A resistência elástica é aplicada amplamente em programas de fortalecimento muscular nos processos de reabilitação física. No entanto, as conseqüências biomecânicas para o músculo exercitado com esta forma de sobrecarga são pouco estudadas. A ausência de fundamentação científica no que tange a aplicação da resistência elástica fez com que surgissem algumas suposições a respeito de sua caracterização biomecânica. Uma delas sugere que o exercício com resistência elástica pode ser caracterizado como sendo isocinético. Neste contexto, o objetivo global deste trabalho foi o de caracterizar o comportamento biomecânico do músculo quadríceps femoral frente ao exercício com resistência elástica. Tal caracterização foi realizada através da utilização de um modelo biomecânico bidimensional da articulação do joelho. O seu comportamento mioelétrico também foi avaliado. Conclui-se de uma forma geral, que o desenvolvimento deste estudo permitiu um entendimento a respeito da interação biomecânica entre o músculo e a resistência elástica durante o exercício. Permitindo dessa forma elucidar algumas questões ligadas a aplicação clínica desta modalidade de exercício / The elastic resistance is applied in programs of muscular fortification in processes of physical rehabilitation. However, the biomechanicals consequences for the muscle exercised with this resistance form aren’t very studied. The low scientific fundamentation for the application of the elastic resistance, results in some suppositions about its biomechanic characterization. One of them suggests that the exercise with elastic resistance can be characterized as isokinetic. In this context, the global objective of this work was characterizing the biomechanic behavior of the quadriceps muscle front to the exercise with elastic resistance. Such characterization was accomplished through the use of a bidimensional biomechanic model of the knee joint. The electromiographic behavior was also evaluated. In a general conclusion, the development of this study allowed an understanding of the biomechanic interaction between the muscle and the elastic resistance during the exercise. Allowing to elucidate some subjects of the clinical application of this exercise modality

A avaliação da força muscular caracteriza um aspecto fundamental dentro do processo de avaliação de um paciente. O déficit de força muscular, muitas vezes, não só é a fonte de processos patológicos, como também, uma conseqüência bastante comum na presença de uma patologia. A articulação do ombro é altamente dependente de uma função muscular preservada, pois os músculos do ombro, principalmente os do manguito rotador, são os responsáveis pelo mecanismo de estabilização articular, mecanismo este fundamental para que a articulação se mantenha saudável. Portanto, a quantificação da força dos músculos do ombro se traduz como fundamental para os processos de diagnóstico e reabilitação. De uma maneira geral é praticado o teste de função muscular manual, com a finalidade de se avaliar a função muscular. No entanto, há pouca precisão com este procedimento. Desta forma, o presente estudo tem por objetivo a construção de um protótipo, de baixo custo, que possibilita a avaliação objetiva e quantitativa do torque isométrico dos músculos do ombro. Após extensa pesquisa, foi confeccionado um protótipo inicial com materiais de fácil obtenção e preço acessível, capaz de quantificar o torque dos músculos do ombro, levando em consideração os aspectos biomecânicos dentro do processo de avaliação. Tal protótipo foi elaborado possibilitando ajustes para atender às variações antropométricas individuais. Como instrumento de medida foi utilizado um torquímetro devidamente calibrado, em que foi acoplado um braço de resistência. O protótipo foi submetido a teste de adaptabilidade e eficiência, avaliando-se os músculos rotadores do ombro de 20 indivíduos saudáveis de ambos os sexos. Após o teste foi verificada boa adaptabilidade do protótipo nos indivíduos testados, demonstrando também ser eficiente na avaliação da força muscular do ombro. / The evaluation of the muscular strength characterizes a fundamental aspect within the process of a patient\'s evaluation. The deficit of muscular strength many times is the source of pathological processes, as well as, a quite common consequence in the presence of a pathology. The articulation of the shoulder is highly dependent on a preserved muscular function, therefore the shoulder muscles, mainly the ones of the rotator cuff are the ones responsible for the mechanism of articulate stabilization, this mechanism is fundamental to healthy maintenance of the articulation. Therefore, the strength quantification of the shoulder muscles is told as fundamental to the diagnosis process and rehabilitation. In a general way the test of manual muscular function is practiced, with the purpose of evaluating the muscular function. However there is little accuracy with this procedure. This way, the present study has as its main objective the construction of a low cost prototype that makes the objective and quantitative evaluation of the isometric strength of the shoulder muscles possible. After an extensive research a prototype was built with easily obtained materials and low price, capable of quantifying the muscles strength of the shoulder muscles taking to account the biomechanics aspects within the evaluation process. The prototype was elaborated making different possible fittings to match the individual anthropometrical variations. As measurement instrument a torquimeter properly calibrated was used, where a resistance arm was coupled. The prototype was submitted to adaptability and efficiency tests, evaluating the shoulders\' rotator muscles of 20 healthy individuals of both sexes. After the test the good adaptability of the prototype was observed in the tested individuals and it also demonstrated to be efficient in the evaluation of the shoulder muscular strength.

