Assessment Of Anti-Saccades Within 24 To 48 Hours Post-Concussion, Nathan D'Amico

College of Graduate Studies: Theses & Dissertations

INTRODUCTION: Oculomotor control dysfunction is present in about 90% of concussed athletes, with anti-saccades being the most prominent. PURPOSE: To investigate anti-saccades, reflexive gaze deviations from a fixed point or area of interest, between NCAA Division I athletes 24 to 48 hours post-concussion (PC) and healthy, matched controls (MC). METHODS: 10 PC (4 female, 6 male; age: 18.9 ± 0.9 years) and 10 MC (4 female, 6 male; age: 18.3 ± 0.6 years) wore a monocular eye tracker (240Hz) while performing 2 trials of the 60-second WiiFit Soccer Heading game. During play, participants were instructed to not deviate their gaze …

Estimates Of Persistent Inward Current Decline In Human Soleus Motor Units During Fatigue, Kirby Mendes

Theses and Dissertations (Comprehensive)

Fatigue is defined as any exercise induced reduction in strength or power, and can be attributed to central and peripheral components. Many central and peripheral mechanisms have been extensively studied, but few studies have looked at the changes in the intrinsic properties of motor neurons and their contribution to fatigue. Persistent inward current (PIC) is an important intrinsic property of motor neurons responsible for setting a large increase in the gain of motor output and may contribute to fatigue. Inhibitory inputs such as reciprocal inhibition (RI) have been shown to turn off PICs and reducing the gain of output. PIC …

An Exploratory Approach To Manipulating Dynamic Stability: Investigating The Role Of Visual Control During A Precision Foot Placement Task, Russell Cg Kennedy

Theses and Dissertations (Comprehensive)

ABSTRACT

Background: The visual system provides the body with an accurate sensory system; designed to gather information at a distance and acts as a feedforward control mechanism during human locomotion. By doing so, visual information contributes coordination of the head-arm-trunk (HAT) segment and modulating foot placement. The purpose of this study was to examine the effects of a constrained pathway during a complex navigational stone-stepping task on HAT segment control and how the visual system guides locomotion during a complex foot placement task.

Methods: Nine university-aged females (Mean age: 22.5 years old +/-1.75) participated in this study. Participants …

The Effects Of A Low Back Pain Vibration Modality On Trunk Postural Control, Adam R. Cornwall

Theses and Dissertations (Comprehensive)

Abstract

Introduction: Low back pain (LBP) is prevalent worldwide and is affecting even more individuals as the population ages. There has recently been an increase in production of low back pain (LBP) vibration modality belts that apply localized vibration to the lumbar region of the spine as it has shown to reduce pain. However, vibration is also known to perturb muscle spindles and thus interfere with proprioception. If a LBP vibration modality causes a proprioceptive deficit in the trunk lumbar region it could potentially increase an individual’s risk of injury due to poor postural control. Therefore, the effects of a …

The Effects Of External Focus Of Attention Exercise Rehabilitation On Dual Task Walking In Parkinson's Disease, Eric N. Beck

Theses and Dissertations (Comprehensive)

Parkinson’s disease impairs control of well-learned movements, and therefore, individuals with Parkinson’s disease are forced to walk with greater conscious control. This causes difficulties while walking and completing a secondary task simultaneously (dual tasking), in that distractions from conscious control of walking increase the risk of falls and injury. Although, attention-based exercise may be a potential avenue to decrease the demands associated with walking in Parkinson’s disease. For example, an external focus of attention (on manipulated objects) has been found to recruit the networks that are important for walking with little conscious control (automatic control networks). In contrast, an internal …

The 2d:4d Ratio, Handedness, And Sex Across The Age Span, Helen A M Protopapas Ms.

Theses and Dissertations (Comprehensive)

The ratio of the difference between the 2nd and 4th digits of the hand (2D:4D ratio) has been demonstrated to be an indirect indicator of prenatal testosterone levels. Prenatal testosterone has been found to play a role in brain development in utero, and thus may influence lateral asymmetries, such as handedness. Consequently, one of the aims of the current study was to examine relationships between the 2D:4D ratio, hand preference, and hand performance with the factors of sex (males and females), handedness (right handers and left handers), and age considered. A total of 104 participants were tested, 90 right handers …

The Influence Of Joint-Site, Limb Preference, And Physical Activity On Joint Position Sense, Amanda N. Forsyth

Theses and Dissertations (Comprehensive)

Joint position sense provides the body with information about where limb segments are relative to one another in three-dimensional space. The ability to utilize this sense is imperative for smooth, coordinated, and accurate movement in everything from activities of daily living to competitive sport (Ghez & Sainburg, 1995). Researchers currently use joint position sense as a measure of proprioceptive acuity. However, limited research has investigated the influence of potential confounding factors on proprioception. Specifically, literature on how joint-site specificity and lateral preference influence proprioception displays several incongruent findings. Therefore, the purpose of the current study was (1) to determine if …

