Biomechanics and Biotransport Commons^™

Engineering Nanofibers: Laboratory Characterization, Microstructural Analysis, And Image Processing Insights, Sayed Ahmadreza Razian, Mohammad Arjomandi, Kaspars Maleckis

UNO Student Research and Creative Activity Fair

Polymer nanofibers have attracted high interest in a wide array of applications, including biomaterial scaffolding, textiles, sensors, reinforcement in composites, and filtration systems. Many of these applications combine nanofibers into non-woven fabrics for better properties and easier manipulation. The properties and performance of nanofiber-based fabrics are affected by various microstructure parameters, including fiber alignment, diameter, and gap sizes between the nanofibers. These structural parameters can be controlled by adjusting various process parameters during manufacturing process, but the exact process parameter-microstructure relationships vary depending on the polymer system and need to be studied individually. The goal of this study is to …

Histological Evidence For The Therapeutic Effect Of Chitosan Nanofibrous Dressing On Acute Skin Wounds In A Rat Model, Mahboubeh Ghanbari, Sayed Ahmadreza Razian, Sara Cartwright, Yury Salkovskiy, Jason Mactaggart, Mark A. Carlson

UNO Student Research and Creative Activity Fair

Introduction: Large-area skin traumas, such as thermal burns, are among the most severe health issues that decrease patients’ quality of life and burden healthcare systems. The CDC estimates that there are 1.1 million burns requiring medical attention each year, with more than 20,000 cases involving at least 25% of the body surface, resulting in 4,500 deaths. In addition, about 10,000 people die from burn-related infections. A promising solution to alleviate this problem is using wound dressings based on biopolymers with inherent wound healing properties and biodegradability. One of these biopolymers is chitosan, which is derived from arthropod shells and exhibits …

The Effects Of Demographics And Risk Factors On The Morphological Characteristics Of Human Femoropopliteal Arteries, Sayed Ahmadreza Razian, Majid Jadidi, Alexey Kamenskiy

UNO Student Research and Creative Activity Fair

Background: Disease of the lower extremity arteries (Peripheral Arterial Disease, PAD) is associated with high morbidity and mortality. During disease development, the arteries adapt by changing their diameter, wall thickness, and residual deformations, but the effects of demographics and risk factors on this process are not clear.

Methods: Superficial femoral arteries from 736 subjects (505 male, 231 female, 12 to 99 years old, average age 51±17.8 years) and the associated demographic and risk factor variables were used to construct machine learning (ML) regression models that predicted morphological characteristics (diameter, wall thickness, and longitudinal opening angle resulting from the …

Time Evolution Is A Source Of Bias In The Wolf Algorithm For Largest Lyapunov Exponents, Kolby Brink, Tyler Wiles, Nicholas Stergiou, Aaron Likens

UNO Student Research and Creative Activity Fair

Human movement is inherently variable by nature. One of the most common analytical tools for assessing movement variability is the largest Lyapunov exponent (LyE) which quantifies the rate of trajectory divergence or convergence in an n-dimensional state space. One popular method for assessing LyE is the Wolf algorithm. Many studies have investigated how Wolf’s calculation of the LyE changes due to sampling frequency, filtering, data normalization, and stride normalization. However, a surprisingly understudied parameter needed for LyE computation is evolution time. The purpose of this study is to investigate how the LyE changes as a function of evolution time …

Reducing Loading On The Contralateral Limb Using Human-In-The-Loop Optimization, Siena Senatore

UNO Student Research and Creative Activity Fair

In most everyday activities, we head towards a specific goal by updating our choices for a more direct path. However, there are specific clinical tasks where taking the direct path is more challenging. Clinical investigations of optimizing a prosthesis involve the assessment of multiple parameter settings through trial and error rather than goal-directed optimization. We investigate if a human-in-the-loop optimization algorithm can guide manual alterations to a prosthesis-simulating device to reduce the ground reaction force on the contralateral limb. In most participants, the optimal condition reduced the loading rate on the contralateral limb compared to the initial condition tested. These …

Changes In Ankle Muscle Force And Power During Walking In Patients With Peripheral Artery Disease, Hafizur Rahman, Cody Anderson, Iraklis I. Pipinos, Jason M. Johanning, Jianghu Dong, Sara A. Myers

UNO Student Research and Creative Activity Fair

Background: Patients with peripheral artery disease (PAD) have significantly reduced lower extremity muscle strength compared with healthy individuals as measured during isolated, single plane joint motion by isometric and isokinetic strength dynamometers. The objective of this study was to understand the contribution of the ankle muscles during walking in patients with PAD and compared to healthy older individuals.

