Biomechanics Commons^™

Increased Minimum Toe Clearance Variability In Patients With Peripheral Arterial Disease, Troy Rand, Shane R. Wurdeman, Jason M. Johanning, Iraklis Pipinos, Sara A. Myers

Journal Articles

Individuals with peripheral arterial disease (PAD) report difficulty walking and experience 73% more falls than their healthy counterparts, but no studies have investigated functional mechanisms contributing to increased falls. Minimum toe clearance (MTC) is the minimum vertical distance between the toe of the swinging leg and the walking surface when the leg is swinging, and decreased values are associated with an increased risk for falls. This study is the first such analysis in patients with PAD. Eighteen individuals with PAD and eighteen healthy controls walked on a treadmill before and after the onset of claudication pain. Mean MTC and the …

Glucose-Fructose Likely Improves Gastrointestinal Comfort And Endurance Running Performance Relative To Glucose-Only, P. B. Wilson, S. J, Ingraham

Athletic Performance Research

This study aimed to determine whether glucose-fructose (GF) ingestion, relative to glucose-only, would alter performance, metabolism, gastrointestinal (GI) symptoms, and psychological affect during prolonged running. On two occasions, 20 runners (14 men) completed a 120-min submaximal run followed by a 4-mile time trial (TT). Participants consumed glucose-only (G) or GF (1.2:1 ratio) beverages, which supplied ~1.3 g/min of carbohydrate. Substrate use, blood lactate, psychological affect [Feeling Scale (FS)], and GI distress were measured. Differences between conditions were assessed using magnitude-based inferential statistics. Participants completed the TT 1.9% (−1.9; −4.2, 0.4) faster with GF, representing a likely benefit. FS ratings were …

Misrepresentation Of Carbohydrate For Exercise: ‘It Is Time To Bust The Myth Of Physical Inactivity And Obesity: You Cannot Outrun A Bad Diet’, Patrick B. Wilson

Athletic Performance Research

The contention from Malhotra et al1 regarding the unimportance of carbohydrate for exercise is misguided. First, the reference they provide is an editorial2 that should not be viewed as high-quality evidence. Several oft-cited exercise studies showing benefits with high-fat diets simultaneously utilized carbohydrate restoration strategies,3 which involves “carbohydrate loading” after a high-fat diet. Thus, the evidence provided does not contradict the established belief that carbohydrate is an important fuel for endurance exercise. Second, the authors’ use of the term “carbohydrate loading” is misleading in this context. No public health organizations advocate a diet containing carbohydrate in amounts used in “carbohydrate …

Step Activity And Stride-To-Stride Fluctuations Are Negatively Correlated In Individuals With Transtibial Amputation, Jenny A. Kent, Nicholas Stergiou, Shane Wurdeman

Journal Articles

Background

Variability occurs naturally from stride to stride in healthy gait. It has been shown that individuals with lower limb loss have significantly increased stride-to-stride fluctuations during walking. This is considered indicative of movement disorganization and is associated with less healthy movement. Given that lower limb prosthesis users perform on average less physical activity than able bodied individuals, the purpose of this study was to determine whether increased fluctuations also correspond to a reduced level of activity in daily life.

Methods

Twenty-two transtibial amputees wore an activity monitor (Actigraph, Pensacola, FL, USA) for 3 weeks. Lower limb kinematics during treadmill …

Optic Flow Improves Adaptability Of Spatiotemporal Characteristics During Split-Belt Locomotor Adaptation With Tactile Stimulation, Diderik Jan Anthony Eikema, Jung Chien, Nicholas Stergiou, Sara Myers, Melissa Scott-Pandorf, Jacob J. Bloomberg, Mukul Mukherjee

Journal Articles

Human locomotor adaptation requires feedback and feed-forward control processes to maintain an appropriate walking pattern. Adaptation may require the use of visual and proprioceptive input to decode altered movement dynamics and generate an appropriate response. After a person transfers from an extreme sensory environment and back, as astronauts do when they return from spaceflight, the prolonged period required for re-adaptation can pose a significant burden. In our previous paper, we showed that plantar tactile vibration during a split-belt adaptation task did not interfere with the treadmill adaptation however, larger overground transfer effects with a slower decay resulted. Such effects, in …

Biomechanical Investigation Of Elite Place-Kicking, Chase M. Pfeifer

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Many studies aim to understand the fundamentals of kicking commonly displayed by soccer players [4,6,10,16,17,18,24,25,28,29,30,34,36,38,40]. Of those studies, most are limited to a two-dimensional (2D) analysis using high-speed cameras for position tracking or utilizing electromyography to observe the activity of select muscles [4,6,18,25,29,36]. The few studies that investigate kicking using a three-dimensional (3D) model are limited in their position tracking capabilities and focus mainly on joint flexion potentials and foot speed.

