Medicine and Health Sciences Commons^™

Joint Loading Factors Of Articular Cartilage Structure In Healthy And Acl-Injured Knees, Elizabeth Wellsandt

Theses & Dissertations

Articular cartilage structure and chondrocyte health are sensitive and reliant on dynamic joint loading during activities. The risk of osteoarthritis (OA) is high after anterior cruciate ligament (ACL) injury, but mechanisms underlying its development are poorly understood. The overall goals of this work were 1) to determine the association between measures of individual and cumulative knee joint loading with T2 relaxation times in the knee cartilage of young individuals without injury and 2) to determine if these same knee joint loading factors are associated with cartilage T2 relaxation time one month after ACL injury. The central hypotheses was that lower …

Assessment Of Landing Biomechanics And Rehabilitation After Anterior Cruciate Ligament Reconstruction, Sheila S. Gagnon

Electronic Thesis and Dissertation Repository

Aberrant landing biomechanics increase the risk of anterior cruciate ligament (ACL) injury and are a focus of rehabilitation after ACL reconstruction. The purpose of the present thesis was to develop and evaluate methods of assessing landing mechanics and investigate the effects of different rehabilitation strategies after ACL reconstruction. Three studies were conducted. The first study used a Delphi process to develop the content of a Clinician-Rated Drop Vertical Jump Scale to evaluate jump landing mechanics during rehabilitation after ACL reconstruction. Twenty experts participated in four rounds of questioning, resulting in 92% agreement for knee valgus collapse, lateral trunk lean, insufficient …

Validation Of An Inertial-Measurement-Unit System For Calculating Hip And Knee Flexion Angles During Gait, Joonsun Park

Master's Theses

Technological advances regarding Inertial Measurements Units (IMUs) have positioned this type of sensor as an alternative for camera-based motion capture. This study introduces a new IMU based system (IMU_sys) to measure hip and knee flexion angles. PURPOSE: To validate the use of a five-sensor IMU_sys for the measurement of knee and hip flexion angles during gait in adults and pediatrics at two different time points. METHODS: Bilateral hip and knee flexion patterns (LH, RH, LK, and RK) of twenty-two healthy participants (12 adults and 10 pediatric) between the ages of 8 – 35 years were investigated. Participants …

An Investigation On The Influences Of Radial Head Hemiarthroplasty Stem Fixation Techniques On Articular Mechanics, Jakub Szmit

Electronic Thesis and Dissertation Repository

Radial head hemiarthroplasty design has been extensively studied with a focus on utilizing the geometrical characteristics of the native radial dish as a guide of implant placement and design. Although implant design has been studied, optimal radial head implant fixation technique remains unknown. This thesis focused on the effect of stem fit on radiocapitellar contact mechanics, using both finite element and experimental bench-top approaches. Additionally, investigation into the impact of varus/valgus malalignment of the radial head in both the native state and following hemiarthroplasty was conducted. It was found that loose fitting a smooth stem axisymmetric radial head implant through …

Effect Of Unilateral Lower-Limb Amputation On Intact Limb Biomechanics: A Systematic Review, Amanda Boyd

Master's Theses

The United States will perform 30,000-40,000 amputations this year (Ertl et al., 2019). As a common medical intervention, there is extensive research regarding rehabilitation strategies and post-operative care. Many studies have explored the effects of the affected limb and prosthetic intervention yet have neglected that of the contralateral limb (De Asha et al., 2014; Jones et al., 2006; Winter & Sienko, 1988). Studies have reported an increase in secondary musculoskeletal conditions among unilateral lower-limb amputees, particularly in the intact limb, indicating the need for additional research (Gailey et al., 2008). The purpose of this systematic review was to investigate the …

Countermovement Jump Assessment For Monitoring Prolonged Fatigue In Collegiate Female Soccer Players, Jeffrey A. Wilkins

Boise State University Theses and Dissertations

Introduction: Females are 4 to 6 times more likely to sustain an anterior cruciate ligament (ACL) injury than their male counterparts during running and cutting sports, such as soccer. This sex disparity is thought to result from altered lower limb neuromuscular control that females present when fatigued at the end of practice or games. Yet, current fatigue monitoring techniques typically vary in their reliability, applicability and efficiency. Purpose: The purpose of this study is to test the feasibility of the countermovement jump (CMJ) to quickly and reliably monitor fatigue in female soccer athletes. Methods: Twenty-two (age: 19.3 ± 1.1 yrs, …

Neuromotor Control Of The Hand During Smartphone Manipulation, Prasanna Kumar Acharya

LSU Doctoral Dissertations

The primary focus of this dissertation was to understand the motor control strategy used by our neuromuscular system for the multi-layered motor tasks involved during smartphone manipulation. To understand this control strategy, we recorded the kinematics and multi-muscle activation pattern of the right limb during smartphone manipulation, including grasping with/out tapping, movement conditions (MCOND), and arm heights.

In the first study (chapter 2), we examined the neuromuscular control strategy of the upper limb during grasping with/out tapping executed with a smartphone by evaluating muscle-activation patterns of the upper limb during different movement conditions (MCOND). There was a change in muscle …

Comparing Motion Outcomes In Salvage Procedures For Wrist Arthritis, Stacy Fan

Electronic Thesis and Dissertation Repository

Scaphoidectomy and four corner fusion (4CF), and proximal row carpectomy (PRC) are salvage procedures that may be offered in advanced wrist arthritis. The optimal clinical treatment remains unclear. Biomechanical studies comparing outcomes of these procedures often only report uniplanar motion, rather than multiplanar motion which is more representative of functional wrist motion. Further, the impact of altering the relationship of the proximal and distal carpal rows in the coronal plane during 4CF has not been well-studied.

