Musculoskeletal System Commons^™

The Shared Contributions Of The Capsule, Labrum, And Bone On The Suction Seal Of The Hip, Alexander J. Hoffer

Electronic Thesis and Dissertation Repository

The hip capsule, labrum, and bone contribute to hip stability. Abnormalities in these structures are associated with pain and microinstability. Previous studies have quantified the individual stabilizing roles of the capsule and labrum and have associated cam over-resection with decreased hip stability.

The first objective of this thesis was to identify the relative biomechanical contributions of the capsule, labrum, and bone to the hip suction seal, as a representation of hip stability. The second objective was to assess the effectiveness of a labral reconstruction in restoring the suction seal after a cam over-resection.

Ten human cadaveric hips were tested in …

Amphisbaenian Head Movement And Burrowing Forces In Damp Granular Media, Jacob Newell

Williams Honors College, Honors Research Projects

Damp granular media is a difficult environment to study because it is both practically complex and it lacks equations which fully describe its behavior. In this study, an oscillatory lateral head movement and its effects while penetrating damp granular media were tested using a robophysical model. This experimental research was inspired by the burrowing behavior of the clade Amphisbaenia, a group of usually limbless squamates that employ a variety of different burrowing behaviors, but it can apply to a wide range of burrowers. This research could help with both human burrowing technologies and the further investigation of animal behaviors.

Visuomotor Adaptation During Asymmetric Walking, Charles Napoli

Masters Theses

Necessary for effective ambulation, head stability affords optimal conditions for the perception of visual information during dynamic tasks. This maintenance of head-in-space equilibrium is achieved, in part, by the attenuation of the high frequency impact shock resulting from ground contact. While a great deal of experimentation has been done on the matter during steady state locomotion, little is known about how head stability or dynamic visual acuity is maintained during asymmetric walking.

In this study, fifteen participants were instructed to walk on a split-belt treadmill for ten minutes while verbally reporting the orientation of a randomized Landolt-C optotype that was …

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 …

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 …

Impact Of Parity On Gait Biomechanics, Bekah P. Stein

Masters Theses

Background: Symptomatic knee osteoarthritis (OA) is an incurable condition that affects nearly 50% of adults, and women are twice as likely as men to develop OA. Throughout pregnancy, women experience large changes in morphology and gait mechanics, as well as changes in joint loading. It is possible these adaptations could cause lasting changes postpartum, which may potentially contribute to initiation of OA, thereby increasing the overall risk of OA for women.

Purpose: This exploratory study looked to identify differences between lower limb gait mechanics of healthy nulliparous women and healthy parous women.

Methods: 28 healthy female participants (14 parous, 14 …

Ulnar Collateral Ligament Reconstruction With Traditional Docking Compared To Novel Surgical Techniques, Kayley D. Guy, Brendon P. Mcdermott, Kaitlin Gallagher, Tyrone Washington

Health, Human Performance and Recreation Undergraduate Honors Theses

Background: Ulnar Collateral Ligament Reconstruction (UCLR) is a surgical procedure on one of the main ligaments that provides normal stability for the elbow joint against excessive valgus stress. Damage to this ligament is common in athletes performing overhead throwing activities, primarily baseball players, due to excessive valgus stress during the throwing motion. The most common form of treatment for this type of injury is reconstructive surgery of the ligament, especially if athletes wish to return to sport participation. This type of surgery is extremely invasive and requires extensive post-operative rehabilitation in order to facilitate return to play. To date, many …

Acromial Insufficiency Fractures In Reverse Total Shoulder Arthroplasty: A Biomechanical Study, Alicia Kerrigan

Electronic Thesis and Dissertation Repository

Reverse total shoulder arthroplasty (RTSA) is increasingly utilized in the aging population, with a growing list of surgical indications including rotator cuff tear arthropathy, proximal humerus fractures, and revision arthroplasty. Acromial insufficiency fractures following RTSA are poorly understood, difficult to diagnose, and associated with inferior clinical outcomes. There is limited knowledge in the literature regarding the etiology of post-operative acromial fractures. The purpose of this study is to evaluate the role of implant parameters on acromial strain following RTSA.

Using a cadaveric model, a custom designed modular RTSA system was implanted that allowed for evaluation of modifiable parameters including glenoid …

Biomechanical Testing Of An Exercise For Strengthening The Proximal Femur., Alyssa Osbourne

Electronic Theses and Dissertations

Based on the principles of cutting edge bone remodeling research, a unique therapeutic exercise device was designed specifically to improve bone quality at the most critical location of the proximal femur prone to fracture: the superior-lateral femoral neck where the fracture first initiates during a fall. The exercise/device is intended to work by inducing enough strain in the bone to stimulate the body’s natural bone remodeling mechanisms to increase bone density in the proximal femur and consequently prevent a fracture from arising if a fall to the side does occur.

In order to test the proposed exercise, experiments simulating the …

Variability And Stability Of 13 To 19 Month Olds Infants' Gait Affect By Wet And Dry Diaper And Underwear, Sally Marie Futch

Electronic Theses and Dissertations

Research has been conducted on the effect of diaper perturbation versus unclothed on gait, but there is little research on different diaper perturbations on gait. PURPOSE: The purpose of this study was to examine how physical perturbations (dry and wet diaper and underwear) affected 13 to 19 month old infant’s gait. METHODS: Sixty infants (13-19 month old) were recruited for the study. Five trials for 3 conditions (dry and wet diaper and underwear) were conducted on a GaitRite walkway. Step length (m/step), cadence (steps/s), support base (m) and stance time (sec) were analyzed. A mixed model with repeated measures along …

Markerless Radiostereogammetry Of The Shoulder Joint In Humans: Comparisons Of Scapulohumeral Kinematics Between Individuals With Healthy And Supraspinatus-Impaired Shoulders, Ashley N. Hannon

Electronic Thesis and Dissertation Repository

The purpose of this collection of studies was to further develop the knowledge of shoulder motion in order to better understand joint function through direct measurement of 3D scapulohumeral joint kinematics using a technique of high accuracy. Markerless, bi-planar fluoroscopic radiostereometric analysis using a generic shoulder model was developed in this thesis, reducing the amount of radiation exposure to subjects. The studies compared kinematic data of the scapulohumeral joint in six degrees of freedom with a precise, in-vivo measuring technique. Data were collected on young and older healthy individuals, individuals with a torn supraspinatus and post-surgical intervention.

Although this generic …

Neuromuscular Factors Affecting Stretch-Induced Torque Loss, Gabriel Siqueira Trajano

Theses: Doctorates and Masters

The mechanisms underpinning the immediate torque loss induced by acute, static muscle stretching are still not clear. The current research was designed to examine the neuromuscular factors influencing this torque loss. In Study 1, the contributions of central versus peripheral factors to the stretch-induced torque loss were investigated. Measures of central drive, including the EMG amplitude normalised to the muscle compound action potential amplitude (EMG:M), percent voluntary activation (%VA) and first volitional wave amplitude (V:M), and measures of peripheral function, including the twitch peak torque and 20:80 Hz tetanic torque ratio were made before, and immediately and 15 min after …