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Full-Text Articles in Life Sciences

The Foot And Ankle Structures Reveal Emergent Properties Analogous To Passive Springs During Human Walking, Erica Hedrick, Steven J. Stanhope, Kota Z. Takahashi Jun 2019

The Foot And Ankle Structures Reveal Emergent Properties Analogous To Passive Springs During Human Walking, Erica Hedrick, Steven J. Stanhope, Kota Z. Takahashi

Journal Articles

An objective understanding of human foot and ankle function can drive innovations of bio-inspired wearable devices. Specifically, knowledge regarding how mechanical force and work are produced within the human foot-ankle structures can help determine what type of materials or components are required to engineer devices. In this study, we characterized the combined functions of the foot and ankle structures during walking by synthesizing the total force, displacement, and work profiles from structures distal to the shank. Eleven healthy adults walked at four scaled speeds. We quantified the ground reaction force and center-of-pressure displacement in the shank’s coordinate system during ...


Walking Adaptations To An Ankle Foot Orthosis In Individuals With Peripheral Artery Disease, Todd Leutzinger, Iraklis Pipinos, Jason Johanning, Mahdi Hassan, Holly Despiegelaere, Mukul Mukherjee, Sara Myers Mar 2019

Walking Adaptations To An Ankle Foot Orthosis In Individuals With Peripheral Artery Disease, Todd Leutzinger, Iraklis Pipinos, Jason Johanning, Mahdi Hassan, Holly Despiegelaere, Mukul Mukherjee, Sara Myers

Student Research and Creative Activity Fair

Single Session Walking Adaptations to an Ankle Foot Orthosis in Patients with Claudication and Peripheral Artery Disease

Todd Leutzinger1, 2, Iraklis Pipinos2, 3, Jason Johanning2, 3, Mukul Mukherjee1, Sara Myers1, 2

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

2Nebraska and Western Iowa Veterans Affairs’ Medical Center, Omaha, NE USA

3Department of Surgery, University of Nebraska Medical Center, Omaha, NE USA

Email: tleutzinger@unomaha.edu

Peripheral artery disease (PAD) is an atherosclerotic disease affecting the arteries of the lower extremities [1]. The primary symptom of PAD is intermittent claudication ...


The Effects Of Stiffness Of A Prosthetic Shock-Absorbing Pylon On Mechanical Work During Walking, Jenny Anne Maun Mar 2019

The Effects Of Stiffness Of A Prosthetic Shock-Absorbing Pylon On Mechanical Work During Walking, Jenny Anne Maun

Student Research and Creative Activity Fair

Name: Jenny Anne Maun

Title: The effects of stiffness of a prosthetic shock-absorbing pylon on mechanical work during walking

Degree: Masters

Faculty Advisor: Kota Z. Takahashi, PhD

Co-authors: Steven A. Gard, PhD; Matthew J. Major, PhD

A prosthetic shock-absorbing pylon (SAP) is intended to attenuate impact forces, provide comfort, and reduce residual limb pain for prosthesis users. However, the effect of an SAP and its spring stiffness on the mechanical work done by the prosthetic limb during walking remains unclear. The purpose of this study: to investigate the effects of SAP spring stiffness and walking speed on the mechanical work ...


How Prosthetic Ankle Stiffness & Load Carriage Affect Metabolic Energy Expenditure During Walking, Erica A. Hedrick, Philippe Malcolm, Jason M. Wilken, Kota Z. Takahashi Mar 2019

How Prosthetic Ankle Stiffness & Load Carriage Affect Metabolic Energy Expenditure During Walking, Erica A. Hedrick, Philippe Malcolm, Jason M. Wilken, Kota Z. Takahashi

Student Research and Creative Activity Fair

The ankle structures play a key role in body support, forward propulsion and leg swing. One important property of the human ankle is its ‘quasi-stiffness’, or resistance to angular motion. The ankle joint stiffness can play a role in aiding the lower leg as its rocks over the foot. Human biological ankle stiffness changes in response to changes in the mechanical demands of walking (e.g. added load or changes in speed), using active muscle contractions. However, the role of ankle stiffness in regulating metabolic energy across walking conditions is unknown. Therefore, the purpose of this study is to determine ...


Effect Of Dual-Task Walking On Long-Range Correlations In People With Parkinson's Disease, Shane Meltz Mar 2019

Effect Of Dual-Task Walking On Long-Range Correlations In People With Parkinson's Disease, Shane Meltz

Student Research and Creative Activity Fair

Parkinson’s Disease (PD) causes gait to be more variable and more random. Gait variability is related to disease severity, and may be a marker of fall risks. Gait in PD is attention-dependent, meaning a distraction while walking could be detrimental. The effects of dual-task walking on gait variability in PD are unclear (in particular fractal fluctuations). This study will determine if dual-task walking impacts stride-to-stride variability compared to normal walking in people with Parkinson’s Disease. We predict that dual-tasking will lead to more random stride-to-stride variability in people with PD, compared to controls. Also, within the PD group ...


