Biomechanics Commons^™

Age-Related Differences In Motor Performance, Jessica Anne Prebor

Rehabilitation Sciences Theses & Dissertations

The purpose of this work was to study the age effects on average performance and variability of movement responses in children, young adults, and older adults across multiple motor tasks. Optimal motor performance is observed in healthy young adults with declines observed at either end of the lifespan. This pattern has been represented as a U-shaped/inverted U-shaped curve. Little is known about if this pattern persists in chewing dynamics. While chewing has been found to improve aspects of attention, a cognitive function, research is limited on the relationship between chewing and other motor tasks.

The first aim of this research …

Obstacle Crossing In Healthy Young And Older Individuals, Hope M. Hanson, Ashlyn M. Jendro, Abigail C. Schmitt

Health, Human Performance and Recreation Undergraduate Honors Theses

Introduction: In the United States, the average population age is rising and will continue to increase in the coming years.With an older population comes increased risk of injury associated with falls. Falls are considered a leading cause of injury and death in older individuals, and many falls are caused by body imbalance or obstacle collision due to a clearly visible stationary object (e.g., rug, chair, branch). Older adults tend to cross obstacles with increased toe clearance in order to prevent tripping, but much of what is known about obstacle crossing in older adults is limited to artificial obstacles that are …

A Biomechanical Approach To Prevent Falls In Ergonomic Settings, Sachini Kodithuwakku Arachchige

Theses and Dissertations

Introduction: Fall-related injuries are exceptionally prevalent in occupational settings. While endangering the workers’ health, falls cause poor productivity and increased economic burden in the workplace. Hence, identifying these threats and training workers to achieve proper postural control is crucial. Purpose: Study 1: To investigate the ankle joint kinematics in unexpected and expected trip responses during single-tasking (ST), dual-tasking (DT), and triple-tasking (TT), before and after a physically fatiguing exercise. Study 2: To investigate the impact of virtual heights, DT, and training on static postural stability and cognitive processing. Methods: Study 1: Twenty collegiate volunteers (10 males and females, one left …

Electromechanical Fatigue Properties Of Dielectric Elastomer Stretch Sensors Under Orthopaedic Loading Conditions, Andrea Karen Persons

Theses and Dissertations

Fatigue testing of stretch sensors often focuses on high amplitude, low-cycle fatigue (LCF) behavior; however, when used for orthopaedic, athletic, or ergonomic assessments, stretch sensors are subjected to low amplitude, high-cycle fatigue (HCF) conditions. As an added layer of complexity, the fatigue testing of stretch sensors is not only focused on the life of the material comprising the sensor, but also on the reliability of the signal produced during the extension and relaxation of the sensor. Research into the development of a smart sock that can be used to measure the range of motion (ROM) of the ankle joint during …

Full-Body Biomechanical Characterization Of Children With Hypermobile Ehlers-Danlos Syndrome During Gait And Activities Of Daily Living, Anahita Alahmoradiqashqai

Theses and Dissertations

Hypermobile Ehlers-Danlos syndrome (hEDS) is an inherited connective tissue disorder, often under-diagnosed, and presenting with frequent chronic pain and severe musculoskeletal symptoms that can drastically reduce the quality of life during one’s life span. While there are limited quantitative approaches in the literature on adult movements, the biomechanics of movements during activities of daily living (ADLs) in children have not been investigated comprehensively. Therefore, the primary purpose of this dissertation was to characterize the biomechanics of the musculoskeletal system and investigate the biomechanics of hEDS by quantifying joint dynamics and muscle activations during ADLs and gait in the pediatric population. …

Characterizing Locomotor Disturbance Perception In Young Adults, Daniel James Liss

Graduate Theses, Dissertations, and Problem Reports

Falls during walking are a leading cause of injuries across aging. Many of these falls are due to slips and trips. The ability to perceive disturbances to ongoing motion may play an important role in the control of walking balance. However, disturbance perception has been investigated in standing balance, but its role in walking balance due to slip- and trip-like disturbances remains largely unknown. Characterizing locomotor disturbance perception in young adults may lead to a more comprehensive understanding of sensorimotor walking balance control.

