Biomechanics Commons^™

Differences In Loading Rate In Shod And Unshod Treadmill Walking, David Austin Kropushek

Master's Theses

The purpose of this study was to compare the loading rates of shod and unshod conditions in treadmill walking. It was hypothesized that walking barefoot would demonstrate higher loading rates than walking with shoes. It was also hypothesized that walking barefoot on a treadmill would result in greater stride-to-stride variability than walking with shoes. Sixteen healthy adult females volunteered and provided their consent to participate in this study. Participants were given time to accommodate to the instrumented treadmill both while wearing shoes and without. Two 10-minute trials were collected with a rest period between. Data were analyzed using Vicon Nexus …

Effects Of Altered Somatosensory Input On Gait Kinetics And Kinematics Via Different Footwear In Individuals With Chronic Post-Stroke Hemiparesis, Daniela Casillas, Lesley Ruiz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose/Hypothesis: Individuals with post-stroke hemiparesis walk with significant asymmetries, leading to slow, effortful walking, and a high risk of falls. One contributing factor is altered sensation on the plantar surface. Studies examining altered somatosensory input via insoles, vibration and other tactile stimuli observed improvements in hemiparesis gait. This study investigates whether altering somatosensory input through different footwear can affect kinetics, kinematics and muscle activity during walking post-stroke. We hypothesized the barefoot conditions would have increased dorsiflexion (heel-strike, swing), increased plantarflexion during toe-off, increased muscle activity and kinetics, compared to memory foam conditions.

Participants: 13 individuals with chronic post-stroke hemiparesis (4F/9M, …

A Comparison Of Spinal Reflex Function And Morphological Adaptations Of The Achilles Tendon Between Individuals Chronically Post-Stroke And Healthy Controls, Migi Contreras, Mira Seekins, Johanna Mendez, Trevor Diez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose/Hypothesis: The hallmark gait deviation in individuals with post-stroke hemiparesis is slow walking speed. Reduction in gait speed after stroke is influenced by decreased propulsive forces, which may likely be related to impaired spinal circuit function and spasticity of the paretic plantarflexors. Chronic muscle tone maladaptations in paretic ankle plantarflexors can result in altered Achilles tendon (AT) morphology, therefore leading to altered mechanical properties, force transmission capabilities and subsequent insufficient propulsive forces during walking. The purpose of this study is to characterize the chronic maladaptations in both the spinal Ia afferent loop excitability and AT morphology after stroke lesions in …

Altered Gait Mechanics In Marfan Syndrome, Amara G. Sharp

Theses and Dissertations--Kinesiology and Health Promotion

FBN1 is a gene responsible for the production of fibrillin, a major component of connective tissue throughout the body including skeletal muscle tissue. In individuals with Marfan Syndrome these mutations in FBN1 result in widespread muscle weakness and a correspondingly higher incidence of lower extremity joint pain. Despite the widespread musculoskeletal impacts of Marfan Syndrome there is a dearth of research on the potential impacts of Marfan Syndrome on gait mechanics that may be related to the high incidence of lower extremity joint pain in the Marfan Syndrome population. Therefore, the purpose of this study was to determine the potential …

Mimicking An Asymmetrically Walking Visual Cue Alters Gait Symmetry In Healthy Adults, Krista G. Clark, Louisa D. Raisbeck, Scott E. Ross, Christopher K. Rhea

Rehabilitation Sciences Faculty Publications

Gait asymmetries are a common problem in clinical populations, such as those with a history of stroke or Parkinson’s disease. The use of a split-belt treadmill is one way to enhance gait symmetry but relies on specialty (and typically expensive) equipment. Alternatively, visual cues have been shown as a method to alter gait mechanics, but their utility in altering gait symmetry has been relatively understudied. Before deploying this method to clinical populations, a proof-of-concept study is needed to explore using visual cues to alter gait symmetry in healthy adults. Therefore, the purpose of this study was to examine the extent …

Accelerations And Emg Differences Between Isocaloric High-Incline Walking And Level Grade Jogging, Taj Krieger

Cal Poly Humboldt theses and projects

Purpose: To examine muscle activation and biomechanical differences between high-incline walking (HIW) at 20% grade and level-grade jogging (LGJ) at isocaloric intensity on a treadmill. Methods: Physically inactive men and women between 18-31 completed the study. Participants (n=19) completed two isocaloric exercise trials (HIW and LGJ), each ten minutes in duration. EMG data was obtained from the Bicep Femoris (BF), Gluteus Maximus (GM), Lateral Gastrocnemius (LG), Tibialis Anterior (TA), Vastus Lateralis (VL), Anterior Deltoid (AD), Erector Spinae (ES) and Soleus (SOL). Resultant accelerations on the foot and sacrum were measured by IMU.