How The Foot Modulates Its Mechanics During Uphill And Downhill Walking, Jeffrey M. Patterson, Kota Z. Takahashi Mar 2019

How The Foot Modulates Its Mechanics During Uphill And Downhill Walking, Jeffrey M. Patterson, Kota Z. Takahashi

Student Research and Creative Activity Fair

The foot's biomechanical role in walking on sloped surfaces is currently unclear. While previous biomechanics studies have examined the hip, knee, and ankle, the foot is oversimplified as a rigid-body segment. This oversimplification overshadows its complex structure and function. In this project, we use an innovative multi-segment foot model to explore how the foot adapts its mechanics to incline and decline walking. Preliminary results have revealed that the foot is capable of adapting its mechanical work profile to both incline and decline walking. Specifically, the foot can increase its positive work output (i.e., increased energy generation) during inclined ...


Skeletal Muscle Mitochondrial Biogenesis In Response To Exercise And Cold Exposure, Camille Larson Mar 2019

Skeletal Muscle Mitochondrial Biogenesis In Response To Exercise And Cold Exposure, Camille Larson

Student Research and Creative Activity Fair

BACKGROUND: Aerobic exercise triggers mitochondrial biogenesis, the generation of new mitochondria, by ATP depletion and subsequent activation of the AMPK signaling pathway. This leads to enhanced expression of PGC-1α, a positive regulator of respiration, mitochondrial biogenesis, and adaptive thermogenesis. Previous research from our lab has shown that exercise followed by cold recovery enhances the transcription of genes associated with mitochondrial growth and division, however the recovery period was necessary for this response. Perhaps exercising in a colder external environment would induce a greater thermoregulatory response and gradient between ambient skin and core temperature that may lead to altered mitochondrial turnover ...


Effect Of Handrail Use During Stair Climbing In Oa Patients: A Pilot Study, Jenna Ackerman Mar 2019

Effect Of Handrail Use During Stair Climbing In Oa Patients: A Pilot Study, Jenna Ackerman

Student Research and Creative Activity Fair

Introduction: For the patients with osteoarthritis of the knee, stairs are commonly a difficult task and may be the first thing affect by osteoarthritis.1 This population often employs altered strategies when they approach, ascend, and descend the stairs compared to a healthy population. Within 12 years, 80% of patients develop knee osteoarthritis in the contralateral limb.2 Handrails play an important role by assisting with balance, control, and confidence, but their use needs to be assessed even further to fully understand how handrails impact the contralateral limb in osteoarthritic patients and how they may be integrated optimally into gait ...


The Effects Of Swimming Training On Arterial Stiffness, Muscular Strength And Cardiorespiratory Endurance In Postmenopausal Women With Stage 2 Hypertension, Steven Scott Mar 2019

The Effects Of Swimming Training On Arterial Stiffness, Muscular Strength And Cardiorespiratory Endurance In Postmenopausal Women With Stage 2 Hypertension, Steven Scott

Student Research and Creative Activity Fair

Objective:

Aging is associated with progressive decreases in arterial health and function as well as overall fitness. It is crucial to prevent or reduce the negative effects of aging on vasculature and fitness components by implementing appropriate lifestyle interventions, such as exercise training. We examined the effects of a swimming (SWM) regimen on arterial stiffness (pulse wave velocity, PWV), blood pressure (BP), wave reflection (AIx), muscle strength and aerobic capacity in postmenopausal women with stage 2 hypertension.

Methods:

Using a parallel experimental design, participants were randomly assigned to either a SWM (n=52) or non-exercising control group (n=48) for ...


3d Prosthetics Effects On Standing Posture In Unilateral Upper Limb Deficient Children, Keaton Young Mar 2019

3d Prosthetics Effects On Standing Posture In Unilateral Upper Limb Deficient Children, Keaton Young

Student Research and Creative Activity Fair

3D Prosthetics Effects on Standing Posture in Unilateral Upper Limb Deficient Children

Keaton Young

Department of Biomechanics, University of Nebraska at Omaha

Introduction

Upper Limb Reduction Deficiency (ULD) is a congenital disability that affects the upper limb, which the Center for Disease Control and Prevention estimates that nearly 1,500 babies are born with ULD in the United States yearly 1,2. Prior research has focused on functional treatment of the upper limbs but has lacked observance of the effects that prosthetics and limb loss incur to the trunk. Therefore, the purpose of this study is to examine the acute ...