This work defined locomotor disturbance perception in response to slip and trip-like disturbances in young adults. We …

Description, Reliability And Validation Of A Novel Ground-Reaction-Force-Triggered Protocol For Simulation Of Tripping Perturbations During Gait, James Anderson, Samuel Hadley, Denise Ng, Catrina Fabian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Tripping is a common cause of falls across different age populations particularly in older adults. Concerns regarding the validity of simulated-fall research protocols reside in the current literature. The purpose of this study was to develop a novel treadmill-based tripping protocol that allowed researchers to deliver unanticipated tripping perturbations during walking with a high level of timing precision. The protocol utilized a side-by-side split-belt treadmill instrumented with force platforms. Treadmill belt acceleration profiles (two levels of perturbation severity: small perturbation vs large perturbation) were delivered unilaterally when the tripped leg bore 20% of the body weight during early stance. Peak …

An Emg Optimization Model Of The Kinetic Demands On The Lower Back During Asymmetrical Gait And Load Carriage, Jacob J. Banks

Doctoral Dissertations

Gait asymmetries are associated with a high incidence of lower back pain (LBP). Although there are several causes of gait asymmetry (i.e. amputation, injury, or deformities), lower back kinetic demands have not been quantified and suitably compared due to experimental limitations in these clinical populations. Further, the impact of gait asymmetry on lower back demands during carrying tasks has not been established. This dissertation addressed these issues by artificially and safely inducing gait asymmetry in healthy able-bodied participants during walking and carrying tasks. LBP risk was assessed by L5/S1 vertebral joint force levels estimated with an OpenSim musculoskeletal model of …

Current Recommendations For Lower Body Aerobic Exercise In Chronic Unilateral Stroke - A Systematic Review, Jordan N. Brown

Electronic Theses and Dissertations

Background: Chronic stroke patients (i.e., > six months since the onset of stroke) continue to experience persistent gait complications. Once formal physical therapy concludes, exercise professionals can implement exercise interventions designed to improve quality of life and reduce risk of secondary stroke. This systematic review aimed to evaluate whether lower-body aerobic exercise transferred to gait improvements in chronic unilateral stroke. Methods: An electronic search of the following databases were undertaken: MEDLINE, CINHAL, Ovid, and SPORTdiscus. Two independent reviewers selected articles using predetermined inclusion criteria: adults (i.e., >18 years old) who suffered from a chronic unilateral stroke. Additionally, all included studies were …

Laboratory Versus Daily Life Gait Characteristics In Patients With Multiple Sclerosis, Parkinson’S Disease, And Matched Controls, Vrutangkumar V. Shah, James Mcnames, Martina Mancini, Patricia Carlson-Kuhta, Rebecca I. Spain, John G. Nutt, Mahmoud El-Gohary, Carolin Curtze, Fay B. Horak

Journal Articles

Background and purpose

Recent findings suggest that a gait assessment at a discrete moment in a clinic or laboratory setting may not reflect functional, everyday mobility. As a step towards better understanding gait during daily life in neurological populations, we compared gait measures that best discriminated people with multiple sclerosis (MS) and people with Parkinson’s Disease (PD) from their respective, age-matched, healthy control subjects (MS-Ctl, PD-Ctl) in laboratory tests versus a week of daily life monitoring.

Methods

We recruited 15 people with MS (age mean ± SD: 49 ± 10 years), 16 MS-Ctl (45 ± 11 years), 16 people with …

Impact Of Parity On Gait Biomechanics, Bekah P. Stein

Masters Theses

Background: Symptomatic knee osteoarthritis (OA) is an incurable condition that affects nearly 50% of adults, and women are twice as likely as men to develop OA. Throughout pregnancy, women experience large changes in morphology and gait mechanics, as well as changes in joint loading. It is possible these adaptations could cause lasting changes postpartum, which may potentially contribute to initiation of OA, thereby increasing the overall risk of OA for women.

Purpose: This exploratory study looked to identify differences between lower limb gait mechanics of healthy nulliparous women and healthy parous women.

Methods: 28 healthy female participants (14 parous, 14 …

To Walk Or To Run – A Question Of Movement Attractor Stability, Peter C. Raffalt, Jenny A. Kent, Shane R. Wurdeman, Nicholas Stergiou

Journal Articles

During locomotion, humans change gait mode between walking and running as locomotion speed is either increased or decreased. Dynamical systems theory predicts that the self-organization of coordinated motor behaviors dictates the transition from one distinct stable attractor behavior to another distinct attractor behavior (e.g. walk to run or vice versa) as the speed is changed. To evaluate this prediction, the present study investigated the attractor stability of walking and running across a range of speeds evoking both self-selected gait mode and non-self-selected gait mode. Eleven subjects completed treadmill walking for 3 min at 0.89, 1.12, 1.34, 1.56, 1.79, 2.01, 2.24 …