Os equinos são animais muitas vezes utilizados para práticas esportivas sendo assim o sistema músculo esquelético o mais importante dentro da prática da Medicina Veterinária nestes animais. As claudicações decorrentes de esforços físicos excessivos ou repetidos somados às deficiências de aprumos e nutrição inadedequadas apresentam uma importância econômica bastante relevante na equinocultura mundial. Diversos esforços tem sido realizados na tentativa de aperfeiçoar o exame tradicional de claudicação. Métodos objetivos, por avaliações cinéticas e cinemáticas, apresentam a vantagem de serem mais precisos, possibilitarem comprovação científica dos achados clínicos e eliminam o viés de interpretação por parte do examinador. O presente estudo teve por objetivo avaliar a utilização da acelerometria na determinação dos tempos de apoio, tempos de suspensão e tempo total das passadas de equinos ao trote (3,5 m/seg.) em esteira de alta velocidade. Cinco equinos adultos (10 a 20 anos de idade) da raça Puro Sangue Árabe foram instrumentados com um acelerômetro triaxial na região dorsal dos cascos dos membros anteriores. Foram analisadas 120 passadas de cada membro para determinação dos tempos de apoio, suspensão e totais e foram calculadas as diferenças estatísticas entre os tempos dos mesmos membros, entre os membros direito e esquerdo do mesmo animal e entre os animais. Todos os valores obtidos dos mesmos membros foram estatisticamente semelhantes em todos os animais (variância &le; a 0,0087 seg.). Os tempos de apoio entre os membros direito e esquerdo foram diferente estatisticamente em 3 animais, os tempos de suspensão em 1 animal, e os tempos totais não diferiram em nenhum animal, porém esta variação encontrou-se em milésimos de segundo. Quando realizada a comparação entre os animais, houve diferença estatística em todos os valores mensurados, utilizando para p <0,05. Podemos concluir que a utilização da acelerometria foi eficiente na obtenção dos tempos de apoio, de suspensão e tempos da passada no modelo proposto e que as diferenças estatísticas encontradas em alguns resultados possivelmente não apresentam significância na aplicabilidade clínica sugerida. Estudos futuros com a utilização de animais claudicantes e grupo controle são necessárias para validação da utilização do método para exames de claudicação e controles de tratamentos. / Horses are animals usually used for sports, so the locomotor system plays the most important role in the equine veterinary medicine practice. Lameness resulting from excessive or repetitive physical efforts, plus conformation defects, nutrition and training represents a relevant economical amount in the global equineculture. Many efforts have been made to try improving the traditional lameness exam. Objective methods, like kinetic and kinematics evaluations, shows advantages such a precision, possibility of scientific evidences of clinical findings and elimination of observer interpretation bias. The present study has the objective to evaluate the utilization of acceletometry in the determination of stance phase, swing phase and total time of steps of horses trotting (3,5 m/s) on high speed treadmill. Five adult horses (10 -20 years old) Arabs were instrumented with a triaxial accelerometer in the dorsal aspect of forelimb hooves. It was analyzed 120 steps for each limb to determine the stance, swing phases and total time of steps and the statistical differences between the same limb, between the right and left limb of the same horse and between horses were calculated. All values obtained from the same limb were statistically similar in all horses (variance &le; 0,0087 sec.). The stance phase time between right and left forelimbs were statistically different in 3 horses, the swing phase time were different in 1 horse and the total time was not different in all horses; nevertheless the variation was found in thousandth of a second. When compared the values between the horses, there was statistical difference in all measured values, considering p <0, 05. We could conclude that the utilization of accelerometry was capable to obtain the stance phase, swing phase and total time of steps in the proposed model and the statistical differences founded in some results possible do not represent significance in the clinical applicability. Future researches utilizing lame horses and control groups are necessary to validate the utilization the method for lameness examination and treatment controls.

