Motor Control Commons^™

Locomotor Skill Development In Response To An Electronic Visual Exercise System In Children With Sensory Impairments, Sara Johnson

Online Theses and Dissertations

Children with sensory impairments associated with a physical or intellectual disability often have delay in fundamental motor skill development. The dual purpose of this study was to observe locomotor skill development, in response to an electronic visual exercise system, as well as interrater reliability of the assessment method. Eight children between the ages of seven and fourteen were recruited from an adapted physical education program. Pre-and post-test analysis of data collected via the Test of Gross Motor Development - Second Edition revealed no significant changes in motor skill development. Interrater reliability statistical analysis revealed a strong ICC value, suggesting excellent …

The Effect Of Repetitive Head Impacts On Postural Control Over The Course Of A Single Season, Katelyn E. Grimes

College of Graduate Studies: Theses & Dissertations

INTRODUCTION: Recently neurocognitive dysfunction has been linked to poor postural control in concussed athletes. While the detrimental effect of repetitive head impacts on cognitive function have been shown to mirror the effects of concussive injury, very little research has investigated the physical consequences of repetitive head impacts. PURPOSE: To observe the effects of RHI on postural control, both static and dynamic, in NCAA Division I athletes over the course of a single season. METHODS: 9 NCAA Division I football athletes (CON) were recruited from a single university as the experimental group, as well as 9 NCAA Division I baseball players …

The Effects Of A Concussion On Dynamic Stability And Cognitive Performance During Single And Dual Task Tandem Gait, Erin Lodwick

Cal Poly Humboldt theses and projects

PURPOSE: It is estimated that between 1.6 and 3.8 million concussions occur in the United States every year during competitive sports. To limit the risk of returning an athlete to play too soon a sensitive and reliable assessment is needed. Static balance assessments that are used currently only detect very short term balance deficits (1-3 days). The purpose of this study is to examine the effects of a concussion on dynamic stability and more specifically if those effects are seen to a greater degree with the addition of a secondary cognitive task. METHODS: This study used 18 Humboldt State University …

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 …

Are Maximum Ground Forces And Leg Compression In Phase? A Test Of The Classical Spring Mass Model Of Running Gaits, Seth Donahue

Graduate Student Theses, Dissertations, & Professional Papers

The mechanical understanding of human running has classically been described as a spring-mass system, with subsequent models predicting the movements of the body’s center of mass and the forces applied by the leg against the ground. A central requirement of any spring system is the phasic relationship between the length of the elastic elements and the forces applied to these structures. Specifically, elastic elements compress under load and extend as the load is released. We tested whether this model applies to individuals with specialization for extreme performance in human gait. Recent work from elite level sprint runners suggest that their …

Task-Dependent Modulation Of Cortical Excitability And Balance Control In Individuals With Post-Concussion Syndrome, Kristen Kaster, Jayne M. Kalmar Ms., Michael E. Cinelli Mr

Theses and Dissertations (Comprehensive)

