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The Effects Of Acidosis On Calcium Dependent Binding Of A Single Crossbridge, Matthew Unger Oct 2019

The Effects Of Acidosis On Calcium Dependent Binding Of A Single Crossbridge, Matthew Unger

Masters Theses

Intracellular acidosis is a putative agent of skeletal muscle fatigue, in part, because acidosis depresses the calcium (Ca2+) sensitivity and force production of muscle (18, 50). However, the molecular mechanisms behind this depression in Ca2+ sensitivity and force production are unknown. This gap in knowledge poses a significant challenge in generating a complete understanding of the fatigue process. To close this gap, the ability of myosin to bind to a single actin filament was measured under acidic conditions, in a laser trap assay, with and without regulatory proteins. Decreasing pH from 7.4 to 6.5 reduced the ...


Walking For Object Transport: An Examination Of The Coordinative Adaptations To Locomotor, Perceptual, And Manual Task Constraints, Avelino Amado Jul 2019

Walking For Object Transport: An Examination Of The Coordinative Adaptations To Locomotor, Perceptual, And Manual Task Constraints, Avelino Amado

Doctoral Dissertations

The goal of this dissertation was to understand how the intrinsic dynamics of gait adapt to support the performance of an ecologically relevant object transport task. A common object transport task is walking with a cup of water. Because the water can move relatively independent of the cup, the cup and water system is classified as a complex object. To model this task participants carried a cup with a wooden lid placed on top. On the lid there was a circular region with the same circumference as the cup and a ball. The object of the task was to keep ...


Metabolic Cost And Stability Of Locomotion In People With Lower Limb Amputation, Ryan Wedge Jul 2019

Metabolic Cost And Stability Of Locomotion In People With Lower Limb Amputation, Ryan Wedge

Doctoral Dissertations

It is generally accepted that metabolic energy expenditure and gait stability are key factors that influence the selection of able-bodied locomotor patterns. It is unclear how energy expenditure and gait stability are prioritized during walking in people with lower limb amputation. People with lower limb amputation generally have greater metabolic energy expenditure during walking and increased incidence of falls. People with unilateral lower limb amputation spend more time on the intact limb compared with the prosthetic limb, while able-bodied individuals generally walk with symmetrical timing between limbs. Restoring symmetry is often a goal of rehabilitation and assistive devices, yet the ...


Feasibility And Efficacy Of A Recess-Based Combined Fitness Intervention On Cognition And Academic Performance In Elementary School Children, Christine St Laurent Jul 2019

Feasibility And Efficacy Of A Recess-Based Combined Fitness Intervention On Cognition And Academic Performance In Elementary School Children, Christine St Laurent

Doctoral Dissertations

Youth physical activity and fitness have been reported to influence cognition and academic related outcomes. Despite the potential benefits of muscular fitness, few intervention studies have examined the impact of an intervention that has incorporated both cardiorespiratory and muscular fitness training on cognition and academic performance in children. Previous studies have mainly been implemented either during the school day or immediately after-school. Although recess may be an ideal time to promote physical activity because it does not compete with other academic demands, it has been an understudied setting. Therefore, the purpose of this dissertation project was to examine the feasibility ...


Tropomyosin-Based Effects Of Acidosis On Thin-Filament Regulation During Muscle Fatigue, Brent Scott Jul 2019

Tropomyosin-Based Effects Of Acidosis On Thin-Filament Regulation During Muscle Fatigue, Brent Scott

Masters Theses

Skeletal muscle fatigue is defined as a loss in the force/velocity generating capacity of a muscle. A portion of the loss in function is attributable to effects of acidosis (i.e. low pH) on the regulatory proteins, troponin and tropomyosin (Tm), which regulate the binding of myosin and actin in a calcium (Ca++) dependent manner. However, the relative role of troponin and Tm on myosin-actin function during acidosis is not clear, nor are the mechanisms underlying these effects. PURPOSE: To determine the role of Tm in the acidosis-induced depression of muscle function using isolated muscle proteins in an in ...


