Biomechanics Commons^™

Prosthesis Preference Is Related To Stride-To-Stride Fluctuations At The Prosthetic Ankle, Shane R. Wurdeman, Sara A. Myers, Adam L. Jacobsen, Nikolaos Stergiou

Journal Articles

The purpose of this study was to determine the relationship between stride-to-stride fluctuations and prosthesis preference. Thirteen individuals with unilateral, transtibial amputation consented to participate. Individuals walked on a treadmill for 3 min with their prescribed and an alternate prosthesis. Stride-to-stride fluctuations were quantified with the largest Lyapunov exponent (LyE) of each joint flexion/extension time series. The change in the LyE was calculated for each major lower-limb joint for both conditions. Participants indicated preference between the prostheses on a continuous visual analog scale. The change in the LyE was correlated with the degree of preference between the two prostheses at …

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 …

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 …

Understanding Affordances: History And Contemporary Development Of Gibson’S Central Concept, Dobromir Dotov, Lin Nie, Matthieu M. De Wit

Journal Articles

Gibson developed the affordance concept to complement his theory of direct perception that stands in sharp contrast with the prevalent inferential theories of perception. A comparison of the two approaches shows that the distinction between them also has an ontological aspect. We trace the history and newer formalizations of the notion of affordance and discuss some competing opinions on its scope. Next, empirical work on the affordance concept is reviewed in brief and the relevance of dynamical systems theory to affordance research is demonstrated. Finally, the striking but often neglected convergence of the ideas of Gibson and those of certain …

External Work Is Deficient In Both Limbs Of Patients With Unilateral Pad, Shane R. Wurdeman, Sara A. Myers, Jason Johanning, Iraklis Pipinos, Nikolaos Stergiou

Journal Articles

External work was utilized to measure differences between the unaffected and the affected limb in patients with unilateral peripheral arterial disease compared to healthy controls. Patients with unilateral peripheral arterial disease have shown deficits in peak joint powers during walking in the unaffected and affected legs. However, no research has detailed the amount of work that is being performed by each leg compared to healthy controls even though such an analysis would provide valuable information on the energy output from the affected and the unaffected legs. Two hypotheses were tested: a) the unaffected and affected leg would perform less work …

Shock Attenuation In Landing, Bryon Christopher Applequist

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shock attenuation (SA) has been well studied in activities such as walking and running (Chu, et al. 2004; Derrick, et al. 2004; Mercer, et al. 2003); however, there is a lack of research regarding SA during landing. Furthermore, there is lack of information regarding which structures attenuate shock. The purpose of this study was to examine SA among the leg-hip, hip-head, and leg-head segments during landing. Each subject (n=10, Age 26.3 ± 2.71 years, Height 1.68 ± 0.08 m, Mass 70.49 ± 16.03 kg) was instrumented with accelerometers at the leg, hip and forehead. Subjects then performed landings from three …

Sensitivity Of The Wolf’S And Rosenstein’S Algorithms To Evaluate Local Dynamic Stability From Small Gait Data Sets: Response To Commentaries By Bruijn Et Al., Fabien Cignetti, Leslie M. Decker, Nikolaos Stergiou

Journal Articles

Assessing gait stability using the Largest Lyapunov Exponent (λ₁) has become popular, especially because it may be a key measure in evaluating gait abnormalities in patient populations. However, clinical settings usually involve having small gait data sets and accurate determination of λ₁ estimates from such sets is difficult. In an effort to address this issue, Cignetti et al.2 recently identified that λ₁ estimates using the algorithm of Wolf et al.9 (W-algorithm) were more sensitive than those using the algorithm of Rosenstein et al.7 (R-algorithm) in order to capture age-related …

Peripheral Arterial Disease Affects The Frequency Response Of Ground Reaction Forces During Walking, Denise Mcgrath, Timothy N. Judkins, Iraklis Pipinos, Jason Johanning

Journal Articles

Background—Walking is problematic for patients with Peripheral Arterial Disease. The purpose of this study was to investigate the frequency domain of the ground reaction forces during walking to further elucidate the ambulatory impairment of these patients.

