Biomechanics Commons^™

Coordination Of Swimbench Freestyle In Elite And Non-Elite Swimmers: A Dynamical System Approach, Tracy H. Spigelman

University of Kentucky Doctoral Dissertations

Elite swimmers can be distinguished from novice swimmers by freestyle stroke technique. Elite swimmers move through multiple coordination modes, increases in stroke lengths, stroke rates, and body roll allowing for a more symmetrical stroke and increased speed compared with novice swimmer during 100m freestyle.

Coaches strive to improve swimmers’ performance by providing feedback about stroke technique, mostly from the pool deck where view of the full stroke cycle is obstructed by the water. Tools to assess swimming are often expensive and require extra training, which does not provide a pragmatic solution. A dryland rotational swimbench would provide a means to …

Electromyographic Response Is Altered During Robotic Surgical Training With Augmented Feedback, Timothy N. Judkins, D. Oleynikov, Nikolaos Stergiou

Journal Articles

There is a growing prevalence of robotic systems for surgical laparoscopy. We previously developed quantitative measures to assess robotic surgical proficiency, and used augmented feedback to enhance training to reduce applied grip force and increase speed. However, there is also a need to understand the physiological demands of the surgeon during robotic surgery, and if training can reduce these demands. Therefore, the goal of this study was to use clinical biomechanical techniques via electromyography (EMG) to investigate the effects of real-time augmented visual feedback during short-term training on muscular activation and fatigue. Twenty novices were trained in three inanimate surgical …

Peripheral Arterial Disease Affects Kinematics During Walking, Ronaldo Celis, Iraklis Pipinos, Melissa Scott-Pandorf, Sara A. Myers, Nikolaos Stergiou, Jason Johanning

Journal Articles

Objective: Claudication is the most common manifestation of peripheral arterial disease (PAD) producing significant ambulatory compromise. The purpose of this study was to use advanced biomechanical analysis to characterize the kinematic ambulatory pattern of claudicating patients. We hypothesized that compared with control subjects, claudicating patients have altered kinematic gait patterns that can be fully characterized utilizing advanced biomechanical analysis.

Methods: The study examined fourteen PAD patients (age: 58 ± 3.4 years; weight: 80.99 ± 15.64 kg) with clinically diagnosed femoro-popliteal occlusive disease (Ankle Brachial Index (ABI): 0.56 ± 0.03, range 0.45 to 0.65) and five healthy controls (age: 53 ± …

Effects Of Augmented Real-Time Auditory Feedback On Top-Level Precision Shooting Performance, Stacy Marie Underwood

University of Kentucky Master's Theses

This study examined the effects of training with real-time auditory feedback in precision shooting. Top-level shooters (N=9) were randomly assigned to the feedback or nonfeedback group. Each group performed a pre-test, a 4-week training intervention and a post-test. The feedback group was provided with augmented real-time auditory feedback based on postural and rifle barrel stability during training sessions. Increases in performance were measured through changes in postural stability, rifle barrel stability, shot outcome and shot group diameter. Real-time auditory feedback did not increase postural or rifle barrel stability in the feedback group. No meaningful differences were found related to shot …

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 …

Effects Of Knee Bracing On Vertical Jumping Performance In Healthy College Aged Males, Rebecca E. Rausch

All-Inclusive List of Electronic Theses and Dissertations

Knee bracing is used at all levels of athletics to prevent or support existing knee injuries; however, little research has been conducted on the effects of knee braces on athletic performance. Therefore, the purpose of this study was to examine how two different types of knee braces, semi-customizable braces and knee sleeves, affect vertical jumping performance. Subjects were nine college aged males who regularly participated in athletic activity. Subjects performed a task consisting of a drop jump from a height of 18 inches, landing in a squat position, followed immediately by a maximal vertical jump while wearing two different knee …

Effects Of An Angled Starting Block On Sprint Start Kinematics, Nathaniel A. Brown

All-Inclusive List of Electronic Theses and Dissertations

The purpose of the present study was to investigate the effects of an angled proto-type starting block on sprint start kinematics. The angled starting block rotates the foot medially at a 16 degree angle, which emulates the 16 degree angle of the ankle on the medial axis of the foot. This 16 degree should allow for the athlete to apply more force against the block, resulting in a higher velocity at take-off and a faster block clearance time. In the present study, six female collegiate sprinters were filmed and analyzed using the angled starting block and a standard starting block. …