This dissertation is a comprehensive biomechanical analysis (kinematic and EMG) of the field-goal place-kicking techniques of four elite kickers in American football. Data were compared and contrasted with ball …

Breast Cancer Rehabilitation: Clinical Examination And Outcomes Assessment, Nicole L. Stout, Shana Harrington, Lucinda Pfalzer, Mary Insana Fisher

Physical Therapy Faculty Publications

Breast cancer is the most commonly diagnosed cancer in women in the United States. The treatment for breast cancer occurs along a protracted time period and includes many different disease treatment modalities. These treatments carry with them a large number of adverse effects that negatively impact function in both the short term and long term. It is necessary for rehabilitation providers to interface with patients being treated for breast cancer throughout the continuum of care so that interval assessments can be conducted to identify emerging impairments and alleviate disability. To achieve this, the rehabilitation provider must have an understanding of …

Home Exercise Adherence In An Underserved Ecuadorian Community, Joseph M. Day, Jean Irion, Meridith Anile, Jared Henson, Ben Roussel, Christina Shepherd, Huybrechts Bindele

Physical Therapy Faculty Publications

Purpose: Physical therapy service learning projects and volunteer experiences in foreign countries are becoming more commonplace. Patients in underserved regions are not likely to receive therapy services regularly; therefore, adherence to a home exercise program (HEP) is critical. The primary purpose of this study was to observe home exercise adherence rates between the 1st and 2nd visits in an underserved population. The secondary purpose of this study was to determine specific factors that affect HEP adherence in this population.

Methods: Consecutive patients seen in Santo Domingo, Ecuador were considered for participation in this observational study. All patients were recruited from …

Locomotor Sensory Organization Test: How Sensory Conflict Affects The Temporal Structure Of Sway Variability During Gait, Jung Hung Chien, Mukul Mukherjee, Ka-Chun Siu, Nikolaos Stergiou

Journal Articles

When maintaining postural stability temporally under increased sensory conflict, a more rigid response is used where the available degrees of freedom are essentially frozen. The current study investigated if such a strategy is also utilized during more dynamic situations of postural control as is the case with walking. This study attempted to answer this question by using the Locomotor Sensory Organization Test (LSOT). This apparatus incorporates SOT inspired perturbations of the visual and the somatosensory system. Ten healthy young adults performed the six conditions of the traditional SOT and the corresponding six conditions on the LSOT. The temporal structure of …

How To Sync To The Beat Of A Persistent Fractal Metronome Without Falling Off The Treadmill?, Melvyn Roerdink, Andreas Daffertshofer, Vivien Marmelat, Peter J. Beek

Journal Articles

In rehabilitation, rhythmic acoustic cues are often used to improve gait. However, stride-time fluctuations become anti-persistent with such pacing, thereby deviating from the characteristic persistent long-range correlations in stride times of self-paced walking healthy adults. Recent studies therefore experimented with metronomes with persistence in interbeat intervals and successfully evoked persistent stride-time fluctuations. The objective of this study was to examine how participants couple their gait to a persistent metronome, evoking persistently longer or shorter stride times over multiple consecutive strides, without wandering off the treadmill. Twelve healthy participants walked on a treadmill in self-paced, isochronously paced and non-isochronously paced conditions, …

Removable Shoe Spike System, Alex Adams, Nutech Ventures, Inc.,

Athletic Performance Research

The present system, method and apparatus are adapted for the quick and easy exchange of spikes on athletic shoes. More specifically, the system, apparatus and methods comprise a spike having an opening, an aglet adapted for coupling to the shoe, for example by way of a shoelace, and a coupling head affixed to the aglet which is adapted to couple with the opening on the spike so as to allow a user to quickly and easily replace, remove or install spikes in the athletic shoe. The disclosure thus allows the user to have the tool attached to their shoe at …

Development Of A Muscle Model Parameter Calibration Method Via Passive Muscle Force Minimization, Allison Kinney, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Computational predictions of subject-specific muscle and knee joint contact forces during walking may improve individual rehabilitation treatment design. Such predictions depend directly on specified model parameter values. However, model parameters are difficult to measure non-invasively. Methods for muscle model parameter calibration have been developed previously. However, it is currently unknown how the musculoskeletal system chooses muscle model parameter values. Previous studies have hypothesized that muscles avoid injury during walking by generating little passive force and operating in the ascending region of the force-length curve. This hypothesis suggests that muscle model parameter values may be selected by the body to minimize …

