Life Sciences Commons^™

Neuromuscular Adaptations To Voluntary Contraction Following Postactivation Potentiation, Cameron B. Smith

Electronic Thesis and Dissertation Repository

Muscle contractile properties are history-dependent, and following a conditioning contraction, muscle tissue may be fatigued (slower, weaker) or potentiated (faster, stronger). Postactivation potentiation of evoked contractions, such as the electrically stimulated twitch, has been thoroughly studied. However, the effects of potentiation on voluntary contraction are not well understood, and prior study is largely equivocal.

The following studies propose to determine the effects of potentiation during 1) submaximal contractions at different muscle lengths 2) ballistic contractions following tetanic and voluntary conditioning, and 3) motor evoked potentials following tetanic and voluntary conditioning contractions. Evoked twitch potentiation was assessed with all of the …

Validation Of The Multi-Segment Foot Model With Bi-Planar Fluoroscopy, Aïda Valevicius

Electronic Thesis and Dissertation Repository

A multi-segment foot model (MSFM) is a useful tool for measuring foot joint kinematics although soft-tissue artefact is often present. Quantifying this error is needed to evaluate the accuracy of this model. This study validated the MSFM against bi-planar radiostereometric analysis (RSA) fluoroscopy. Heel-strike, mid-stance, and toe-off events during the stance phase were compared between motion capture and fluoroscopy. Rise/drop of the medial longitudinal arch showed a significant difference (p < 0.05) during toe-off, but no significant difference during heel-strike or mid-stance. Hindfoot supination/pronation and internal/external rotation, and forefoot supination/pronation motions showed no significant difference between the two techniques. The lack of significant difference will allow the MSFM to be used as a sufficiently accurate technique for measuring foot joint motions.

Knoxville Moves: Log-In And Get Mobile, Courtney Marie Monroe

Doctoral Dissertations

This dissertation evaluated 1) the efficacy of a course-based Internet-technology intervention rooted in social cognitive theory (SCT) for increasing step counts in university faculty and staff, and 2) the effect of online social support tools on step counts among adults using a randomized control trial.

Thirty-six sedentary/insufficiently active university faculty and staff participated in an eight-week, Internet-delivered walking intervention. They received an Omron HJ-720ITC pedometer, personal step goals, and access to a Blackboard LearnTM website comprised of SCTbased features. Outcomes included daily steps, social support, self-regulation, self-efficacy, and outcome expectations. Participants significantly increased their average daily steps (p < 0.001) between baseline and week 1 by 1800. A similar increase in daily steps was observed between baseline and all other intervention weeks (p < 0.001). Social support and self-regulation significantly improved (p < 0.001). These findings helped inform the design of the second study.

In this …

Investigating The Role Of A Reduced-Instruction Approach In Implicit And Explicit Motor Learning Strategies, Kevin Michael Fisher

Doctoral Dissertations

Traditional explanations of motor learning contend that skills are learned explicitly in a process in which learners accumulate declarative knowledge and progress through distinct stages of learning (e.g., Fitts & Posner, 1967). More recently, implicit approaches to instruction have been used in an attempt to bypass accumulation of explicit knowledge. Such approaches have been shown to facilitate motor learning compared to explicit instruction by enhancing skill retention and transfer under conditions involving distraction, increased pressure, or physical stress (Masters & Poolton, 2012). One method thought to invoke implicit learning involves instructions in the form of an analogy (Liao & Masters, …

Kinetic And Kinematic Properties Of D-I Male Sprinters, Zhanxin Sha

Electronic Theses and Dissertations

The purpose of the study was to explore and determine kinetic and kinematic variables that related to D-I male sprinters maximal running velocity performance. The current study was separated into 3 individual chapters: 1.) Kinematic analysis magnitude of acceleration for braking and propulsion phases during foot contact phase at maximal speed sprinting; 2.) Using kinetic isometric mid-thigh pull variables to predict D-I male sprinters’ 60m performance; 3.) Relationship of whole and lower body angular momentum cancellation during terminal swing phase to sprint performance.