Acl Deficiency Affects Stride-To-Stride Variability As Measured Using Nonlinear Methodology, Constantina O. Moraiti, Nikolaos Stergiou, Stavros Ristanis, Anastasios D. Georgoulis

Journal Articles

Previous studies suggested that the small fluctuations present in movement patterns from one stride to the next during walking can be useful in the investigation of various pathological conditions. Previous studies using nonlinear measures have resulted in the development of the “loss of complexity hypothesis” which states that disease can affect the variability and decrease the complexity of a system, rendering it less able to adjust to the ever changing environmental demands. The nonlinear measure of the Lyapunov Exponent (LyE) has already been used for the assessment of stride-to-stride variability in the anterior cruciate ligament (ACL) deficient knee in comparison …

Approximate Entropy Detects The Effect Of A Secondary Cognitive Task On Postural Control In Healthy Young Adults: A Methodological Report, James T. Cavanaugh, Vicki S. Mercer, Nikolaos Stergiou

Journal Articles

Background: Biomechanical measures of postural stability, while generally useful in neuroscience and physical rehabilitation research, may be limited in their ability to detect more subtle influences of attention on postural control. Approximate entropy (ApEn), a regularity statistic from nonlinear dynamics, recently has demonstrated relatively good measurement precision and shown promise for detecting subtle change in postural control after cerebral concussion. Our purpose was to further explore the responsiveness of ApEn by using it to evaluate the immediate, short-term effect of secondary cognitive task performance on postural control in healthy, young adults.

Methods: Thirty healthy, young adults performed a modified version …

Peripheral Arterial Disease Affects Ground Reaction Forces During Walking, Melissa Scott-Pandorf, Nikolaos Stergiou, Jason Johanning, Leon Robinson, Thomas G. Lynch, Iraklis Pipinos

Journal Articles

Objective: Claudication is the most common manifestation of peripheral arterial disease (PAD), producing significant ambulatory compromise. The gait of claudicating patients has been evaluated using primarily temporal and spatial parameters. With the present study, we used advanced biomechanical measures to further delineate the ambulatory impairment of claudicating patients. We hypothesized that the claudicating legs of PAD patients have an altered kinetic gait pattern compared with normal legs from control subjects.

Methods: Ambulation kinetics (ground reaction forces) were evaluated in claudicating patients and compared with age-matched healthy controls. Forces were analyzed in the vertical, anterior–posterior, and medial–lateral directions. Time from heel …

Do Horizontal Propulsive Forces Influence The Nonlinear Structure Of Locomotion?, Max J. Kurz, Nikolaos Stergiou

Journal Articles

Background: Several investigations have suggested that changes in the nonlinear gait dynamics are related to the neural control of locomotion. However, no investigations have provided insight on how neural control of the locomotive pattern may be directly reflected in changes in the nonlinear gait dynamics. Our simulations with a passive dynamic walking model predicted that toe-off impulses that assist the forward motion of the center of mass influence the nonlinear gait dynamics. Here we tested this prediction in humans as they walked on the treadmill while the forward progression of the center of mass was assisted by a custom built …

Fabrication Of Ankle-Foot Orthoses Using Selective Laser Sintering Technology, Allison Kinney, M. C. Faustini, Richard R. Neptune, R. H. Crawford, S. J. Stanhope

Mechanical and Aerospace Engineering Faculty Publications

Passive dynamic ankle-foot orthoses (AFOs) are often prescribed to improve gait performance for those with various neuromuscular disorders. Designs and materials used for AFOs range from simple polypropylene braces to advanced custom carbon fiber dynamic AFOs that passively store and release mechanical energy during gait. AFO designs vary in the shape and length of the foot component as well as the stiffness and length of the tibial component, depending on the desired functional outcomes. However, the current fabrication technology is not ideally suited for refined customization of AFO characteristics to optimize performance, or for rapid lowcost, high volume manufacturing and …

Development And Analysis Of A Software Package To Quantify In Vivo Polyethylene Wear After Total Hip Arthroplasty, Allison Kinney, Catherine G. Ambrose

Mechanical and Aerospace Engineering Faculty Publications

Since the first total hip arthroplasty (THA) in 1938, THA evolved and developed into one of the major concentrations of orthopaedic research. The typical hip implant device used today incorporates a femoral and an acetabular component that serve to replicate the anatomical and mechanical functions of the natural hip joint. However, several problems exist that can effect the function of the implant device. Wear in the polyethylene liner of the acetabular component of the total hip replacement device is known as one of the major factors that affects the longevity of total hip replacement devices. Both manual and computer-aided techniques …

