Biomechanics Commons^™

Correlation Of Shoulder And Elbow Kinetics With Ball Velocity In College Baseball Pitchers, Eric Post

Theses and Dissertations

Specific injuries at the elbow and glenohumeral joints have been linked to several kinetic variables that occur throughout the throwing motion. Ulnar collateral ligament (UCL) sprains have been linked to excessive elbow valgus and shoulder external rotation torques occurring during the late-cocking phase of throwing. Shoulder external rotation torque during the late arm-cocking phase and shoulder distraction forces during the deceleration phase contribute to tears of the labrum. Additionally, it is believed that the peak distraction force generated during the arm deceleration phase also contributes to SLAP tears and rotator cuff pathologies. Very little research has been done to directly …

Formulation To Predict Lower Limb Muscle Forces During Gait, Gil Serrancolí, Jonathan P. Walter, Allison Kinney, A. Barjau, Benjamin J. Fregly, Josep M. Font-Llagunes

Mechanical and Aerospace Engineering Faculty Publications

The human body has more muscles than Degrees of Freedom (DoF), and that leads to indeterminacy in the muscle force calculation. This study proposes the formulation of an optimization problem to estimate the lower-limb muscle forces during a gait cycle of a patient wearing an instrumented knee prosthesis. The originality of that formulation consists of simulating muscle excitations in a physiological way while muscle parameters are calibrated. Two approaches have been considered. In Approach A, measured contact forces are applied to the model and all inverse dynamics loads are matched in order to get a physiological calibration of muscle parameters. …

University Of Nebraska At Omaha Biomechanics Research Building Newsletter, Fall 2013, Biomechanics Research Building

Biomechanics Annual Report

This issue features:

Updates - Featured Story: Our New Home, American Society of Biomechanics Meting, Nonlinear Workshop 2013, European Nonlinear Workshop, and Staff Updates;

Projects - VA Peripheral Arterial Disease, Motor Development, Optical Topography System, Effects of Virtual Reality, Virtual Reality, Robotic Surgery, Sports Medicine, Amputee, Proof of Concept Grant, Lateral Stepping, The Marriage of Music and Math, Chronic Obstructive Pulmonary Disease, Balance, NASA Grant, Back Pain Research, and Faculty Research International Grants.

Other Content - Other Visitors/Tours, Student Awards, Travels, and Campaign for Nebraska.

A Miniaturised Spectrometer Device For The Detection Of Nitrogen Dioxide In An Urban Environment, Brian Devine

Doctoral

Monitoring of air pollutants, such as Nitrogen Dioxide (NO2), that are toxic or environmentally damaging is a key metric for environmental protection agencies worldwide. There is a constant need to develop new technologies and methodologies that provide real-time, low cost pollution measurements over a broad range of sampling sites, particularly in urban and industrial areas. Typically, detection of pollutants in urban environments is performed using a variety of techniques, many of which are expensive, require complex setups and are in fixed locations. The novel system presented in this thesis is designed for portable, low cost and in-situ detection of pollutants …

Balance Affects Prism Adaptation: Evidence From The Latent Aftereffect, Dobromir Dotov, Till D. Frank, Michael T. Turvey

Journal Articles

In prism adaptation experiments, the effect on throwing to a target is reduced (primary aftereffect is smaller) when the throwing condition with prisms removed (first test phase) is different from the throwing condition with prisms (the training phase). The missing adaptation, however, can be revealed through further testing (second test phase) in which the throwing condition during training is fully reinstated. We studied throwing underhand to a target flush with the floor. During training, participants wore left-shifting prism glasses while standing on the floor (Group 1) or on a balance board (Groups 2 and 3). Tests 1 and 2 following …

Center Of Pressure And The Projection Of The Time-Course Of Sitting Skill Acquisition, Joshua L. Haworth, Regina T. Harbourne, Srikant Vallabhajosula, Nikolaos Stergiou

Journal Articles

A normal time-course for the acquisition of sitting is essential. A delay in sitting may affect other developmental milestones, resulting in deficiencies in overall skill. Therefore, our aim was to identify variables whose measures at the very beginning of sitting would allow for the projection of the evolution of the sitting skill. Center of pressure data were collected from the postural sway of twenty-six typically developing infants while sitting on a force platform with a beginning ability to sit upright. Spatial, temporal and frequency variables of postural sway were obtained from both the medial/lateral and anterior/posterior directions of sway. Discriminant …

Effect Of Warm-Up Activity On Vertical Ground Reaction Forces In Basketball Players During Drop Jump Landings, Jacob Wesley Hinkel-Lipsker

Master's Theses

ABSTRACT

Effect of Warm-Up Activity on Vertical Ground Reaction Forces in Basketball Players During Drop Jump Landings