Methods: for sprint measurement all the athletes were participated 2 trials of 100% effort running through 60 …

Foot And Ankle Kinematic And Lower Extremity Muscle Activity During Descent From Varying Step Heights, Emily Gerstle

Theses and Dissertations

Ankle injuries are common during activities of daily living, particularly in negotiation of steps. Previous studies examining steps have generally focused on the ankle, knee, or hip and descent of multiple steps. Joint motion within the foot, utilizing a multi-segment foot model, during step descent has not been extensively studied. Although peroneal muscle activity differences have been identified between participants with healthy and unstable ankles during static activities, little is known about peroneal activity during activities of daily living. A better understanding of the foot kinematics and muscle activity in persons with uninjured ankles may help future studies elucidate the …

An Optimization Method For Estimating Joint Parameters Of The Hip And Knee, Ben Tesch

Theses and Dissertations

Biomechanics, generally speaking, concerns the application of engineeringprinciples to the study of living things. This work is concerned withhuman movement analysis, a subfield of biomechanics, where the methodsof classical mechanics are applied to human movement. This field hascontributed to the general understanding of human movement, and itstechniques are used in the diagnosis and treatment of disease. Centralto the field is the process of measuring human movement. Since classicalmechanics deals with the motion of rigid bodies, and ideal measurementsystem would be able to accurately record the exact pose --- combinedposition and orientation --- of the bones. The techniques that reachthis ideal …

Investigating The Effects Of Biochemical And Biophysical Signals On Vascular Smooth Muscle Cell Differentiation, Ruikai Chen

All Dissertations

In blood vessel engineering, an optimal bioartifical scaffold can be characterized as a 3D tubular structure with high porosity for nutrient diffusion and enough mechanical strength to sustain in vivo dynamic environment. The luminal surface of the scaffold is supposed to have a continuous layer of endothelial cell that is ideally non-immunogenic and non-thrombogenic while the media layer of the construct is assigned for the ingrowth of vascular smooth muscle cell which can provide structural integrity and contractility. While reconstructing endothelial cell layer has been at the center of interest in most polymeric vascular replacements related research, growing VSMCs has …

Role Of Sensation In Altered Phalanx Grip Force In Persons With Stroke, Leah R. Enders

Theses and Dissertations

Many individuals experience hand impairment after stroke leading to decreased ability to perform daily living activities. Previous research studies have investigated how stroke survivors' pinch grip control differs from healthy individuals, even though many individuals can only grasp with power grip after stroke. Furthermore, many stroke survivors experience tactile sensory deficit in their paretic limb in addition to motor deficit. It is currently unknown how stroke induced tactile sensory deficit affects power grip force directional control, which is important in terms of preventing object slippage and power grip normal force generation. Additionally it is unknown if power grip could be …

The Effects Of Worksite Health Promotion Programs On Employee Biometric Data, Jamie M. Pratt

Theses and Dissertations

INTRODUCTION: Worksite health promotion programs (WHPP) promote maintenance and changes of health-related behaviors of employees. Some companies opt to contract with a third party provider to implement a WHPP. PURPOSE: This study evaluated the participation rates, availability and use of health coaching, and changes in biometric data over a 2-year time period of employees in 13 companies for whom the WHPP was implemented by Wellness Corporate Solutions (WCS). METHODS: We had 2 years of biometric, health risk appraisal (HRA), or health coaching data on 4,473 employees. The statistical analysis included biometric screening data (percent body fat, body mass index (BMI), …

A Randomized Controlled Trial To Study The Effects Of Breakfast On Energy Intake, Physical Activity, And Body Fat In Women, Gabrielle Marie Lecheminant

Theses and Dissertations

PURPOSE: The purpose of this study was to determine the effects of eating breakfast on energy intake, physical activity, body weight, and body fat in women who were nonhabitual breakfast eaters over a one-month period. METHODS: We tested 49 premenopausal, nonhabitual breakfast-eating women to compare the effects of eating breakfast versus not eating breakfast. Each participant was randomized to one of two conditions: breakfast or no breakfast. Breakfast eaters were required to eat within an hour and a half of awakening and had to be finished eating their breakfast meal by 8:30 A.M. Non-breakfast eaters were defined as not consuming …

Ground Forces Impact On Release Of Rotational Shot Put Technique, Niklas B. Arrhenius

