Life Sciences Commons^™

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, …

Effect Of Seat Tube Angle And Exercise Intensity On Muscle Activity Patterns In Cyclists, Will Duggan, Bernard Donne, Neil Fleming

International Journal of Exercise Science

International Journal of Exercise Science 10(8): 1145-1156, 2017. Previous studies have reported improved efficiency at steeper seat tube angle (STA) during ergometer cycling; however, neuromuscular mechanisms have yet to be fully determined. The current study investigated effects of STA on lower limb EMG activity at varying exercise intensities. Cyclists (n=11) were tested at 2 workloads; 160W and an individualised workload (IWL) equivalent to lactate threshold (T_Lac) minus 10%δ (derived from maximal incremental data), using 3 STA (70, 75 and 80°). Electromyographic data from Vastus Medialis (VM), Rectus Femoris (RF), Vastus Lateralis (VL) and Biceps Femoris (BF) were assessed. …

Functional Changes Through The Usage Of 3d-Printed Transitional Prostheses In Children, Jorge Zuniga, Jean Peck, Rakesh Srivastava, James E. Pierce, Drew Dudley, Nicholas T. Than, Nicholas Stergiou

Journal Articles

Introduction: There is limited knowledge on the use of 3 D-printed transitional prostheses, as they relate to changes in function and strength. Therefore, the purpose of this study was to identify functional and strength changes after usage of 3 D-printed transitional prostheses for multiple weeks for children with upper-limb differences.

Materials and methods: Gross manual dexterity was assessed using the Box and Block Test and wrist strength was measured using a dynamometer. This testing was conducted before and after a period of 24 ± 2.61 weeks of using a 3 D-printed transitional prosthesis. The 11 children (five girls and six …

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 …

The Runsmart Training Program: Effect On Oxygen Consumption And Lower Extremity Biomechanics During Running, Jennifer Bogulski, Steven Gonser, Doug Bush, Raechel Bugner, Lindsay Clark, Lisa Farrell, Kristen Swanson, Michael Ross

Articles & Book Chapters

As recreational running continues to gain popularity, more individuals are seeking ways to improve running performance. RunSmart is a running intervention program designed to enhance a runner’s form. In addition to correcting flaws in a runner’s form, RunSmart offers the opportunity for runners to continue a regular regimen while slowly integrating changes in form. The purpose of this case series was twofold: to determine if the RunSmart program coincides with improvements in oxygen consumption (VO₂), a variable often associated with better running performance times, and to evaluate the RunSmart program in regard to enhancing gait biomechanics. Five recreational …

The Influence Of Crossfit Training On Running Mechanics, Sophia D. Bradley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction

40 million Americans run regularly.1 Contrary to many runner’s beliefs, increased strength may be beneficial while not adding body mass. An increase in strength in specific muscles may improve running gait and performance. 9,6 Strength training may also play an important role in preventing common overuse injuries in running 11,12 Depending on the style of strength training, it may also have an enhanced benefit on running economy.4,16

Participation in CrossFit is also widely popular, with an increase in participation of 923% in the past ten years.2 CrossFit is a type of strength training in which most movements performed utilize …

Dynamic Balance Changes Within Three Weeks Of Fitting A New Prosthetic Foot Component, Jenny A. Kent, Nicholas Stergiou, Shane R. Wurdeman

Journal Articles

Balance during walking is of high importance to prosthesis users and may affect walking during baseline observation and evaluation. The aim of this study was to determine whether changes in walking balance occurred during an adaptation period following the fitting of a new prosthetic component.

Margin of stability in the medial-lateral direction (MOSML) and an anterior instability margin (AIM) were used to quantify the dynamic balance of 21 unilateral transtibial amputees during overground walking. Participants trialled two prosthetic feet presenting contrasting movement/balance constraints; a Higher Activity foot similar to that of their own prosthesis, and a Lower Activity foot. Participants …

The Development Of A Platform Interface With The Use Of Virtual Reality To Enhance Upper-Extremity Prosthetic Training And Rehabilitation, Ashley D. Knight

USF Tampa Graduate Theses and Dissertations

This dissertation focuses on the investigation and development of an effective prosthetic training and rehabilitation platform with the use of virtual reality to facilitate an effective process to return amputees to the highest level of independence and functioning possible.