Methods—Nineteen bilateral peripheral arterial disease patients and nineteen controls were included in this study. Subjects were matched for age and gait speed. Participants walked over a force plate sampling at 600Hz. PAD patients were tested before (pain-free condition) after the onset of claudication symptoms (pain). We calculated median frequency, frequency bandwidth, and frequency containing 99.5% of the signal for the vertical and …

Frictional Forces Of A Fixed, Esthetic Orthodontic Appliance System, Brady Michael Nance

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The demands of an all esthetic fixed orthodontic appliance system are ever increasing in today's world. Frictional values of an esthetic, fixed orthodontic appliance system are needed to evaluate their clinical effectiveness for orthodontic treatment. The aim of this study is to evaluate the frictional values of various esthetic orthodontic archwires ligated to an esthetic orthodontic bracket.

Methods: Three types of stainless steel and nickel titanium alloy (niti) esthetic orthodontic archwires (epoxy, poly, plastic) in four sizes (.016, .018, .017 x .025, .019 x .025 inches) were ligated to both a stainless steel bracket system and a ceramic (esthetic) …

Peripheral Arterial Disease Affects The Frequency Response Of Ground Reaction Forces During Walking, Denise Mcgrath, Timothy N. Judkins, Iraklis Pipinos, Jason M. Johanning, Sara A. Myers

Journal Articles

Background

Walking is problematic for patients with peripheral arterial disease. The purpose of this study was to investigate the frequency domain of the ground reaction forces during walking to further elucidate the ambulatory impairment of these patients.

Methods

Nineteen bilateral peripheral arterial disease patients and nineteen controls were included in this study. Subjects were matched for age and gait speed. Participants walked over a force plate sampling at 600 Hz. PAD patients were tested before (pain-free condition) after the onset of claudication symptoms (pain). We calculated median frequency, frequency bandwidth, and frequency containing 99.5% of the signal for the vertical …

Hamstring-Dominant Strategy Of The Bone–Patellar Tendon–Bone Graft Anterior Cruciate Ligament–Reconstructed Leg Versus Quadriceps-Dominant Strategy Of The Contralateral Intact Leg During High-Intensity Exercise In Male Athletes, Kostas Patras, Franceska Zampeli, Stavros Ristanis, Elias Tsepis, Giorgos Ziogas, Nikolaos Stergiou, Anastasios D. Georgoulis

Journal Articles

Purpose

The purpose of this study was to investigate the effect of anterior cruciate ligament (ACL) reconstruction on the quadriceps-dominant strategy as a parameter associated with the neuromuscular control of the knee joint.

Methods

In this study 14 competitive soccer players who had undergone ACL reconstruction with bone–patellar tendon–bone autograft and 14 healthy competitive soccer players performed two 10-minute treadmill runs, 1 at moderate intensity and 1 at high intensity. Electromyographic recordings were acquired by use of a telemetric system at the third, fifth, seventh, and tenth minute of the runs from the vastus lateralis and the biceps femoris bilaterally. …

Mutations In Dmrt3 Affect Locomotion In Horses And Spinal Circuit Function In Mice, Lisa S. Andersson, Martin Larhammar, Fatima Memic, Hanna Wootz, Doreen Schwochow, Carl-Johan Rubin, Kalicharan Patra, Thorvaldur Arnason, Lisbeth Wellbring, Göran Hjälm, Freyja Imsland, Jessica Lynn Petersen, Molly E. Mccue, James R. Mickelson, Gus Cothran, Nadav Ahituv, Lars Roepstorff, Sofia Mikko, Anna Vallstedt, Gabriella Lindgren, Leif Andersson, Klas Kullander

Department of Animal Science: Faculty Publications

Locomotion in mammals relies on a central pattern-generating circuitry of spinal interneurons established during development that coordinates limb movement. These networks produce left–right alternation of limbs as well as coordinated activation of flexor and extensor muscles. Here we show that a premature stop codon in the DMRT3 gene has a major effect on the pattern of locomotion in horses. The mutation is permissive for the ability to perform alternate gaits and has a favorable effect on harness racing performance. Examination of wild-type and Dmrt3-null mice demonstrates that Dmrt3 is expressed in the dI6 subdivision of spinal cord neurons, takes …

Net Impulse And Net Impulse Characteristics In Vertical Jumping, Satoshi Mizuguchi

Electronic Theses and Dissertations

The purpose of this dissertation was to explore the potential use of net impulse and its characteristics in vertical jumping to monitor athletes' performance status and responses/adaptations to interventions. Five variables were proposed as net impulse characteristics: net impulse height and width, rate of force development, shape factor, and net impulse proportion. The following were then examined: 1) test-retest reliability of a new approach to identify net impulse in a force-time curve and of net impulse characteristics and criterion validity of the new approach; 2) effective measures of net impulse characteristics; 3) relationships between training-induced changes in its characteristics and …