The Feedforward And Feedback Controls On Gait In Adults With Diabetes, Chun-Kai Huang

Theses & Dissertations

There are nearly 26 million people with diabetes mellitus (DM) in the US, and half of chronic DMs develop somatosensory deficits due to diabetic polyneuropathy or diabetic peripheral neuropathy (DPN). The absence or impaired somatosensory feedback (e.g. touch sensation or joint proprioception) resulted from the damage of large nerve fiber, and motor deficits such as attenuated muscle strength and abnormal plantar pressure of lower extremity have been identified in DPN, and these sensorimotor impairments lead to an increased number of falls. To reduce the risk of falling, a well-coordinated and adapted limb movement driven by the feedforward (anticipatory) and feedback …

Glucose-Fructose Likely Improves Gastrointestinal Comfort And Endurance Running Performance Relative To Glucose-Only, P. B. Wilson, S. J, Ingraham

Athletic Performance Research

This study aimed to determine whether glucose-fructose (GF) ingestion, relative to glucose-only, would alter performance, metabolism, gastrointestinal (GI) symptoms, and psychological affect during prolonged running. On two occasions, 20 runners (14 men) completed a 120-min submaximal run followed by a 4-mile time trial (TT). Participants consumed glucose-only (G) or GF (1.2:1 ratio) beverages, which supplied ~1.3 g/min of carbohydrate. Substrate use, blood lactate, psychological affect [Feeling Scale (FS)], and GI distress were measured. Differences between conditions were assessed using magnitude-based inferential statistics. Participants completed the TT 1.9% (−1.9; −4.2, 0.4) faster with GF, representing a likely benefit. FS ratings were …

Misrepresentation Of Carbohydrate For Exercise: ‘It Is Time To Bust The Myth Of Physical Inactivity And Obesity: You Cannot Outrun A Bad Diet’, Patrick B. Wilson

Athletic Performance Research

The contention from Malhotra et al1 regarding the unimportance of carbohydrate for exercise is misguided. First, the reference they provide is an editorial2 that should not be viewed as high-quality evidence. Several oft-cited exercise studies showing benefits with high-fat diets simultaneously utilized carbohydrate restoration strategies,3 which involves “carbohydrate loading” after a high-fat diet. Thus, the evidence provided does not contradict the established belief that carbohydrate is an important fuel for endurance exercise. Second, the authors’ use of the term “carbohydrate loading” is misleading in this context. No public health organizations advocate a diet containing carbohydrate in amounts used in “carbohydrate …

Removable Shoe Spike System, Alex Adams, Nutech Ventures, Inc.,

Athletic Performance Research

The present system, method and apparatus are adapted for the quick and easy exchange of spikes on athletic shoes. More specifically, the system, apparatus and methods comprise a spike having an opening, an aglet adapted for coupling to the shoe, for example by way of a shoelace, and a coupling head affixed to the aglet which is adapted to couple with the opening on the spike so as to allow a user to quickly and easily replace, remove or install spikes in the athletic shoe. The disclosure thus allows the user to have the tool attached to their shoe at …

The Temporal And Directional Dependencies Of Sway During 10 Seconds Of Single Leg Stance In Young, Healthy College Students, David Vanderheyden

Symposium Of University Research and Creative Expression (SOURCE)

Background: Single Leg Stance (SLS) testing is used in clinical assessments of balance, but little is known about the temporal structure of sway parameters during this test. SLS research is equivocal on the effects of sway over time and the direction of balance initiation. Sway data in a healthy young population may provide insight on how balance is initiated and maintained in relation to the initial step direction. This may lead to novel approaches to help healthy elderly populations decrease fall risk and fall-related mortality. Purpose: The purpose of the study was to examine the temporal and directional dependencies of …

Comparing Functional Motor Control And Gait Parameters In Children With Autism To Those Of Age-Matched Peers Who Are Typically Developing, Patricia Stevenson, Samantha Novotny, Jillian May, Christopher Ancell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to compare motor performance of children with Autism Spectrum Disorder (ASD) to that of age-matched peers who are typically developing (TD) on motor control tasks plus symmetry and variability of gait parameters across four walking conditions. A sample of convenience of children with ASD (n=6) and peers who are TD (n=6) were recruited. Motor control was assessed using initiation and completion times on the Timed Up and Go (TUG) test. Gait parameters were collected using a computerized walkway under four trial conditions: 1) walking at self-selected velocity (SSV); 2) walking during a tray-carrying task …

A Pilot Study Investigating The Reasons For Playing Through Pain And Injury: Emerging Themes In Men’S And Women’S Collegiate Rugby, Leilani Madrigal, Jamie Robbins, Diane L. Gill, Katherine Wurst

