Biomechanics Commons^™

Balance Recovery Response In Community-Dwelling Adults With Unilateral Transtibial Amputation And The Potential Benefits Of A Weight-Shifting Balance Training Intervention, Hui-Ting Shih

UNLV Theses, Dissertations, Professional Papers, and Capstones

Previous studies have shown that individuals with various physical, sensory and neuromuscular impairments are at higher risks of falls. Individuals with unilateral transtibial amputation (UTTA) suffered from all these impairments, and tripping not surprisingly caused a considerable number of falls in this population. To study falls, researchers have to put participants in a well-protected environment and reproduce tripping fall scenarios. Furthermore, the perturbation delivery needs to be precise in terms of temporo-spatial timing. These features would ensure the quality of responses elicited and reproducibility of the results. Thus, in Chapter 2, we developed a treadmill-based perturbation delivery protocol and confirmed …

Investigation Of Swimming Physiology And Swimming Kinematics While Wearing Different Triathlon Wetsuit Styles At Submaximal Front Crawl Swimming In Recreational Population, Boram Lim

UNLV Theses, Dissertations, Professional Papers, and Capstones

Triathlon wetsuits are commonly used due to the potential benefits in swimming performance and thermoregulation. Triathletes may select different wetsuit styles depending on many factors such as temperature regulation, swimming technique, body type, and training purpose. However, there is a lack of empirical evidence for how different wetsuit styles affect physiological responses and swimming kinematics during submaximal swimming intensity. Therefore, this studyaimed to investigate the physiological responses and swimming kinematics during submaximal intensity front crawl swimming while wearing different wetsuit styles. Fourteen participants (n=6 male, n=8 female; all recreational triathletes or swimmers) completed a swimming graded exercise test (GXT) wearing …

Predicting The Progression Of Diabetes Mellitus Using Dynamic Plantar Pressure Parameters, Mathew Sunil Varre

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction: Diabetic peripheral neuropathy is one of the common complications of type-2 diabetes mellitus (DM). Changes in the intrinsic plantar tissue coupled with repetitive mechanical loads and loss of sensation may lead to foot related complications (skin break down, ulcerations, and amputations) in persons with neuropathy if left untreated. The purpose of this dissertation was to stratify individuals with pre-diabetes, diabetes with and without neuropathy using dynamic plantar pressure parameters during walking, using machine learning algorithms.Methods: Plantar pressure data was collected from one hundred participants during walking with pressure measuring insoles fixed between the feet and thin socks. Simultaneously high-definition …

Description, Reliability And Validation Of A Novel Ground-Reaction-Force-Triggered Protocol For Simulation Of Tripping Perturbations During Gait, James Anderson, Samuel Hadley, Denise Ng, Catrina Fabian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Tripping is a common cause of falls across different age populations particularly in older adults. Concerns regarding the validity of simulated-fall research protocols reside in the current literature. The purpose of this study was to develop a novel treadmill-based tripping protocol that allowed researchers to deliver unanticipated tripping perturbations during walking with a high level of timing precision. The protocol utilized a side-by-side split-belt treadmill instrumented with force platforms. Treadmill belt acceleration profiles (two levels of perturbation severity: small perturbation vs large perturbation) were delivered unilaterally when the tripped leg bore 20% of the body weight during early stance. Peak …

The Influence Of Sports-Related Concussion On Lower Extremity Injury Risk In Adolescent And Collegiate Athletes, Jason M. Avedesian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Sports-related concussion (SRC) represents a major epidemiological concern in the adolescent and collegiate athlete populations, with conservative estimates of approximately four million SRCs occurring each year in the United States. While the majority of previous research has emphasized the management and recovery of the cognitive aspects of SRC, recent data indicates subtle motor behavior is altered following a concussive event. Injury surveillance literature indicates that adolescent and collegiate athletes are at an approximately 2–4 greater risk for lower extremity (LE) injury following an SRC when compared to matched controls and pre-SRC LE injury rates. Furthermore, athletes with a previous SRC …