In most cases, symptoms resolve between 7-10 days post-concussion. However, in 10-15% of the concussed population, symptoms can remain unresolved for months to years following the head injury. The purpose of this thesis was two-fold, and was broken up into two studies, where the same individuals participated in both studies. The purpose of the first study was to quantify the differences in balance control between individuals with PCS (i.e., had been experiencing symptoms for <30 days) and non-concussed individuals during a lower-limb reaching task. Participants completed a static balance assessment before and after a lower-limb reaching task, which incorporated a Go/No-Go paradigm. Results from this study revealed no differences in the static stability assessments, however, individuals with PCS demonstrated increased medial-lateral COP displacement as well as greater trunk pitch during the reaching task. Overall, the findings reveal persistent balance impairments in individuals with PCS, which may put this population at an increased risk of further injury. The purpose of the second study was to assess task-dependent modulation of cortical excitability prior to planned index finger abduction contractions comparing a non-concussed population to a population with PCS. The protocol in this study consisted of both single and paired-pulse transcranial magnetic stimulation (TMS) which was applied prior to the beginning of 3 different tasks (i.e., a rest condition with no plan to contract, a precision contraction, and a powerful contraction). In addition to the three tasks, participants also had to respond to a Go/No-Go cue. The results of this study revealed an increase in excitability prior to a precision contraction in both non-concussed and PCS groups. No differences in task-dependent modulation were found between the two groups with respect to intracortical facilitation and inhibition, however a negative correlation between number of symptoms reported (SCAT3 symptom evaluation) and intracortical facilitation was revealed. The increase in corticospinal excitability prior to a precision contraction was not explained by the two cortical mechanisms we assessed and may therefore be due to spinal modulation or a different cortical mechanism. Overall, based on the results from this thesis, it appears that individuals with PCS have balance impairments, which may be a result of an inability to maximally activate their postural muscles. Furthermore, it appears that those individuals who reported a higher number of symptoms had greater reductions in intracortical facilitation, likely reflecting the heterogeneity of this clinical group.

Peripheral Visual Motion Sensitivity In Previously Concussed, Asymptomatic Individuals, Alyssa Prangley

Theses and Dissertations (Comprehensive)

Background: Individuals acquire information about self-motion from the environment which specifies actions necessary to be successful (Fajen & Matthis, 2011). However, concussed individuals demonstrate residual disturbance in execution of postural movement at 30 days post injury, depicting an impaired ability to perceive self-motion in a visually conflicting environment (Slobounov et al. 2006). The objective of this thesis was to investigate the extent to which one’s behaviours on a central field of view task are influenced by the amount and type of peripheral visual movement during a collision avoidance task, as well as to determine the additive effects of changes to …

Motor Control In Individuals With Multiple Sclerosis, David Arpin

Theses & Dissertations

This dissertation explored motor control in individuals with multiple sclerosis (MS) by quantifying the behavioral and neurophysiological deficits present in these individuals. We behaviorally quantified the precision of the ankle plantarflexor musculature of individuals with MS. Our results indicated that the individuals with MS had a greater amount of variability in the precision of the isometric ankle torques, and that this greater variability was related to decreased walking performance. To further explore whether these motor control deficits were due to aberrant cortical activity associated with planning motor actions, we used magnetoencephalography to assess the motor planning and execution stages of …

A Comparison Of Cervical And Trunk Musculoskeletal Characteristics Between Female And Male Army Helicopter Pilots, Takashi Nagai, Karen A. Keenan, John P. Abt, Timothy C. Sell, Brian W. Smalley, Michael D. Wirt, Scott M. Lephart

International Journal of Aviation, Aeronautics, and Aerospace

Introduction: Neck pain (NP) and low back pain (LBP) are prevalent among military helicopter pilots. Although there have been few studies on sex differences in the NP/LBP prevalence in this population, females are shown to be at a greater risk of NP/LBP in civilian studies. This disparity may be due to musculoskeletal characteristics differences that predispose females for NP/LBP. The purpose of this study was to compare cervical and trunk musculoskeletal characteristics between male and female pilots. Methods: A total of 8 female pilots (Age: 27.6 ± 4.2yrs, HT: 166.1 ± 7.7cm, WT: 67.9 ± 10.6kg) were tested, and they …

Mobility Of Individuals With Multiple Sclerosis And The Influence Of Physical Therapy, Brenda L. Davies

Theses & Dissertations

One main purpose was to explore the compensatory gait strategies of individuals with multiple sclerosis (MS). To address this purpose, we quantified the mechanical work generated by the lower extremity joints during walking. The outcomes from this investi­gation suggested that individuals with MS redistribute positive mechanical work during walking to the hip in order to compensate for a reduced ability of the ankle to generate positive mechanical work. Additionally, we also explored the motor control of the ankle as a potential contributing factor to the mobility limitations of individuals with MS. The outcomes from this investigation indicated that individuals with …

