Biomechanics Commons^™

Hpcnmf: A High-Performance Toolbox For Non-Negative Matrix Factorization, Karthik Devarajan, Guoli Wang

COBRA Preprint Series

Non-negative matrix factorization (NMF) is a widely used machine learning algorithm for dimension reduction of large-scale data. It has found successful applications in a variety of fields such as computational biology, neuroscience, natural language processing, information retrieval, image processing and speech recognition. In bioinformatics, for example, it has been used to extract patterns and profiles from genomic and text-mining data as well as in protein sequence and structure analysis. While the scientific performance of NMF is very promising in dealing with high dimensional data sets and complex data structures, its computational cost is high and sometimes could be critical for …

Task-Oriented Ankle And Foot Training For Improving Gait, Balance, And Strength In Individuals With Multiple Sclerosis: A Pilot Study, Cizelle Rodriques, Kurt Jackson, Joaquin Alberto Barrios, Lloyd L. Laubach, Kimberly Edginton Bigelow

Physical Therapy Faculty Publications

The purpose of this pilot study was to investigate the effects and feasibility of a task-oriented ankle and foot exercise program on gait, balance, and strength in 6 adults with mild to moderate disability from multiple sclerosis (MS). The subjects participated in an 8-wk task-specific home-based ankle and foot exercise program. Outcome measures included stance phase ankle joint torque and power, limits of stability, isometric and isokinetic ankle strength, gait speed, and the 12-item Multiple Sclerosis Walking Scale (MSWS-12). Five subjects completed the 8- wk intervention. Following training, there were significant increases in ankle power during early (38.1%) and late …

Volumetric Flow Imaging Reveals The Importance Of Vortex Ring Formation In Squid Swimming Tail-First And Arms-First, Ian K. Bartol, Paul S. Krueger, Rachel A. Jastrebsky, Sheila Williams, Joseph T. Thompson

Biological Sciences Faculty Publications

Squids use a pulsed jet and fin movements to swim both arms-first (forward) and tail-first (backward). Given the complexity of the squid multi-propulsor system, 3D velocimetry techniques are required for the comprehensive study of wake dynamics. Defocusing digital particle tracking velocimetry, a volumetric velocimetry technique, and high-speed videography were used to study arms-first and tail-first swimming of brief squid Lolliguncula brevis over a broad range of speeds [0-10 dorsal mantle lengths (DML) s^-1) in a swim tunnel. Although there was considerable complexity in the wakes of these multi-propulsor swimmers, 3D vortex rings and their derivatives were prominent reoccurring features …

Mastoid Vibration Affects Dynamic Postural Control During Gait, Jung Chien, Mukul Mukherjee, Nicholas Stergiou

Journal Articles

Our objective was to investigate how manipulating sensory input through mastoid vibration (MV) could affect dynamic postural control during walking, with and without simultaneous manipulation of the visual and the somatosensory systems. We used three levels of MV (none, unilateral, and bilateral) via vibrating elements placed on the mastoid processes. We combined this with the six conditions of the Locomotor Sensory Organization Test (LSOT) paradigm to challenge the visual and somatosensory systems. We hypothesized that MV would affect both amount and temporal structure measures of sway variability during walking and that, in combination with manipulations of the visual and the …

Chapter 5: Surrogation, Sara A. Myers

Journal Articles

One of the goals of time series analysis is to understand the underlying mechanisms that generate different dynamics for different time series. If a time series is not a product of random process, then we can assume that some kind of dynamics govern the time series. The question is what kinds of dynamics are controlling the time series. For nonlinear time series analysis, our focus is on nonlinear dynamics, and one of the goals is to characterize those dynamics by applying nonlinear tools. However, it is important to establish evidence of nonlinearity in a time series first in order to …

Chapter 8: Autocorrelation Function, Mutual Information, And Correlation Dimension, Nathaniel Hunt

Journal Articles

In this chapter, we will discuss in greater detail the autocorrelation function and the mutual information we mentioned in Chapter 3 on the reconstruction of the state space. We will also cover a new measure called the correlation dimension, which quantifies the dimensionality of an attractor.

