pain-free females. Then, after grouping each individual based on her quantitative sensory test results into a centrally …

Role Of Sex Differences On Cancer Cachexia Progression And Fibrosis During Cancer Cachexia Development, Wesley Haynie

Graduate Theses and Dissertations

Cancer cachexia is a multifactorial wasting syndrome characterized by losses in bodymass >5% and occurs in approximately 80% of all cancer patients. Chronic inflammation and fibrosis play roles in cancer cachexia and a greater understanding of these contributing pathways to this pathology will pave the way for potential therapeutic avenues. While inflammation and fibrosis have been researched in various models of cancer cachexia, little to no studies have been performed in both sexes as most previous studies focus on males. PURPOSE The purpose of these studies is to investigate the role of fibrosis on cancer cachexia development as well as …

Coordination Variability And Injury Risk In Experienced Collegiate Dancers, Emily Klinkman

All NMU Master's Theses

Dance is a sport that places a number of physical demands upon the human body, and injuries are a common occurrence in the sport. While it has not yet been linked to dance-related injury, coordination variability (CV) is a measure of how much movement strategy changes between repetitions of a task and low levels of CV have been linked to injury in other sports. This study aimed to determine the relationship between CV and dance injury in collegiate dancers. Eight (8) undergraduate student subjects were recruited from the dance major and minor, BFA major and minor, and recreational dancers who …

Development Of A Novel Haptic Feedback System For Gait Training Applications, Mohsen Alizadeh Noghani

Electronic Theses and Dissertations

Until recently, study and correction of motor or gait functions required costly sensors and measurement setups (e.g., optical motion capture systems) which were only available in laboratories or clinical environments. However, due to (1) the growing availability and affordability of inertial measurement units (IMUs) with high accuracy, and (2) progress in wireless, high bandwidth, and energy-efficient networking technologies such as Bluetooth Low Energy (BLE), it is now possible to measure and provide feedback in real-time for biomechanical parameters outside of those specialized settings. To enable gait training without an expert who can provide verbal feedback, augmented feedback, which is divided …

Shear Wave Propagation Speeds And Estimation Of Mechanical Properties In Soft, Fibrous, Nonlinear Anisotropic Materials, Zuoxian Hou

McKelvey School of Engineering Theses & Dissertations

The mechanical properties of brain tissue may reflect or influence growth, remodeling, development, aging, and disease. However, brain tissue, especially white matter, is structurally anisotropic and has nonlinear strain-stress relationships, so common methods are not very useful to describe the mechanical properties of brain tissue. Magnetic resonance elastography (MRE), based on the MRI imaging technique, can be used for measuring tissue mechanical properties non-invasively. Therefore, the mathematical model that describes the relation between wave speed and tissue mechanical properties will essentially influence the accuracy of the prediction. The objective of this dissertation is to investigate the relationship between shear wave …

Movement Patterns During Functional Activities In People With Chronic Low Back Pain, Quenten Lowell Hooker

Arts & Sciences Electronic Theses and Dissertations

People with chronic LBP display an altered movement pattern where the lumbar spine moves more readily than other joints that can contribute to the activity. The pattern is of particular clinical relevance because across multiple studies the magnitude of altered pattern is associated with LBP and function. One session of motor skill training (MST) during functional activities can improve the altered pattern. However, of the few studies investigating MST for people with LBP, none have examined the short-term or long-term effects of MST on the altered pattern. Additionally, no study has systematically examined if person-specific characteristics moderate the altered pattern …

The Effects Of Maturation On Acl Loading, Muscle Coordination, And Metabolic Cost In Adolescent Female Soccer Players, Lauren E. Schroeder

Doctoral Dissertations

Anterior cruciate ligament (ACL) injuries remain a significant, season-ending injury in youth soccer, with young female athletes exhibiting higher incidence rates compared to young male athletes. ACL injury rates increase with older ages, with female soccer players 15 years or older being at an almost twofold increased rate of injury compared to young female soccer players. Several biomechanical and neuromuscular changes occur during the maturation process, becoming more prevalent in young females, that can place them at an increased risk for ACL injury. These biomechanical and neuromuscular changes can affect how efficient young females are when completing high-risk, dynamic tasks …

The Effects Of The Dual-Tasking: Walking While Texting On Slip Recovery Mechanics, Ileana Abril Jarquin