The purpose of this in-vitro biomechanical study was to quantify changes in wrist kinematics during wrist flexion-extension, radial-ulnar deviation, and circumduction in “anatomic 4CF”, …

Effect Of Sport-Specific Demands On Swimmer's Shoulder, Jordan A. Thielbar

Honors Thesis

Swimming is a unique sport in that the shoulders generate most of the propulsive force. Therefore, due to the large amounts of repetitive force, the shoulders generate during freestyle, swimmer’s shoulder is the most common injury among competitive swimmers. Freestyle biomechanics, muscular imbalances and posture all play a pertinent role in a swimmer’s risk for developing a shoulder injury during their swimming career. Swimmers typically develop large muscular imbalances between their dominant and nondominant shoulders due to several sport-specific demands including freestyle stroke mechanics, breathing, and body roll. These muscular imbalances alter a swimmer’s posture and freestyle biomechanics which eventually …

The Effects Of Somatosensory Input On Gait In Individuals Post-Stroke, Victor Hung, Amanda Reilly, Rachel Wood, Nikita Yuskov

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background and Purpose: Stroke is a leading cause of disability that results in various neurological deficits, one of which is hemiplegia. This deficit alters the gait cycle, resulting in decreased propulsion force by plantar flexor muscles, decreased activation of dorsiflexor (DF) muscles, and increased coactivation of antagonistic ankle muscles. Stroke also leads to altered somatosensory input which results in decreased balance and gait speed, ultimately increasing fall risk. Therapies targeting increased somatosensory input have been shown to be beneficial in stroke as well as other neurological populations. However, no known studies have investigated the acute effects of local vibration to …

The Effects Of A 6-Week Controlled Whole-Body Vibration Training Program In Reducing Falls Risk Among Healthy Older Adults, Fabricio Saucedo Jr.

Open Access Theses & Dissertations

Falling is the second leading cause of accidental or injury-related death in the aging population worldwide and a leading cause of serious injury. Whole-body vibration (WBV) training has been implemented as a way to improve functional performance among the elderly and reduce the falls risk. The purposes of this study were: 1) examine to what extent a six-week course of WBV training reduced falls risk and improved fall outcomes in response to slips, and 2) examine whether the benefits of WBV training could be retained at least 2 months after the completion of the entire training session. A total of …

An Evaluation Of Postural Control And Balance After Anterior Cruciate Ligament Reconstruction, Kathryn Lucas

Theses and Dissertations--Rehabilitation Sciences

Over 100,000 anterior cruciate ligament reconstructions (ACLR) occur annually in the United States, with one in four individuals sustaining a second injury within the first two years after reconstruction. Due to the proprioceptive nature of the anterior cruciate ligament, the lack of regaining postural control and balance are likely large contributors to the rate of secondary injuries after ACLR. Recent literature has identified cerebral changes after anterior cruciate ligament injury and surgery, likely due to altered sensation and feedback loops. However, no study thus far has investigated the neurological feedback loops that may place this group at higher risk of …

Atv Dynamics And Pediatric Rider Safety, James T. Auxier Ii

Theses and Dissertations--Biomedical Engineering

It has been observed through numerous academic and governmental agency studies that pediatric all-terrain vehicle ridership carries significant risk of injury and death. While no doubt valuable to safety, the post-hoc approach employed in these studies does little to explain the why and how behind the risk factors. Furthermore, there has been no prolonged, widespread, organized, and concerted effort to reconstruct and catalog the details and causes of the large (20,000+) number of ATV-related injuries that occur each year as has been done for road-based motor vehicle accidents. This dissertation takes the opposite approach from a meta-analysis and instead examines …

Influences Of Functional And Psychological Factors On Biomechanics Following An Anterior Cruciate Ligament (Acl) Reconstruction, Chelsey Roe

Theses and Dissertations--Rehabilitation Sciences

Objective: The aims of this research were to identify gaps in the literature related to return to sport (RTS) test batteries following primary anterior cruciate ligament reconstruction (ACLR) (Aim 1) and define recovery in athletes from 4-9 months after ACLR across three domains: 1) psychological recovery and biomechanics (Aim 2), 2) rehabilitation quantity and biomechanics (Aim 3), and 3) functional performance and biomechanics (Aim 4). Ultimately, the results of this research would quantify recovery following ACLR in athletes with a desire to RTS and identify objective criteria throughout rehabilitation prior to RTS.

Participants: Twenty-two post-ACLR athletes 17 females, 8 males, …

Gait Entrainment In Coupled Oscillator Systems: Clarifying The Role Of Energy Optimization In Human Walking, Ryan T. Schroeder

Theses: Doctorates and Masters

Empirical evidence suggests that parameters of human gait (e.g. step frequency, step length) tend to minimize energy expenditure. However, it is unclear if individuals can adapt to dynamic environments in real time, i.e. continuously optimize energy expenditure, and to what extent. Two coupled oscillator systems were used to test the learned interactions of individuals within dynamic environments: (1) experienced farmworkers carrying oscillating loads on a flexible bamboo pole and (2) individuals walking on a treadmill while strapped to a mechatronics oscillator system providing periodic forces to the body. Reductionist trajectory optimization models predicted energy-minimizing gait interactions within the coupled oscillator …