It has been reported that approximately 10 million people live with a limb loss worldwide, with around 30% being an upper-extremity amputee. The sudden loss of a hand or arm causes the loss of fine, coordinated movements, reduced joint range of motion (ROM), proprioceptive feedback and aesthetic appearance, all which can be improved with the use of a prosthesis and proper …

Patients With Chronic Obstructive Pulmonary Disease Walk With Altered Step Time And Step Width Variability As Compared With Healthy Control Subjects, Jennifer M. Yentes, Stephen I. Rennard, Kendra K. Schmid, Daniel Blanke, Nikolaos Stergiou

Journal Articles

Rationale: Compared with control subjects, patients with chronic obstructive pulmonary disease (COPD) have an increased incidence of falls and demonstrate balance deficits and alterations in mediolateral trunk acceleration while walking. Measures of gait variability have been implicated as indicators of fall risk, fear of falling, and future falls.

Objectives: To investigate whether alterations in gait variability are found in patients with COPD as compared with healthy control subjects.

Methods: Twenty patients with COPD (16 males; mean age, 63.6 ± 9.7 yr; FEV1/FVC, 0.52 ± 0.12) and 20 control subjects (9 males; mean age, 62.5 ± 8.2 yr) walked for 3 …

Step Activity And 6-Minute Walk Test Outcomes When Wearing Low-Activity Or High-Activity Prosthetic Feet, Shane Wurdeman, Kendra K. Schmid, Sara A. Myers, Adam L. Jacobsen, Nicholas Stergiou

Journal Articles

Objective

To determine changes in average daily step count (ADSC) and 6-minute walk test (6MWT) due to use of low-activity feet (LA) and high-activity energy-storage-and-return (ESAR) feet, and examine the sensitivity of these measures to properly classify different prosthetic feet.

Design

Individuals with transtibial amputations (n = 28) participated in a 6-week, randomized crossover study. During separate 3-week periods, participants wore either a LA foot (eg, solid-ankle-cushioned-heel) or an ESAR foot. Differences in 6MWT and ADSC at the end of the 3-week period were recorded.

Results

Subjects performed similarly in the 6MWT with the LA and ESAR foot (P …

Cognitive Contributions To Anterior Cruciate Ligament Injury Risk, Thomas Gus Almonroeder

Theses and Dissertations

The purpose of this dissertation was to explore how cognitive factors contribute to non-contact anterior cruciate ligament (ACL) injury risk in young females. We specifically wanted to develop a better understanding of how the movement patterns of females with varying cognitive attributes/abilities are influenced as the cognitive demands associated with a task progress (Chapter 2). We also wanted to explore how task-related cognitive demands influence movement. We altered the cognitive demands associated with a movement task by requiring participants to execute a maneuver while attending to a simulated teammate (Chapter 3) or to a ball overhead (Chapters 4 & 5). …

Stride Leg Ground Reaction Forces Pre- And Post-Fatigue In Collegiate Baseball Pitchers, Courtney Alley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Context: Baseball pitching requires the coordination of the lower and upper extremities to effectively generate and transfer force to the ball. High-velocity pitchers have been found to have significantly greater stride leg force generation than low-velocity pitchers. The influence of stride leg fatigue on pitching has yet to be investigated. Objective: The purpose of this study was to examine the effect of stride leg fatigue on peak vertical ground reaction forces (vGRFs) and hand velocity. Design: Pretest-posttest. Setting: Biomechanics laboratory. Patients or Other Participants: A convenience sample of 11 collegiate baseball pitchers (19.27 ± 0.64 years old; 85.88 ± 12.16 …

Effects Of Synthetic Turf Systems With And Without A Shock Pad On Lower Extremity Biomechanics During A 90° Cutting Movement With Differing Approach Velocities, Thomas Kenneth Elvidge

