Biomechanics Commons^™

Feather Biomechanics Of Penguins And Other Seabirds, Katherine Elizabeth Johnson

Theses Digitization Project

Although many aspects of penguin biology have been studied, the feathers have received less attention except with regard to thermoregulation. The biomechanics of penguin feathers are the focus of this thesis. By studying penguins in comparison to other wing-propelled aquatic fliers, it may be possible to understand how penguin feathers evolved. Fourteen species were sampled, including aerial flyers, aerial flyers that are also wing propelled divers, as well as flightless wing propelled divers.

An Eccentric Intervention Of The Flexor-Pronator Mass To Impact Overhead Throwing Distance And Velocity, Ricker Stanton Adkins

Online Theses and Dissertations

This study focused on the pronator-flexor mass of the elbow and its role in the overhead throwing motion. This specific muscle group is responsible for primary pronation and flexion at the elbow joint, while also reducing valgus stress from compromising the ulnar collateral ligament.

Twenty-three participants were put through a short throwing progression that was focused on their velocity and overall distance thrown from a standing position. After baseline testing was completed participants underwent a short intervention to determine if the intervention would impact all dependent variables. Experimental and non-experimental groups were compared using a repeated measures ANOVA which found …

Nebraska Biomechanics Core Facilty 2011-2012 Annual Report, Issue 10, Nebraska Biomechanics Core Facility

Biomechanics Annual Report

June 2011 - August 2012

This issue features Featured news, Staff updates, Grants and Projects, Collaborations, Visitors, Awards, Publications, Travels, and Support.

Biophysical And Biochemical Factors In The Cellular Microenvironment; Effects On Cell Migration And Invasion, Shalini Menon

Wayne State University Dissertations

Cellular migration is a vital process central to many physiological events including development, immune surveillance and wound healing. However, migration and invasion are not unique to normal physiology, they are also key determinants in the progression of disease states such as cancer. Given the significance of migration it is important that we understand how the process is regulated intracellularly and the various stimuli that can promote it. Even though the role of biochemical factors in mediating migration has been studied extensively, the role of biophysical factors in modulating migration and invasion is less appreciation. The biochemical and biophysical components of …

Impacts On Balance When Walking In Occupational Footwear, Harish Chander

Electronic Theses and Dissertations

Hazards and challenges present in the workplace pose a number of potential risks for injuries and illness. Nearly 3.1 million nonfatal workplace injuries and illness were reported in 2010 (BLS, 2010). The probability of falls has been related to balance decrements. Further, an important point of distinction is 45% of all falls have been attributed to inappropriate footwear (Menant et al. 2008) Previous studies have shown decrements in balance as a result of different footwear (Menant et al. 2008) and after an increased workload over a specific period of time (Yaggie & McGregor, 2002; Gribble & Hertel, 2004). Occupational footwear …

An Unstable Shoe With A Rocker Bottom Redistributes External Work, Shane R. Wurdeman, Jenna M. Yentes, Neil B. Huben, Nikolaos Stergiou

Journal Articles

The purpose of this study was to examine the external work performed by individuals wearing a rocker bottom shoe compared to a standard shoe. It was hypothesized that individuals wearing a rocker bottom shoe would have changes in the amount of work over the course of contact with the ground. External work on the body’s centre of mass (BCOM) was calculated for individuals in both conditions. Comparisons for external work were done for positive and negative work for the entire stance phase as well as the initial double support, single support and terminal double support periods. The results revealed that …

Reliability Of Semiautomated Computational Methods For Estimating Tibiofemoral Contact Stress In The Multicenter Osteoarthritis Study, Donald D. Anderson, Neil A. Segal, Andrew M. Kern, Michael C. Nevitt, James C. Torner, John A. Lynch

Journal Articles

Recent findings suggest that contact stress is a potent predictor of subsequent symptomatic osteoarthritis development in the knee. However, much larger numbers of knees (likely on the order of hundreds, if not thousands) need to be reliably analyzed to achieve the statistical power necessary to clarify this relationship. This study assessed the reliability of new semiautomated computational methods for estimating contact stress in knees from large population-based cohorts. Ten knees of subjects from the Multicenter Osteoarthritis Study were included. Bone surfaces were manually segmented from sequential 1.0 Tesla magnetic resonance imaging slices by three individuals on two nonconsecutive days. Four …

Training Dual-Task Walking In Community-Dwelling Adults Within 1 Year Of Stroke: A Protocol For A Single-Blind Randomized Controlled Trial, Prudence Plummer-D'Amato, Anastasia Kyvelidou, Dagmar Sternad, Bijan Najafi, Raymond M. Villalobos, David Zurakowski

Journal Articles

No abstract provided.