Effects Of Head Position And Head-Supported Mass On Nerve Function Of The Flexor Carpi Radialis Muscle In Healthy Individuals, Bethany Lauren Shivers

Graduate Theses and Dissertations

Long-term exposure to head-supported mass (HSM) has been linked with spinal degeneration including foraminal stenosis and disc deterioration. Anecdotally, HSM has also been linked to neck and arm pain and muscle atrophy, but nerve function has not been tested specifically. The combined effect of various head positions and HSM may be sufficient to compress the nerve root in aviators and Soldiers during job performance, potentially leading to short- and long-term neuromuscular effects. The Hoffmann (H) reflex, a well-established measure of nerve function, has shown to be sensitive to changes in nerve root space which occurs with different head positions. This …

Taking Balance Measurement Out Of The Laboratory And Into The Home: Discriminatory Capability Of Novel Centre Of Pressure Measurement In Fallers And Non-Fallers, Denise Mcgrath, Emer P. Doheny, Lorcan Walsh, David Mckeown, Clodagh Cunningham, Lisa Crosby, Rose Anne Kenny, Nikolaos Stergiou, Brian Caulfield, Barry R. Greene

Journal Articles

We investigated three methods for estimating centre of pressure excursions, as measured using a portable pressure sensor matrix, in order to deploy similar technology into the homes of older adults for longitudinal monitoring of postural control and falls risk. We explored the utility of these three methods as markers of falls risk in a cohort of 120 community dwelling older adults with and without a history of falls (65 fallers, 55 non-fallers). A number of standard quantitative balance parameters were derived using each centre of pressure estimation method. Rank sum tests were used to test for significant differences between fallers …

Postural Control Strategy During Standing Is Altered In Patients With Multiple Sclerosis, Jessie M. Huisinga, Jenna M. Yentes, Mary Filipi, Nikolaos Stergiou

Journal Articles

Disturbances in balance are one of the first reported symptoms of Multiple Sclerosis (MS), yet limited research has been performed to classify the postural control deficits in this population. This study investigated the variability present in the sway patterns during quiet standing in patients with MS (PwMS) and healthy controls. Subjects were assessed (eyes open, closed) standing on a force platform. Variability of the sway patterns was quantified using a measure of amount of variability (root mean square; RMS) and two measures of temporal structure of variability (Lyapunov Exponent – LyE; Approximate Entropy – ApEn). RMS results revealed significantly higher …

The Effect Of Footwear On The Mechanics Of The Lower Back During Treadmill Running, Jeffrey Ray Mcclellan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Little is known regarding the effect that footwear cushioning can have on the mechanics of the low back. The purpose of this study was to 1) determine the material characteristics of a minimalist running shoe tested with and without a commercially available shoe insole, 2) determine if there are differences in lower back or knee kinematics when minimalist shoes are worn with and without a shoe insole during treadmill running, and 3) determine if there are differences in levels of muscle activation when minimalist shoes are worn with and without a shoe insole during treadmill running. Following the receipt of …

Kinematics And Muscle Activation Patterns During Simulated Uphill Pedaling On An Indoor Cycle Ergometer, Benjamin Thomas Stein

Boise State University Theses and Dissertations

INTRODUCTION: An indoor cycle ergometer allows for competitive and recreational mountain bike cyclists to simulate uphill conditions with precisely controlled and monitored pedaling. While simulating an uphill condition indoors, with or without a climbing block, the cyclist body may not be in the same position as while pedaling outdoors. This possible difference in body position may have training implications. PURPOSE: The purpose of this study was to determine if there are differences in kinematics and/or muscle activation patterns while pedaling on a level surface compared to an inclined surface while pedaling on a mountain bike on an indoor cycle …

Changes In In Vivo Knee Contact Forces Through Gait Modification, Allison Kinney, Thor F. Besier, Amy Slider, Scott L. Delp, Darryl D. D'Lima, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Gait modification represents a non-invasive method for reducing knee joint loading in patients with knee osteoarthritis. Previous studies have shown that a variety of gait modifications are effective in reducing the external knee adduction moment. The external knee adduction moment is often used as a surrogate measure of medial compartment force. However, a recent study showed that reductions in the external knee adduction moment do not guarantee reductions in medial compartment loads. Therefore, direct measurement of changes in knee contact force is important for determining the effectiveness of gait modifications. A previous study found that medial thrust gait and walking …