Development And Cross-Validation Of A Cadence-Based Metabolic Equation For Walking, Christopher C. Moore Jul 2019

Mechanisms And Mitigation Of Skeletal Muscle Fatigue In Single Fibers From Older Adults, Aurora Foster Jul 2019

Mechanisms And Mitigation Of Skeletal Muscle Fatigue In Single Fibers From Older Adults, Aurora Foster

Masters Theses

Skeletal muscle fatigue is the contraction-induced decline in whole muscle force or power, and can be greater in older versus young adults. Fatigue primarily results from increased metabolism elevating phosphate (Pi) and hydrogen (H+), which alters myosin-actin interactions; however, which steps of the myosin-actin cross-bridge cycle are changed and their reversibility are unclear. PURPOSE: This study sought to: 1) Examine the effects of elevated Pi and H+ on molecular and cellular function, and 2) Test the ability of deoxyadenosine triphosphate (dATP), an alternative energy to adenosine triphosphate (ATP), to reverse the contractile changes induced with high Pi ...


Cardiovascular Disease Risk And Menopause: Effects Of Cardiorespiratory Fitness, Exercise, And Follicle Stimulating Hormone, Corinna Serviente Nov 2018

Cardiovascular Disease Risk And Menopause: Effects Of Cardiorespiratory Fitness, Exercise, And Follicle Stimulating Hormone, Corinna Serviente

Doctoral Dissertations

Menopause is associated with adverse changes in cardiovascular disease risk factors. A reduction in estrogens is most commonly associated with changing cardiovascular disease risk; however, recent observations suggest that the increase in follicle stimulating hormone that accompanies menopause may also influence risk, potentially through its influence on lipid levels. The changes in cardiovascular disease risk factors may adversely affect endothelial cell function, a pre-clinical marker for cardiovascular disease. Whether cardiorespiratory fitness is protective of endothelial health in this population, thereby mitigating the changes in risk that accompany menopause, is unclear. This dissertation evaluated differences in endothelial health and endothelial responses ...


Feasibiity And Efficacy Of A Movement-Training Program On Physical Fitness, Fundamental Movement Skills, And Physical Activity In Third And Fourth Grade Students, Brittany Masteller Oct 2018

Feasibiity And Efficacy Of A Movement-Training Program On Physical Fitness, Fundamental Movement Skills, And Physical Activity In Third And Fourth Grade Students, Brittany Masteller

Doctoral Dissertations

Recent initiatives have focused on exploring the relationship between fitness, fundamental movement skills, psychosocial mediators, and physical activity in children to help design better interventions to improve these behaviors. FUNdamental Integrative Training (FIT) is an approach to physical education that uses age-appropriate exercises to improve physical fitness in youth, with the longer-term goal to physically prepare children for an active lifestyle beyond childhood. We evaluated the feasibility and efficacy of a 12-week, FIT program on physical fitness, fundamental movement skills, psychosocial mediators (self-efficacy, enjoyment and social support), and physical activity, among third and fourth grade students. Seven classrooms in one ...


Application And Evaluation Of Lighthouse Technology For Precision Motion Capture, Soumitra Sitole Oct 2018

Application And Evaluation Of Lighthouse Technology For Precision Motion Capture, Soumitra Sitole

Masters Theses

This thesis presents the development towards a system that can capture and quantify motion for applications in biomechanical and medical fields demanding precision motion tracking using the lighthouse technology. Commercially known as SteamVR tracking, the lighthouse technology is a motion tracking system developed for virtual reality applications that makes use of patterned infrared light sources to highlight trackers (objects embedded with photodiodes) to obtain their pose or spatial position and orientation. Current motion capture systems such as the camera-based motion capture are expensive and not readily available outside of research labs. This thesis provides a case for low-cost motion capture ...


Observing The Molecular Basis Of Thin Filament Activation With A Three Bead Laser Trap Assay, Thomas Longyear Mar 2018

Observing The Molecular Basis Of Thin Filament Activation With A Three Bead Laser Trap Assay, Thomas Longyear

Doctoral Dissertations

Muscle contracts after calcium (Ca++) is released into the muscle cell, resulting from a cascade of events which result in myosin, the molecular motor of muscle, to produce force and motion. Myosin cyclically binds to a regulated thin filament, using the chemical energy of ATP to produce force and motion. Perturbations in muscle, such as a build-up of metabolic by-products or point mutations in key contractile proteins, can inhibit these functions in both skeletal and cardiac muscle either acutely or chronically. Despite the many years we have studied skeletal and cardiac muscle, we still do not have a clear picture ...