Features Of Acceleration And Angular Velocity Using Thigh Imus During Walking In Water, Koichi Kaneda, Yuji Ohgi, Mark Mckean, Brendan Burkett

International Journal of Aquatic Research and Education

Ten participants were assessed while walking in water and on land with wearable inertial measurement units (IMUs) attached to the right thigh. Longitudinal acceleration, anterior-posterior acceleration, and frontal axis angular velocity were measured at 100 Hz, matched with video analysis sampled at 25 Hz during the walking trials. The longitudinal acceleration showed almost 1 g from initial heel contact to 70% of one cycle, and the anterior-posterior acceleration showed a sinusoidal pattern, synchronizing the approximate posture of the thigh in water. The frontal axis angular velocity fluctuated less while walking in water compared with on land, because thigh motion speed …

Step Width Variability As A Discriminator Of Age-Related Gait Changes, Andreas Skiadopoulos, Emily E. Moore, Harlan Sayles, Kendra K. Schmid, Nicholas Stergiou

Journal Articles

Background

There is scientific evidence that older adults aged 65 and over walk with increased step width variability which has been associated with risk of falling. However, there are presently no threshold levels that define the optimal reference range of step width variability. Thus, the purpose of our study was to estimate the optimal reference range for identifying older adults with normative and excessive step width variability.

Methods

We searched systematically the BMC, Cochrane Library, EBSCO, Frontiers, IEEE, PubMed, Scopus, SpringerLink, Web of Science, Wiley, and PROQUEST databases until September 2018, and included the studies that measured step width variability …

The Influence Of Over-Ground Versus Treadmill Walking On Gait Mechanics In Children With Autism Spectrum Disorder, Emily Ann Chavez

Open Access Theses & Dissertations

Treadmill (TM) walking may be a way to combat obesity and socio-behavioral barriers associated with children with Autism Spectrum disorder (ASD), though tripping-risk has not yet been assessed for this population through use of spatial-temporal gait analysis. The aim of this project/study was to examine spatial-temporal walking mechanics and lower extremity tripping descriptors between over ground (OG) and TM gait conditions in children with ASD compared to children with neurotypical development (NT). Kinematics data were obtained through tridimensional motion analysis where participants, 10 children with ASD and 9 age- and sexmatched NT controls, were outfitted with retroreflective markers on their …

Biomechanics And Neural Control Of Movement: Cmi's Effects On Downstream Motor Processing And Gait In Forwards And Backwards Walking, Christopher Choi

CMC Senior Theses

Analyzing the effects of cognitive motor interferences (CMI) on walking is usually done in patients with neurological comorbidity or during forward walking (FW). However, there are few studies that examine gait differences between FW and backward walking (BW) under the presence of CMI when speed is kept constant on a treadmill. In this study we examined how CMI would disrupt sensory feedback and affect the descending motor pathway. We hypothesized that subjects that walked backwards and were given a cognitive task would show the greatest differences in gait due to a lack of visual input and the presence of CMI. …

Locomotor Patterns Change Over Time During Walking On An Uneven Surface, Jenny A. Kent, Joel H. Sommerfeld, Mukul Mukherjee, Kota Z. Takahashi, Nicholas Stergiou

Journal Articles

During walking, uneven surfaces impose new demands for controlling balance and forward progression at each step. It is unknown to what extent walking may be refined given an amount of stride-to-stride unpredictability at the distal level. Here, we explored the effects of an uneven terrain surface on whole-body locomotor dynamics immediately following exposure and after a familiarization period. Eleven young, unimpaired adults walked for 12 min on flat and uneven terrain treadmills. The whole-body center of mass excursion range (COM_exc) and peak velocity (COM_vel), step length and width were estimated. On first exposure to uneven terrain, …

Walking For Object Transport: An Examination Of The Coordinative Adaptations To Locomotor, Perceptual, And Manual Task Constraints, Avelino Amado

Doctoral Dissertations

The goal of this dissertation was to understand how the intrinsic dynamics of gait adapt to support the performance of an ecologically relevant object transport task. A common object transport task is walking with a cup of water. Because the water can move relatively independent of the cup, the cup and water system is classified as a complex object. To model this task participants carried a cup with a wooden lid placed on top. On the lid there was a circular region with the same circumference as the cup and a ball. The object of the task was to keep …

An Altered Spatiotemporal Gait Adjustment During A Virtual Obstacle Crossing Task In Patients With Diabetic Peripheral Neuropathy, Chun-Kai Huang, Vijay Shivaswamy, Pariwat Thaisetthawatkul, Lynn Mack, Nicholas Stergiou, Ka-Chun Siu

