Dissertations / Theses on the topic 'Running coupling'

Physical Therapy
Ph.D.
The etiology of iliotibial band syndrome (ITBS) is not fully understood, however, dysfunction at the hip and decreased resistance to fatigue have been suggested to contribute to development of the syndrome. The objective of this study was to investigate differences in hip abductor strength and fatigue resistance, hip muscle activation timing and hip joint kinematic, kinetic and joint coupling patterns in female runners with and without ITBS. In addition, this study examined the effects of a run to exertion on these variables. Twelve female runners with ITBS and 20 healthy female runners participated in this study. Gluteus medius strength and electromyographic (EMG) data were collected during isometric testing. In addition, EMG data from the gluteus medius and tensor fascia latae muscles as well as 3-dimensional kinematic, kinetic and joint coupling data were collected during overground running. All data were collected prior-to and following a run to exertion. Prior to the run to exertion, with runners in a "fresh" state, there were no differences in hip abductor strength, kinematic joint coupling and terminal swing phase muscle activation timing between runners with ITBS and healthy runners. In a "fresh" state, ITBS runners demonstrated less resistance to fatigue at their gluteus medius muscle than did the healthy runners. As a result of exertion, runners with ITBS demonstrated decreased peak hip adduction angles during the stance phase of running gait. There were no group-by-exertion interactions for peak hip internal rotation angles, hip abductor and external rotator moments, kinematic joint coupling or hip abductor strength. There was a main effect of exertion for hip abductor moments, hip external rotator moments and hip abductor strength whereby both healthy and injured runners demonstrated 3.8, 4.2 and 7.3% decreases respectively following the run to exertion. In addition, there was a main effect of exertion on hip frontal/knee transverse plane kinematic joint coupling during the first half of loading where runners demonstrated a 7.3% increase in joint coupling values following the run to exertion. Our data did not detect group-by-exertion interactions or main effects of group or exertion with respect to terminal swing muscle activation timing. There was a significant group-by-exertion interaction when examining fatigue resistance. In a fresh-state, runners with ITBS demonstrated less resistance to fatigue than their healthy counterparts. Following the run to exertion, these differences did not exist. The results of this study suggest that currently symptomatic runners with ITBS demonstrate a potentially compensatory pattern of decreased stance phase hip adduction as compared with healthy runners. Hip internal rotation, abductor moments, external rotator moments or kinematic joint coupling do not appear to discriminate between the two groups. The results of this study also suggest that hip abductor strength may not be as large of a factor in the development of ITBS as previously thought. Instead, this muscle's endurance, or its ability to resist fatigue may play a larger role.
Temple University--Theses

In dieser Arbeit studieren wir durch numerische Simulationen die Theorie der starken Wechselwirkung Quantenchromodynamik auf einem Raumzeit-Gitter (Gitter-QCD) mit vier dynamischen Quark-Flavors. In den Anfaengen der Gitter QCD wurden die Effekte der Quark-Polarisation aufgrund von technischer Begrenzung der Rechenkapazitaet vernachlaessigt und die sogennante "quenched Approximation" angewendet. Der Grund fuer die "quenched" Approximation war, dass der numerische Aufwand um die Fermion-Determinante auszuwerten die damaligen technischen Moeglichkeiten ueberstieg. In der Tat ist dies immer noch eine grosse Herausforderung fuer die numerische Simulation der QCD aber durch neue technische und algorithmische Entwicklungen kann man heutzutage die Quark-Polarisationseffekte mit mindestens zwei Quark-Flavors beruecksichtigen. Seit einigen Jahren werden solche Simulationen in verschiedenen Kollaborationen durchgefuehrt. In unserem Projekt wird die Gitter-QCD mit vier degenerierten O(a) verbesserten Wilson Quarks im Schroedinger Funktional Schema untersucht mit dem Ziel, die Energieabhaengigkeit der starken Kopplung zu berechnen. Zu diesem Zweck bestimmen wir erst den O(a) Verbesserungskoeffizienten csw mit vier Flavors und benutzen dieses Ergebnis um die Step-Scaling Funktion der QCD zu bestimmen, die das Laufen der Kopplung ueber einen grossen Skalenbereich beschreibt. Unter Benutzung eines Finite-Size Verfahrens berechnen wir den Lambda Parameter in Einheiten von einer Skala Lmax, die eine eindeutig definierte Laenge im hadronischen Bereich darstellt. Die QCD-Kopplung alpha_SF im sogenannten Schroedinger Funktional Schema wird dann ueber einen weiten Bereich der Energie bestimmt und ein Vergleich mit 2-loop und 3-loop Stoerungstheorie sowie mit dem nicht-perturbativen Ergebnis fuer den Fall von zwei Flavors durchgefuehrt.
In this thesis we study the theory of strong interaction Quantum Chromodynamics on a space-time lattice (lattice QCD) with four flavors of dynamical fermions by numerical simulations. In the early days of lattice QCD, only pure gauge field simulations were accessible to the computational facilities and the effects of quark polarization were neglected. The so-called fermion determinant in the path integral was set to one (quenched approximation). The reason for this approximation was mainly the limitation of computational power because the inclusion of the fermion determinant required an enormous numerical effort. However, for full QCD simulations the virtual quark loops had to be taken into account and the development of new machines and new algorithmic techniques made the so-called dynamical simulations with at least two flavors possible. In recent years, different collaborations studied lattice QCD with dynamical fermions. In our project we study lattice QCD with four degenerated flavors of O(a) improved Wilson quarks in the Schroedinger functional scheme and calculate the energy dependence of the strong coupling constant. For this purpose, we determine the O(a) improvement coefficient csw with four flavors and use this result to calculate the step scaling function of QCD with four flavors which describes the scale evolution of the running coupling. Using a recursive finite-size technique, the Lambda parameter is determined in units of a technical scale Lmax which is an unambiguously defined length in the hadronic regime. The coupling alpha_SF of QCD in the so-called Schroedinger functional scheme is calculated over a wide range of energies non-perturbatively and compared with 2-loop and 3-loop perturbation theory as well as with the non-perturbative result for only two flavors.