Methods: A total of 12 patients diagnosed with Fontaine stage II PAD and 10 healthy older controls were recruited for the study. Each subject walked across a 10-meter pathway with reflective markers placed on specific anatomical locations on lower limbs while the …

Breaks In Longitudinal Elastic Fibers Of Human Femoropopliteal Arteries, Elham Zamani

UNO Student Research and Creative Activity Fair

Breaks in Longitudinal Elastic Fibers of Human Femoropopliteal Arteries

Elham Zamani1, Majid Jadidi1

1 Department of Biomechanics, University of Nebraska Omaha, Omaha, NE

Introduction: Elastin is a major protein in the body with half-life >50 years. It is thought that elastic fibers are formed before the postnatal period. In the femoropopliteal artery (FPA), the main artery in the leg, longitudinal elastic fibers are present in External Elastic Lamina (EEL). Our team has studied more than 1000 cadaveric human FPA and has noticed that there are big breaks in their longitudinal elastic fibers in some subjects. Our goal in this work …

Foot Temperature Before And After Walking In Patients With Peripheral Artery Disease, Jose Anguiano-Hernandez

UNO Student Research and Creative Activity Fair

Peripheral Artery Disease (PAD) is a pathology that can decrease blood flow to the lower limbs, resulting in the inability to regulate body temperature [1]. The effects of impaired blood flow caused by PAD on body temperature are unclear. The purpose of this study is to compare foot temperature changes before and after walking in healthy people and in patients with PAD. We hypothesize that 1) feet affected by PAD will experience a greater increase in temperature than healthy feet during walking and 2) feet affected by PAD will experience a slower rate of temperature recovery after walking compared …

Modeling Spatial Asymmetry In Visuomotor Coordination, Kolby Brink, Aaron Likens, Nikolaos Stergiou

UNO Student Research and Creative Activity Fair

Coordination is foundational to human movement. One prominent model of coordination is the Haken-Kelso-Bunz which predicts change in relative phase between two oscillators during movement. Use of this model has shown that the body has a natural tendency to prefer certain coordination patterns over others. The generalizability of the model has sparked its use throughout the scientific community to observe movement through the lens of dynamical systems theory. We contend that this model can be advanced further through incorporation of visually perceived spatial asymmetries, a component not currently accounted for by the model. That is, we sought to find if …

Implementation And Evaluation Of A Baseball Pitching Program And Its Impact On Injury Prevention And Performance, Tyler Hamer

UNO Student Research and Creative Activity Fair

The purpose of this study sought to examine the efficacy of biomechanical evaluations on collegiate baseball pitchers. Through this, we seek to develop a model for identifying at-risk athletes through a longitudinal assessment of pitching mechanics spanning pre-season to post-season along with in-season tracking of pathomechanics.

Design And Development Of A Semi-Rigid Hip Exoskeleton To Reduce Metabolic Cost, Arash Mohammadzadeh Gonabadi, Prokopios Antonellis, Sara Myers, Iraklis Pipinos, Philippe Malcolm

UNO Student Research and Creative Activity Fair

Robotic exoskeletons can reduce metabolic cost in healthy individuals and restore mobility in patients with peripheral artery disease (PAD). PAD is a cardiovascular disease produced by atherosclerosis of the leg arteries. The primary symptom of PAD is claudication or pain in the legs during walking, which severely shortens the distance a patient can walk. Knowing that up to 40% of the metabolic cost of walking comes from the hip muscles, different groups have been developing rigid exoskeletons and soft exosuits that assist the hip. Assisting at the hip has the advantage that the exoskeleton mass is positioned close to the …