Chapter 2: Time Series, Sara A. Myers

Journal Articles

Time series is “simply a list of numbers assumed to measure some process sequentially in time” (Stergiou et al. 2004). Mathematicians have a more formal definition, that is, a set or a sequence of observations, with each one recorded at specific times, or at least sequentially (Brockwell and Davis 2002; Box et al. 2008). Time series are created from multiple sources for research purposes to understand various behaviors. For example, social scientists could collect graduation rates, physiologists record heart rates, economists study consumer spending, and climatologists examine weather patterns. Basically, any time observations are taken repeatedly over time, from any …

Examining The Reliability, Validity And Factor Structure Of The Drs-15 With College Athletes, Leilani Madrigal, Diane L. Gill, Kent M. Eskridge

Athletic Performance Research

Hardiness, comprising feelings of commitment, control and challenge, is most frequently measured with the Dispositional Resiliency Scale (DRS), but little work has been done with the brief 15-item version. To examine the factor structure, reliability, validity, and item functioning for gender invariance of the 15-item DRS with 525 collegiate athletes from a wide range of sports. Convergent and divergent validity were examined through relationships with mental toughness, grit and competitive anxiety. Participants completed measures of mental toughness, optimism, grit, competitive anxiety, and the DRS-15. Confirmatory Factor Analysis revealed a poor fit for the three-factor hardiness model, and subsequent exploratory factor …

Development Of An Elderly Female Torso Finite Element Model For Restraint System Research And Development Applications, Anil Kalra Kalra

Wayne State University Dissertations

Elderly females are found to be one of the most vulnerable segments of population during motor vehicle crashes and their population is increasing in the coming decades. Current design of restraint systems as well as other passive safety measures are designed based on anthropomorphic details of younger population. Developing another dummy representing elderly female population is a costly effort, while a finite element (FE) model of elderly female with similar anthropomorphic details and age- and gender-specific material properties can be a better alternative solution. The current research focuses on the development of a FE model of an elderly female torso, …

Validation Of An Error Sonification Auditory Feedback Training Program On Proper Sagittal Plane Squat Technique, Rena Hale

Open Access Theses & Dissertations

Osteoarthritis (OA) is one of the most common degenerative joint diseases that hinders an individual's quality of life. A large portion of knee OA instances can be correlated to previous anterior cruciate ligament (ACL) injury. Knee joint injury leading to OA is most prevalent in males aged 20-55 years old and can be caused by improper form during execution of a given task or lack of neuromuscular control. Screening protocols are used to assess deficits of an athlete, with the goal of reducing the risk of injury during both training and in competition. Neuromuscular training programs have been created to …

Electromyography Study Of Muscle Fatigue During Isometric Exercises In Swimmers And Non-Swimmers, Tiffany Aeling

Theses, Dissertations and Capstones

The use of electromyography (EMG) techniques offer strong evaluation of musculature fatigue during activity in different exercises. Studies show that EMG can be used to monitor fatigue patterns in muscles composing the upper extremities and thoracic areas of the human body by analyzing median frequency values. Advances in muscle fatigue research have been critical for improving rehabilitation programs for patients with musculoskeletal conditions. Despite these developments, many collegiate athletes are still at high risk for muscle injury on and off the playing field. Therefore, in order to help reduce injury numbers, it is important that current research focus on the …

Il-15 Mediates Mitochondrial Activity Through A Ppar𝛿-Dependent-Ppar𝛼-Independent Mechanism In Skeletal Muscle Cells, Shantaé M. Thornton, James E. Krolopp, Marcia J. Abbott

Health Sciences and Kinesiology Faculty Articles

Molecular mediators of metabolic processes, to increase energy expenditure, have become a focus for therapies of obesity. The discovery of cytokines secreted from the skeletal muscle (SKM), termed “myokines,” has garnered attention due to their positive effects on metabolic processes. Interleukin-15 (IL-15) is a myokine that has numerous positive metabolic effects and is linked to the PPAR family of mitochondrial regulators. Here, we aimed to determine the importance of PPAR𝛼 and/or PPAR𝛿 as targets of IL-15 signaling. C2C12 SKM cells were differentiated for 6 days and treated every other day with IL-15 (100 ng/mL), a PPAR𝛼 inhibitor (GW-6471), a PPAR𝛿 …