The Investigation Of The Influence Of Long-Distance Running On Foot Volume In Healthy Female Collegiate Distance Athletes, Mufaro M. Hungwe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine the change, if any, in foot volume over time after exercise, specifically a long-distance 5 Km run. Five UNLV Women’s Track & Field and Cross- Country distance athletes (n = 5; 20 ± 1.87 years; 54.50 ± 3.71 kg; 160.88 ± 4.98 cm) were recruited to participate in this study. The dependent variables were foot volume and foot size. These variables were measured pre and post a 5 Km run at a self-selected somewhat hard pace over the independent variable time. Foot volumetrics were performed five times, (Pre-run, post- run(5 min), post-run(10 …

Relationship Between Jump Performance And Asymmetry, Cordero Roche

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this dissertation is to investigate the relationship between jump performance and asymmetry. This investigation was divided into three separate studies. The first aim investigated which asymmetry variables for eccentric and concentric phases best predicted jump height (JH) during different jump types. The aim of the second study was to determine if asymmetry variables differed between jump type and genders.

Fourteen participants performed countermovement jumps (CMJ) and drop vertical jumps (DVJ). The DVJ were administered from a 30.5 cm platform leading with dominant leg striking separate force platforms with each foot. Vertical ground reaction forces were used to …

Patient-Specific Finite Element Analysis For Mandibular Fracture Fixation, Ethan Snyder

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis proposes an approach for Finite Element Analysis (FEA) of mandibular fracture fixation. Using a Computerized Tomography (CT) scan of mandible obtained from a specific person, the material characteristics, density and modulus of elasticity, were determined from a set of discrete points within the mandible that are 1mm spaced based on the Hounsfield Units of these points. The mandible geometry was sectioned to simulate a fracture. Muscle and mastication forces were added to replicate post-surgery loading. Using a standard linear miniplate, this material model was compared with two commonly used mandibular cortical shell bone models: isotropic and orthotropic. A …

Relationship Of Shoe Wetness To Mechanical Performance, Sara Lyn Crawford

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to mechanically impact test shoes that underwent both saturation and repetitive loading protocols to determine if these interventions affected the impact absorption and energy return properties of a shoe. Six pairs of the same make and model of shoe were divided into Control and Experimental Groups and tested on an impact machine before and after undergoing a protocol. The repetitive load protocol involved subjecting the shoes to impacts commensurate with a 5 km race. The water saturation protocol involved soaking the shoes until reaching their maximum saturation. The Control shoes underwent initial testing and …

Does Wearing Multiple Pairs Of Shoes Influence Injury Rates?, Julien Mihy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Running research has attempted to better understand the causes of movement-related injuries and a large segment of this research revolves around footwear and training regimens. A survey has reported lower injury rates in runners who wore multiple shoes with in a 5-month period. Previous literature lacks the analysis of variables leading to training related decisions and whether wearing multiple pairs of shoes can have an extended influence on injury rates. PURPOSE: To determine whether wearing multiple pairs of shoes has an influence on injury rates. METHODS: A survey was developed to ask participant’s injury related history along with their footwear, …

Do Compression Garments Work? The Effect Of Compression Garments On Biomechanical And Physiological Factors, Andrew Craig-Jones

UNLV Theses, Dissertations, Professional Papers, and Capstones

New and innovative technology is consistently being introduced to help runners gain an edge over their competition. One of the more popular ergogenic aids in running today is compression garments. It is estimated that the compression garment market will surpass $5 billion by the year 2022. Despite the popularity, there is no clear consensus as to if or why compression is effective as an ergogenic aid. Although there has been a large variety of variables tested, there is little agreement on any of them as to the effect compression has. It appears as if the rate at which compression is …

Partitioning The Mechanical Cost Of Human Walking: Unveiling Cost Asymmetries For Bionic Technologies, Michael Richard Isaacs