The Effect Of Weighted Body Armor On Close Combat Reaction Time And Core Muscle Activation 2016, Christopher Banta

Master's Theses

The purpose of this study was to measure the choice reaction time and myoelectric activity of the right and left rectus abdominus, and right and left external obliques required to initiate movement in response to a visual stimulus that signaled performance of four different closecombat movements (left or right cross and left or right dodge). Reaction time and myoelectric activity were then compared with performing the movements in response to the visual stimulus while wearing a weighted vest that simulated wearing tactical body armor. Myoelectric activity was measured as the average root mean square (RMS) of the surface electromyography (sEMG) …

Power Output And Loads On The Lumbar Vertebrae During A Power Clean 2016, Joseph Keleher

Master's Theses

The purpose of the present study was to compare the peak resultant torque, shear, and compressive forces acting at the L3/L4 junction of the lumbar vertebrae and the peak power output during 40% one repetition maximum (1RM) and 80% 1RM attempts of the power clean. It was hypothesized that performance of a power clean at 80% 1RM will result in greater peak resultant compressive force, torque and shear force at the L3/L4 junction of the lumbar spine than that of a 40% 1RM attempt. Power cleans at 80% 1RM will also result in higher maximum instantaneous power outputs than that …

The Effects Of Hypohydration On Neurocognitive, Balance, Vestibular Ocular Motor Functions And Mood State, Satoshi Iida

Graduate Theses and Dissertations

Inconsistent findings have been observed on the impact of hydration state on cognitive functions. The isolated effect of hypohydration on neurocognitive performance, balance, vestibular ocular motor function and mood outcomes in widely used concussion assessment tools has not been studied. The purpose of this study was to investigate how hypohydration affected the results in concussion testing batteries. A single-blind randomized crossover design was used. Thirteen healthy males (22 ± 4y, 180.9 ± 5.7cm) without history of concussion within the past six months or any condition or disease that could influence outcome measurements participated in this study. Each subject completed concussion …

Electromyographic And Mechanomyographic Time And Frequency Responses During Fatiguing, Submaximal, Isokinetic Muscle Actions Of The Biceps Brachii, Ethan C. Hill

College of Education and Human Sciences: Dissertations, Theses, and Student Research

The purpose of the present investigation was to examine the time-course of changes in electromyographic (EMG) and mechanomyographic (MMG), time and frequency domain responses during repeated, submaximal, concentric, isokinetic, forearm flexion muscle actions. Twelve men (mean age ± SD = 22.6 ± 2.2 yrs; body weight = 84.0 ± 8.3 kg; height = 178.6 ± 8.3 cm) performed 50 repeated, submaximal (65% of concentric peak torque), concentric muscle actions of the dominant forearm flexors on an isokinetic dynamometer at 60°·s^-1. Surface EMG and MMG signals were simultaneously recorded from the biceps brachii muscle. Polynomial regression analyses (first, second, …

Time Course Of Changes In Neuromuscular Parameters During Fatiguing High-Load And Low-Load Concentric Dynamic Constant External Resistance Leg Extension Muscle Actions, Cory M. Smith

Department of Nutrition and Health Sciences: Dissertations, Theses, and Student Research

The purpose of this study was to simultaneously assess electromyographic (EMG) and mechanomyographic (MMG) signals to examine the time course of changes in EMG amplitude, EMG frequency, MMG amplitude, and MMG frequency from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) muscles during high-load (70%1 repetitions maximum; 1-RM) and low-load (30% 1-RM) concentric, dynamic constant external resistance (DCER) leg extension muscle actions to failure. Twelve men performed two randomized visits consisting of either 30 or 70% 1-RM DCER leg extension muscle actions to failure. Maximal voluntary isometric contractions (MVIC) and 1-RM measurements were performed before and after …