Theses and Dissertations

In the shot put throw, the primary power is generated in the form of ground reaction forces as a result of action of the lower extremities (Coh, Stuhec, & Supej, 2008). The purpose of this study was to determine how the ground reaction force and ground contact time during the delivery phase of rotational shot put relates to the predicted distance of the throw. This will allow us to determine the optimal approach of force application for maximum throwing distance (Linthorne, 2001). Eight male subjects were used in this study (age 23 ± 4 y; body mass 123 ± 14 …

Microvascular Function In Metabolically Healthy Groups Differing In Bmi And Waist Circumference, Nathan R. Earl

Theses and Dissertations

BACKGROUND: Microvascular dysfunction (MD: impaired performance of blood flow, tissue perfusion, blood pressure, etc.) is one of the earliest stages in the progression of various chronic diseases. OBJECTIVE: The aim of this study was to determine if a difference in microvascular function existed between two metabolically healthy groups that differed in BMI and waist circumference. DESIGN: This study employed a causal comparative design, with two groups: I) normal weight (n =14, BMI 28 kg/m2). METHODS: Microvascular function was assessed by measuring skin blood flow (SkBF) using laser Doppler flowmetry during postocclusive reactive hyperemia (PORH). The area under the SkBF time …

A Movement Tool Kit For The Divergent And Convergent Cps Guidelines: Instruction Cards And Activity Floor Mats, Adela Vangelisti

Creativity and Change Leadership Graduate Student Master's Projects

A Movement Tool Kit for the Divergent and Convergent CPS Guidelines:

Instruction Cards and Activity Floor Mats

Movement is as natural to humans as breathing is, and, yet, passivity starts early in schools. We are taught to sit still and in silence for long periods of time. By the time we reach adulthood and enter the workforce, we have almost forgotten our sense of embodiment. This lack of movement is counter-productive, not only to learning but to the development of creativity as well. For this project, I designed a tool to recapture the joy and playfulness of movement. Furthermore, the …

The Influence Of Observational Learning On Self-Reported Physical Activity, Self-Efficacy For Physical Activity, And Health-Related Fitness Knowledge For Physical Activity, Charles Gregory Bullock

Dissertations

The obesity epidemic has caused tremendous burden to our economy and healthcare system. Physical activity is one method that can reduce the obesity rate. However, physical activity declines in high school and does not recover. The likelihood of adolescents continuing their involvement in physical activity depends on how they navigate the highs and lows of their physical activity experiences (Feltz & Magyar, 2006). The purpose of this study is to look at the role of observational learning in physical activity and behaviors in an adolescent population. Specifically, this research examines the influence of observational learning on self-reported physical activity, self-efficacy …

Postural Sway And Brain Hemispheric Power Spectral Density Under Different Attentional Focus Conditions, Sharon Jalene

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine the differences, if any, in the root mean square error (RMSE) of postural sway and hemispheric power spectral density (PSD) in the alpha and beta bands (8-12Hz and 12-25Hz) during different conditions of attentional focus (i.e., internal focus (IF), and external focus (EF) and a control condition (C)). Previous studies have shown that the adoption of IF and EF significantly alter motor performance and that EF promotes automaticity (Wulf, 2013). Sports performance and balance studies utilizing EEG spectral analyses report increased alpha oscillations during expert performance and stable balance and increased beta …

Application Of The Transtheoretical Model: Assessing Exercise Behavior In African Americans In A Church-Based Setting, Robin Marie White

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sedentary behavior rates are higher among African-American men and women than in other American races and ethnicities, placing them at greater risk for chronic illness. Routine physical activity reduces the risk of chronic health problems such as: (a) overweight and obesity, (b) type 2 diabetes, (c) hypertension, (d) coronary artery disease, (e) stroke, (f) congestive heart failure, and (g) cancers. Assessment of African-Americans' exercise attitudes in a church-based setting may provide information with which to develop effective interventions to improve physical activity. This descriptive, cross-sectional study used components of the Transtheoretical Model (TTM) to assess whether any associations exist between …

Relationship Of Dna Methylation With Cardiovascular Fitness And Body Composition, Mihaela A. Ciulei