Development And Initial Testing Of A Low-Cost, Electronic, Microprocessor-Controlled Prosthetic Knee, Lucas Jonathan Galey

Open Access Theses & Dissertations

Cost-effective lower-limb prostheses have been successful in restoring mobility, independence, and a way of life to millions of global amputees who do not have the means to afford more sophisticated prosthetics. Comprehensively, the current above knee (AK) prosthetic market is segmented into two extremes â?? very affordable relief style knees that offer basic functionality with high risk of accident due to falls, and very expensive styles that offer electronic microprocessor stumble control and adaptive cadence. There remains a gap for a middle-ground system that provides stumble control and greater stability within an achievable price bracket for the developing world. This …

Effects Of Controlled-Whole Body Vibration Training On Reducing Risk Of Falls In People With Multiple Sclerosis, Maria Cristal Sanchez

Open Access Theses & Dissertations

Falls present a serious challenge among people affected by multiple sclerosis (MS). Controlled whole-body vibration (CWBV) training has been recently introduced into the physical therapy field to prevent falls in older adults. The purpose of this study was to examine the effects of an 8-week vibration-training program in reducing the risk of falls in people living with MS. The study adopted a single-group pre-test â?? post-test longitudinal design. Twenty-five adults with clinicallyâ??confirmed MS were enrolled in this study to undergo the 8-week intervention on a side-alternating vibration machine. The training was delivered three times a week for eight weeks a …

Frontal Plane Comparison Between Drop Jump And Vertical Jump: Implications For The Assessment Of Acl Risk Of Injury, Guilherme Manna Cesar, Curtis L. Tomasevicz, Judith M. Burnfield

Athletic Performance Research

The potential to use the vertical jump (VJ) to assess both athletic performance and risk of anterior cruciate ligament (ACL) injury could have widespread clinical implications since VJ is broadly used in high school, university, and professional sport settings. Although drop jump (DJ) and VJ observationally exhibit similar lower extremity mechanics, the extent to which VJ can also be used as screening tool for ACL injury risk has not been assessed. This study evaluated whether individuals exhibit similar knee joint frontal plane kinematic and kinetic patterns when performing VJs compared with DJs. Twenty-eight female collegiate athletes performed DJs and VJs. …

Weight Control Practices Of Division I National Collegiate Athletic Association Athletes, Patrick B. Wilson, Leilani Madrigal, Judith M. Burnfield

Athletic Performance Research

Objectives: Altering body weight can have substantial effects on an athlete’s performance and well-being. Limited information is available describing the weight control practices of Division I National Collegiate Athletic Association (NCAA) athletes.

Methods: Weight control practices data from 188 (138 male and 50 female; 18-23 y) Division I NCAA athletes were analyzed as a part of this cross-sectional, retrospective study. Participants completed questionnaires on weight control practices and weight control nutrition knowledge at the end of their season and were classified into weight-sensitive and less weight-sensitive sports.

Results: A higher proportion of females attempted to lose weight than males among …

The Effect Of Cardiorespiratory Fitness On The Assessment Of The Physical Working Capacity At The Fatigue Threshold, Brittney M. Mikkelsen, Jorge Zuniga, William K. Herron, Frances E. Frauso, Anne N. Pulliam

Journal Articles

Purpose: The purpose of this study was to determine if different cardiorespiratory fitness levels (maximal oxygen uptake or VO2max) affect neuromuscular fatigue as measured by the physical working capacity at the fatigue threshold (PWCFT). Methods: Fourteen adults (14 men; mean ± SD; age = 20.79 ± 0.89 years; body weight = 80.7 ± 10.91 kg; height = 178.4 ± 5.29 cm) volunteered to participate in the investigation. Each participant performed an incremental cycle ergometry test to fatigue while electromyographic (EMG) signals were measured from the vastus lateralis (VL) muscle. Mean, standard deviation, and range values were calculated for …