Open Access Theses & Dissertations

Introduction: The number of induced falls has increased exponentially over the last decade. Previous studies have determined that the cognitive demands of texting affect the processing of cognitive and motor tasks.Research question: What effect does the dual-tasking of texting and walking has on slip recovery mechanics? Methods: Three-dimensional kinematic data were collected while 20 participants between the ages of 18 and 30 years three different conditions; 1) baseline, 2) walking + slip perturbation, and 3) texting and walking + slip perturbation. Results: Walking speed, numbers of falls, and recovery time from the slip were not affected by the texting dual-task. …

Neuromuscular Control Strategy During Object Transport While Walking: Adaptive Integration Of Upper And Lower Limb Movements, Ahyoung Song

LSU Doctoral Dissertations

When carrying an object while walking, a significant challenge for the central nervous system (CNS) is to preserve the object’s stability against the inter-segmental interaction torques and ground reaction forces. Studies documented several strategies used by the CNS: modulation of grip force (GF), alterations in upper limb kinematics, and gait adaptations. However, the question of how the CNS organizes the multi-segmental joint and muscle coordination patterns to deal with gait-induced perturbations remains poorly understood. This dissertation aimed to explore the neuromuscular control strategy utilized by the CNS to transport an object during walking successfully. Study 1 examined the inter-limb coordination …

Development And Evaluation Of An Attachable Anti-Vibration Handle For Blueberry Hand Shaker, Jashwant Thota

Electronic Theses and Dissertations

Blueberry production has skyrocketed in the past two decades due to an exponential increase in consumer demand around the world. The harvesting of fresh, high-quality blueberries requires extensive care. Large-scale automatic harvesters damage the fruit and make it unsuitable for storage and transportation, which requires more than two weeks to complete. Therefore, hand harvesters are used, avoiding damage to the fruit, and increasing harvesting efficiency multifold when compared with that of hand-picking. The downside of these hand harvesters is their high Hand Arm Vibration (HAV), which is very dangerous for the worker and can cause hand-arm vibration syndrome (HAVS). This …

A Radiographic Investigation Of Anthropometrics, Neck Posture, And Neck Strength In Individuals With Enlarged External Occipital Protuberances, Caleb Burruss

Graduate Theses and Dissertations

Overview: Enlarged external occipital protuberances (EEOPs) are found in 41% of young adults. These EEOPs have the potential to lead to pain throughout life and possibly surgery. Little is known of the pathophysiology or characteristics that could lead to these EEOPs. Purpose: The purpose of this study is to use radiographic measurements to investigate how anthropometrics, neck posture and neck strength in flexion and extension differ between those with and without an EEOP. Methods: 80 radiographs from three different studies were digitized and the marking of landmarks performed in ImageJ. The cut-off for an EEOP was established as any EOP …

A Constitutive-Based Deep Learning Model For The Identification Of Active Contraction Parameters Of The Left Ventricular Myocardium, Igor Augusto Paschoalotte Nobrega

USF Tampa Graduate Theses and Dissertations

Modern breakthroughs in biomedical engineering, computer science, and data mining have created new opportunities for detecting important mechanical properties of soft tissues that can be employed to identify possible signs of diseases or physiological difficulties. However, the scarcity of different mechanical properties obtained through noninvasive testing emphasizes the importance of incorporating authentic biological data into computer models capable of replicating the behavior of soft tissues.

The field of continuum theory of large deformation hyperactivity permits the formulation of highly descriptive mathematical research and computational models capable of perfectly describing the minute mechanical characteristics of soft materials. By including features about …

These Fish Were Made For Walking: Morphology And Walking Kinematics In Balitorid Loaches, Callie Hendricks Crawford

Dissertations

Terrestrial excursions have been observed in multiple lineages of marine and freshwater fishes. These ventures into the terrestrial environment may be used when fish are searching out new habitat during drought, escaping predation, laying eggs, or seeking food sources. The physiological demands for life under water and on land are vastly different and require different functional adaptations. Fish with terrestrial excursions must be capable of dealing with the stresses of both aquatic and terrestrial environments for varying periods of time. To deal with these stresses, amphibious fishes exhibit many morphological and behavioral adaptations. These adaptations have led to a range …