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biomechanics studies over the past 150 years, suggest that animals, including humans, move at speeds that “optimize” their cost of transport. These optimizations can be metabolic, mechanical, or a mixture of the two; however, the consensus on the relationship between metabolic and mechanical cost has been muddied by our current conceptualizations of mechanical cost. Our prior considerations in assessing mechanical cost of transport for animal locomotion often rely upon the exchange of potential and kinetic energy for a rising and falling center of mass that is supported by rigid legs. As a result, our understanding of the mechanical costs associated …

Discovering Motor Phenotypes In Autism Spectrum Disorder: A Cross-Syndrome Approach, Daniel Edwin Lidstone

UNLV Theses, Dissertations, Professional Papers, and Capstones

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder with a behavioral phenotype characterized by persistent deficits in social communication and social interaction accompanied by restricted, repetitive patterns of behaviors, interests, or activities. Currently in the US, approximately 2.5% of children have a diagnosis of ASD. The etiology of ASD is complex, however the disorder does have a strong genetic basis. Specific genetic mutations can lead to neuroanatomical and neurophysiological changes during development resulting in a behavioral phenotype that falls along the ASD spectrum and may result in a diagnosis of ASD. The severity of ASD-specific behaviors falls on a continuum …

The Effects Of Injury On Running Status And Gait Biomechanics, Kristyne Wiegand

UNLV Theses, Dissertations, Professional Papers, and Capstones

Over the past several decades, endurance running has grown steadily as a popular form of physical activity. Running is easily accessible, does not require expensive equipment, and can be performed without specific skill training. Individuals who run also experience health benefits like increased cardiovascular health and reduced risk of all-cause morbidity. Despite these benefits, running is also associated with high rates of musculoskeletal injury. Although researchers have attempted to identify injury risks and mitigate the incidence of running injury, there is still no consensus as to why runners become injured. Research has also attempted to identify biomechanical movement patterns that …

Comparison Of Cervical Angle During Different Equipment Removal Techniques Used In Ice Hockey For Suspected Cervical Injuries, Kendell Sarah Galor

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of the study was to compare cervical movement between two different methods of removal of the helmet and shoulder pads. Seven college age male subjects (height: 172.54 ± 7.98 cm; weight: 85.70 ± 15.75 kg) with hockey experience volunteered to participate in the study. Each subject agreed to and signed the institutional review board approved informed consent before articipation. Subjects used their own game fit hockey helmet and were fitted with a pair of shoulder pads (CCM Tacks 1052 Sr Shoulder Pads). Cervical spine motion was measured using 3D kinematics (Vicon Motion Systems Ltd., UK). Reflective markers affixed …

Biomechanical Analysis Of Jumping: The Influence Of External Load And Countermovement Depth On Deceleration Strategies And Performance, Leland Adam Barker

UNLV Theses, Dissertations, Professional Papers, and Capstones

Jumping performance has traditionally been measured by jump height alone. In recent years, the reactive strength index (RSI = Jump height / jump time)) has been used as another measure of jump performance. According to RSI, which was developed to assess eccentric force production, jump performance can improve by increasing jump height, decreasing jump time, or both simultaneously. However, it is not clear how force production correlates to RSI variables. If RSI is meant to be a practical measure of eccentric force production, it should correlate strongly to eccentric and amortization force production during jumping. Thus, the purpose of the …

Digging Biomechanics In Geomyoid Rodents, Alexis Moore Crisp

UNLV Theses, Dissertations, Professional Papers, and Capstones

Subterranean digging behaviors provide opportunities for protection, access to prey, and predator avoidance for a diverse array of vertebrates, yet studies of the biomechanics of burrowing have been limited by the technical challenges of measuring kinetics and kinematics of animals moving within a substrate. Prior studies of burrowing have recorded a single axis of x-ray video and/or force. However, empirical observations show that burrowing is not restricted to a single axis or plane. I describe a new system called a ‘tunnel-tube’ for measuring 3D reaction force during burrowing. This tunnel-tube has two separate tubes, one ‘entry tube’ that has no …