The Effect Of Walking Speed And Magnitude Of Perturbation On Compensatory Responses, Farahnaz Fallah Tafti, Jenna Yentes

UNO Student Research and Creative Activity Fair

Imposing a perturbation can induce an unstable condition during gait. Measuring the compensatory responses may be an accurate indicator of the ability to control stability. Responses to a perturbation can be quantified through the perturbed walking pattern deviations from an unperturbed condition. The aim of this study was to determine the effect of perturbation magnitude or speed of walking on compensatory responses to lateral perturbations during walking. Twenty healthy young participants recruited to this study and they were perturbed with the medium magnitude of perturbation, while walking on the treadmill at three different speeds (slow, preferred, and fast). They also …

Autocorrelation And Probability Distributions In Gait-Metronome Synchronization, Charles Sloan

UNO Student Research and Creative Activity Fair

Recent research has shown that the structure of different pacing signals influences gait dynamics during coordination to those signals. Those studies, however, have not looked at the impact that probability distribution functions play in influencing our gait. This study looks at how both autocorrelation functions and probability distribution has in noisy metronomes to look for sources of synchronization. 10 healthy subjects volunteered to complete this study. The participants were required to wear custom-built glasses with a small screen projected on the lens. The screen showed a visual stimulus that correlated with various signals. The results of the study suggest that …

Effects Of Novel Tool Use: Cortical And Functional Measures In Children Using A Prosthetic Simulator, Chris Copeland

UNO Student Research and Creative Activity Fair

As of 2005, there were a total of 1.6 million people living with the loss of a limb, with this population projected to double to 3.6 million by 2050 [1]. While prostheses aim to enhance the function of these individuals, it is estimated that 45% of pediatric prosthetic users reject their prosthesis [2]. The literature which describes the neurological control mechanisms of prosthetic use is sparse and often low-powered due to an inadequate number of participants. However, prosthetic simulators may be a solution to chronically low-powered prosthetic-centric studies by serving as functional homologues, though this has yet to be tested. …

Gait Alterations After Anterior Cruciate Ligament Injury And Implications For Return-To-Play Testing, Lindsey Remski

UNO Student Research and Creative Activity Fair

Introduction: Reoccurring injury to the anterior cruciate ligament (ACL) is a major problem for individuals who undergo ACL reconstructive surgery despite them meeting current requirements for return-to-play. Previous studies have found alterations in gait kinetics and kinematics of ACL deficient and ACL reconstruction patients. It is unknown if gait parameters, such as peak joint angles and moments, provide different information about patient function from what is provided by return-to-play outcomes. Purpose: To assess the relationships between peak joint angles, peak joint moments, and return-to-play outcomes for individuals with ACL injury. Methods: 6 subjects (3 ACL reconstruction, 3 ACL deficient) performed …

Effects Of A Passive Dynamic Lower-Leg Exoskeleton During Walking, Blake Beier

UNO Student Research and Creative Activity Fair

The ankle joint is one of the most important joints during walking. If the muscles surrounding the ankle are weak, there are reductions in the ability to generate appropriate torques and powers at the ankle. This leads to slower self-selected walking speeds, which correlate with poor physical functioning, more disabilities, increased hospitalization visits and costs, and even mortality. Because of this, many orthotic and exoskeletal devices have been created to restore proper ankle function by promoting ankle plantar flexion. Utilizing 3D printing and an extension spring, we created an easily accessible, reproducible, and modifiable exoskeleton that has the potential to …

Intensity And Pattern Of Daily Physical Activity Of Claudicating Patients, Cody Anderson

UNO Student Research and Creative Activity Fair

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Visual Contributions To Balance Control During Gait, Kyle Brozek

UNO Student Research and Creative Activity Fair

We propose to isolate the contributions of continuous OF to the orthogonal relationship between balance and gait control during treadmill walking using a series of conditions. Manipulating the direction of OF using a CAREN (Motek Medical, Amsterdam, Netherlands) virtual reality treadmill environment will isolate these visual contributions in human subjects as they walk. We plan to tease out the effect of OF direction on the relationship between gait and balance control by having healthy young adults perform a series of treadmill walking trials while immersed in a VR environment. This will be done by manipulating the direction of walking and …