Quantifying Muscle Fatigue Of The Low Back During Repetitive Load Lifting Using Lyapunov Analysis, Elias Spyropoulos, Anastasia Kyvelidou, Nicholas Stergiou, George Athanassiou

Journal Articles

Background: Occupational low back disorders are often associated with exposure to work-related physical risk factors such as muscle fatigue in the low back.
Objective: The objective of this study was to investigate the possible relationship between the divergence of the kinematic trajectories of the low back system and the different stages of fatigue during the execution of a repetitive lifting task.
Methods: The patterns of the low back system were recorded using markers on specific vertebras during the repetitive load lifting from the floor to a 0.75 m height table. The maximum Lyapunov exponent, λmax of the recorded patterns was …

Gait Kinematics And Kinetics Are Affected More By Peripheral Arterial Disease Than By Age, Sara A. Myers, Bryon Applequist, Jessie M. Huisinga, Iraklis Pipinos, Jason M. Johanning

Journal Articles

—Peripheral arterial disease (PAD) produces abnormal gait and disproportionately affects older individuals. The current study investigated PAD gait biomechanics in younger (<65 yr) and older (>/=65 yr) subjects. The study included 61 patients with PAD (31 younger, age: 57.4 +/– 5.3 yr, and 30 older, age: 71.9 +/– 5.2 yr) and 52 nondisabled age-matched control subjects. Patients with PAD were tested during pain-free walking and compared with control subjects. Joint kinematics and kinetics (torques) were compared using a 2 x 2 analysis of variance (groups: patients with PAD vs control subjects, age: younger vs older). Patients with PAD had significantly increased ankle and …

Freezing Of Gait Associated With A Corpus Callosum Lesion, Marian L. Dale, Martina Mancini, Carolin Curtze, Fay B. Horak, Brett W. Fling

Journal Articles

Freezing of gait (FoG) is a debilitating feature of Parkinson’s disease and other parkinsonian disorders. This case demonstrates a variant of freezing of gait in a non-parkinsonian patient with a lesion of the anterior corpus callosum. The freezing improved with increased upper extremity sensory input, suggesting that compensatory circuits for use of somatosensory inputs from the arms to postural and locomotor centers were intact.

An Exploratory Approach To Manipulating Dynamic Stability: Investigating The Role Of Visual Control During A Precision Foot Placement Task, Russell Cg Kennedy

Theses and Dissertations (Comprehensive)

ABSTRACT

Background: The visual system provides the body with an accurate sensory system; designed to gather information at a distance and acts as a feedforward control mechanism during human locomotion. By doing so, visual information contributes coordination of the head-arm-trunk (HAT) segment and modulating foot placement. The purpose of this study was to examine the effects of a constrained pathway during a complex navigational stone-stepping task on HAT segment control and how the visual system guides locomotion during a complex foot placement task.

Methods: Nine university-aged females (Mean age: 22.5 years old +/-1.75) participated in this study. Participants …

The Effects Of Manipulated Somatosensory Input On Simulated Falls During Walking, Sarah Mitchell-Ewart

Theses and Dissertations (Comprehensive)

Previous research has demonstrated that there is a distinct relationship between aging and instability. The somatosensory system plays a significant role in balance control in conjunction with vision and the vestibular system (Qiu et al., 2012). Evidence has shown that manipulation of the mechanoreceptors on the plantar surface of the foot has a direct effect on balance control. By manipulating these receptors with hypothermic anesthesia and vibration, researchers are capable of simulating the effect of sensory modification on healthy individuals, in order to understand the role that plantar-surface sensation has in adapting to perturbation during gait (Perry et al., 2001; …

The Influence Of Hip Mobility And Fatigue On Spinal Flexion And Muscle Activation In Rugby Scrum Performance, Joshua D. Clayton

Theses and Dissertations (Comprehensive)