Jacob Hinkel-Lipsker

Purpose: The purpose of this study was to examine the effect of certain warm-up activities on vertical ground reaction forces (GRF_v) during a drop jump landing. Methods: Eight women and twelve men (mean age 22.6 ± 1.82 years) completed three warm-up activities on three separate days in a counterbalanced order: a passive stretching warm-up, a dynamic warm-up, and a no warm-up control. After completing each activity, participants were asked to perform eight drop jump landings on a force platform. …

Gait Variablility Is Altered In Older Adults When Listening To Auditory Stimuli With Differing Temporal Structures, Jeffrey P. Kaipust, Denise Mcgrath, Mukul Mukherjee, Nikolaos Stergiou

Journal Articles

Gait variability in the context of a deterministic dynamical system may be quantified using nonlinear time series analyses that characterize the complexity of the system. Pathological gait exhibits altered gait variability. It can be either too periodic and predictable, or too random and disordered, as it is the case with aging. While gait therapies often focus on restoration of linear measures such as gait speed or stride length, we propose that the goal of gait therapy should be to restore optimal gait variability, which exhibits chaotic fluctuations and is the balance between predictability and complexity. In this context, our purpose …

Vascular Occlusion Affects Gait Variability Patterns Of Healthy Younger And Older Individuals, Sara A. Myers, Jason Johanning, Iraklis Pipinos, Kendra K. Schmid, Nikolaos Stergiou

Journal Articles

Insufficient blood flow is one possible mechanism contributing to altered gait patterns in lower extremity peripheral arterial disease (PAD). Previously, our laboratory found that induced occlusion alters gait variability patterns in healthy young individuals. However the effect of age was not explored. The purpose of this study was to account for age by investigating gait variability following induced vascular occlusion in healthy older individuals and to identify amount of change from baseline to post vascular occlusion between younger and older individuals. Thirty healthy younger individuals and 30 healthy older individuals walked on a treadmill during baseline and post vascular occlusion …

Optimization Problem Formulation For Predicting Knee Muscle And Contact Forces During Gait, Gil Serrancolí, Jonathan P. Walter, Allison Kinney, Benjamin J. Fregly, Josep M. Font-Llagunes

Mechanical and Aerospace Engineering Faculty Publications

The human body has more muscles than degrees of freedom (DOF), which leads to indeterminacy in the muscle force calculation. In this study, an optimization problem to estimate the lower-limb muscle forces during a gait cycle of a patient wearing an instrumented knee prosthesis is formulated. It consists of simulating muscle excitations in a physiological way while muscle parameters are calibrated.

Multiple Sclerosis Alters The Mechanical Work Performed On The Body's Center Of Mass During Gait, Shane R. Wurdeman, Jessie M. Huisinga, Mary Filipi, Nikolaos Stergiou

Journal Articles

Patients with multiple sclerosis (MS) have less-coordinated movements of the center of mass resulting in greater mechanical work. The purpose of this study was to quantify the work performed on the body’s center of mass by patients with MS. It was hypothesized that patients with MS would perform greater negative work during initial double support and less positive work in terminal double support. Results revealed that patients with MS perform less negative work in single support and early terminal double support and less positive work in the terminal double support period. However, summed over the entire stance phase, patients with …

Effects Of Ankle Immobilization On Lower Extremity Joint Coupling Variability, Kristin M. Gundy

Human Movement Studies & Special Education Theses & Dissertations

Human movement is a complex system that encompasses several factors within the body to create coordination. It is not fully understood how the many degrees of freedom (DOF) of the body organize to create movement. Both internal and external influence how the DOF problem works to produce varying movement goals.

The purpose of this study was to better understand the organization patterns of the body by eliminating a DOF. The ankle joint was immobilized to determine if there were differences at the hip and knee joint couplings. It was hypothesized that there would be an increase in movement variability at …

Effect Of A Lateral Wedge Insole Over A One Week Period In A Healthy Population, Sarah E. Sudheimer

Human Movement Studies & Special Education Theses & Dissertations

Medial knee osteoarthritis is a disease that is projected to affect approximately 45% of the U.S. population and is associated with significant morbidity, chronic pain, and limited activity. Laterally wedged insoles are used as an intervention to laterally shift the mechanical axis of the limb and decrease the external knee adduction moment, possibly indicating a shift in load distribution to the lateral compartment of the knee. The aim of this study was to examine the acute effects of a laterally wedged insole in those with valgus and normally aligned knees and to determine prolonged effects after the insole was worn …

Executive Function Orchestrates Regulation Of Task-Relevant Gait Fluctuations, Leslie M. Decker, Fabien Cignetti, Nikolaos Stergiou