Journal Articles

This study investigates spatiotemporal gait adjustments that occur while stepping over virtual obstacles during treadmill walking in people with/without diabetic peripheral neuropathy (DPN). Eleven adults with Type 2 diabetes mellitus, ten DPN, and 11 age-matched healthy adults (HTY) participated in this study. They stepped over forthcoming virtual obstacles during treadmill walking. Outcomes such as success rate, spatiotemporal gait characteristics during obstacle crossing, and correlations between these variables were evaluated. The results partially supported our hypotheses that when comparing with HTY and DM, people with DPN adopted a crossing strategy which decreased obstacle crossing success rate and maximal toe elevation, …

Uneven Terrain Exacerbates The Deficits Of A Passive Prosthesis In The Regulation Of Whole Body Angular Momentum In Individuals With A Unilateral Transtibial Amputation, Jenny A. Kent, Kota Z. Takahashi, Nicholas Stergiou

Journal Articles

Background

Uneven ground is a frequently encountered, yet little-studied challenge for individuals with amputation. The absence of control at the prosthetic ankle to facilitate correction for surface inconsistencies, and diminished sensory input from the extremity, add unpredictability to an already complex control problem, and leave limited means to produce appropriate corrective responses in a timely manner. Whole body angular momentum, L, and its variability across several strides may provide insight into the extent to which an individual can regulate their movement in such a context. The aim of this study was to explore L in individuals with a transtibial amputation, …

Stride-Time Variability Is Related To Sensorimotor Cortical Activation During Forward And Backward Walking, Boman Groff, Prokopios Antonellis, Kendra K. Schmid, Brian Knarr, Nicholas Stergiou

Journal Articles

Previous research has used functional near-infrared spectroscopy (fNIRS) to show that motor areas of the cortex are activated more while walking backward compared to walking forward. It is also known that head movement creates motion artifacts in fNIRS data. The aim of this study was to investigate cortical activation during forward and backward walking, while also measuring head movement. We hypothesized that greater activation in motor areas while walking backward would be concurrent with increased head movement. Participants performed forward and backward walking on a treadmill. Participants wore motion capture markers on their head to quantify head movement and pressure …

Walking Biomechanics And Energetics Of Individuals With A Visual Impairment: A Preliminary Report, Hunter J. Bennett, Kevin A. Valenzuela, Kristina Fleenor, Steven Morrison, Justin A. Haegele

Human Movement Sciences Faculty Publications

Purpose.

Although walking gait in sighted populations is well researched, few studies have investigated persons with visual impairments (VIs). Given the lack of physical activity in people with VIs, it is possible that reduced efficiency in walking could adversely affect activity. The purposes of this preliminary study were to (1) examine the biomechanics and energetics utilized during independent and guided walking in subjects with VIs, and (2) compare gait biomechanics between people with VIs and sighted controls.

Methods.

Three-dimensional motion capture and force platforms were used during independent and guided walking at self-selected speeds. Joint angles, moments, external work, and …

Sampling Frequency Influences Sample Entropy Of Kinematics During Walking, Peter C. Raffalt, John D. Mccamley, William Denton, Jennifer M. Yentes

Journal Articles

Sample entropy (SaEn) has been used to assess the regularity of lower limb joint angles during walking. However, changing sampling frequency and the number of included strides can potentially affect the sample entropy. The present study investigated the effect of sample frequency and the number of included strides on the calculations of SaEn in joint angle signals recorded during treadmill walking. Eleven subjects walked at their preferred walking speed for 10 minutes, and SaEn was calculated on sagittal plane hip, knee and ankle angle signals extracted from 50, 100, 200, 300 and 400 strides at sampling frequencies of 60, 120, …

On The Calculation Of Sample Entropy Using Continuous And Discrete Human Gait Data, John D. Mccamley, William Denton, Peter C. Raffalt, Jennifer M. Yentes

Journal Articles

Sample entropy (SE) has relative consistency using biologically-derived, discrete data >500 data points. For certain populations, collecting this quantity is not feasible and continuous data has been used. The effect of using continuous versus discrete data on SE is unknown, nor are the relative effects of sampling rate and input parameters m (comparison vector length) and r(tolerance). Eleven subjects walked for 10-minutes and continuous joint angles (480 Hz) were calculated for each lower-extremity joint. Data were downsampled (240, 120, 60 Hz) and discrete range-of-motion was calculated. SE was quantified for angles and range-of-motion at all sampling rates and multiple combinations …

Gait Asymmetry In People With Parkinson’S Disease Is Linked To Reduced Integrity Of Callosal Sensorimotor Regions, Brett W. Fling, Carolin Curtze, Fay B. Horak

Journal Articles

Background: Individuals with Parkinson’s disease (PD) often manifest significant temporal and spatial asymmetries of the lower extremities during gait, which significantly contribute to mobility impairments. While the neural mechanisms underlying mobility asymmetries within this population remain poorly understood, recent evidence points to altered microstructural integrity of white matter fiber tracts within the corpus callosum as potentially playing a substantial role.