Synergy-Based Two-Level Optimization For Predicting Knee Contact Forces During Walking, Gil Serrancolí, Allison Kinney, Josep M. Font-Llagunes, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Musculoskeletal models and optimization methods are combined to calculate muscle forces. Some model parameters cannot be experimentally measured due to the invasiveness, such as the muscle moment arms or the muscle and tendon lengths. Moreover, other parameters used in the optimization, such as the muscle synergy components, can be also unknown. The estimation of all these parameters needs to be validated to obtain physiologically consistent results. In this study, a two-step optimization problem was formulated to predict both muscle and knee contact forces of a subject wearing an instrumented knee prosthesis. In the outer level, muscle parameters were calibrated, whereas …

Predictors Of Orthopaedic Surgery In Ncaa Athletes, Dean Wang, Caitlin M. Rugg, Erik Mayer, Pamela Sulzicki, Jeremy Vail, Sharon L. Hame

Athletic Training Faculty Publications

Objectives: Orthopaedic injury and surgery is relatively common in National Collegiate Athletic Association (NCAA) athletes and can have devastating career consequences. However, there is a paucity of data regarding predictors of orthopaedic surgery in collegiate athletes. The purpose of this study was to analyze player-related predictors of orthopaedic surgery, including that of the shoulder, hip, and knee, in NCAA athletes. Methods: All NCAA Division I collegiate athletes at a single institution who began participation from the 2003-2004 through 2008-2009 seasons were retrospectively identified. Player-related factors, including gender, sport, and any pre-college upper or lower extremity orthopaedic surgery, were elicited through …

Plantar Tactile Perturbations Enhance Transfer Of Split-Belt Locomotor Adaptation, Mukul Mukherjee, Diderik Jan Anthony Eikema, Jung Hung Chien, Sara A. Myers, Melissa Scott-Pandorf, Jacob J. Bloomberg, Nikolaos Stergiou

Journal Articles

Patterns of human locomotion are highly adaptive and flexible and depend on the environmental context. Locomotor adaptation requires the use of multisensory information to perceive altered environmental dynamics and generate an appropriate movement pattern. In this study, we investigated the use of multisensory information during locomotor learning. Proprioceptive perturbations were induced by vibrating tactors, placed bilaterally over the plantar surfaces. Under these altered sensory conditions, participants were asked to perform a split-belt locomotor task representative of motor learning. Twenty healthy young participants were separated into two groups: no-tactors (NT) and tactors (TC). All participants performed an overground walking trial, followed …

The Influence Of Neuromusculoskeletal Model Calibration Method On Predicted Knee Contact Forces During Walking, Gil Serrancolí, Allison Kinney, Benjamin J. Fregly, Josep M. Font-Llagunes

Mechanical and Aerospace Engineering Faculty Publications

This study explored the influence of three model calibration methods on predicted knee contact and leg muscle forces during walking. Static optimization was used to calculate muscle activations for all three methods. Approach A used muscle-tendon model parameter values (i.e., optimal muscle fiber lengths and tendon slack lengths) taken directly from literature. Approach B used a simple algorithm to calibrate muscle-tendon model parameter values such that each muscle operated within the ascending region of its normalized force-length curve. Approach C used a novel two-level optimization procedure to calibrate muscle-tendon, moment arm, and neural control model parameter values while simultaneously predicting …

Human Movement Variability And Aging, Nicholas Stergiou, Jenny A. Kent, Denise Mcgrath

Journal Articles

An optimal level of variability enables us to interact adaptively and safely to a continuously changing environment, where often our movements must be adjusted in a matter of milliseconds. A large body of research exists that demonstrates natural variability in healthy gait (along with variability in other, healthy biological signals such as heart rate) and a loss of this variability in aging and injury, as well as in a variety of neurodegenerative and physiological disorders. We submit that this field of research is now in pressing need of an innovative “next step” that goes beyond the many descriptive studies that …

Subjective Reports And Postural Performance Among Older Adult Passengers On A Sea Voyage, Justin Munafo, Michael G. Wade, Nicholas Stergiou, Thomas A. Stoffregen

Journal Articles

We sought to evaluate changes in subjective experience and postural performance among older adult passengers during the first 2 days of a sea voyage. On a vacation cruise, volunteer passengers gave verbal ratings of subjective bodily stability and awareness of ship motion followed by performance on the tandem Romberg test while facing fore-aft and athwartship. Data were collected when the ship was at the dock and on each of the first 2 full days at sea. Ship motion reduced subjective bodily stability and performance on the Romberg test and increased awareness of ship motion. On the first day at sea, …

A Comparison Of The Upper Limb Lift Test Between Women With Breast Cancer And Healthy Control Subjects, Mary Insana Fisher, Lucinda Pfalzer, Ellen W. Levy, Shana Harrington, Lynn H. Gerber, Nicole L. Stout

Physical Therapy Faculty Publications

Presentation at the World Confederation for Physical Therapy Congress, held May 1-4, 2015, in Singapore.