Physical Activity And Age-Related Mechanical Risk Factors For Knee Osteoarthritis, Jocelyn F. Hafer Nov 2017

Physical Activity And Age-Related Mechanical Risk Factors For Knee Osteoarthritis, Jocelyn F. Hafer

Doctoral Dissertations

Knee osteoarthritis is an age-related disease which will affect nearly 50% of individuals in their lifetime. Because there are currently no treatments to substantially slow the progression of this disease, it is important to identify mechanisms to reduce the risk of osteoarthritis initiation. Osteoarthritis is a disease which is at least partially mediated by mechanical factors which may result from age-related changes in gait. The extent to which habitual physical activity can modify the impact of age on gait, knee mechanics, and thus cartilage loading is unknown. The aim of this dissertation was to examine the effects of age and ...


A Comprehensive Validation Of Activity Trackers For Estimating Physical Activity And Sedentary Behavior In Free-Living Settings, Albert R. Mendoza Nov 2017

A Comprehensive Validation Of Activity Trackers For Estimating Physical Activity And Sedentary Behavior In Free-Living Settings, Albert R. Mendoza

Doctoral Dissertations

The aim of study one of this dissertation was to compare consumer activity trackers (ATs) with the research-grade ActiGraph™ GT3X-BT accelerometer (AG) in estimating energy expenditure (EE) and steps during orbital shaking at different frequencies. To address this aim, we utilized an electronic orbital shaking protocol (twenty-four, 3-minute trials; 2-hour trials). For all comparisons, the AG served as the reference measure. In the 3-min protocol, we showed that on average, the NL-1000 pedometer (NL) produced the lowest error (-9 steps/3-min) at 0.9 Hz (corresponding to moderate intensity). The magnitude of the error for the NL was 14 steps ...


Quantifying Gait Adaptability: Fractality, Complexity, And Stability During Asymmetric Walking, Scott W. Ducharme Nov 2017

Quantifying Gait Adaptability: Fractality, Complexity, And Stability During Asymmetric Walking, Scott W. Ducharme

Doctoral Dissertations

Successful walking necessitates modifying locomotor patterns when encountering organism, task, or environmental constraints. The structure of stride-to-stride variance (fractal dynamics) may represent the adaptive capacity of the locomotor system. To date, however, fractal dynamics have been assessed during unperturbed walking. Quantifying gait adaptability requires tasks that compel locomotor patterns to adapt. The purpose of this dissertation was to determine the potential relationship between fractal dynamics and gait adaptability. The studies presented herein represent a necessary endeavor to incorporate both an analysis of gait fractal dynamics and a task requiring adaptation of locomotor patterns. The adaptation task involved walking asymmetrically on ...


A Magnetic Resonance Compatible Knee Extension Ergometer, Youssef Jaber Jul 2017

A Magnetic Resonance Compatible Knee Extension Ergometer, Youssef Jaber

Masters Theses

The product of this thesis aims to enable the study of the biochemical and physical dynamics of the lower limbs at high levels of muscle tension and fast contraction speeds. This is accomplished in part by a magnetic resonance (MR) compatible ergometer designed to apply a load as a torque of up to 420 Nm acting against knee extension at speeds as high as 4.7 rad/s. The system can also be adapted to apply the load as a force of up to 1200 N acting against full leg extension. The ergometer is designed to enable the use of ...


Burrowing And Walking Mechanisms Of North American Moles, Yi-Fen Lin Jul 2017

Burrowing And Walking Mechanisms Of North American Moles, Yi-Fen Lin

Doctoral Dissertations

Moles (Family Talpidae) are a classic example of extreme specialization, in their case highly derived forelimb morphologies associated with burrowing. Despite many observations of mole burrows and behaviors gathered in the field, we know very little about how and how well moles use their forelimbs to dig tunnels and to walk within the built tunnels to collect and transport food. The first chapter investigates the effect of soil compactness on two sympatric mole species under controlled laboratory conditions. My results demonstrate that increasing soil compactness impedes tunneling performance as evidenced by reduced burrowing speed, increased soil transport, shorter tunnels, shorter ...