Supervised Resistance Training Results In Changes In Postural Control In Patients With Multiple Sclerosis, Jessie M. Huisinga, Mary Filipi, Nikolaos Stergiou

Journal Articles

Postural disturbances are one of the first reported symptoms in patients with Multiple Sclerosis (MS). The purpose of this study was to investigate the effect of supervised resistance training on postural control in MS patients. Postural control was assessed using amount of sway variability [Root Mean Square (RMS)] and temporal structure of sway variability [Lyapunov Exponent (LyE)] from 15 MS patients. Posture was evaluated before and after completion of three months of resistance training. There were significant differences between MS patients pretraining and healthy controls for both LyE (p = .000) and RMS (p = .002), but no differences between …

Football Helmet Fitment And Its Effect On Helmet Performance, Ron Jadischke

Wayne State University Theses

A method and system to objectively quantify helmet fitment was designed and developed. It measures the pressure between the energy-absorbing material in the helmet and the athlete's head. This system is also capable of measuring surface pressure during impact events. A volunteer-based field study was conducted to quantify how helmets were fitting athletes in a real-life setting. The helmets fit athletes in varying degrees of tightness and evenness. Most athletes (59%) had the highest pressures in the frontal area and 29% had the highest pressure in the occipital area. A large-sized helmet on the Hybrid III headform represented how most …

Contact Pressure Distribution Of Osteochondral Defects Of The Knee: Effects Of Non-Vertical Walls, Scott Ensminger

Wayne State University Theses

Purpose: To examine the relationship between well-shouldered osteochondral defects and

defects of different geometries by studying their effects on rim stress concentration and

load redistribution in the human knee.

Methods: Ten fresh-frozen cadaveric knees were mounted at 30° of flexion in a materials

testing machine. Digital electronic pressure sensors were placed in the medial and lateral

compartments of the knee. Dynamic pressure readings were recorded throughout the

loading and holding phases as each knee was loaded to 700N and held for 5 seconds.

Artificial defects were created in each knee to simulate well-shouldered defects and

beveled-defects. Loading was repeated for …

The Biomechanics Of Tongue Projection In The Frog _Rana Pipiens_: Dynamics And Temperature Effects, Paula Sandusky

USF Tampa Graduate Theses and Dissertations

Ectotherms such as frogs must either function within environments with temperatures amenable to their physiological needs, or find means to reduce the impact of temperature on their activities. Recent studies on reptile and amphibian feeding have shown convergent use of elastic recoil to drive feeding movements, thereby decoupling temperature's effects on muscle from movement and allowing the animals to feed over broader temperature ranges. Rana pipiens specimens (n=5) were exposed to three ambient temperatures (10°, 15°, and 25° C) at which feeding behavior was imaged at 6000 Hz. The image sequences yielded detailed kinematic and dynamic information for jaw, tongue, …

Variability Of Gait Is Dependent On Direction Of Progression: Implications For Active Control, Shane R. Wurdeman, Neil B. Huben

Journal Articles

Typical healthy walking displays greater variability in the mediolateral direction compared to the anteroposterior direction. This greater variability is thought to represent increased uncertainty in movement. As a result, it has been postulated that the mediolateral direction of gait requires more active control by the central nervous system while the anteroposterior direction is controlled through passive actions. However, this theory has only been tested on gait where progression occurs in the anteroposterior direction. Therefore, the purpose of this study was to investigate how the amount of variability is affected if progression occurs in the mediolateral direction using a lateral stepping …

Estimates Of Critical Power And Anaerobic Work Capacity From A Single, All-Out Test Of Less Than 3-Min, H C. Bergstrom, T J. Housh, Jorge M. Zuniga, C L. Camic, D A. Traylor, R W. Lewis, R J. Schmidt, G O. Johnson

Journal Articles

The purpose of this study was to determine if Critical Power (CP) and Anaerobic Work Capacity (AWC) could be estimated from a single, all-out test of less than 3-min. Twenty-eight subjects (mean ± SD: age 23.3 ± 3.3 years, body mass 71.6 ± 16 kg) performed an incremental cycle ergometer test to exhaustion to determine peak oxygen consumption rate and heart rate peak. The 3-min all-out test was used to determine the criterion and six estimated values of CP and AWC. The criterion critical power (CP180) and anaerobic work capacity (AWC180) values were determined from the 3-min all-out test and …

Computational Approaches To Understand Phenotypic Structure And Constitutive Mechanics Relationships Of Single Cells, Scott Wood