Background: Objective measures of upper limb (UL) function specific to breast cancer survivors (BC) are limited. Motion, strength, and muscular endurance are measurable components of UL function. A clinical test that quantifies these components is needed.

Purpose: This study compares the Upper Limb Lift Test (ULLT) between women with BC and healthy control subjects (HC) at baseline, 1-3 months, and 12+ months post-operatively enrolled in a prospective surveillance trial with early intervention. A secondary purpose was to validate the ULLT by comparing findings to self-reported …

Temporal Structure Of Support Surface Translations Drive The Temporal Structure Of Postural Control During Standing, Troy J. Rand, Sara A. Myers, Anastasia Kyvelidou, Mukul Mukherjee

Journal Articles

A healthy biological system is characterized by a temporal structure that exhibits fractal properties and is highly complex. Unhealthy systems demonstrate lowered complexity and either greater or less predictability in the temporal structure of a time series. The purpose of this research was to determine if support surface translations with different temporal structures would affect the temporal structure of the center of pressure (COP) signal. Eight healthy young participants stood on a force platform that was translated in the anteroposterior direction for input conditions of varying complexity: white noise, pink noise, brown noise, and sine wave. Detrended fluctuation analysis was …

Manipulating The Mass Distribution Of A Golf Putter, Paul J. Hessler Jr.

Senior Honors Projects

Putting may appear to be the easiest but is actually the most technically challenging part of the game of golf. The ideal putting stroke will remain parallel to its desired trajectory both in the reverse and forward direction when the putter head is within six inches of the ball. Deviation from this concept will cause a cut or sidespin on the ball that will affect the path the ball will travel.

Club design plays a large part in how well a player will be able to achieve a straight back and straight through club head path near impact; specifically the …

Mechanisms To Increase Propulsive Force For Individuals Poststroke, Haoyuan Hsiao, Brian A. Knarr, Jill S. Higginson, Stuart A. Binder-Macleod

Journal Articles

Background: Propulsive force generation is critical to walking speed. Trialing limb angle and ankle moment are major contributors to increases in propulsive force during gait. For able-bodied individuals, trailing limb angle contributes twice as much as ankle moment to increases in propulsive force during speed modulation. The aim of this study was to quantify the relative contribution of ankle moment and trailing limb angle to increases in propulsive force for individuals poststroke.

Methods: A biomechanical-based model previously developed for able-bodied individuals was evaluated and enhanced for individuals poststroke. Gait analysis was performed as subjects (N = 24) with …

Biomechanical Analyses Of Stair-Climbing While Dual-Tasking, Srikant Vallabhajosula, Chi Wei Tan, Mukul Mukherjee, Austin Davidson, Nicholas Stergiou

Journal Articles

Stair-climbing while doing a concurrent task like talking or holding an object is a common activity of daily living which poses high risk for falls. While biomechanical analyses of overground walking during dual-tasking have been studied extensively, little is known on the biomechanics of stair-climbing while dual-tasking. We sought to determine the impact of performing a concurrent cognitive or motor task during stair-climbing. We hypothesized that a concurrent cognitive task will have a greater impact on stair climbing performance compared to a concurrent motor task and that this impact will be greater on a higher-level step. Ten healthy young adults …

Sitting Postural Control Affects The Development Of Focused Attention In Children With Cerebral Palsy, Swati Surkar, Christina Edelbrock, Nicholas Stergiou, Sarah Berger, Regina T. Harbourne

Journal Articles

Purpose:

To investigate whether focused attention (FA) changes over time as sitting postural control improves and whether an impairment in sitting postural control affects the development of FA in children with cerebral palsy (CP).

Methods:

Nineteen children with CP, mean ages 21.47 months, were assessed for FA and sitting scores pre- and postintervention.

Results:

Longest, total, and global FA increased and frequency of FA decreased in children who achieved independent sitting. However, children who achieved mobility postintervention exhibited a decrease in longest FA and an increase in frequency of FA.