Honors College Theses

Global DNA Methylation (GDM), an epigenomic modification has been linked to the development of cardiovascular disease and its risk factors. Our focus was to identify potential relationships between epigenetic alterations and both cardiovascular fitness and body composition measures. Purpose: As increases in aerobic fitness have a beneficial effect on cardiovascular disease, one purpose was to determine if a relationship was evident between global DNA methylation and VO2max. A secondary purpose was to determine if the relationship extends to body composition measured via Dual X-ray Absorbtometry (DXA). Methods: Fifty-two (male n=25, female n=27) subjects provided a blood sample for DNA …

Postural Sway In Infants At Low And High Risk For Autism Spectrum Disorder, Rachel C. Harris

Open Access Theses

ABSTRACT Harris, Rachel C. M. S., Purdue University, December 2014. Postural Control in Infants at Low and High Risk for Autism Spectrum Disorder. Major Professor: Laura J. Claxton. Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder more commonly known for deficits in social and communication skills. More recently, aspects of motor development have been shown to be delayed in children with ASD, including deficits in their postural control abilities. Children with ASD have difficulty integrating information from their sensory systems to help control their balance. Infants at risk for ASD and infants who are later diagnosed with ASD have delays …

Unilateral Traditional Weight Lifting Generates Greatest Acute Upper Body Power Output, Evan H. Nakachi

Theses and Dissertations

Bilateral deficit (BLD) is a phenomenon where the force generated from simultaneous bilateral limb contractions is less than the sum force generated by separate right and left limb contractions. There have been many BLD studies, but the measures of force generation have predominantly been with isometric and isokinetic contractions. There are, however, no dynamic upper body isotonic unilateral weight lifting studies on acute power output. The purpose of this study was to determine acute power output between bilateral and unilateral weight lifting under the conditions of traditional and circuit weight lifting. Seventeen male BYU rugby players (age = 21.8 ± …

Maximal Motor Unit Discharge Rates Of The Medial And Lateral Gastrocnemeii Of Young Males, Mitchell T. Graham

Electronic Thesis and Dissertation Repository

The triceps surae is composed of the mono-articular soleus and the bi-articular gastrocnemeii. Mean maximal motor unit discharge rates (MUDRs) reported for the soleus (~16Hz) are lower than other limb muscles tested (Dalton et al., 2009). Because of differences in fibre-type and functional anatomy it is important to determine maximal MUDRs in the two heads of gastrocnemeii, as compared with the soleus, to fully understand the interplay of these three muscles for plantar flexion. The purpose of the study was to record maximal MUDRs of the medial (MG) and lateral gastrocnemeii (LG) in 9 recreationally active, young men (age 24.2 …

Downhill Treadmill Running Does Not Induce Muscle Damage In Fvb Mice, Brenda Benson

Theses and Dissertations

Downhill treadmill running is a commonly used method to cause exercise-induced muscle damage, especially in rodents. Previous studies have evaluated which muscles in rats are more prone to damage. However research using downhill run mice (DHR) has shown some inconsistencies in which muscle is best analyzed for damage. Purpose: The purpose of this study was to quantify the damage in various muscles in a mouse after a single bout of DHR. Methods: Male FVB mice (5 months) were injected with Evans Blue dye (EBD) and then either used as control (CON) or run downhill (-16°) at 20 meters per minute …

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 …

Decreased Peak Muscle Power Is Associated With Motor Unit Loss In The Lower Limb Of Older Adults, Neal B. Mckinnon

Electronic Thesis and Dissertation Repository

This study investigated the relationship between motor unit (MU) properties and the strength and power of two lower limb muscles in healthy young and old adults. Twelve older adults (mean age, 77 ± 5 yrs) and twelve young adults (mean age, 24 ± 3 yrs) were studied. MU properties of the tibialis anterior (TA) and vastus medialis (VM) muscles were determined using decomposition-enhanced spike-triggered averaging (DE-STA). Motor unit number estimates (MUNE) of the TA were significantly reduced (p>0.05) in older adults (102 ± 76) compared to young adults (234 ± 109), primarily as a result of significantly larger surface-detected …

Evaluating The Similarity In Postures Between Forklift Operators In Virtual Reality And The Workplace, Youngmin Jun