Atualmente observa-se que as queixas de afecção física mais comuns do aparelho locomotor na clínica médica e do esporte, entre adultos jovens e adolescentes ativos, estão relacionadas ao joelho, sendo o sintoma de dor femoropatelar, a mais freqüente. Porém, essa condição é uma incógnita, para os especialistas em joelho, quando se tenta definir uma causa específica e de consenso. Como forma de tentar contribuir na elucidação desse problema resolveu-se executar este trabalho investigativo, buscando-se encontrar diferenças clínicas e biomecânicas entre indivíduos do sexo feminino, com e sem o referido sintoma, com idade entre 15 e 20 anos. Foram avaliadas 23 jovens com dor femoropatelar bilateral, sem afecção conhecida presente e 20 sem sintoma (46 joelhos sintomáticos e 40 assintomáticos). Todas foram submetidas a exames radiográficos (incidências: antero-posterior, perfil e axial), onde se verificou o alinhamento femorotibial, a altura patelar, o ângulo do sulco, o ângulo de congruência, e o ângulo femoropatelar lateral. Também se mensurou a retração dos isquiotibiais e o ângulo Q em exame clínico e, os indivíduos da pesquisa ainda se submeteram a avaliação da força, por dinamometria isocinética, dos grupos musculares extensores e flexores do joelho e do quadril, além dos rotadores mediais e laterais e os adutores e abdutores do quadril. Após análise dos resultados, pode ser observado que as diferenças, estatisticamente significativas, entre os grupos estudados, foram quanto ao alinhamento do membro inferior, com o ângulo Q apresentando um p < 0,001, o ângulo femoropatelar lateral com um p = 0,006, o ângulo do sulco com o p < 0,001, o ângulo de congruência com o p = 0,027 e, o único parâmetro diferente estatisticamente na dinamometria isocinética, foi o ângulo do pico de torque da extensão do quadril, com um p = 0,03. De acordo com os resultados da comparação entre o grupo sintomático e o assintomático, observa-se que há uma relação importante do mau alinhamento da articulação do joelho com a sintomatologia estudada, porém não pode ser apontado um ou outro ângulo como o mais importante para o surgimento da dor, ou talvez ainda possa ser dito que estes desalinhamentos predispõem o joelho ao sintoma, mas talvez não sejam as causas primárias da afecção. Ficou demonstrado que o aumento do ângulo Q e o encurtamento dos isquiotibiais não são causas de dor femoropatelar. Foi verificado que indivíduos com e sem o sintoma não apresentam diferença quanto a força muscular de músculos envolvidos na ação do quadril e do joelho. O ângulo femoropatelar lateral apresentou média maior no grupo assintomático, enquanto que a média do ângulo do sulco, no mesmo grupo, foi menor. Já o ângulo de congruência apresentou média positiva no grupo assintomático e negativa no grupo com dor, mostrando que a patela do grupo com dor, tem seu ápice mais medializado que a do grupo controle / Presently it has been observed that the most common physical affection in the locomotor system in medical and sportive clinic, among active young adults and adolescents are related to the knee, being femoropatellar pain symptom the most frequent. Although, this condition is unknown for those who are specialists in knee when they try to identify a specific cause and an agreement. As a way of trying to contribute for the elucidation of this problem, it has been decided to execute this investigative study trying to find clinic, radiographic and isokinetic differences among female individuals, with and without the above mentioned symptom, between 15 and 20 years old. 23 young females with bilateral femoropatellar pain were analyzed, with unknown affection, and 20 without symptoms (46 symptomatic knees and 40 asymptomatic). All of them were submitted to radiographic exams (anteroposterior, profile and axial incidences), were it was verified the femorotibial alignment, the patellar height, the groove angle, the congruence angle and the femoropatellar lateral angle. It was also measured the hamstring shortness and Q angle in clinic exam and, the individuals of this study were submitted to strength evaluation, by isokinetic dynamometry of the extensor and flexor muscles of knees and hips, besides hip medial and lateral rotators and the adducts and abducts. After analyzing the results, it can be observed that the statistically