Analysis Of Human Movement Patterns During Endurance Running, Joshua Paul Bailey

UNLV Theses, Dissertations, Professional Papers, and Capstones

Endurance running and participation in racing events has flourished over the last decade. Recreational runners enter the training period for an upcoming race at differing levels of fitness and training. As individuals sign-up for the race, they typically follow the commitment with an increase in training load. The increases in training load are accomplished through a combination of increasing mileage, or duration of running, and running intensity through increase velocity. These increases are theoretically being applied in a progressive overload principle, where the musculoskeletal system has time to adapt to the breakdown provided from the previous training session. Progressive overload …

The Influence Of Crossfit Training On Running Mechanics, Sophia D. Bradley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Introduction

40 million Americans run regularly.1 Contrary to many runner’s beliefs, increased strength may be beneficial while not adding body mass. An increase in strength in specific muscles may improve running gait and performance. 9,6 Strength training may also play an important role in preventing common overuse injuries in running 11,12 Depending on the style of strength training, it may also have an enhanced benefit on running economy.4,16

Participation in CrossFit is also widely popular, with an increase in participation of 923% in the past ten years.2 CrossFit is a type of strength training in which most movements performed utilize …

Optimization Of Prosthetic Hands: Utilizing Modularity To Improve Grip Force, Grasp, And Versatility, Jordan William Harris

UNLV Theses, Dissertations, Professional Papers, and Capstones

It has been demonstrated that although many varieties of upper limb prosthetics exist, commercially available prosthetics are outdated and unsatisfactory. Ineffectiveness and limitations have led to some prosthesis wearers having to own multiple devices, whereas others have given up on them entirely. Even though ample research has been conducted to design and test new hand designs, the industry appears to rest in an overall stagnated state.

It was proposed here, that one problem with prosthetic research is an excess of variables involved in testing, and therefore the improper application of the scientific method. It seems that each time a research …

The Effects Of An Inclined And Declined Slope On Backward Locomotion: A Kinematic And Electromyographic Analysis Of Retrowalking, Song Dan Vo

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to investigate the effects of an inclined and declined slopeon kinematic properties and muscle activation magnitudes. This purpose was achieved by using a +10% grade for inclined backward walking (IBW) and -10% grade for declined backwardwalking (DBW) on a treadmill. Eleven participants (24.6 ± 4.1 yrs, 68.5 ± 14.6 kg, 1.7 ± 0.1 m) were recruited from the UNLV student body and were subject to a three day adaptation protocol to allow them to choose a preferred walking speed and to familiarize themselves with such a novel task. Two consecutive practice days included a …

Investigation Of Sequential Intermittent Pneumatic Compression Effect On Run Performance, Max Evan Jones

UNLV Theses, Dissertations, Professional Papers, and Capstones

The main aim of this study was to determine if IPC after a 5000 m run influences maximal effort 1600 m run performance. A secondary purpose was to determine if the level of IPC pressure used influences run performance. Nine subjects (6 male and 3 female were included in the study; 30 years±5.19 years; Height 173.72cm±8.25; Weight; 72.54±9.97 kg). These subjects were recruited to be in this study via word of mouth or social media advertisement in the Las Vegas area. Participant inclusion criteria was 18- 50 year old apparently healthy, had been running a minimum of 20 miles a …

Changes In Sprint Kinetics Or Kinematics Following Static Or Dynamic Stretching, Kristyne Bartel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine the effects of static or dynamic stretching on hip kinematics and kinetics during intermittent sprinting. To achieve this aim, intermittent sprint athletes were asked to complete either a static or dynamic stretch, followed by a repeated-sprint protocol. Hip joint kinematics and performance measures were evaluated during the sprint, including changes that occurred in these variables over the course of the sprint protocol. In addition, hip flexion torque was measured with an isokinetic dynamometer. Ten male (age = 25±2.3 years, 175±3.2 cm, 76.2±2.7 kg) and female (age = 20±1 years, 166±1.3 cm, 60±1.1 …

