Biomechanics Commons^™

Field Testing The Upright Versus The Aero Cycling Position, Curtis Scrugham

UNLV Theses, Dissertations, Professional Papers, and Capstones

Body position can be of great importance to athletes who want to maximize their performance on the bike. Aerodynamic resistance can account for 70-90% of resistance encountered by cyclists, and a strategy used to reduce this resistance is riding in the aero position Research has been done in the lab to determine if there are trade-offs to using this position (Jobson et al. 2008, Welbergen and Clijsen 1990, Hubenig, Game and Kennedy 2011, Peveler 2004, Origenes et al. 1993, Ryschon and Stray-Gunderson 1991, Gnehm et al. 1997, Ashe et al. 2003). . Researchers have reported that riders untrained in the …

Skeletal Muscle Contraction Simulation: A Comparison In Modeling, Jonathan M. Ford

USF Tampa Graduate Theses and Dissertations

Computer generated three-dimensional (3-D) models are being used at increasing rates in the fields of entertainment, education, research, and engineering. One of the aspects of interest includes the behavior and function of the musculoskeletal system. One such tool used by engineers is the finite element method (FEM) to simulate the physics behind muscle mechanics. There are several ways to represent 3-D muscle geometry, namely a bulk, a central line of action and a spline model. The purpose of this study is to exmine how these three representations affect the overall outcome of muscle movement. This is examined in a series …

Correlation Of Shoulder And Elbow Kinetics With Ball Velocity In College Baseball Pitchers, Eric Post

Theses and Dissertations

Specific injuries at the elbow and glenohumeral joints have been linked to several kinetic variables that occur throughout the throwing motion. Ulnar collateral ligament (UCL) sprains have been linked to excessive elbow valgus and shoulder external rotation torques occurring during the late-cocking phase of throwing. Shoulder external rotation torque during the late arm-cocking phase and shoulder distraction forces during the deceleration phase contribute to tears of the labrum. Additionally, it is believed that the peak distraction force generated during the arm deceleration phase also contributes to SLAP tears and rotator cuff pathologies. Very little research has been done to directly …

Effect Of Warm-Up Activity On Vertical Ground Reaction Forces In Basketball Players During Drop Jump Landings, Jacob Wesley Hinkel-Lipsker

Master's Theses

ABSTRACT

Effect of Warm-Up Activity on Vertical Ground Reaction Forces in Basketball Players During Drop Jump Landings

Jacob Hinkel-Lipsker

Purpose: The purpose of this study was to examine the effect of certain warm-up activities on vertical ground reaction forces (GRF_v) during a drop jump landing. Methods: Eight women and twelve men (mean age 22.6 ± 1.82 years) completed three warm-up activities on three separate days in a counterbalanced order: a passive stretching warm-up, a dynamic warm-up, and a no warm-up control. After completing each activity, participants were asked to perform eight drop jump landings on a force platform. …

Effect Of Remote Vibrotactile Noise On Pinch Force Maintenance Ability And Brain Activity, Ying-Ling Tseng

Theses and Dissertations

Noise has been used to enhance detection of signals thereby improving performance of nonlinear systems (referred to as "stochastic resonance"). In biological systems, the noise and signal integration may occur not only at the receptor level but also in the central nervous system, thereby allowing noise remotely applied from a signal to enhance the system's response to the signal. However, integration of tactile signal and noise within the central nervous system has not been demonstrated in humans. In addition, whether the enhanced detection of tactile signals with remote noise results in changes in motor behavior is unknown.

The objectives of …

Design And Development Of A Stair Ascension Assistive Device For Transfemoral Amputees, Casey Michael Barbarino

Master's Theses

Transfemoral amputees around the world experience increased difficulty in climbing stairs due to lack of muscle, balance, and other factors. The loss of a lower limb greatly diminishes the amount of natural force generation provided that is necessary to propel oneself up stairs. This study investigated possible solutions to the problem of stair ascension for transfemoral amputees by the means of designing and developing an externally attachable device to a prosthesis. The number of amputations from military service has greatly increased since 2008, which shows there is a clear need for assistive devices (Wenke, Krueger, & Ficke, 2012). With the …

Investigations Toward Tunability Of Mechanical, Thermal, And Impact Properties Of Thiol-Ene Networks For Novel High Energy Absorbing Materials, Olivia Devon Mcnair

Dissertations

The UV polymerization of thiols with electron rich alkenes is a highly resourceful reaction that has been utilized by scientists within various disciplines to produce an even more versatile display of applications. This dissertation focuses on a newer application, thiol-ene network (TEN) materials for energy absorption devices. TEN networks display a host of positive polymer properties such as low stress, high optical clarity and uniformity, but they also suffer from unfavorable mechanical properties such as low toughness and elongation at break. The poor mechanical properties demonstrated by TENs prohibit them as choice materials for applications requiring thicker material forms, including …

Effects Of Foot Type On Multi-Segment Foot Motion In High- And Low-Arched Female Recreational Athletes, Douglas W. Powell