Masters Theses

The purpose of this study was to examine differences in lower extremity kinematics and kinetics on two different synthetic turf systems (turf only and turf with a shock pad) for two approach velocities (3.0 and 4.0 m/s) during a 90° cutting movement. Twelve recreational male American football and soccer players were recruited to perform five trials for each of the four conditions. A three-dimensional motion analysis system synchronized to a force platform was used to collect marker coordinate and ground reaction force (GRF) data respectively. A 2 x 2 (surface x approach velocity) ANOVA was used to analyze kinematic and …

Children With Moderate To Severe Cerebral Palsy May Not Benefit From Stochastic Vibration When Developing Independent Sitting, Anastasia Kyvelidou, Regina T. Harbourne, Joshua L. Haworth, Kendra K. Schmid, Nicholas Stergiou

Journal Articles

Purpose: Determine sitting postural control changes for children with cerebral palsy (CP), using a perceptual-motor intervention and the same intervention plus stochastic vibration through the sitting surface. Methods: Two groups of children with moderate or severe CP participated in the 12 week interventions. The primary outcome measure was center of pressure data from which linear and nonlinear variables were extracted and the gross motor function measure (GMFM). Results: There were no significant main effects of intervention or time or an interaction. Both treatment groups increased the Lyapunov exponent values in the medial–lateral direction three months after the …

An Investigation Of The Relationship Between Intervertebral Disc Puncture, Inflammation, And Tissue Mechanics Using A Rat-Tail Model., Brigitte Laird

Theses and Dissertations (Comprehensive)

Introduction: The intervertebral disc (IVD) is composed of the annulus fibrosus (AF), which surrounds and contains the nucleus pulposus (NP). It is hypothesized that when the IVD becomes injured, in the case of IVD herniation, a localized innate immune response is initiated. Although the presence of pro-inflammatory cytokines in injured IVDs has been well documented, the extent to which inflammation affects the mechanical properties of the IVD remains poorly understood. The purpose of this study was to determine the effect of IVD damage (via puncture) and inflammation (via lipopolysaccharide (LPS) exposure) on the mechanical and structural properties of the IVD. …

The Effects Of A 12-Week Custom Foot Orthotic Intervention On The Intrinsic Muscles Of The Foot, And Dynamic Stability During Unexpected Gait Termination In Healthy Young Adults, Katrina Protopapas

Theses and Dissertations (Comprehensive)

Introduction: Custom-made foot orthotics (CFO’s) are a commonly prescribed intervention to help individuals that are suffering from foot pain and foot disorders. However, the mechanisms of CFO’s are still poorly understood and are not well known. With the plantar intrinsic muscles of the foot being in direct contact with the CFO, it puts these structures at risk for disuse muscle atrophy as a result of being offloaded. Therefore, the purpose of the current study was to determine the effect of a 12-week custom-made foot orthotic intervention on the intrinsic muscles of the foot and dynamic stability during unexpected gait termination. …

Differences In The Muscle Activity For Baseball Hitters Of Varying Skill, Ethan M. Stewart

Theses and Dissertations--Kinesiology and Health Promotion

INTRODUCTION: Muscle activity and timing of the swing phases may contribute to the differences we see in athletes at different skill levels. The purpose of this study is to analyze the differences between mean muscle activity, peak muscle active and time to peak muscle activity for select muscles in the lower extremity as well as the differences between start times for swing phases and bat velocity prior to impact for a skilled and recreational group. METHODS: Twelve healthy subjects were split into two groups based on competitive level and analyzed hitting off of a tee. RESULTS: No significant differences were …

The Effect Of Delayed Onset Muscle Soreness On Jumping Mechanics And Performance, Ryan J. Engels

Electronic Theses and Dissertations

Background: Delayed onset muscle soreness (DOMS) is an exercise-induced muscle soreness resulting from high-intensity eccentric muscular contractions. DOMS appears to be more prevalent in athletes at the beginning of an athletic season or when new movements or exercise are first introduced. The acute effect of DOMS on jumping mechanics is currently unknown. PURPOSE: The purpose of this study is to determine the effect of delayed onset muscle soreness on vertical jump performance and jumping mechanics. METHODS: Twenty college aged, recreationally active males participated in this study (age: 21.54 ± 2.61; height: 1.82 ± 0.067; mass: 81.36 ± 9.53). Participants were …