Interfacing Continuous Measurement Of Glucose And Physical Activity To Predict Glycemic Control In Individuals With Type 2 Diabetes, Jennifer Blankenship Mar 2017

Interfacing Continuous Measurement Of Glucose And Physical Activity To Predict Glycemic Control In Individuals With Type 2 Diabetes, Jennifer Blankenship

Doctoral Dissertations

Physical activity is a cornerstone in the management of hyperglycemia and risk of cardiovascular disease in type 2 diabetes (T2D). However, the dose response relationship between physical activity and glucose regulation is not well defined. The overall goal of this dissertation was to assess the magnitude and timing of changes of daily glucose concentrations in response to continuous and intermittent light physical activity in T2D. Through utilizing continuous glucose monitors (CGM) and physical activity monitoring concurrently, we were able to assess the glycemic impact of physical activity and sedentary behavior in the free-living environment.

Study 1 aimed to examine the ...


The Consequences Of Speed: Studies Of Cavitation During The Mantis Shrimp Strike And The Control Of Rapid Deceleration During Toad Landing, Suzanne M. Cox Nov 2016

The Consequences Of Speed: Studies Of Cavitation During The Mantis Shrimp Strike And The Control Of Rapid Deceleration During Toad Landing, Suzanne M. Cox

Doctoral Dissertations

There are consequences of moving quickly in this world. Here we investigate how two very different species, mantis shrimp (Odontodactylus scyllarus) and cane toads (Bufo marinus), negotiate forces that result from moving rapidly in different environments. To study the mechanical principles and fluid dynamics of ultrafast power-amplified systems, we built Ninjabot, a physical model of the extremely fast mantis shrimp. While mantis shrimp produce damaging cavitation upon impact with their prey, they do not cavitate during the forward portion of their strike despite extreme speeds. In order to study cavitation onset in non-linear flows common during the mantis shrimp strike ...


Feasibility Of A Combined Physical Activity And Sleep Education Intervention For Girls Living In A Low Socioeconomic Status Urban Community, Cory J. Greever Jul 2016

Feasibility Of A Combined Physical Activity And Sleep Education Intervention For Girls Living In A Low Socioeconomic Status Urban Community, Cory J. Greever

Doctoral Dissertations

Declining sleep duration and poor sleep quality is a public health epidemic disproportionately effecting elementary age girls living in low socioeconomic status urban communities. The Girls Dancing and Sleeping for Health (Girls DASH) program was designed to test the feasibility, acceptability, and efficacy of a combined physical activity and sleep education program in this population. In combination with baseline data from a previously conducted intervention in elementary age urban girls living in a low SES community in Springfield, MA, results from a cross-sectional analysis indicated that greater screen time was positively associated with parental reports of child’s sleep quality ...


Mechanisms Of Slowed Foot Tap Speed In Older Adults, Erica L. Hartman Jul 2016

Mechanisms Of Slowed Foot Tap Speed In Older Adults, Erica L. Hartman

Masters Theses

Rapid repetitive tapping, like the Foot Tap Test (FTT), slows with age, but the underlying mechanisms are unknown. Purpose: 1. Test the hypotheses that greater performance variability, increased muscle coactivation, and slowed muscle contractile speeds are related to lower foot tap count (FTC) in older adults; 2. Examine the relationship between FTC and physical function in older adults, using the advanced SPPB-A. Methods: 18 (25.0±3.1years, 9F, mean±SD), and 28 (73.4±4.9, 14F) adults were recruited; the later were divided into Higher (HFO) and Lower (LFO) Functioning based on SPPB-A score. Participants performed 10s of ...