Subject-Specific Musculoskeletal Modeling Of Hip Dysplasia Biomechanics, Ke Song

McKelvey School of Engineering Theses & Dissertations

Developmental dysplasia of the hip (DDH) is characterized by abnormal bony anatomy, causes pain and functional limitations, and is a prominent risk factor for premature hip osteoarthritis. Although the pathology of DDH is believed to be mechanically-induced, little is known about how DDH anatomy alters hip biomechanics during activities of daily living, partly due to the difficulties with measuring hip muscle and joint forces. Musculoskeletal models (MSMs) are useful for dynamic simulations of joint mechanics, but the reliability of MSMs for DDH research is limited by an accurate model representation of the unique hip anatomy. To address such challenges, this …

Synthetic Gene Circuits For Self-Regulating And Temporal Delivery Of Anti-Inflammatory Biologic Drugs In Engineered Tissues, Lara Pferdehirt

McKelvey School of Engineering Theses & Dissertations

The recent advances in the fields of synthetic biology and genome engineering open up new possibilities for creating cell-based therapies. We combined these tools to target repair of articular cartilage, a tissue that lacks a natural ability to regenerate, in the presence of arthritic diseases. To this end, we developed cell-based therapies that harness disease pathways and the unique properties of articular cartilage for prescribed, localized, and controlled delivery of biologics, creating the next generation of cell therapies and new classes of synthetic circuits. We created tissue engineered cartilage from murine induced pluripotent stem cells that had the ability to …

Description, Reliability And Validation Of A Novel Ground-Reaction-Force-Triggered Protocol For Simulation Of Tripping Perturbations During Gait, James Anderson, Samuel Hadley, Denise Ng, Catrina Fabian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Tripping is a common cause of falls across different age populations particularly in older adults. Concerns regarding the validity of simulated-fall research protocols reside in the current literature. The purpose of this study was to develop a novel treadmill-based tripping protocol that allowed researchers to deliver unanticipated tripping perturbations during walking with a high level of timing precision. The protocol utilized a side-by-side split-belt treadmill instrumented with force platforms. Treadmill belt acceleration profiles (two levels of perturbation severity: small perturbation vs large perturbation) were delivered unilaterally when the tripped leg bore 20% of the body weight during early stance. Peak …

Quantifying Fear Of Falling By Utilizing Objective Body Sway And Muscle Contraction Measures, Chenfan Gui

Theses & Dissertations

Fear of falling (FOF) is a psychological condition that can lead to increased morbidity and mortality in the elder population. However, the subjective and multidimensional nature of FOF resulted in the limitations of existing FOF measurements, which could influence the quality of those studies. The present study aimed to quantify FOF by using objective center of pressure (COP) trajectories and muscle contraction of the lower extremity to compensate for those limitations. Nineteen young healthy adults (24 years ± 2.47) were recruited in the present study. Subjects were required to watch three 360-degree videos, one control video and two roller coaster …

Musculoskeletal Modeling Analysis Of Knee Joint Loading During Uphill And Downhill Waling In Patients With Total Knee Replacement, Tanner A. Thorsen

Doctoral Dissertations

The purposes of these studies were to determine differences in total (TCF), medial (MCF) and lateral (LCF) tibiofemoral compartment compressive forces and related muscle forces between limbs (replaced, non-replaced, and control), and different slopes during uphill [0° (level), 5°, 10°], and downhill [0° (level), 5° 10°] using statistical parametric mapping (SPM). Static optimization was used to determine muscle and compressive forces for 9 patients with total knee arthroplasty (TKA) and 9 control participants during walking trials. Total , loading-response, and push-off TCF impulse were calculated. A 3×3 [Limb (replaced, non-replaced, control] × Slope (0°, 10°, 15°)] SPM[F] repeated measures ANOVA …

Effects Of Different Stretching Modalities On The Antagonist And Agonist Muscles On Isokinetic Strength And Vertical Jump Performance, Samuel Montalvo

Open Access Theses & Dissertations

Warm-ups are essential components of all training sessions, sports, and physical activities. Warm-ups are typically composed of a variety of stretches. Two stretching modalities that are commonly performed before any physical activity are the static and dynamic stretching modalities. Historically, static stretching has been used as a preferred stretching modality during the warm-up period. However, research indicates that static stretching â?? if done prior to the training session â?? may inhibit the expression of muscular strength, muscular activation, and vertical jump height. On the contrary, dynamic stretching has been shown to improve the expression of muscular strength, muscular activation, and …