significant differences among studied groups were related to the inferior member alignment, with the Q angle presenting p value < 0,001, the femoropatellar lateral angle p value = 0,006, the groove angle p value < 0,001, the congruence angle p value = 0,027 and, the only one statistically different parameter in isokinetic dynamometry was the torque peak angle of hip extension with p value = 0,03. According to the results of comparison between symptomatic and asymptomatic groups there is an important relationship between bad alignment of the knee joint with the studied symptomatology, but it cannot be appointed one or another as the most important for the appearing of the pain, or maybe it still can be said that these disarrangements can predispose the knee to the symptom, but maybe they are not the primary causes of the affection. It was shown that the raise of the Q angle and the hamstring shortness are not the causes of femoropatellar pain. It was verified that individuals with or without the symptom do not show difference in relation to the muscular strength of the involved muscles in movement of the hip and knee. The femoropatellar lateral angle presented higher average in the asymptomatic group, while the average of the groove angle, in the same group, was smaller. Yet the congruence angle presented a positive average in the asymptomatic group and a negative average in the group with pain, showing that the patella in the group with pain has its apex more medially than the control group

O transporte de cargas pode causar lesões e dores na coluna. Entre as mães é frequente a existência de lombalgia, sendo o carregamento de bebês no colo uma tarefa comum e relevante. Apesar disso não há trabalhos reportando os efeitos biomecânicos do transporte de bebês. Objetivo: O objetivo deste estudo foi investigar o impacto do transporte de bebês sobre as curvaturas da coluna vertebral e sobre o deslocamento do centro de gravidade (CG) do corpo de mães. Secundariamente, foi verificada a possibilidade dos efeitos serem diferentes dos decorrentes do transporte de cargas inanimadas, bem como do transporte por mulheres que nunca tiveram filhos. Método: 20 mães com seus filhos de aproximadamente 10 kg (grupo Mães) e 44 mulheres que nunca tiveram filhos (grupo Não-Mães) participaram deste estudo. Todas as participantes foram avaliadas usando um sistema de captura de movimento em 3D, durante a realização das seguintes tarefas: (1) caminhar em linha reta em uma superfície plana com velocidade confortável auto-selecionada por cerca de 7 m e (2) manter-se na postura ereta quieta por trinta segundos, em cima de uma plataforma de força. Para ambas as tarefas, havia três condições para o grupo Mães: (A) carregando nada (sem carga), (B) carregando seu bebê no colo (bebê), e (C) carregando um boneco de peso ajustado ao peso do bebê e com 50 cm de comprimento (boneco). O grupo Não-mães realizou apenas as condições sem carga e boneco, com peso fixo de 10kg. O bebê e o boneco foram carregados sempre à frente do corpo, com os dois braços. Resultados: Os dois grupos apresentaram-se semelhantes com relação à idade das participantes (p<0,05). O transporte da carga influenciou apenas os ângulos do plano sagital para o grupo Mães (p<0,001): inclinação pélvica (sem carga= 12°; boneco= 10°; bebê= 10°), cifose torácica (sem carga= 25°; boneco= 29°; bebê= 30°), lordose lombar (sem carga= 17°; boneco=27°; bebê= 25°) e extensão do tronco (sem carga= 6°; boneco= -4°; bebê= -2°). Da mesma forma, alterações destas curvaturas foram observadas no grupo Não-Mães (p<0,001): inclinação pélvica (sem carga= 14°; boneco= 12°), cifose torácica (sem carga= 25°; boneco= 28°), lordose lombar (sem carga= 19°; boneco= 24°) e extensão do tronco (sem carga= 5°; boneco= -2°). As condições bebê e boneco imprimiram alterações diferentes na cifose torácica, na lordose lombar e na extensão do tronco de mães (p<0,05). Diferenças entre os ajustes posturais realizados pelas mulheres dos dois grupos só foram notáveis nos ângulos médios de lordose lombar e extensão do tronco (p<0,001). O efeito do peso extra no deslocamento do CG para cima foi similar entre as condições de carga realizadas pelo grupo Mães (sem carga= -4 cm; boneco= 2 cm; bebê= 2 cm) e pelo grupo Não-mães (sem carga= -4 cm; boneco= 1 cm), sem diferença entre os