The Influence Of Musculoskeletal Geometry On The Metabolic Cost Of Pedaling, Lex Gidley Mar 2016

The Influence Of Musculoskeletal Geometry On The Metabolic Cost Of Pedaling, Lex Gidley

Doctoral Dissertations

The human musculoskeletal system consists of several muscles crossing each joint. In the human lower limb, most major muscles cross either one or two joints; labeled as uniarticular or biarticular muscles, respectively. The major biarticular muscles of the leg are the rectus femoris, hamstrings, and gastrocnemius. Several suggestions have been proposed as to how biarticular muscles may reduce the metabolic cost of human movement. Using experimental protocols, it is difficult to address the energetic effects of biarticular muscles, as individual muscle contributions to human movement cannot be measured and there is no way to determine what the effect might be ...


Multi-Segment Foot Coordination Of The Treated Clubfoot, Amy Whited Nov 2015

Multi-Segment Foot Coordination Of The Treated Clubfoot, Amy Whited

Masters Theses

Idiopathic congenital clubfoot can be treated either operatively (comprehensive surgical release (CSR)) or conservatively (ponseti technique (PCT)). This thesis compared the mid-term outcomes after CSR and PCT treatments to a typically developing sample. A Dynamical Systems Analysis (DSA) approach and a multi-segment foot model were used to examine group differences in multi-segment foot and lower extremity kinematics, kinetics, coordination and coordination variability during walking. Ten children with clubfoot treated with PCT and seven children with clubfoot treated with CSR were evaluated retrospectively and compared to ten typically developing children. Multi-segment foot and lower extremity kinematic (240 Hz) and kinetic (1080 ...


Inter-Segment Coordination Variability Post Anterior Cruciate Ligament Reconstruction, Devin K. Kelly Nov 2015

Inter-Segment Coordination Variability Post Anterior Cruciate Ligament Reconstruction, Devin K. Kelly

Masters Theses

INTER-SEGMENT COORDINATION VARIABILITY POST ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

SEPTEMBER 2015

DEVIN K. KELLY, B.S., UNIVERSITY OF MASSACHUSETTS AMHERST

M.S., UNIVERSITY OF MASSACHUSETTS AMHERST

Directed by: Dr. Joseph Hamill

There is an increased risk for ipsilateral graft rupture and contralateral ACL rupture following ACL reconstruction surgery (ACLR) despite return to sport clearance. The reason for this increased risk is not well understood. Previous literature has shown that decreased coordination variability is indicative of an injured system regardless of the absence of pain. PURPOSE: To quantify inter-segment coordination variability during three portions of the stance phase of gait in athletes ...


Molecular Mechanisms Underlying The Contralateral Repeated Bout Effect (Crbe) In Human Skeletal Muscle, Ling Xin Aug 2015

Molecular Mechanisms Underlying The Contralateral Repeated Bout Effect (Crbe) In Human Skeletal Muscle, Ling Xin

Doctoral Dissertations

Eccentric (muscle lengthening) exercise induces temporary muscle damage that can lead to long-term muscle adaptation, a process known as the repeated bout effect where subsequent exercise results in less damage. The existence of a contralateral repeated bout effect (CRBE) has been controversial. The primary goals of this study were to: 1) validate the existence of the CRBE; and 2) define the underlying molecular mechanisms.

Thirty-six young men performed 100 maximal eccentric actions of the knee extensors using one leg (bout 1) and repeated the exercise with the contralateral leg five weeks later (bout 2). Vastus lateralis muscle biopsies were ...


Impact Of A Preschool Workplace Intervention On Classroom Teachers’ Physical Activity Levels And Quality Of Life, Ogechi O. Nwaokelemeh Aug 2015

Impact Of A Preschool Workplace Intervention On Classroom Teachers’ Physical Activity Levels And Quality Of Life, Ogechi O. Nwaokelemeh

Doctoral Dissertations

PURPOSE: To examine the feasibility and efficacy of a three-month, cluster-randomized workplace PA intervention on PA levels and wellbeing measures in preschool classroom teachers. METHODS: Ten preschool centers were randomized into two groups; short-bouts of structured PA (SBS-PA, n=5) or traditional unstructured PA (TRAD-PA, n=5). The SBS-PA intervention consisted of 10-minute structured, teacher-led PA routines implemented within the classroom setting, followed by 20 minutes of unstructured playtime. The TRAD-PA intervention consisted of supervised 30-minute of unstructured free playtime. Both interventions were implemented during the morning and afternoon designated gross-motor playtime for 30 min/session, five days/week for ...