Introduction: Rugby scrumming is a means of restarting play following a minor rule infringement that can occur up to 28 times per game. The scrum poses a significant injury risk, with more days missed due to injury per event than any other rugby activity. Rugby players also have a significantly higher rate of spine injury than the general population, perhaps due to flexion in combination with high compression forces, which has been cited as the main mechanism of injury. Flexion of the spine has also been associated with poor hip mobility and quadriceps fatigue in other athletic tasks and may …

Spine Lifting Biomechanics Between Varying Occupational Activity Levels And Recreational Physical Activity Levels, Caitlin Rose Francis

Electronic Theses and Dissertations

Background: Moderate to vigorous physical activity as the optimum movement patterns for health have continued to be the dominant focus of health and fitness research. Yet, emerging evidence of deleterious, adverse health effects of prolonged inactivity, independent of regular physical activity, presents a new element to establishing the ideal model of movement patterns for health. The musculoskeletal trunk of the body becomes unbalanced as a result of prolonged inactivity, and a biomechanical analysis can help to identify high-risk loading behavior associated with these unbalances. Moreover, poor spine biomechanics can indicate a need for adjustment to present recommendations for optimum movement …

Treadmill-Based Perturbation Training For Preventing Falls Among Young Adults, Patrick Anthony Cereceres

Open Access Theses & Dissertations

Falls present a serious challenge not only among older adults, but for young adults, especially those whose working conditions exposes them to a high fall hazard. Treadmill-based perturbation training, as a task-specific training modality, has emerged as a new paradigm used to prevent falls. However, the training program in previous studies contained up to 30 perturbation trials. It is unclear if a reduced number of perturbation trials could still induce positive effect in preventing falls. The purpose of this study was to investigate the effect of a treadmill-based perturbation training paradigm consisting of 8 slip perturbations on reducing slip-related falls …

The Effects Of A Low Back Pain Vibration Modality On Trunk Postural Control, Adam R. Cornwall

Theses and Dissertations (Comprehensive)

Abstract

Introduction: Low back pain (LBP) is prevalent worldwide and is affecting even more individuals as the population ages. There has recently been an increase in production of low back pain (LBP) vibration modality belts that apply localized vibration to the lumbar region of the spine as it has shown to reduce pain. However, vibration is also known to perturb muscle spindles and thus interfere with proprioception. If a LBP vibration modality causes a proprioceptive deficit in the trunk lumbar region it could potentially increase an individual’s risk of injury due to poor postural control. Therefore, the effects of a …

A Complete Kinematic, Kinetic, And Electromyographical Analysis Of The Football Throw In Collegiate Quarterbacks, Kyle R. Bohnert

Theses and Dissertations--Kinesiology and Health Promotion

The biomechanics of the overhead throw has been extensively studied in regards to baseball pitching. However, an understanding of the proper mechanics needed to successfully throw a football has not previously been investigated. Thus, the purpose of this study was to investigate the kinematics, kinetics, and electromyography of the football throws in elite quarterbacks. Three collegiate quarterbacks were evaluated using a multi-camera motion capture system and electromyography electrodes. The results of this study are able to give a breakdown in the types of mechanics needed in each of the phases of the throw. This study demonstrated that during the early …

Central And Peripheral Weight Gain Affect Trunk Kinematics And Lower-Extremity Muscle Activation Differently During Sit-To-Stand, Michelle Christine Walaszek

Theses and Dissertations--Kinesiology and Health Promotion

Background: Obesity-induced alterations in biomechanics and muscle recruitment during activities of daily living, such as sit-to-stand (STS) are often attributed to increases in adipose tissue (AT) mass. Central or peripheral distribution of AT may differently affect biomechanics and muscle recruitment.

Methods: Fifteen healthy, normal weight (BMI 22.4 ± 1.9 kg/m², 24.1 ± 4.2 years) subjects volunteered. External loads equivalent to a 5 kg/m² BMI increase were applied in three conditions: unloaded (UN), centrally loaded (CL), and peripherally loaded (PL). Subjects completed three successful STS movements in a backless chair under each load condition in random order. Motion …