The vast majority of all experimental results in particle physics can be described by the Standard Model (SM) of particle physics. However, neither the existence of neutrino masses nor the mixing in the leptonic sector, which have been observed, can be described within this model. In fact, the model only describes a fraction of the known energy in the Universe. Thus, we know there must exist a theory beyond the SM. There is a plethora of possible candidates for such a model, such as supersymmetry, extra dimensional theories, and string theory. So far, there are no evidence in favor of these models. These theories often reside at high energies, and will therefore be manifest as effective theories at the low energies experienced here on Earth. A first example in extra-dimensional theories. From our four-dimensional point of view, particles which propagate through the extra dimensions will effectivel be perceived as towers of heavy particles. In this thesis we consider an extra-dimensional model with universal extra dimensions, where all SM particles are allowed to propagate through the extra dimensions. Especially, we place a bound on the range of validity for this model. We study the renormalization group running of the leptonic parameters as well as the Higgs self-coupling in this model with the neutrino masses generated by a Weinberg operator. Grand unified theories, where the gauge couplings of the SM are unified into a single oe at some high energy scale, are motivated by the electroweak unification. The unification must necessarily take place at energies many orders of magnitude greater than those that ever can be achieved on Earth. In order to make sense of the theoru, ehich is given at the grand unified scale, at the electroweak scale, the symmetry at the grand unified scale is broken down to the SM symmetry. Within these models the SM is considered as an effective field theory. We study renormalization group running of the leptonic parameters in a non-supersymmetric SO(10) model which is broken in two steps via the Pati-Salam group. Finally, the discovery of the new boson at the LHC provides a new opportunity to search for physics beyond the SM. We consider an effective model where the magnitudes of the couplings in the Higgs sector are scaled by so-called coupling scale factors. We perform Bayesian parameter inference based on the LHC data. Furthermore, we perform Bayesian model comparison, comparing models where one or several of the Higgs couplings are allowed, to the SM, where the couplings are fixed.

QC 20141020

The vast majority of experiments in particle physics can be described by the Standard Model of particle physics (SM). However, there are indications for physics beyond it. The only experimentally demonstrated problem of the model is the difficulty to describe neutrino masses and leptonic mixing. There is a plethora of models that try to describe these phenomena and this thesis investigates several possibilities for new models, both full theories and effective frameworks.   The values of the parameters in a model are dependent on the energy scale and we say that the parameters run. The exact behavior of the running depends on the model and it provides a signature of the model. For a model defined at high energies it is necessary to run the parameters down to the electroweak scale in order to perform a comparison to the known values of observed quantities. In this thesis, we discuss renormalization group running in the context of extra dimensions and we provide an upper limit on the cutoff scale. We perform renormalization group running in two versions of a non-supersymmetric SO(10) model and we show that the SM parameters can be accommodated in both versions. In addition, we perform the running for the gauge couplings in a large set of radiative neutrino mass models and conclude that unification is possible in some of them.   The Higgs boson provides new possibilities to study physics beyond the SM. Its properties have to be tested with extremely high precision before it could be established whether the particle is truly the SM Higgs boson or not. In this thesis, we perform Bayesian parameter inference and model comparison. For models where the magnitude of the Higgs couplings is varied, we show that the SM is favored in comparison to all other models. Furthermore, we discuss lepton flavor violating processes in the context of the Zee model. We find that these can be sizeable and close to the experimental limits.