The Effects Of Ovarian Hormones And Exercise On Gene Markers Of Cardiac Dysfunction, Anisha S. Patel Jul 2015

The Effects Of Ovarian Hormones And Exercise On Gene Markers Of Cardiac Dysfunction, Anisha S. Patel

Masters Theses

Heart disease is the leading cause of death in women in the United States. Premenopausal women appear to have better cardiac function and lower risk of heart disease compared to male postmenopausal female counterparts. Ovarian hormone loss influences blood pressure homeostasis and causes systemic inflammation, which may result in chronic stress on the heart. Two key physiological changes in cardiac dysfunction are reemergence of the fetal gene pattern and myocardial remodeling. Physical activity has been linked to improved cardiac function. The purpose of this study was to investigate the effects of ovariectomy on early markers of cardiac dysfunction and fibrosis ...


The Role Of The Extracellular Matrix In Mediating Muscle Soreness, Karen L. Riska Mar 2015

The Role Of The Extracellular Matrix In Mediating Muscle Soreness, Karen L. Riska

Doctoral Dissertations

The goal of this dissertation was to examine the role of the extracellular matrix (ECM) in muscle soreness. Study 1 examined how the disruption of the ECM from a minor surgery (e.g. muscle biopsy) affected muscle soreness. Study 1 showed that soreness levels increased at 24 h post-biopsy compared to baseline and resolved within 96 h. However, the level of muscle soreness at 24 h post-biopsy (20 mm) was lower than that reported for performing a strenuous and naïve exercise (40–80 mm). These results will help review boards at institutions where muscle biopsies are performed understand how a ...


Plantar Pressure, Cutaneous Sensation And Stochastic Resonance: An Examination Of Factors Influencing The Control And Perception Of Posture, Michael A. Busa Mar 2015

Plantar Pressure, Cutaneous Sensation And Stochastic Resonance: An Examination Of Factors Influencing The Control And Perception Of Posture, Michael A. Busa

Doctoral Dissertations

The goal of this dissertation was to understand how people control posture in the context of sensory loss. To do so we explored three potential influences on the detection of external information and how they relate to the control of posture and perception of body orientation: 1) does changing posture alter the forces under the foot, and do these changes impact the ability to detect external vibrations? 2) Does decreasing the temperature of the foot influence the ability to detect external vibrations, the perception of body orientation, and the control of posture? And 3) does stochastic resonance (SR) improve the ...


Kinetic Asymmetries During Submaximal And Maximal Speed Running, Devon H. Frayne Aug 2014

Kinetic Asymmetries During Submaximal And Maximal Speed Running, Devon H. Frayne

Masters Theses

An important issue for sports scientists, coaches and athletes is an understanding of the factors within a running stride that can enhance or limit maximal running speed. Previous research has identified many sprint-related parameters as potential kinetic limiters of maximal Center of Mass velocity (Chapman and Caldwell, 1983b; Weyand et al., 2001). Bilateral asymmetry is present for many of these parameters during running; however the degree to which such asymmetries change as running speed increases is unknown. It was hypothesized that asymmetries in key sprinting parameters would be larger at maximal speed than all other tested speeds. Kinematics and kinetics ...


Development And Validation Of Accelerometer-Based Activity Classification Algorithms For Older Adults: A Machine Learning Approach, Jeffer Eidi Sasaki Apr 2014

Development And Validation Of Accelerometer-Based Activity Classification Algorithms For Older Adults: A Machine Learning Approach, Jeffer Eidi Sasaki

Doctoral Dissertations

Machine learning algorithms to classify activity type from wearable accelerometers are important to improve our understanding of the relationship between physical activity (PA) and risk for physical disability in older adults. Therefore, the main objective of this dissertation was to develop and evaluate machine learning algorithms to predict activity type and intensity in older adults from a commercially available accelerometer (ActiGraph GT3X+).

In Study 1, we developed machine learning algorithms to classify activity type and intensity from raw accelerometer data in older adults. Thirty-five older adults performed an activity routine comprised of different activities (5 min/activity) while wearing three ...