Electronic Thesis and Dissertation Repository

Forklift operators must adopt awkward postures in order to gain appropriate lines of sight; these postures are associated with musculoskeletal injuries and disorders such as low back pain and neck pain. The purpose of this thesis was to evaluate the similarity in postures between forklift operators in virtual reality simulation of forklift loading and unloading operations and a corresponding real world workplace. This evaluation will help determine whether the virtual reality system is a useful tool for performing controlled laboratory-based investigations of ergonomics issues in heavy mobile machinery. One certified forklift operator and one uncertified individual performed two cycles of …

Post Exercise Ingestion Of Plant Vs Animal Protein Enhances Exercise Performance Outcomes Similarly, Adam N. Upshaw

Electronic Thesis and Dissertation Repository

Recently, the ingestion of a carbohydrate-protein supplement after exercise has garnered considerable interest among both athletes and scientists. However, debate exists about whether the type of protein consumed, animal vs plant, affects exercise performance differently. Thus, it is the purpose of this dissertation to compare performance outcomes following carbohydrate (CHO)-plant or CHO-animal protein ingestion utilizing a variety of exercise conditions (acute bouts of aerobic exercise, 10 weeks of strength training and six weeks of concurrent training).

Study 1 demonstrated that following a glycogen depleting bout of cycling, dairy chocolate, soy chocolate, hemp chocolate or dairy milk ingestion all enhanced the …

Biosteel High Performance Sports Drink Improves Exercise Performance Following A Simulated Hockey Game, Kolten C. Abbott

Electronic Thesis and Dissertation Repository

INTRODUCTION: BioSteel High Performance Sports Drink (BioSteel) is one of the most popular sports supplements consumed by professional and amateur athletes. BioSteel Inc^® claims that consumption of BioSteel before and during exercise will result in “enhanced energy while delaying the onset of muscular and mental fatigue”. PURPOSE: Assess the efficacy of BioSteel supplementation on anaerobic and aerobic exercise performance as well as sport-specific cognition throughout exercise. METHODS: Eleven exercise-trained men completed a simulated hockey game on a cycle ergometer under two experimental conditions: BioSteel and isoenergetic placebo. Measures of exercise performance and cognition were assessed before, throughout and after …

A Philosophical Analysis Of Ethics Education In The Canadian National Coaching Certification Program For Rowing, Mark M. Williams

Electronic Thesis and Dissertation Repository

This dissertation applies a conception of rationality from the philosophy of science to the coaching education context. The purpose of this dissertation is to present an account of how the exercise of judgment by coaches facing ethical dilemmas can be rational. The discussion in this dissertation begins with a traditional account of rationality that has long been a staple of moral philosophy. Next, the influence of this model in the current Canadian rowing coach education program are highlighted, as are its limitations in providing a complete account of rational ethical-decision making in the coaching context. After establishing these limitations, an …

The Effects Of Oar-Shaft Stiffness And Length On Rowing Biomechanics, Brock Laschowski

Electronic Thesis and Dissertation Repository

This work investigates the effects of oar-shaft stiffness and length on rowing biomechanics. The mechanical properties of the oar-shafts were examined using an end-loaded cantilever system, and theoretical relations were proposed between the mechanics of the oar-shafts and rowing performance. On-water experiments were subsequently conducted and rowing biomechanics measured via the PowerLine Rowing Instrumentation System. The PowerLine system measures force and oar angle on the oarlock, as well as proper boat acceleration. The convergent validity and test-retest reliability of the PowerLine force measurements were determined prior to the on-water experiments. Thereafter, rowers were tested over a set distance using oar-shafts …

Comprehensive Analysis Of Abdominal Tendon Length:Muscle Length Ratios In Human And Rat Specimens, Alexander J. Stephen

Electronic Thesis and Dissertation Repository

Introduction: This study measured and described the tendon to muscle length ratios (TMRs) of the external oblique (EO), internal oblique (IO), rectus abdominus (RA), and transverse abdominus (TrA) muscles in humans and rats. Methods: The abdominal muscles of human and rat specimens were dissected and the length of the muscle fibers from their posterior attachments to the lumbodorsal fascia or the rib cage, and the lengths of their tendons, were measured. The tendon length was divided by muscle fiber length to calculate the TMR. Results: The TMRs for the human EO, IO, and TrA muscles were significantly larger than the …