Athletic Performance Research

Collegiate rugby is a competitive, collision sport, yet insufficient empirical evidence exists regarding participants’ perspectives on pain and injury. This study addressed male and female rugby players’ experiences with injury, and their views about playing through pain and injury. Eleven rugby players (five male; six female) competing in USA Rugby’s National College 7’s tournament participated in semi structured interviews, which were recorded, transcribed, and content-analyzed. Two major themes emerged: passion for sport and sport ethic. Passion for sport was composed of (a) love of the sport, (b) meaning of the sport, and (c) desire to be on the field. Sport …

Alternate Foot Placement: Investigating The Role Of Gait Parameters, Planar Obstacle Complexity, And Athletic Training, Brittany A. Baxter

Theses and Dissertations (Comprehensive)

On a daily basis modifications, based upon environmental demands and the capabilities of the individual, are made to the locomotor pattern to enable avoidance of undesirable landing areas (i.e. planar obstacles). Athletes and dancers have been suggested to have superior perception-action coupling compared to non-athletes, allowing them to perform various tasks at a greater speed without a loss of precision (Federici et al., 2005; Gerin-Lajoie et al. (2007). The current study assessed non-athletes, dancers, and field athletes to investigate whether training influences the maintenance of forward progression and stability in relation to alternate foot placement during planar obstacle avoidance. Eleven …

Influence Of Planning Resources On Gait Control In Parkinson’S Disease, Frederico P. Faria

Theses and Dissertations (Comprehensive)

Movement disturbances in individuals with Parkinson’s disease (PD) have been associated with difficulties to plan complex actions. Performance of simple and complex actions overloads resources for individuals with Parkinson’s disease (PD). However, it is unclear if central resources required to plan gait adjustments while walking exacerbate gait disturbances of patients with PD. More specifically, it is unclear how gait impairments, sensory processing, and the dopaminergic system influence the load on processing resources (e.g. cognitive load) during the planning of step modifications. In order to investigate the relative influence of these factors on cognitive load and its impact on gait control, …

Estimates Of Persistent Inward Current In Human Motor Neurons During Postural Sway, Ryan Foley, Jayne M. Kalmar Dr.

Theses and Dissertations (Comprehensive)

Persistent inward current (PIC) is a membrane property critical for increasing gain of motor neuron output. In humans, most estimates of PIC are made from plantarflexor or dorsiflexor motor units with the participant in a seated position with the knee flexed. This seated and static posture neglects the task-dependent nature of the monoaminergic drive that modulates PIC activation. Seated estimates may drastically underestimate the amount of PIC that occurs in human motor neurons during functional movement. The current study estimated PIC using the conventional paired motor unit technique which uses the difference between reference unit firing frequency at test unit …

An Athletic Approach To Studying Perception-Action Integration: Does Sport-Specific Training, And The Impact Of Injury, Influence How Individuals Visually Guide Navigation?, Carmen Baker, Jennifer Campos Ph.D, Michael E. Cinelli Ph.D.

Theses and Dissertations (Comprehensive)

The objective of this thesis was to investigate perception-action integration capabilities of individuals during a choice navigation task. This task assessed navigation strategies in open space while individuals avoided colliding with two vertical obstacles that created a body-scaled, horizontal gap, at three varying obstacle distances from the starting location (3m, 5m, 7m). The two studies completed in this thesis employed the same paradigm to assess the hypothesized group differences. Gaze behaviours and kinematics of navigation strategies were compared between: 1) athletes specifically trained in navigating in open space versus non-athletes; and 2) athletes with post-concussion syndrome (PCS) versus non-concussed, specifically …

The Effect Of Training Older Adults In Tai Chi And Compensatory Stepping On Balance Control, Hannah L. Moore Miss

Theses and Dissertations (Comprehensive)

Abstract

Introduction: In Canadian society, there is a growing prevalence of older adults and one of the main problems facing this generation today is the risk of falling. Tai Chi (TC) is a martial art that has demonstrated improvements in balance control. It uses a series of fluid movements that engage head, neck and trunk rotation while simultaneously reducing base of support. In addition, it has been demonstrated that training older adults by administering unpredictable perturbations to challenge balance better equips them to react successfully in response to balance perturbations. This study aims to determine the potential balance specific benefits …

The Application Of Hand Switch Costs Towards Understanding Bimanual Movements: An Investigation Throughout The Lifespan, Gordon Young

Theses and Dissertations (Comprehensive)

The objective of the present study was to examine the different kind of switch costs among a varied population using a modified bimanual serial reaction time task. Alternating between responses produce a cost of increased response time, which is termed a switch cost. However, not all switch costs are equal, and its effect on response time is dependent on what previous hand and digit combination was utilized. A detachable touchscreen tablet PC running a custom built JavaScript based software prompted participants to press down with their digits (2^nd-5^th) to corresponding buttons which would light up in …