Biomechanics Commons^™

Aging And Partial Body Weight Support Affects Gait Variability, Anastasia Kyvelidou, Max J. Kurz, Julie L. Ehlers, Nikolaos Stergiou

Journal Articles

Background: Aging leads to increases in gait variability which may explain the large incidence of falls in the elderly. Body weight support training may be utilized to improve gait in the elderly and minimize falls. However, before initiating rehabilitation protocols, baseline studies are needed to identify the effect of body weight support on elderly gait variability. Our purpose was to determine the kinematic variability of the lower extremities in young and elderly healthy females at changing levels of body weight support during walking.

Methods: Ten young and ten elderly females walked on a treadmill for two minutes with a body …

Development Of A Technique To Diagnose Subtalar Joint Instability, Ajaya Dhakal

Mechanical & Aerospace Engineering Theses & Dissertations

Most patients escape diagnosis of subtalar joint instability for years before treatment. Therefore, a clinically relevant technique to diagnose subtalar joint instability will improve its management. Towards this goal, a six degree of freedom positioning and loading device was developed to apply physiologic loads to the hindfoot. Because the ideal loading configuration to detect subtalar joint instability is unknown, the device was designed to apply rotational and translational forces simultaneously. Specifically, plantarflexion/dorsiflexion, inversion/eversion, and internal/external rotation can be applied individually or as coupled motions along with an anterior/posterior drawer. Kinematic data were collected from calcaneus, talus and tibia using a …

Experimental Analysis And Modeling Validation Of A Knee Brace In Shock Mitigation, Manish Prakash Dhekane

Mechanical & Aerospace Engineering Theses & Dissertations

An experimental setup simulating the dynamic environment in a high sea state is developed for the lower extremities to study the mitigation of shock impact. A single degree of freedom machine is equipped with six linear induction motors to produce impact acceleration ranging from 0.5G to 4G. The experiments are carried out along the dummy leg by using two configurations, one without a knee brace and one with a knee brace. Force and acceleration data is collected using a data acquisition system.

To develop the analytical model of the same experimental setup, the knee brace and dummy leg were scanned …

Nebraska Biomechanics Core Facilty 2007 Annual Report, Issue 6, Nebraska Biomechanics Core Facility

Biomechanics Annual Report

This issue features UNO Announces the Nebraska Biomechanics Core Facility (NBCF), Exciting Growth, This Project was FUN!, Tours!, Welcome and Hello! - Open House for Two Colleges, Laboratory Updates, Latest Developments, Other Global Connections, and Other Exciting News.

Effects Of Static And Dynamic Flexibility Protocols On Lower Extremity Range Of Motion, Samar K. Mccann

Human Movement Studies & Special Education Theses & Dissertations

The purpose of this study was to compare the effects of either a dynamic or static stretching protocol on range of motion during hip flexion, hip extension, and hip abduction, knee flexion and extension, and ankle dorsiflexion over time. Forty eight physically active participants, 18 males and 30 females (age=21.77±2.77 years, height=l66.60±1 l.70 cm, mass=75.08±16.99 kg) with no history of injury within the last month to the lower extremity, no previous surgery in the lower extremity in the past six months, and a previous experience with both types of stretching protocols volunteered for the study. Each subject performed both stretching …

Measuring Bite Force In Small Mammals With A Piezo-Resistive Sensor, Patricia W. Freeman, Cliff A. Lemen

University of Nebraska State Museum: Mammalogy Papers

We tested the use of piezo-resistive force sensors to measure bite force in small mammals. These force sensors are thin (less than 1 mm) and can be used to measure forces up to 4,500 N. A battery-operated unit, ideal for field research, can be built easily and inexpensively. We tested this sensor in the laboratory and in the field on a variety of small mammals. Although our results indicate that the sensor is somewhat less accurate (coefficient of variation = 4%) than a conventional load cell, the small size and ease of use of the piezo-resistive detector is highly desirable. …

Statistical Approach To The Characterization And Recognition Of Human Gaits, Derrick M. Chelliah

Theses and Dissertations

This thesis addresses the final portion of a complete process for human gait recognition. The thesis takes as input information that has been generated from videotaping walking individuals and converting their gaits into numerical data that measures the locations of various points on the body through time. Beginning with this data, this thesis uses a variety of mathematical and statistical methods to create identifying signatures for each individual and identify them on the basis of that signature. The end goal is to achieve under controlled laboratory conditions human gait recognition, an identification method which does not require contact or cooperation …

Claudication Distances And The Walking Impairment Questionnaire Best Describe The Ambulatory Limitations In Patients With Symptomatic Peripheral Arterial Disease, Sara A. Myers, Jason Johanning, Nikolaos Stergiou, Thomas G. Lynch, G. Matthew Longo, Iraklis Pipinos

Journal Articles

Background

Claudication secondary to peripheral arterial disease leads to reduced mobility, limited physical functioning, and poor health outcomes. Disease severity can be assessed with quantitative clinical methods and qualitative self-perceived measures of quality of life. Limited data exist to document the degree to which quantitative and qualitative measures correlate. The current study provides data on the relationship between quantitative and qualitative measures of symptomatic peripheral arterial disease.