Results: When subjects were matched at isocaloric intensities …

Exploring The Relationship Of Intact Limb Knee Joint Loading With Step Lengths And Step Length Symmetry In Individuals With Lower Limb Amputation, Edward D. Syrett

Theses and Dissertations

Individuals with unilateral lower limb amputation (LLA) frequently experience intact limb knee pain, dysfunction, and osteoarthritis. These problems can worsen pre-existing reductions in mobility and quality of life that this population regularly experiences. It is widely accepted that knee joint loading is implicated in the development of knee joint issues, and intact limb knee joint load alterations are thought to be widespread in individuals with LLA. Prior work suggests that gait deviations frequently present in this population may be a contributory cause of these altered forces. These deviations can take many forms, but individuals with LLA commonly demonstrate alterations in …

Multifractality In Stride-To-Stride Variations Reveals That Walking Involves More Movement Tuning And Adjusting Than Running, Taylor J. Wilson, Madhur Mangalam, Nicholas Stergiou, Aaron Likens

Journal Articles

Introduction: The seemingly periodic human gait exhibits stride-to-stride variations as it adapts to the changing task constraints. The optimal movement variability hypothesis (OMVH) states that healthy stride-to-stride variations exhibit “fractality”—a specific temporal structure in consecutive strides that are ordered, stable but also variable, and adaptable. Previous research has primarily focused on a single fractality measure, “monofractality.” However, this measure can vary across time; strideto-stride variations can show “multifractality.” Greater multifractality in stride-tostride variations would highlight the ability to tune and adjust movements more.

Methods: We investigated monofractality and multifractality in a cohort of eight healthy adults during self-paced walking and …

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 …

Investigation Of Lower Extremity Neuromuscular Function In Individuals With And Without Diabetes, Roya Hoveizavi

Theses and Dissertations--Kinesiology and Health Promotion

Background: Diabetes mellitus is associated with notable neuromuscular and motor dysfunctions that could lead to an increased risk of plantar ulcers and amputations. Several contributing factors, including increased muscle-tendon stiffness and abnormal muscle activation pattern may influence the kinematics and kinetics of walking in people with diabetes and promote formation of plantar ulcers. Hyperglycemia and the resultant accelerated rate of glycation have been recognized as the leading cause of muscle and tendon degeneration, yet the precise mechanisms by which diabetes affects the biomechanical properties of the muscle-tendon unit remains unclear. Altered muscle activity during gait is observed in people with …

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 …

Characterizing Locomotor Disturbance Perception In Young Adults, Daniel James Liss

Graduate Theses, Dissertations, and Problem Reports (ETD)

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 …

The Influence Of Resistance Training On Post Surgical Outcomes In Individuals With Anterior Cruciate Ligament Injury, Kevin H. Choe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The anterior cruciate ligament (ACL) is commonly injured, especially in individuals under the age of 25. ACL reconstruction (ACLR) is the most common treatment after ACL injury, followed by physical therapy. However, successful surgery and completion of rehabilitation, individuals still demonstrate quadriceps weakness and asymmetries during locomotion. To improve these deficits, an intervention that improves quadriceps strength and lower extremity biomechanics during locomotion is required. First, we aimed to complete a systematic review of the literature to determine the efficacy of resistance training in improving outcomes after ACLR. Second, we aimed to identify if a history of resistance training positively …

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

College of Graduate Studies: Theses & 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 …

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. …

Muscle Synergy Adaptation During A Novel Postural Stabilization Task, Rajat Emanuel Singh

Theses and Dissertations

Background: In human postural studies, it is believed that low dimensional motor modules are combined to simplify the movement. These lower dimensional modules are termed as muscle synergies (MS). Therefore, understanding MS evoked by postural perturbation may provide us the specific muscle co-activation pattern for stability. Research Aim: The scope of our study is to identify synergies associated with postural stability while walking on a perturbing platform and study the effect of different proficiency levels on their size and structure. Methodology: We asked nine human participants to walk overground and on a slackline to study task-specific modulation of synergy structures. …

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, …

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 Studies & Special Education 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, …