Preliminary Results On Organization On The Court, Physical And Technical Performance Of Brazilian Professional Futsal Players: Comparison Between Friendly Pre-Season And Official Match, Luiz Henrique Palucci Vieira, Sera N. Doğramaci, Ricardo Augusto Barbieri, Fabio Milioni, Felipe Arruda Moura, Vitor Luiz De Andrade, Guilherme Manna Cesar, Paulo Roberto Pereira Santiago

Athletic Performance Research

The main aim of this study was to verify possible differences between a friendly pre-season match (FM) and an official in-season match (OM) regarding physical, technical, and organizational performances of a professional Brazilian futsal team. Ten professional futsal athletes participated in this study. The matches were monitored with video cameras (30 Hz) and athlete trajectories obtained with automatic tracking. The values obtained for distance covered per minute, percentage of distance covered at moderate intensity, team coverage area, spread, passes, possessions, ball touches and successful passes per minute were greater for the OM than FM. On the contrary, percentage of distance …

Hpcnmf: A High-Performance Toolbox For Non-Negative Matrix Factorization, Karthik Devarajan, Guoli Wang

COBRA Preprint Series

Non-negative matrix factorization (NMF) is a widely used machine learning algorithm for dimension reduction of large-scale data. It has found successful applications in a variety of fields such as computational biology, neuroscience, natural language processing, information retrieval, image processing and speech recognition. In bioinformatics, for example, it has been used to extract patterns and profiles from genomic and text-mining data as well as in protein sequence and structure analysis. While the scientific performance of NMF is very promising in dealing with high dimensional data sets and complex data structures, its computational cost is high and sometimes could be critical for …

Frontal Plane Comparison Between Drop Jump And Vertical Jump: Implications For The Assessment Of Acl Risk Of Injury, Guilherme Manna Cesar, Curtis L. Tomasevicz, Judith M. Burnfield

Athletic Performance Research

The potential to use the vertical jump (VJ) to assess both athletic performance and risk of anterior cruciate ligament (ACL) injury could have widespread clinical implications since VJ is broadly used in high school, university, and professional sport settings. Although drop jump (DJ) and VJ observationally exhibit similar lower extremity mechanics, the extent to which VJ can also be used as screening tool for ACL injury risk has not been assessed. This study evaluated whether individuals exhibit similar knee joint frontal plane kinematic and kinetic patterns when performing VJs compared with DJs. Twenty-eight female collegiate athletes performed DJs and VJs. …

Weight Control Practices Of Division I National Collegiate Athletic Association Athletes, Patrick B. Wilson, Leilani Madrigal, Judith M. Burnfield

Athletic Performance Research

Objectives: Altering body weight can have substantial effects on an athlete’s performance and well-being. Limited information is available describing the weight control practices of Division I National Collegiate Athletic Association (NCAA) athletes.

Methods: Weight control practices data from 188 (138 male and 50 female; 18-23 y) Division I NCAA athletes were analyzed as a part of this cross-sectional, retrospective study. Participants completed questionnaires on weight control practices and weight control nutrition knowledge at the end of their season and were classified into weight-sensitive and less weight-sensitive sports.

Results: A higher proportion of females attempted to lose weight than males among …

Examining The Reliability, Validity And Factor Structure Of The Drs-15 With College Athletes, Leilani Madrigal, Diane L. Gill, Kent M. Eskridge

Athletic Performance Research

Hardiness, comprising feelings of commitment, control and challenge, is most frequently measured with the Dispositional Resiliency Scale (DRS), but little work has been done with the brief 15-item version. To examine the factor structure, reliability, validity, and item functioning for gender invariance of the 15-item DRS with 525 collegiate athletes from a wide range of sports. Convergent and divergent validity were examined through relationships with mental toughness, grit and competitive anxiety. Participants completed measures of mental toughness, optimism, grit, competitive anxiety, and the DRS-15. Confirmatory Factor Analysis revealed a poor fit for the three-factor hardiness model, and subsequent exploratory factor …

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 …

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 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 …

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 …

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 …

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 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 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 …