grupos (p>0.05). Conclusão: carregar bebês no colo produz alterações significantes nas curvaturas da coluna vertebral de mães, principalmente na região lombar da coluna. Há diferenças significativas do transporte de carga inanimada e dos ajustes posturais realizados por mulheres que nunca tiveram filhos / Background: Load carriage may cause spinal pain and biomechanics lumbar spine alteration. Among women, carrying babies is a frequent and relevant spinal load but there are no data regarding its biomechanical effect. Purpouse: This study aims to investigate the impact of transporting babies in spinal curvature and in the displacement of center of gravity (COG) on the body of mothers. Secondly, this effect was compared to those effects arising from inanimate cargo transportation, and transportation for women who never had children. Method: Twenty consecutive mothers with babies with approximately 10kg (M-group) and 44 women never pregnant (NM-group) were included in the study. All of them were evaluated using 3D movement analysis system and data were calculated as 2D projection angles in the following conditions: no load (NL); carrying a dummy (D) with similar weight of their respective babies for M-group and with 10kg for NM-group and carrying baby (B) just for mothers. Babies and dummies were carried at the front of the trunk with both arms and tasks performed were: walking 10 trials straight on a flat floor at a comfortable speed, one trial standing still and upright for 30 seconds. Results: The two groups had comparable mean of age (p<0,05). Load affected only the sagital plane angles for the M-group (p<0,001): pelvic inclination (NL= 12°; D= 10°; B= 10°), thoracic kyphosis (NL= 25°; D= 29°; B= 30°), lumbar lordosis (NL= 17°; D= 27°; B= 25°) and trunk extension (NL= 6°; D= -4°; B= -2°). Likewise, alterations in these curvatures was observed in NM-group (p<0,001): pelvic inclination (NL= 14°; D= 12°), thoracic kyphosis (NL= 25°, D= 28°), lumbar lordosis (NL= 19°, D= 24°) and trunk extension (NL= 5°; D= -2). The load conditions printed different alterations in thoracic kyphosis, lumbar lordosis and trunk extension for the M-group (p<0,05). Differences between the postural adjustments made by women in both groups were only notable angles average lumbar lordosis and trunk extension (p <0.001). The effect of extra weight in the upward displacement of the CG was similar between the loading conditions conducted by the group Mothers (no load = -4 cm = 2 cm doll, baby = 2 cm) and the group non-mothers (no load = -4 cm; dummy = 1 cm), with no difference between groups (p> 0.05). Conclusion: In conclusion, carrying babies produces significant alterations on the spinal curvatures of mothers, mainly at the lumbar region. There are significant differences of the inanimate load transport and postural adjustments made by women who never had children

La cinématique de l’articulation du genou est complexe. Elle est déterminée par des paramètres géométriques et des paramètres mécaniques. Les paramètres géométriques sont principalement définis par la géométrie des os, des surfaces articulaires et par les insertions des différents tissus mous. Les paramètres mécaniques sont définis par les caractéristiques des tissus mous exprimés par les lois qui relient les distances entre leurs insertions et les efforts qu’ils génèrent. Les muscles, tendons et ligaments sont caractérisés par leur constante de raideur et leur pré-tension à une position donnée de l’articulation du genou : l’extension totale. Cette thèse analyse à l’aide d’un modèle multi-corps rigides le comportement de l’articulation du genou. La première partie de la thèse décrit la constitution du modèle. La seconde partie positionne le modèle dans des conditions aux limites. La troisième partie présente les résultats du modèle et les compare à différentes publications de la bibliographie. La quatrième et dernière partie fait varier les différents paramètres mécaniques et quantifie leur influence sur la cinématique du genou. Une synthèse des résultats permet de mettre en évidence les paramètres les plus influents sur la rotation interne/externe du tibia par rapport au fémur et sur l’avancée/recul du fémur par rapport au tibia pendant le mouvement de flexion du genou. / Knee kinematic is complex. It depends of geometric parameters and