Determining The Relationship Between Walking Activity And Inter-Day Patterns In Stroke Survivors, Sydney Andreasen

UNO Student Research and Creative Activity Fair

Populations that have suffered from stroke are generally less active than people of otherwise similar demographics and are more susceptible to further health problems, such as another stroke. This study seeks to assess the validity of a treatment that encourages stroke survivors to walk more steps each day, in order to improve their active abilities and become less idle by establishing motivation for activity and therefore, also establishing patterns in the distribution of that activity throughout a stroke survivor’s day. 172 subjects (6 months post-stroke) have participated in a step activity monitoring program to record steps taken using wearable pedometers. …

Gait Alterations In Peripheral Arterial Disease Are Not Worsened By The Presence Of Diabetes, Hafizur Rahman

UNO Student Research and Creative Activity Fair

Peripheral arterial disease (PAD) is a vascular disease where atherosclerotic blockages restrict blood flow to muscles in the lower extremities. Diabetes is a common co-morbid condition in PAD and has been shown to increase the risk of lower extremity amputation compared to PAD without diabetes. Although there is a clear pathological relationship between diabetes and PAD, the gait mechanics involved remain indistinct. Therefore, the purpose of this study was to determine whether the presence of diabetes in addition to PAD results in greater functional impairment during ambulation. Twenty-three subjects with PAD and twelve controls consented to participate in the research. …

Collision Work Performed By Patients With Peripheral Artery Disease, Alex Dzewaltowski, Sara A. Myers, Jason M. Johanning, Iraklis I. Pipinos

UNO Student Research and Creative Activity Fair

The goal of this study was to assess the differences in collision work performed by healthy, aged-matched controls compared to patients with peripheral artery disease (PAD) to provide foundations for an eventual exoskeleton design. Collision work is energy dissipated into the surrounding environment from impact, in this study’s case, upon heel strike. When designing an exoskeleton for patients with PAD, harvesting energy lost to collision work could be a valuable mechanism to improve walking performance. Devices designed to utilize the normally dissipated energy for assisting propulsion to improve walking performance are under-explored [1, 2]. The purpose of this study was …

Bimanual Coordination Assessment Using Prosthetic Simulators, Chris Copeland

UNO Student Research and Creative Activity Fair

There were a total of 1.6 million people living with loss of a limb in 2005. This number is projected to double to 3.6 million by 2050 [1]. While prosthetics aim to enhance the function of these individuals, it is estimated that 45% of pediatric prosthetic users reject their prosthesis [2]. The literature which describes the motor control mechanisms of prosthetic use is sparse and often low-powered due to inadequate number of subjects. However, prosthetic simulators may be a solution to chronically low-powered prosthetic studies by serving as functional homologues. The purpose of this investigation was to determine the efficacy …

A Comparative Study For Feature Selection Algorithms To Analyze Gait Patterns For Health Purposes, Donovan Orn

UNO Student Research and Creative Activity Fair

A Comparative Study for Feature Selection Algorithms to Analyze Gait Patterns for Healthcare Purposes

Donovan Orn

Abstract

With the explosive use of wearable devices, there is an urgent need to find ways to utilize the data collected by such devices. In many cases, wearable devices contain accelerometers that collected different types of data. It is not always clear which data points can be used to extract information that can be used to provide useful knowledge about the health of the individuals. In this study, we proposed to research, implement, and comparing various feature selection techniques used for analyzing on gait …

Simulation Of Joint Contact Forces In Total Knee Arthroplasty Patients Using Opensim, Benjamin Frazier

UNO Student Research and Creative Activity Fair

The occurrence of Total Knee Arthroplasty (TKA) is projected to increase markedly in the coming decade, and a better method of rehabilitating TKA patients is becoming necessary. Rehabilitation of these patients is of utmost importance such that patients are capable of using the limb effectively. Focus towards improving the rehabilitation of patients that have undergone TKA operations requires a metric for comparison of performance between control groups and experimental groups. Joint contact forces (JCF) calculated via simulation in OpenSim using Motion Capture and Force Plate data provide effective means comparing these groups. Subjects are outfitted with a marker set and …