Tibial Rotation In Anterior Cruciate Ligament (Acl)-Deficient And Acl-Reconstructed Knees, Nikolaos Stergiou, Stavros Ristanis, Constantina O. Moraiti, Anastasios D. Georgoulis

Journal Articles

Excessive tibial rotation has been documented in ACL deficiency during walking. ACL reconstruction has been unable to correct this abnormality in activities that are more demanding than walking and involve both anterior and rotational loading of the knee. These findings persist regardless of graft selection for the ACL reconstruction [bone-patellar tendon-bone (BPTB) or semitendinosus-gracilis (ST/G)]. Based on this research work, we propose a theoretical perspective for the development of osteoarthritis in both the ACL deficient and the ACL reconstructed knee. We propose that excessive tibial rotation will lead to abnormal loading of the cartilage areas that are not commonly loaded …

Hper Biomechanics Laboratory 2006 Annual Report, Issue 5, Nebraska Biomechanics Core Facility

Biomechanics Annual Report

This issue features Peripheral Arterial Disease and Geriatrics Research Update, Lab Expands with New Personnel, Labor on NIH Grant Is, “Gratifying Labor” States Dr. Stergiou, Federal Grant On Cerebral Palsy: Joint Venture Demonstrates Progress, Evolution of Wireless Gait Analysis, Innovations of Robotic Assisted Surgery Research, Incorporating Virtual Reality, Events in the Lab, Dr. Stergiou Awarded Outstanding Graduate Mentor , Collaborations in Orthopedics, The Media Features Efforts in HPER Biomechanics Lab , Other Continuing Collaborations, Other Exciting News, Publications for 2006 and The 2006-2007 HPER Biomechanics Laboratory.

Methods To Improve The Reliability Of The Functional Reach Test In Children And Adolescents With Typical Development, Kathleen G. Volkman, Nikolaos Stergiou, Wayne A. Stuberg, Daniel Blanke, Julie Stoner

Journal Articles

Purpose: Test-retest reliability of the Functional Reach Test was examined in children with typical development by comparing standard and alternate methods.

Methods: Eighty subjects ages seven to 16 years were tested and 69 retested for four methods of Functional Reach Test (ie, one-arm finger-to-finger, two-arm finger-to-finger, one-arm toe-to-finger, and two-arm toe-to-finger). Intraclass correlation coefficients and limits of agreement were calculated.

Results: Intraclass correlation coefficients were high in toe-to-finger measurement methods (0.97– 0.98) for the entire group and specific age groups (00.83–0.93). Toe-to-finger methods were more reliable than finger-to-finger methods. The two-arm toe-to-finger method had the best limis of agreement with …

Herodicus, The Father Of Sports Medicine, Anastasios D. Georgoulis, Irini-Sofia Kiapidou, Lamprini Velogianni, Nikolaos Stergiou, Arthur Boland

Journal Articles

Herodicus (fifth century bc) is the first person in the history of medicine who actually combined sports with medicine. He used to be a sports teacher, who later studied medicine and managed to succeed Euryphon in the medical school of Cnidos, one of the most prominent in ancient Greece together with its neighbor medical school of Cos (Hippocrates’ home). In Cnidos Herodicus formed his own theoretical perspective of medicine. He considered, namely, bad health to be the result of imbalance between diet and physical activity and for this reason he recommended strict diet, constant physical activity and regular training. He …

High Dietary Fat Intake Is Not Associated With High Levels Of Circulating Lipoproteins Or Total Cholesterol, C. Jayne Brahler, C. Wilson, Janine Baer

Physical Therapy Faculty Publications

The objective of this study was to determine the association between dietary intake of fats, waist to hip ratio (WHR), body mass index (BMI), and blood lipoproteins and total cholesterol (TC) using food frequency data in one group of apparently healthy, urban African American women and their daughters (n = 110). Subjects were fasted when blood was drawn, waist and hip circumferences and body weight and height were measured, and WHR and BMI were calculated.

Average daily total fat intakes were 91.46 g and 77.83 g for mothers and daughters, respectively, but average LDL levels of 104.4 g/L and 103.1 …