The Time Of Slip Onset During Stance Influences The Characteristics Of The Unconstrained Perturbation, Corbin Rasmussen, Nathaniel Hunt Mar 2019

The Time Of Slip Onset During Stance Influences The Characteristics Of The Unconstrained Perturbation, Corbin Rasmussen, Nathaniel Hunt

Student Research and Creative Activity Fair

Falls pose a significant health hazard, resulting in devastating injuries like broken wrists, fractured hips, and traumatic brain injuries that exceed $50 billion in U.S. medical costs. To address these risks, biomechanists have subjected individuals to simulated slips in order to study the factors that lead to falls. These studies have focused on slips that happen immediately after heel-strike and are unnaturally restricted by the methods used to cause the slip. Therefore, the effects of unconstrained slips that occur throughout stance phase are unknown. To address this knowledge gap, we examined the relationship between the timing of slip onset ...


Isolating Aspects Of Gait Through The Use Of Pacing Signals: A Pilot Study, Joel Sommerfeld Mar 2019

Isolating Aspects Of Gait Through The Use Of Pacing Signals: A Pilot Study, Joel Sommerfeld

Student Research and Creative Activity Fair

A number of recent studies have shown that the temporal structure of pacing signals greatly influences the gait dynamics observed when coordinating with those signals. Typically, those studies have focused on autocorrelation structure (ACF). The current study builds on that work by addressing how the probability distribution (PDF) of pacing signals contributes to the process of synchronization. Results show that people use both of those sources of information when coordinating the timing of the lower limbs with an external pacing signal.


Subthreshold Vibration Influences The Posture And Gait Of Transtibial Amputees, Charles Sloan Mar 2019

Subthreshold Vibration Influences The Posture And Gait Of Transtibial Amputees, Charles Sloan

Student Research and Creative Activity Fair

Unilateral transtibial amputees lose the afferent pathways of the limb when amputation occurs. The addition of vibration has shown to increase sensation on the applied limb. This study looks into how the addition of subthreshold vibration affects amputee gait and posture. Vibration applied to the residual limb was shown to have worked in posture, but not in gait.


Influence Of Hip Abductor Fatigue On Acl Loading During Single-Leg Landing, Namwoong Kim Mar 2019

Influence Of Hip Abductor Fatigue On Acl Loading During Single-Leg Landing, Namwoong Kim

Student Research and Creative Activity Fair

A musculoskeletal simulation study is necessary to identify the cause-effect relationship between hip abductor weakness and ACL loading during athletic events such as landing and jumping. The purpose of this study was to identify the effect of weakness of hip abductors on lower extremity kinematics and ACL loading during single-leg landings. We hypothesized that hip abductor weakness would alter lower extremity joint kinematics. We also hypothesized that hip abductor weakness would increase ACL loading during single-leg landings. This study was a combination of a human experiment and a musculoskeletal modeling simulation. Ten healthy participants performed single-leg landing from a height ...


Gait Mechanics Differences Between Healthy Controls And Patients With Peripheral Artery Disease After Adjusting For Gait Velocity, Stride Length, And Step Width, John D. Mccamley, Eric Cutler, Kendra K. Schmid, Shane R. Wurdeman, Jason Johanning, Iraklis Pipinos, Sara A. Myers Feb 2019

Gait Mechanics Differences Between Healthy Controls And Patients With Peripheral Artery Disease After Adjusting For Gait Velocity, Stride Length, And Step Width, John D. Mccamley, Eric Cutler, Kendra K. Schmid, Shane R. Wurdeman, Jason Johanning, Iraklis Pipinos, Sara A. Myers

Journal Articles

Patients with peripheral artery disease (PAD) experience significant leg dysfunction. The effects of PAD on gait include shortened steps, slower walking velocity, and altered gait kinematics and kinetics, which may confound joint torques and power measurements. Spatiotemporal parameters and joint torques and powers were calculated and compared between 20 patients with PAD and 20 healthy controls using independent t tests. Separate analysis of covariance models were used to evaluate group differences after independently adjusting for gait velocity, stride length, and step width. Compared with healthy controls, patients with PAD exhibited reduced peak extensor and flexor torques at the knee and ...


Improvement Of Lipids And Reduction Of Oxidative Stress With Octacosanol After Taekwondo Training, Sang-Ho Lee, Steven D. Scott, Elizabeth J. Pekas, Jeong-Gi Lee, Song-Young Park Jan 2019

Improvement Of Lipids And Reduction Of Oxidative Stress With Octacosanol After Taekwondo Training, Sang-Ho Lee, Steven D. Scott, Elizabeth J. Pekas, Jeong-Gi Lee, Song-Young Park

Health and Kinesiology Faculty Publications

Athletes in combat sports undergo rapid changes in body weight prior to competition in order to gain a size advantage over their opponent. However, these large weight changes with concomitant high-intensity exercise training create poor lipid profiles and high levels of oxidative stress, which can be detrimental to health and sport performance. Therefore, the purpose of this study was to investigate the ability of the nutritional supplement octacosanol to combat the physiological detriments that occur in taekwondo players during rapid weight loss with high-intensity exercise training. Methods: A total of 26 male taekwondo players were randomly divided into 2 groups ...