QC 20170221

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Elaboramos uma revisão de como o problema da hierarquia aparece na teoria Eletrofraca, pois entendemos que esse assunto ganhou importância e merece atenção especial. Apesar disso, notamos que muitos conceitos necessários para compreender a origem do problema encontram-se espalhados em diferentes livros e artigos, dificultando o acesso à informação. Por isso, apresentamos neste trabalho esses principais conceitos de maneira consolidada.
We develop a review on how the hierarchy problem appears in the Electroweak theory. Nowadays we think that this problem is greater in importance than it was in the past, so it deserves special attention, but we noticed several concepts needed to understand the problem are scattered in different books and papers, which hinders full access to information. Therefore, we intend to present the key subjects in a single document, because we didn't find similar work in previous studies.
2015/19572-0

No
The purpose of this article is determining if and how the kinematic relationship between adjacent body segments changes when an individual’s gait pattern is experimentally manipulated can yield insight into the robustness of the kinematic coupling across the associated joint(s). The aim of this study was to assess the effects on the kinematic coupling between the forefoot, rearfoot and shank during ground contact of running with alteration in foot strike pattern. Twelve subjects ran over-ground using three different foot strike patterns (heel strike, forefoot strike, toe running). Kinematic data were collected of the forefoot, rearfoot and shank, which were modelled as rigid segments. Coupling at the ankle-complex and midfoot joints was assessed using cross-correlation and vector coding techniques. In general good coupling was found between rearfoot frontal plane motion and transverse plane shank rotation regardless of foot strike pattern. Forefoot motion was also strongly coupled with rearfoot frontal plane motion. Subtle differences were noted in the amount of rearfoot eversion transferred into shank internal rotation in the first 10–15% of stance during heel strike running compared to forefoot and toe running, and this was accompanied by small alterations in forefoot kinematics. These findings indicate that during ground contact in running there is strong coupling between the rearfoot and shank via the action of the joints in the ankle-complex. In addition, there was good coupling of both sagittal and transverse plane forefoot with rearfoot frontal plane motion via the action of the midfoot joints.

No
Motion at the midfoot joints can contribute significantly to overall foot motion during gait. However, there is little information regarding the kinematic coupling relationship at the midfoot. The purpose of the present study was to determine whether the coupling relationship at the midfoot and subtalar joints was affected when step width was manipulated during running. Twelve subjects ran over-ground at self-selected speeds using three different step widths (normal, wide, cross-over). Coupling at the midfoot (forefoot relative to rearfoot) and subtalar (rearfoot relative to shank) joints was assessed using cross-correlation techniques. Rearfoot kinematics were significantly different from normal running in cross-over running (P < 0.05) but not in wide running. However, coupling between rearfoot eversion/inversion and shank rotation was consistently high (r > 0.917), regardless of step width. This was also the case for coupling between rearfoot frontal plane motion and forefoot sagittal plane (r < 0.852) and forefoot transverse plane (r > 0.946) motion. There was little evidence of coupling between rearfoot frontal plane motion and forefoot frontal plane motion in any of the conditions. Forefoot frontal plane motion appeared to have little effect on rearfoot frontal plane motion and thus, had no effect on motion at the subtalar joint. The strong coupling of forefoot sagittal and transverse plane motions with rearfoot frontal plane motion suggests that forefoot motion exerts an important influence on subtalar joint kinematics.

The purpose of this series of investigations was to determine how custom foot orthotic intervention influences the lower extremity dynamics and intra-limb coordination in healthy and injured female runners. For the first investigation, dynamic data were collected from 12 healthy female runners (Control group) and 12 female runners with a recent history of overuse knee running injury (Treatment group). Results revealed that the influence of CFO intervention on lower extremity appears to occur with short-term intervention. The intervention produced a similar response in both groups. The knee kinematics were not influenced by the intervention however there were changes observed in knee kinetics. For the second investigation, dynamic data were collected during overground running trials in Treatment group from Study One who had completed 6 weeks of orthotic therapy. Data were collected with the subjects running with (CFO condition) and without (Shod condition) foot orthoses in three running shoes with varying midsole composition. Results revealed that the only kinematic variable influenced by running shoe midsole durometer was maximum rearfoot eversion velocity. However, CFO intervention in the footwear led to significant decreases in rearfoot kinematic variables, tibial internal rotation and internal ankle inversion moments. In addition, it was revealed that when a CFO intervention is added to a shoe of lesser density, the dynamics exhibited by the runner are similar to when wearing a shoe of greater density. For the third investigation, kinematic data were collected from 9 healthy female runners (Control group) and 9 female runners with a recent history of overuse knee running injury (Treatment group). Both groups performed a 30-minute treadmill run and relative motion plots were created for the intra-limb couplings. Results revealed that CFO intervention helped to maintain variability during the early stance phase throughout the course of the run in the injured runners. In the Treatment group, the TibTP/CalFP and KnTP/RFFP coordination variability during the early stance phase significantly decreased throughout the course of the 30-minute run for the Shod condition. While wearing the CFO condition the variability went unchanged and better resembled patterns exhibited by the Control group.