Doctoral Dissertations

Introduction: Mal-alignment and dysfunction of the foot have been shown to result in an increased rate of injury and unique injury patterns. Aberrant foot function has been shown to contribute to repetitive stress and acute injuries. High-arched athletes have been shown to experience a greater rate of bony injury to the lateral aspect of the lower extremity while low-arched athletes experience greater rates of soft-tissue injury to the medial aspect of the lower extremity. Though foot type has been linked to these injury patterns, the mechanism by which these injury patterns occur remains unknown. Multi-segment foot models have been developed …

Effects Of Footstrike Pattern On Low Back Posture, Shock Attenuation, And Comfort During Running, Traci L. Delgado, Emilia Kubera-Shelton, Robert R. Robb

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: Barefoot running (BF) is popular in the running community. Biomechanical changes occur with BF, especially when initial contact changes from rearfoot strike (RFS) to forefoot strike (FFS). In addition, changes in lumbar spine range of motion (ROM), particularly involving lumbar lordosis, have been associated with increased low back pain (LBP). However it is not known how changing from RFS to FFS affects lumbar lordosis or LBP. Thus, the purpose of this study was to determine if a change from RFS to FFS would change lumbar lordosis, and/or decrease shock attenuation, and/or change comfort levels in healthy recreational/experienced runners.

Methods: …

Integrating Biomechanics And Cell Physiology To Understanding Ivd Nutrition And Cell Homeostasis, Yongren Wu

All Dissertations

Back pain associated with degeneration of the intervertebral disc (IVD) is a major public health problem in Western industrialized societies. Degeneration of the IVD changes the osmotic and nutrient environment in the extracellular matrix (ECM) which affects cell behaviors, including: cell proliferation, cell energy metabolism, and matrix synthesis. In addition, a thin layer of hyaline cartilaginous end-plate (CEP) at the superior/inferior disc-vertebral interface was found to play an important role in nutrient supply as well as load distribution in the IVD. Therefore, our general hypothesis is that the CEP regulates the ECM osmotic and nutrient environment which further affects IVD …

Humeral Torsion And Shoulder Biomechanics: Comparison Of A Novel Ultrasonographic Technique With The Computed Tomography Benchmark, Bryan Thurston

All Theses

The rotation angle between the proximal and distal axes of long bones is known as torsion, and it is thought to be indicative of the forces applied to the bone during growth. The humerus, for example, develops an internal twist or antetorsion, as daily activities are anterior to the body. However, the strong posterior stress induced by an overhead throwing motion may counteract this internal twist in young athletes and cause prominent bilateral dimorphism.
To measure torsion in these young athletes, a new technique using ultrasound has been developed and implemented in clinical practice. However, before widespread use in diverse …

Biomechanical Testing Of Salter-Harris Fractures Type I And Ii In The Distal Femur And Proximal Tibia, Margeaux Rogers

All Theses

Salter-Harris fractures of the proximal tibia and distal femur are common in pediatric patients that present to orthopedic surgeons. Salter-Harris type I fractures are characterized by breaks that extend only through the physis while Salter-Harris II fractures are the most common, accounting for 85% of Salter-Harris fractures, and extend past the growth plate, exiting through the metaphyseal bone1. Fixation of these fracture types can be accomplished using a variety of methods including the use of Kirschner wires, cannulated screws, and a combination of both materials. Stability of fracture fixation is of utmost importance as persistent motion at the fracture margin …

The Effects Of Arch Taping On Shock Attenuation During Landing, Shun Jinnouchi

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to investigate the effects of two different arch taping techniques on shock attenuation during landing. Each subject (n=12, age 25.5 ± 3.37 years, height 1.73 ± 0.04 m, mass 82.06 ± 16.23) was instrumented with accelerometers at the leg and forehead (sample rate = 1000 Hz). Subjects performed landings from a 30 cm box under three taping conditions: no tape, Low Dye, and Weave. For each condition, subjects completed 5 landing trials. Rest was provided between each trial and order of conditions was counterbalanced. During each landing, accelerations were recorded at 1000 Hz for …

Effect Of Racing Flats On Running Economy In Male Adolescent Runners, Paul Hafen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to investigate whether running economy differs in racing flats versus standard running shoes in high school cross-country runners. In order to measure running economy the oxygen cost of running (mL O₂∙kg^-1∙min^-1) was measured in 20 male adolescent runners (mean age = 16.25 ± 0.97 years, 5 km best time = 17.52 ± 0.78 min) when running two separate trials at a controlled speed. The speed was determined by estimating treadmill running speed at 85% of each runner's VO_2max. Each trial required the participants to run while …

Biomechanical Comparison Of A Rounded Outsole Shoe And Traditional Outsole Shoe, Sarah Horsch

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of the study was to determine the effects of shoe outsole design on maximum vertical acceleration and select kinematic parameters during level and uphill walking across phases of stance. Twelve participants, 7 males (75.1±9.3 kg, 173.6±3.6 cm, 22.9±3.5 yrs) and 5 females (56.5±5.1 kg, 158.3±4.5 cm, 25.4±11.1 yrs) granted written consent and preferred walking speed was determined. An accelerometer (480 Hz) was attached to the distal leg to measure maximum leg acceleration (Aleg) and an electrogoniometer (480 Hz) was placed on the back to measure sagittal lumbar motion (LumbarROM). Sagittal video capture (60 Hz) included thigh range of …

Examination Of Lower Extremity Muscle Activity During An Overhand Lacrosse Shot In Females, Brianna Millard

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study intends to provide a basic biomechanical understanding of a specific movement within the sport of lacrosse, an overhand goal shot. Its purpose is to identify the different muscles of the lower extremity and the roles they perform during each phase of the lacrosse shot. Specifically, the study will compare how active muscles are between phases as well as between two different shot speeds. This research provides insight into the importance of timing muscle contractions that lead to a more accurate and faster shot.