Objectives: The purpose of this study was to quantify spatial and temporal gait asymmetries as well as transcallosal microstructural integrity of white matter fiber tracts connecting the primary and secondary sensorimotor cortices in people with PD and age-matched control participants. …

The Slippery Slope Between Falling And Recovering: An Examination Of Sensory And Somatic Factors Influencing Recovery After A Slip, Samuel J. Wilson

Electronic Theses and Dissertations

Background: Slips and falls account for large rates of injury and mortality in multiple populations. During an unexpected slip, sensory mechanisms are responsible for signaling the slip to the central nervous system, and a series of corrective responses is generated to arrest the slip and prevent a fall. While previous research has examined the corrective responses elicited, the answer of how these systems break down during a fall remains elusive. Purpose: To examine differences in postural control (slip detection), lower extremity corrective responses (slip recovery), and cortical control of the slip recovery response between individuals who fall and those who …

Prosthetic Energy Return During Walking Increases After 3 Weeks Of Adaptation To A New Device, Samuel F. Ray, Shane R. Wurdeman, Kota Z. Takahashi

Journal Articles

Background: There are many studies that have investigated biomechanical differences among prosthetic feet, but not changes due to adaptation over time. There is a need for objective measures to quantify the process of adaptation for individuals with a transtibial amputation. Mechanical power and work profiles are a primary focus for modern energystorage- and-return type prostheses, which strive to increase energy return from the prosthesis. The amount of energy a prosthesis stores and returns (i.e., negative and positive work) during stance is directly influenced by the user’s loading strategy, which may be sensitive to alterations during the course of an adaptation …

Differences In Walking Mechanics Between A Traditional Walker And The Kb Balance Trainer, Silvia Zanini

Electronic Theses and Dissertations

INTRODUCTION: Millions of individuals with ambulatory difficulties rely on walking aids to maintain independence and mobility. However, users of traditional walkers typically exhibit increased forward lean of their trunk while using the assistive device. The KB Balance Trainer is a new posterior walker designed to facilitate a more erect position during gait. PURPOSE: To compare gait mechanics across three walking conditions: unassisted, using a traditional walker, and using the KB Balance Trainer. METHODS: Seven adults with experience using walkers due to ambulatory difficulties participated in the study. The study consisted of one training session and one gait analysis session. The …

Dynamic Balance Changes Within Three Weeks Of Fitting A New Prosthetic Foot Component, Jenny A. Kent, Nicholas Stergiou, Shane R. Wurdeman

Journal Articles

Balance during walking is of high importance to prosthesis users and may affect walking during baseline observation and evaluation. The aim of this study was to determine whether changes in walking balance occurred during an adaptation period following the fitting of a new prosthetic component.

Margin of stability in the medial-lateral direction (MOSML) and an anterior instability margin (AIM) were used to quantify the dynamic balance of 21 unilateral transtibial amputees during overground walking. Participants trialled two prosthetic feet presenting contrasting movement/balance constraints; a Higher Activity foot similar to that of their own prosthesis, and a Lower Activity foot. Participants …

Patients With Chronic Obstructive Pulmonary Disease Walk With Altered Step Time And Step Width Variability As Compared With Healthy Control Subjects, Jennifer M. Yentes, Stephen I. Rennard, Kendra K. Schmid, Daniel Blanke, Nikolaos Stergiou

Journal Articles

Rationale: Compared with control subjects, patients with chronic obstructive pulmonary disease (COPD) have an increased incidence of falls and demonstrate balance deficits and alterations in mediolateral trunk acceleration while walking. Measures of gait variability have been implicated as indicators of fall risk, fear of falling, and future falls.

Objectives: To investigate whether alterations in gait variability are found in patients with COPD as compared with healthy control subjects.

Methods: Twenty patients with COPD (16 males; mean age, 63.6 ± 9.7 yr; FEV1/FVC, 0.52 ± 0.12) and 20 control subjects (9 males; mean age, 62.5 ± 8.2 yr) walked for 3 …