mechanical parameters. Geometric parameters are mainly defined by bone geometry, articular surfaces and by several soft tissues insertions. Mechanical parameters are defined by soft tissues characteristics designed by laws which link distances between their insertions and generated forces. Muscles, tendons, and ligaments are characterized by linear stiffness and pre-load at one specific position of knee joint: full extension. This work analyzes with rigid-body simulation tool, the knee joint comportment. First part of this work describes model construction. Second part places model inside external loads and constrains. Third part shows model results and compares them to several bibliographies. Last and forth part tests several values of each mechanical parameter. This part evaluates influence of parameter to knee kinematic. Synthesis of results helps to show most influent parameters on internal/external rotation of tibia relative to femur and on femur anterior/posterior displacement during knee flexion movement.

Ce travail est issu de plusieurs constats. Premièrement, il est admis aujourd’hui que la capacité à percevoir et à retirer les informations visuelles les plus pertinentes d’une action adverse est un facteur déterminant de la performance sportive et ce d'autant plus si l'action est incertaine et faussée. Le second constat, découlant du premier, est que la tromperie est mise en jeu dans bon nombre d'interactions humaines, mais qu'elle est particulièrement déterminante et prépondérante dans lecadre des stratégies sportives. Enfin, le dernier constat est que l'exploration de la performance sportive, pour des raisons méthodologiques ou théoriques, ne permet pas dans certains cas d'expliquer pourquoi un expert est meilleur qu'un novice.L’objectif de notre travail est de comprendre ces déterminants (perceptivo-moteurs) de l'expertise lors d’un duel 1 vs. 1 en rugby présentant une tentative de feinte de l’attaquant. Nous résumons ce travail en trois questions concrètes auxquelles nous répondons: Comment réaliser une feinte de corps en rugby? Comment la détecter? Comment y faire face? La première étude s'attache à analyser les différences biomécaniques observables entre un mouvement de simple changement de direction et un mouvement de feinte de corps en rugby. La seconde étude, en immersion virtuelle, met en lien les informations prospectives émanant des mouvements de feinte et la prise de décision du défenseur de rugby (expert ou novice). Enfin, en se basant sur une méthodologie quasi similaire, la troisième étude vient immerger les participants dans une situation complète de défense, nous permettant d'explorer leur stratégie perceptivo-motrice. L'ensemble de ce processus nous permet de témoigner de l'effet de l'expertise mais surtout d'expliquer pourquoi l'expert est meilleur en dressant les différences de stratégie perceptivo-motrice le caractérisant. Si les implications concernent majoritairement le domaine du rugby (connaissances fondamentales et entrainement), elles présentent au sens plus large, un éclairage justifié et démontré des processus mis en jeu lors de toute interaction, humaine ou animal, sollicitant la tromperie. Nous en sommes persuadés; un prédateur animal, un joueur de poker, un défenseur de basket... se doivent deprésenter des stratégies quasi-similaires pour détecter l'intention de bluff chez l'opposant / This work comes from several observations. First, it is now accepted that the ability to pick up and attend to the most relevant visual information from an opponent action is a determinant of performance and even more so if the action is uncertain and deceptive. The second observation, deriving from the first, is that deception is put into play in many human interactions, and it is particularly crucial in sports strategies. Finally the last observation is that exploration of athletic performance, for methodological or theoretical reasons, can’t explain, in certain cases, why an expert is better than a novice.The aim of our work is to understand these determinants (perception and action) of expertise in a 1 vs. 1 duel in rugby, presenting an attempt of deceptive movement by the attacker. We summarize this work in three specific questions we answer: How to make a deceptive movement? How to detect a deceptive movement? How to answer to a deceptive