Subjects (n=5 females, age: 21.8 ± 2 years, height: 162.56 ± 15.24cm, mass: 63.68 ± …

Lower Extremity Biomechanics During Single Leg Drop Landings In Individuals With Patellofemoral Pain, Stacey L. Gaven

Human Movement Sciences Theses & Dissertations

Patellofemoral joint pain (PFP) is one of the most common afflictions of the active population. While etiological factors encompassing the entire lower extremity have been associated with PFP, participation in athletic activities while fatigued may further influence abnormal biomechanics in individuals with this condition. The aim of Project I was to investigate the lower extremity (LE) biomechanics during a single leg(SL) drop landing in individuals with and without PFP. Project II aimed to investigate the LE biomechanics of individuals with PFP during a SL drop landing pre and post an aerobic exercise protocol. Project 111 investigated the LE biomechanics of …

Modulation Of Cell-Matrix Interaction For Cryopreservation Of Engineered Tissue, Angela Christine Seawright

Open Access Theses

Long term preservation of functional engineered tissues can significantly advance tissue engineering industry and regenerative medicine. Several preservation techniques have been proposed and investigated for this purpose, and cryopreservation is a leading candidate. While tissues are cryopreserved, ice forms in both the extracellular and intracellular spaces and causes freezing-induced spatiotemporal deformation of the tissue. During this process the cells undergo dehydration by the freezing-induced osmotic pressure difference and mechanical deformation, transmitted through cell-extracellular matrix adhesions. However, the significance and interaction of these cellular level transport and mechanics processes are not well understood. Therefore, this study aims to establish mechanistic understanding …

Modeling Of Legged Locomotion With A Suspended Load In The Sagittal Plane, Karna P. Potwar

Open Access Theses

Walking or running while carrying loads has always been a tedious task, more so when the loads are heavy. Such a task of carrying loads not only requires extra effort but also leads to physical pain and in some cases injury. Prior studies on human locomotion with a suspended load have used models that are restricted in their DOFs and so are not able to take into account the fore aft movement in human beings. The objective of this thesis is to model the dynamics of sagittal plane center-of-mass locomotion with a suspended load and apply findings to carrying loads …

Biomechanical Comparison Of Titanium And Cobalt Chromium Pedicle Screw Rods In An Unstable Cadaveric Lumbar Spine, James Doulgeris

USF Tampa Graduate Theses and Dissertations

Pedicle screw-rod instrumentation is considered a standard treatment for spinal instability, and titanium is the most common material for this application. Cobalt-chromium has several advantages over titanium and is generating interest in orthopedic practice. The aim of this study was to compare titanium versus cobalt-chromium rods in posterior fusion, with and without transverse connectors, through in vitro biomechanical testing and determine the optimal configuration.

Six cadaveric lumbar spines (L1-S1) were used. Posterior and middle column injuries were simulated at L3-L5 and different pedicle screw constructs were implanted. Specimens were subjected to flexibility tests and range of motion, intradiscal pressure and …

Environmental Effects On The Biomechanics And Motor Physiology Of Elastically Powered Movements In Chameleons, Christopher Van Anderson

USF Tampa Graduate Theses and Dissertations

Environmental temperature exhibits profound effects on the activity and ecology of ectotherms through its impact on muscle contractile physiology. While the performance of locomotor behaviors powered by muscle contraction directly decreases by at least 33% over a 10°C drop in body temperature, chameleons are known to feed, presumably with high performance, at body temperatures where sympatric lizard species remain inactive. I propose that ballistic movements that are powered by the recoil of preloaded elastic and collagenous tissues are less thermally dependent than movements that rely on direct muscular power. Despite the reduced thermal sensitivity of the elastic-recoil powered movement, I …

Modeling The Human Gait Phases Using Granular Computing, Melaku Ayenew Bogale

Open Access Theses & Dissertations

Gait analysis is applied for the provision of diagnosis, evaluation, and for the design of therapeutic intervention for subjects suffering from neurological disorders. The benefits accruing from gait analysis are well established. People with neurological disorders like mild traumatic brain injury, Cerebral Palsy and Multiple Sclerosis, suffer associated functional gait problems. The symptoms and sign of these gait deficits are different from subject to subject and even for the same subject at different stage of the disease. Identifying these gait related abnormalities helps in the treatment planning and rehabilitation process.

The dynamic behavior of gait parameters is cyclic and the …