Conclusion:

Sitting postural control and the development of FA appear …

Lower Extremity Kinematics During A Drop Jump In Individuals With Patellar Tendinopathy, Adam B. Rosen, Jupil Ko, Kathy J. Simpson, Seock-Ho Kim, Cathleen N. Brown

Journal Articles

Background: Patellar tendinopathy (PT) is a common degenerative condition in physically active populations. Knowledge regarding the biomechanics of landing in populations with symptomatic PT is limited, but altered mechanics may play a role in the development or perpetuation of PT.

Purpose: To identify whether study participants with PT exhibited different landing kinematics compared with healthy controls.

Study Design: Controlled laboratory study.

Methods: Sixty recreationally active participants took part in this study; 30 had current signs and symptoms of PT, including self-reported pain within the patellar tendon during loading activities for at least 3 months and ≤80 on the Victorian Institute …

Children’S Looking Preference For Biological Motion May Be Related To An Affinity For Mathematical Chaos, Joshua L. Haworth, Anastasia Kyvelidou, Wayne Fisher, Nikolaos Stergiou

Journal Articles

Recognition of biological motion is pervasive in early child development. Further, viewing the movement behavior of others is a primary component of a child’s acquisition of complex, robust movement repertoires, through imitation and real-time coordinated action. We theorize that inherent to biological movements are particular qualities of mathematical chaos and complexity. We further posit that this character affords the rich and complex inter-dynamics throughout early motor development. Specifically, we explored whether children’s preference for biological motion may be related to an affinity for mathematical chaos. Cross recurrence quantification analysis (cRQA) was used to investigate the coordination of gaze and posture …

Postural Sway And Gaze Can Track The Complex Motion Of A Visual Target, Vassilia Hatzitaki, Nikolaos Stergiou, George Sofianidis, Anastasia Kyvelidou

Journal Articles

Variability is an inherent and important feature of human movement. This variability has form exhibiting a chaotic structure. Visual feedback training using regular predictive visual target motions does not take into account this essential characteristic of the human movement, and may result in task specific learning and loss of visuo-motor adaptability. In this study, we asked how well healthy young adults can track visual target cues of varying degree of complexity during whole-body swaying in the Anterior-Posterior (AP) and Medio-Lateral (ML) direction. Participants were asked to track three visual target motions: a complex (Lorenz attractor), a noise (brown) and a …

The Association Between Critical Thinking And Scholastic Aptitude On First-Time Pass Rate Of The National Physical Therapy Examination, Daniel W. Suckow, C. Jayne Brahler, Betsy Donahoe-Fillmore, Mary Insana Fisher, Philip A. Anloague

Physical Therapy Faculty Publications

Objectives: 1) To investigate the relationships among critical thinking (CT) abilities, overall academic performance in the Doctorate of Physical Therapy (DPT) program as measured by cumulative grade point average (GPA), and National Physical Therapy Examination (NPTE) licensure scores, and 2) To determine if NPTE scores were significantly different between groups of students who were classified as having low, moderate or high CT abilities.

Background: It is well-established that physical therapy practice requires good clinical reasoning skills. Passage of the NPTE is required for licensure. Research to date has been mixed as to whether CT abilities or GPA can predict success …

The Influence Of Push-Off Timing In A Robotic Ankle-Foot Prosthesis On The Energetics And Mechanics Of Walking, Philippe Malcolm, Robert E. Quesada, Joshua M. Caputo, Steven H. Collins

Journal Articles

Background

Robotic ankle-foot prostheses that provide net positive push-off work can reduce the metabolic rate of walking for individuals with amputation, but benefits might be sensitive to push-off timing. Simple walking models suggest that preemptive push-off reduces center-of-mass work, possibly reducing metabolic rate. Studies with bilateral exoskeletons have found that push-off beginning before leading leg contact minimizes metabolic rate, but timing was not varied independently from push-off work, and the effects of push-off timing on biomechanics were not measured. Most lower-limb amputations are unilateral, which could also affect optimal timing. The goal of this study was to vary the timing …

Abnormal Myofiber Morphology And Limb Dysfunction In Claudication, Panagiotis Koutakis, Sara A. Myers, Kim Cluff, Duy M. Ha, Gleb Haynatzki, Rodney D. Mccomb, Koji Uchida, Dimitrios Miserlis, Evlampia Papoutsi, Jason M. Johanning, George P. Casale, Iraklis Pipinos

Journal Articles

Background

Methods