The Energy Paradox Of The Ankle-Foot Complex During Human Walking, Nikolaos Papachatzis, Kota Takahashi

UNO Student Research and Creative Activity Fair

Flexor hallucis longus (FHL) is a multiarticular muscle that possesses the potential to alter foot’s functional and mechanical behavior, since it performs multiple significant functions during walking (e.g supports the medial longitudinal arch of the foot).The purpose of this study was to determine if the functional changes of the FHL are associated with the foot’s adaptations to the mechanical demands of walking. Backward walking is an experimental method capable of altering how the forces propagate underneath the foot and disrupting the mechanical function of the FHL muscle. We hypothesized that: (1) the muscle activity of the FHL will increase during …

Can The Presence Of A 1/F Structure In Stride-To-Stride Variability Enable Us To Withstand Falls?, Jenny A. Kent, Andreas Skiadopoulos, Jordan Wickstrom, Nikolaos Stergiou

UNO Student Research and Creative Activity Fair

Falls are a persistent threat to longevity and quality of life, affecting 1/3 of older adults living in the community each year. There is strong evidence suggesting that a particular pattern within our walking reflects an ability to adapt to a continually changing environment. Specifically, the stride-to-stride patterns of healthy walking have a 1/f frequency spectrum. This has been observed to degrade to varying extents with aging and pathology. The aim of this study was to determine whether the presence of this structure of variability is related to an increased ability to withstand perturbations. We hypothesized that individuals who demonstrated …

Individuals With Peripheral Artery Disease Alter Spatiotemporal Gait Parameters When Walking With Pain Versus Without Pain, Todd Leutzinger, Sara A. Myers, Iraklis Pipinos

UNO Student Research and Creative Activity Fair

This abstract compares the spatiotemporal walking parameters of individuals with peripheral artery disease at the time they first begin walking, the time when they first feel pain, and the time when they can no longer continue walking.

Validation Of Postural Sway Measurements Using Wii Balance Board, Zachary Meade

UNO Student Research and Creative Activity Fair

Standing balance measurements, such as postural sway, are vital for determining functional ability, risk of falling and recovery of injuries. Often the need to collect data outside of the typical clinical or research setting arises. However, obtaining these measurements outside of a laboratory setting can be very difficult, as the mobility of a laboratory-grade force plate (FP) is minimal, and its cost can be upwards of $20,000. The purpose of this study is to create a cheaper alternative by validating the Wii Balance Board’s (WBB; Nintendo, Redmond, Washington, USA) ability to measure postural sway patterns. The WBB can be acquired …

Peak Vertical Ground Reaction Force & Stance Phase Time To Assess Post-Tka Interlimb Asymmetry, Abderrahman Ouattas

UNO Student Research and Creative Activity Fair

In the US, more than 500,000 TKA surgeries are performed annually, to which 97% of those are led by OA¹. Although knee pain is diminished post-TKA, unilateral efficiency and walking asymmetry is still unresolved several years after the surgery². In fact, within a minimum of 10 years after the primary TKA, almost 50% of patients undergo a secondary TKA on the contralateral limb due to OA progression³. The purpose of this study was to determine if post-Total Knee Arthroplasty peak vertical ground reaction force (pVGRF) asymmetry could be identified using stance phase time differences …

Acl Reconstruction Results In Alterations For Force Control Variability During Multidirectional Force Production, Amelia S. Lanier

UNO Student Research and Creative Activity Fair

After anterior cruciate ligament (ACL) rupture most will undergo reconstructive surgery. Within the first year after surgery 25% of patients will re-tear their ACL. Most of those injured attempt to return to sports which include running and cutting. The ability to produce appropriate ground reaction forces may be crucial for the successful return to sports without re-injury. Understanding stability of multidirectional ground reaction force (mGRF) production in healthy and ACL reconstructed (ACL-r) patients can lend insight to the high instance of re-injury. Typically, stability has been measured using linear analyses, but these analyses cannot capture the subtle time varying changes …