movement? The first study aims to analyse the biomechanical differences between a movement with a simple changeof direction and a deceptive movement in rugby. The second study, using virtual reality, links the prospective information of the attacker’s movement and the decision making of the rugby defender (expert or novice). Finally, based on a quasi-similar methodology, the third study immerses the participants in a situation requiring a complete action of defence, allowing us to explore the perception and action strategies of the participants. This whole process allows us to demonstrate the effectof expertise but also to explain why experts are better by drawing up the differences characterizing them in terms of perception and action strategies. If the implications mainly concern the field of rugby (basic knowledge and training), they are also of great interest for any interaction, human or animal, involving deception. We are convinced, a predatory animal, apoker player, a defender of basketball ... must present similar strategies to detect the deceptive intention of an opponent

No description available.

Cross-correlation is often used as the primary technique to compare two biological signals. The cross-correlation technique is an effective means to measure the synchronization of two signals if the relative phases at all frequencies are distributed linearly, that is, there is a group delay. The group delay assumption of cross-correlation analysis imposes an unfavourable restriction on signals with relative phase correlation which varies at different frequencies. Traditional Fourier analysis applied to a short data segments, namely the Short Time Fourier Transform (STFT), provides phase information for each frequency component, but it is not suitable for biological signals with non-stationary statistics for which the ideal segment length is unknown. The application of a wavelet based phase analysis technique is discussed in this study. The frequency decomposition and temporally localized nature of the wavelet transform provides localized phase-frequency information for two signals. A wavelet frequency temporal relative phase pattern (WFT-RPP) technique to extract relative phase information at specific frequencies over the time course of a time-varying signal was developed. The technique was tested on simulated data and surface electromyographic (sEMG) data recorded from upper limb muscles in human subjects as they performed a series of dynamic push and pull tasks. Selected sEMG channel pairs are compared against each other using the WFT-RPP technique to extract the relative phase information and repetitive relative phase patterns for certain muscle pairs were observed. The properties of the WFT-RPP and the merits and weaknesses of using the technique for determining intermuscular sEMG synchronization is discussed. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2011-09-13 11:58:16.014

La construction d'ouvrages de protection répond à la nécessité de se protéger d'aléas naturels comme les phénomènes d'érosion ou de glissement de terrain. Si le béton est classiquement utilisé pour la construction de tels ouvrages, le bois est régulièrement employé sur des aléas engendrant des contraintes faibles ou modérées. Pour cela, les praticiens s'appuient sur deux approches différentes, le génie civil et l'ingénierie écologique, qui requièrent, dans ce contexte, la mise en œuvre d'une structure construite sur la base d'un agencement de rondins de bois d'essence locale. Il existe cependant des lacunes de connaissances freinant la prescription de ces ouvrages. Les verrous scientifiques concernent notamment l'évaluation du niveau de dégradation, au sens des propriétés mécaniques, des rondins pour le suivi des ouvrages existants.L'objectif de cette thèse est de développer deux méthodes d'évaluation du niveau de dégradation de rondins de sapin blanc à partir de la spectroscopie proche infrarouge (SPIR) et de l'analyse vibratoire. Dans ce travail de thèse, le niveau de dégradation d'un rondin est défini à partir du taux de perte en module d'élasticité ou en module de rupture par rapport à leur valeur à l'état intact.Les résultats obtenus ont montré que les méthodes développées permettaient d'évaluer le niveau de dégradation de rondins aussi bien en conditions semi-contrôlées