All Dissertations

The goal of this work is to better understand the relationship between the structure and function of biological cells by simulating their nonlinear mechanical behavior under static and dynamic loading using image structure-based finite element modeling (FEM). Vascular smooth muscle cells (VSMCs) are chosen for this study due to the strong correlation of the geometric arrangement of their structural components on their mechanical behavior and the implications of that behavior on diseases such as atherosclerosis.
VSMCs are modeled here using a linear elastic material model together with truss elements, which simulate the cytoskeletal fiber network that provides the cells with …

Endurance Markers Are Related With Local Neuromuscular Response For The Intact But Not For The Acl Reconstructed Leg During High Intensity Running, Kostas Patras, Giorgos Ziogas, Stavros Ristanis, Elias Tsepis, Vasilis Tsiaras, Nikolaos Stergiou, Anastasios D. Georgoulis

Journal Articles

AIM: It has been demonstrated that the local neuromuscular response during high intensity exercise has a strong relationship with endurance markers. However, a diminished neuromuscular response has been reported for the operated leg in athletes having undergone anterior cruciate ligament reconstruction (ACLR). The purpose of the present study was to examine the relationships between endurance markers and the EMG response during high intensity running in ACLR athletes. METHODS: Fourteen ACLR soccer players underwent a GXT test to volitional exhaustion and a 10-min bout of high intensity running. During the 10-min bout, EMG data were recorded at the 3rd …

From The W-Method To The Canonical-Dissipative Method For Studying Uni-Manual Rhythmic Behavior, Dobromir Dotov, Till D. Frank

Journal Articles

A novel method for the analysis of repetitive limb behavior oscillation is presented. It is based on a model used to account for self-sustained limit cycles that involve energy pumping compensating for dissipative processes. The experiment involved a uni-manual pendulum swinging task paced at five frequencies. The median frequency corresponded to the resonant one for the chosen pendulum and hand parameters. We applied the model-based analysis to explore the relationship between behavioral observables and model parameters not available from previous methods. Oscillation amplitude and energy, and motor variability were the behavioral observables we focused on while energy pumping, attractor strength, …

Human Movement Variability, Nonlinear Dynamics, And Pathology: Is There A Connection?, Nikolaos Stergiou, Leslie M. Decker

Journal Articles

Fields studying movement generation, including robotics, psychology, cognitive science, and neuroscience utilize concepts and tools related to the pervasiveness of variability in biological systems. The concept of variability and the measures for nonlinear dynamics used to evaluate this concept open new vistas for research in movement dysfunction of many types. This review describes innovations in the exploration of variability and their potential importance in understanding human movement. Far from being a source of error, evidence supports the presence of an optimal state of variability for healthy and functional movement. This variability has a particular organization and is characterized by a …

New Insights Into Anterior Cruciate Ligament Deficiency And Reconstruction Through The Assessment Of Knee Kinematic Variability In Terms Of Nonlinear Dynamics, Leslie M. Decker, Constantina O. Moraiti, Nikolaos Stergiou, Anastasios D. Georgoulis

Journal Articles

Purpose

Injuries to the anterior cruciate ligament (ACL) occur frequently, particularly in young adult athletes, and represent the majority of the lesions of knee ligaments. Recent investigations suggest that the assessment of kinematic variability using measures of nonlinear dynamics can provide with important insights with respect to physiological and pathological states. The purpose of the present article was to critically review and synthesize the literature addressing ACL deficiency and reconstruction from a nonlinear dynamics standpoint.

Methods

A literature search was carried out in the main medical databases for studies published between 1990 and 2010.

Results

Seven studies investigated knee kinematic …

Is There A Relationship Between Fatigue Questionnaires And Gait Mechanics In Persons With Multiple Sclerosis?, Jessie M. Huisinga, Mary Filipi, Kendra K. Schmid, Nikolaos Stergiou

Journal Articles

Objective: To evaluate reported fatigue levels and gait deficits in patients with multiple sclerosis (MS) to determine the relationships that may exist between fatigue in patients with MS and alterations in gait mechanics.

Design: Cross-sectional.

Setting: Biomechanics laboratory.

Participants: Subjects with MS (n=32) and age- and sex-matched controls (n=30).

Interventions: None.

Main Outcome Measures: Fatigue Severity Scale (FSS), Modified Fatigue Index Scale (MFIS), and 36-Item Short Form Health Survey (SF-36) to assess fatigue and general health. Biomechanical gait analysis was performed to measure peak joint torques and powers in the sagittal plane at the ankle, knee, and hip. Correlations …