Journal Articles

Humans apply a minimum intervention principle to regulate treadmill walking, rapidly correcting fluctuations in the task-relevant variable (step speed: SS) while ignoring fluctuations in the task-irrelevant variables (step time: ST; step length: SL). We examined whether the regulation of fluctuations in SS and not in ST and SL depends on high-level, executive function, processes. Young adults walked on a treadmill without a cognitive requirement and while performing the cognitive task of dichotic listening. SS fluctuations became less anti-persistent when performing dichotic listening, meaning that taxing executive function impaired the ability to rapidly correct speed deviations on subsequent steps. Conversely, performing …

Preliminary Development Of A Subject Specific Finite Element Model Of The Hindfoot, Liang Dong

Mechanical & Aerospace Engineering Theses & Dissertations

The human hindfoot is a complex structure and its medical treatment can vary from patient to patient. If physicians have access to a patient specific computer model, the optimal treatment option can be explored on the model before preforming it on the patient. The purpose of this study was to create a quasi-static finite element model and to show the stress contour in the cartilage between the bones. Ankle joint contact pressure was collected on one cadaver limb with a 40 lbs ( 178 N) axial load applied and tendon loads applied to simulate the ratio of tendon loading during …

Gait Mechanics Are Different Between Healthy Controls And Patients With Multiple Sclerosis, Jessie M. Huisinga, Kendra K. Schmid, Mary Filipi, Nikolaos Stergiou

Journal Articles

Multiple sclerosis (MS) causes severe gait problems in relatively young individuals, yet there have been limited studies to quantitatively identify the specific gait parameters that are affected. The purpose of this study was to define any differences in biomechanical gait parameters between patients with MS and healthy controls. A total of 31 MS patients and 31 healthy controls were evaluated: joint torques and joint powers were calculated at the ankle, knee, and hip during the stance phase of gait. The self-selected walking velocity was used as a covariate in the analysis to ensure that group differences were not due to …

Design And Development Of A Stair Ascension Assistive Device For Transfemoral Amputees, Casey Michael Barbarino

Master's Theses

Transfemoral amputees around the world experience increased difficulty in climbing stairs due to lack of muscle, balance, and other factors. The loss of a lower limb greatly diminishes the amount of natural force generation provided that is necessary to propel oneself up stairs. This study investigated possible solutions to the problem of stair ascension for transfemoral amputees by the means of designing and developing an externally attachable device to a prosthesis. The number of amputations from military service has greatly increased since 2008, which shows there is a clear need for assistive devices (Wenke, Krueger, & Ficke, 2012). With the …

Biomechanical Testing Of Salter-Harris Fractures Type I And Ii In The Distal Femur And Proximal Tibia, Margeaux Rogers

All Theses

Salter-Harris fractures of the proximal tibia and distal femur are common in pediatric patients that present to orthopedic surgeons. Salter-Harris type I fractures are characterized by breaks that extend only through the physis while Salter-Harris II fractures are the most common, accounting for 85% of Salter-Harris fractures, and extend past the growth plate, exiting through the metaphyseal bone1. Fixation of these fracture types can be accomplished using a variety of methods including the use of Kirschner wires, cannulated screws, and a combination of both materials. Stability of fracture fixation is of utmost importance as persistent motion at the fracture margin …

Integrating Biomechanics And Cell Physiology To Understanding Ivd Nutrition And Cell Homeostasis, Yongren Wu

All Dissertations

Back pain associated with degeneration of the intervertebral disc (IVD) is a major public health problem in Western industrialized societies. Degeneration of the IVD changes the osmotic and nutrient environment in the extracellular matrix (ECM) which affects cell behaviors, including: cell proliferation, cell energy metabolism, and matrix synthesis. In addition, a thin layer of hyaline cartilaginous end-plate (CEP) at the superior/inferior disc-vertebral interface was found to play an important role in nutrient supply as well as load distribution in the IVD. Therefore, our general hypothesis is that the CEP regulates the ECM osmotic and nutrient environment which further affects IVD …

Early Complexity Supports Development Of Motor Behaviors In The First Months Of Life, Stacey C. Dusing, Leroy R. Thacker, Nikolaos Stergiou, James C. Galloway

Journal Articles

Complexity in motor behavior is a hallmark of healthy systems. The purpose of this study was to investigate postural complexity during development of early motor behaviors and under two conditions. Twenty-two infants participated from 1 to 6 months of age. Linear and nonlinear measures of displacement of the center of pressure at the base of support were used to quantify magnitude and temporal structure of postural control. Behavioral coding was used to quantify the emergence of midline head control and early reaching. Results suggest that infants have complexity in postural control strategies early in development. This complexity decreases as infants …