The Influence Of Resistance Training On Post Surgical Outcomes In Individuals With Anterior Cruciate Ligament Injury, Kevin H. Choe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The anterior cruciate ligament (ACL) is commonly injured, especially in individuals under the age of 25. ACL reconstruction (ACLR) is the most common treatment after ACL injury, followed by physical therapy. However, successful surgery and completion of rehabilitation, individuals still demonstrate quadriceps weakness and asymmetries during locomotion. To improve these deficits, an intervention that improves quadriceps strength and lower extremity biomechanics during locomotion is required. First, we aimed to complete a systematic review of the literature to determine the efficacy of resistance training in improving outcomes after ACLR. Second, we aimed to identify if a history of resistance training positively …

Relationship Of Shoe Wetness To Mechanical Performance, Sara Lyn Crawford

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to mechanically impact test shoes that underwent both saturation and repetitive loading protocols to determine if these interventions affected the impact absorption and energy return properties of a shoe. Six pairs of the same make and model of shoe were divided into Control and Experimental Groups and tested on an impact machine before and after undergoing a protocol. The repetitive load protocol involved subjecting the shoes to impacts commensurate with a 5 km race. The water saturation protocol involved soaking the shoes until reaching their maximum saturation. The Control shoes underwent initial testing and …

The Investigation Of The Influence Of Long-Distance Running On Foot Volume In Healthy Female Collegiate Distance Athletes, Mufaro M. Hungwe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine the change, if any, in foot volume over time after exercise, specifically a long-distance 5 Km run. Five UNLV Women’s Track & Field and Cross- Country distance athletes (n = 5; 20 ± 1.87 years; 54.50 ± 3.71 kg; 160.88 ± 4.98 cm) were recruited to participate in this study. The dependent variables were foot volume and foot size. These variables were measured pre and post a 5 Km run at a self-selected somewhat hard pace over the independent variable time. Foot volumetrics were performed five times, (Pre-run, post- run(5 min), post-run(10 …

Relationship Between Jump Performance And Asymmetry, Cordero Roche

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this dissertation is to investigate the relationship between jump performance and asymmetry. This investigation was divided into three separate studies. The first aim investigated which asymmetry variables for eccentric and concentric phases best predicted jump height (JH) during different jump types. The aim of the second study was to determine if asymmetry variables differed between jump type and genders.

Fourteen participants performed countermovement jumps (CMJ) and drop vertical jumps (DVJ). The DVJ were administered from a 30.5 cm platform leading with dominant leg striking separate force platforms with each foot. Vertical ground reaction forces were used to …

The Influence Of Sports-Related Concussion On Lower Extremity Injury Risk In Adolescent And Collegiate Athletes, Jason M. Avedesian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sports-related concussion (SRC) represents a major epidemiological concern in the adolescent and collegiate athlete populations, with conservative estimates of approximately four million SRCs occurring each year in the United States. While the majority of previous research has emphasized the management and recovery of the cognitive aspects of SRC, recent data indicates subtle motor behavior is altered following a concussive event. Injury surveillance literature indicates that adolescent and collegiate athletes are at an approximately 2–4 greater risk for lower extremity (LE) injury following an SRC when compared to matched controls and pre-SRC LE injury rates. Furthermore, athletes with a previous SRC …

Patient-Specific Finite Element Analysis For Mandibular Fracture Fixation, Ethan Snyder

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis proposes an approach for Finite Element Analysis (FEA) of mandibular fracture fixation. Using a Computerized Tomography (CT) scan of mandible obtained from a specific person, the material characteristics, density and modulus of elasticity, were determined from a set of discrete points within the mandible that are 1mm spaced based on the Hounsfield Units of these points. The mandible geometry was sectioned to simulate a fracture. Muscle and mastication forces were added to replicate post-surgery loading. Using a standard linear miniplate, this material model was compared with two commonly used mandibular cortical shell bone models: isotropic and orthotropic. A …

Sex-Based Differences In Acvr2b And Grb10 Expression In Skeletal Muscle During Induced Cancer Cachexia And Disuse, Lauren Martinez

Graduate Theses and Dissertations

Background: Muscle atrophy is the shrinkage of muscle fibers that are largely maintained by a balance of protein synthesis and degradation. Imbalances in protein synthesis and degradation are observed in different muscle atrophy disorders such as cancer cachexia and disuse. These forms of muscle atrophy produce distinct wasting pathologies that are influenced by biological sex. Activin receptor type-2B (ACVR2B) and Growth factor receptor-bound protein 10 (GRB10) have been identified as genes that potentially regulate muscle mass while also displaying sexually dimorphic differences. Purpose: To examine the influence of ACVR2B and GRB10 throughout the development of cancer cachexia and disuse-induced atrophy …