qu'en conditions naturelles. La méthode par SPIR évalue le niveau de dégradation à partir de modèles de prédiction des indicateurs de référence $Dw_{MOE}$ et $Dw_{MOR}$ basés sur les statistiques multivariées. La méthode par analyse vibratoire mesure le taux de perte en module d'élasticité dynamique ($Dw_{E_n}$) des rondins, qui se caractérisent par leurs imperfections géométriques.Ce travail contribue à approfondir les connaissances sur l'évaluation du niveau de dégradation du bois. Les résultats obtenus permettent d'envisager une application sur des structures réelles. Ces deux méthodes sont effectivement adaptables pour effectuer les mesures textit{in-situ}. / The construction of protective works responds to the need to protect themselves from natural hazards such as erosion or landslides. If the concrete is conventionally used for their construction, wood is regularly used on natural hazards generating low or moderate stresses. For this, practitioners rely on two different approaches, civil engineering and ecological engineering, which require, in this context, the implementation of a structure built on the basis of an arrangement of logs. However, there are knowledge gaps hampering the prescription of these works. In particular, scientists locks concern the assessment of the level of decay, in the sense of mechanical properties, of logs for monitoring existing structures.The aim of this thesis is to develop two methods for assessing the level of decay of silver fir logs from near infrared spectroscopy (NIRS) and vibration analysis. In this thesis, the level of decay is set from the rate of loss in modulus of elasticity (MOE) or modulus of rupture (MOR) in relation to their intact value .The results showed that the methods allowed evaluating the log level of decay both in semi-controlled and in natural conditions. The NIRS method assesses the level of decay from prediction models of $Dw_{MOE}$ and of $Dw_{MOR}$ based on multivariate statistics. The method by vibration analysis measuring the loss rate in dynamic MOE ($Dw_{E_n}$)of the logs, which are characterized by their geometric imperfections.This work helps to deepen knowledge on the assessment of the level of decay of wood. The methods may be considered for application on real structures. These two methods are actually suitable for textit{in-situ} measurements.The objective of this thesis is to develop two indicators, DwNIRS and DwE1, from two complementary methods, the near infra-red spectroscopy (NIRS) and the vibration resonant method (VRM), to assess decay-extent of small-diameters silver fir logs decayed by a microbial community. These indicators are intended to help to practitioners in the diagnostic of the structures. The work is based on a mechanical definition of the decay-extent. A reference indicator DwMOE is defined for this purpose from the normalized loss in modulus of elasticity (MOE) of the logs between intact and decayed states.The thesis is composed of three parts. The first part explores the ability of NIRS to assess decay-extent in semi controlled conditions. Small-diameter logs have been degraded in a greenhouse and monitored at different decay levels. The indicator DwNIRS is calculated from a prediction model using multivariate statistics to predict the reference indicator DwMOE. The second part studies VRM. This method allows measuring dynamically the modulus of elasticity of logs at different decay levels. The third part is dedicated to the comparison of both methods in semi-controlled conditions and also in natural conditions.The results show that both methods allow identifying the effects of the microbial community on wood from early stages of decay. The indicators DwNIRS and DwE1 follow faithfully DwMOE even if the intrinsic variability of wood properties coupled with those bring with the microbial activity alter the precision. Thus, the definition of decay classes from DwNIRS and DwE1 limits the undesirable effects of the variability and brings closer the methods from those already used to assess decay in natural conditions. Finally, the classifications obtained from logs decayed in natural conditions are comparable and allow considering an application on real structures. Both methods are effectively adaptable to in-situ measurements with a limited degradation impact on structures.