Comparison Of Muscle Latencies For Diabetic Neuropathy Patients Versus Healthy Controls During A Perturbed Balance Task, Kyle Mefferd

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to compare muscle latencies for patients diagnosed with diabetic neuropathy versus healthy controls during a perturbed balance task, with a secondary purpose to distinguish postural control strategies the groups used based on the muscle latencies. Five participants diagnosed with diabetic neuropathy (DN; 4 male, 99.7 ± 7.95 kg, 176 ± 9.58 cm, 46.6 ± 16.55 years) and 5 healthy control (HC; 4 male, 100.36 ± 12.61 kg, 173.76 ± 9.66 cm, 47 ± 13.42 years) participants were recruited. Participants granted institutionally approved written consent before participating. Delsys Trigino Wireless EMG sensors were placed on …

Reliability Of A Multisegment Foot Model In Shod Running, Austin Coupe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine kinematic and marker placement reliability of the Leardini multisegment foot model (LMFM) for tracking foot kinematics during barefoot and shod running without alteration of footwear. Eleven participants, five males (25.6±5 yrs, 73±15.8 kg, 1.75±0.05m) and six females (22.5±2.9 yrs, 66.6±7.2 kg, 1.71±0.05 m) granted institutionally approved written consent to participate. Three-dimensional motion capture (10 Vicon T40-S cameras) was used to capture kinematic data at 200Hz. Kinetic data was captured with an in-ground force platform (Kistler Instruments AG, Switzerland Model 9281B 60x40cm, 2000Hz). Participants were instructed to run at 3.5m/s ±5%. Velocity was …

Stride Length-Speed Relationship During Body Weight Supported Running, Carmen Chona

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine if body weight support influences the stride length-speed relationship. Additionally, the purpose was to determine if impact characteristics of running are influenced by body weight support and speed. Subjects (n=10; 6 female, 4 male) volunteered to participate in this study. All subjects were injury free and were comfortable running on a treadmill for 30 minutes. Subjects ran on a lower body positive (LBPP, Alter-G, G-Trainer) treadmill for 4 conditions of body weight (100, 40, 30 and 20% of body weight) and 4 running speeds (100, 110, 120 and 130% of the preferred …

A Comparative Evaluation Of The Effects Of Incline On Kinematics And Muscle Function During Backward Walking, Daniel Brent Jensen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to investigate lower extremity kinematics and muscle activation patterns in inclined backward walking (IBW) versus traditional backward walking (BW). This purpose was achieved by evaluating performance of individuals walking backward on a treadmill at inclines of 0%, 6%, 8%, 10%, and 12%. Eleven participants (24.9 ± 4.8 yrs, 71.9 ± 11.6 kg, 1.7 ± 0.09m) recruited from the UNLV student body went through a familiarization training program before any data were collected. The familiarization training, which took place across 3 different days, served to: 1) help the participants become comfortable and familiar with BW …

An Evaluation Of Kinematic Variables During Stance Phase Of A Training Endurance Run, Joshua Paul Bailey

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of the study was to evaluate kinematics of the lower extremity during the stance phase of an endurance training run. Fifteen participants (8 male, 7 female; 30.5 ± 8.4 years; 71.8 ± 11 kg; 1.73 ± 0.07 m) reported that they were currently signed up for, or planned on signing up for, an endurance race within the next six months of participation in the study (9 half marathon, 3 marathon, 1 triathlon, 2 21k trail run). All had a weekly running mileage greater than 20 miles (23.8 ±4.6 miles). Participants were required to complete the 15–kilometer training run …

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 …

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: …