Method

This descriptive case series was set in an academic vascular surgery unit and biomechanics laboratory. The subjects were symptomatic patients with peripheral arterial disease patients presenting with claudication. The quantitative evaluation outcome …

Enhanced Robotic Surgical Training Using Augmented Visual Feedback, Timothy N. Judkins, D. Oleynikov, Nikolaos Stergiou

Journal Articles

The goal of this study was to enhance robotic surgical training via real-time augmented visual feedback. Thirty novices (medical students) were divided into 5 feedback groups (speed, relative phase, grip force, video, and control) and trained during 1 session in 3 inanimate surgical tasks with the da Vinci Surgical System. Task completion time, distance traveled, speed, curvature, relative phase, and grip force were measured immediately before and after training and during a retention test 2 weeks after training. All performance measures except relative phase improved after training and were retained after 2 weeks. Feedback-specific effects showed that the speed group …

Medicine Meets Virtual Reality 16, James D. Westwood, B. Brown-Clerk, K.-C. Siu, D. Kastavelis, I. Lee, D. Oleynikov, Nikolaos Stergiou

Faculty Books and Monographs

Chapter, Validating Advanced Robot-Assisted Laparoscopic Training Task in Virtual Reality, co-authored by Nicholas Stergiou, UNO faculty member.

We humans are tribal, grouping ourselves by a multitude of criteria: physical, intellectual, political, emotional, etc. The Internet and its auxiliary technologies have enabled a novel dimension in tribal behavior during our recent past. This growing connectivity begs the question: will individuals and their communities come together to solve some very urgent global problems? At MMVR, we explore ways to harness information technology to solve healthcare problems – and in the industrialized nations we are making progress. In the developing world however, things …

Evidence Of Self-Correcting Spiral Flows In Swimming Boxfishes, I. K. Bartol, M. S. Gordon, P. Webb, D. Weihs, M. Gharib

Biological Sciences Faculty Publications

The marine boxfishes have rigid keeled exteriors (carapaces) unlike most fishes, yet exhibit high stability, high maneuverability and relatively low drag given their large cross-sectional area. These characteristics lend themselves well to bioinspired design. Based on previous stereolithographic boxfish model experiments, it was determined that vortical flows develop around the carapace keels, producing self-correcting forces that facilitate swimming in smooth trajectories. To determine if similar self-correcting flows occur in live, actively swimming boxfishes, two species of boxfishes (Ostracion meleagris and Lactophrys triqueter) were induced to swim against currents in a water tunnel, while flows around the fishes were quantified …

Swimming Dynamics And Propulsive Efficiency Of Squids Throughout Ontogeny, Ian K. Bartol, Paul S. Krueger, Joseph T. Thompson, William J. Stewart

Biological Sciences Faculty Publications

Synopsis Squids encounter vastly different flow regimes throughout ontogeny as they undergo critical morphological changes to their two locomotive systems: the fins and jet. Squid hatchlings (paralarvae) operate at low and intermediate Reynolds numbers (Re) and typically have rounded bodies, small fins, and relatively large funnel apertures whereas juveniles and adults operate at higher Re and generally have more streamlined bodies, larger fins, and relatively small funnel apertures. These morphological changes and varying flow conditions affect swimming performance in squids. To determine how swimming dynamics and propulsive efficiency change throughout ontogeny, digital particle image velocimetry (DPIV) and kinematic …

Stepping Over Obstacles Of Different Heights And Varied Shoe Traction Alter The Kinetic Strategies Of The Leading Limb, Jeremy J. Houser, Leslie M. Decker, Nikolaos Stergiou

Journal Articles

This study aims to investigate the effects of shoe traction and obstacle height on friction during walking to better understand the mechanisms required to avoid slippage following obstacle clearance. Ten male subjects walked at a self-selected pace during eight different conditions: four obstacle heights (0%, 10%, 20%, and 40% of limb length) while wearing two different pairs of shoes (low and high traction). Frictional forces were calculated from the ground reaction forces following obstacle clearance, which were sampled with a Kistler platform at 960 Hz. All frictional peaks increased with increases in obstacle height. Low traction shoes yielded smaller peaks …