Biomechanics Commons^™

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 …

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 …

The Effect Of Posterior Foot Positions On Electromyography, Joint Kinetics And Energetics During A Sit-To-Stand In Young And Older Adults, Eric A. Pitman

Human Movement Studies & Special Education Theses & Dissertations

The sit-to-stand (STS) movement, defined as standing up from a chair to an upright posture, is a common task performed daily. The inability to accomplish this task may lead to dependence, institutionalization and even death in older adults. A common strategy change for the STS is positioning the feet posteriorly by increasing flexion at the knee joint. This reduces the displacement of the center of mass to the base of support while increasing the joint moment of force at the knee while decreasing it at the hip. The aims of this study were to: 1) examine the joint kinetics, joint …

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 …

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 …

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 …

Lower Extremity Biomechanics In Individuals With And Without Previous Hamstring Injury, Jessica A. Mutchler

Human Movement Studies & Special Education Theses & Dissertations

Primary risk factors for hamstrings strains such as fatigue, previous injury and strength deficits have been identified in the research, yet re-injury rates remain high among the physically active. Sub-acute analysis of the hip, knee and ankle biomechanics following a hamstrings strain have been largely overlooked and may provide additional insight into re-injury risks. It was the aim of this dissertation to explore long-term adaptations in walking and running tasks following a hamstrings strain, and to develop a hip endurance test that could be used in future studies.

Project one used a cross-sectional study with test-retest design to develop and …

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, …

Biomechanical Characterization And Modeling Of Human Tmj Disc, Gregory Wright

All Dissertations

Temporomandibular joint (TMJ) disorder affects over 10 million people in the US each year. The signs and symptoms of temporomandibular joint disorders (TMDs) include limited mouth opening, clicking and locking of the jaw, and significant pain in the craniofacial region. In patients who seek treatment for TMDs, over 70% have TMJ disc displacement related to disc degeneration. The TMJ disc is interposed between the mandible condyle and the glenoid fossa of the temporal bone. The disc reduces contact stresses within the joint and provides lubrication to the joint. It is generally believed that pathological mechanical loadings, such as sustained jaw …

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 …

Changes In Sprint Kinetics Or Kinematics Following Static Or Dynamic Stretching, Kristyne Bartel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine the effects of static or dynamic stretching on hip kinematics and kinetics during intermittent sprinting. To achieve this aim, intermittent sprint athletes were asked to complete either a static or dynamic stretch, followed by a repeated-sprint protocol. Hip joint kinematics and performance measures were evaluated during the sprint, including changes that occurred in these variables over the course of the sprint protocol. In addition, hip flexion torque was measured with an isokinetic dynamometer. Ten male (age = 25±2.3 years, 175±3.2 cm, 76.2±2.7 kg) and female (age = 20±1 years, 166±1.3 cm, 60±1.1 …

Comparison Of Muscle Latencies For Diabetic Neuropathy Patients Versus Healthy Controls During A Perturbed Balance Task, Kyle Mefferd

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to compare muscle latencies for patients diagnosed with diabetic neuropathy versus healthy controls during a perturbed balance task, with a secondary purpose to distinguish postural control strategies the groups used based on the muscle latencies. Five participants diagnosed with diabetic neuropathy (DN; 4 male, 99.7 ± 7.95 kg, 176 ± 9.58 cm, 46.6 ± 16.55 years) and 5 healthy control (HC; 4 male, 100.36 ± 12.61 kg, 173.76 ± 9.66 cm, 47 ± 13.42 years) participants were recruited. Participants granted institutionally approved written consent before participating. Delsys Trigino Wireless EMG sensors were placed on …

Impacts Of Micrornas On Skeletal Muscle Protein Synthesis And Mitochondrial Quality, David Lee

Graduate Theses and Dissertations

microRNA (miRNA) post-transcriptional modification is becoming a well-established mechanism for controlling mRNA translation. microRNAs -1, -133, and -206 are under the control of skeletal muscle promoters and affect muscle plasticity and metabolic health. A detailed review on the generation and processing of miRNAs with a view to skeletal muscle brings up intriguing connections in the transcriptional connections between multiple miRNAs. Additionally, exciting new research has defined a role of miRNAs in skeletal muscle mitochondria showing an additional, direct link to metabolic function. Multiple investigations in models of exercise, aging, hypertrophy, and injury have shown how these interventions can affect miRNA …

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 …

Reliability Of A Multisegment Foot Model In Shod Running, Austin Coupe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine kinematic and marker placement reliability of the Leardini multisegment foot model (LMFM) for tracking foot kinematics during barefoot and shod running without alteration of footwear. Eleven participants, five males (25.6±5 yrs, 73±15.8 kg, 1.75±0.05m) and six females (22.5±2.9 yrs, 66.6±7.2 kg, 1.71±0.05 m) granted institutionally approved written consent to participate. Three-dimensional motion capture (10 Vicon T40-S cameras) was used to capture kinematic data at 200Hz. Kinetic data was captured with an in-ground force platform (Kistler Instruments AG, Switzerland Model 9281B 60x40cm, 2000Hz). Participants were instructed to run at 3.5m/s ±5%. Velocity was …

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 …