Ever since the first plate-tectonic model for the Appalachians was proposed, the Laurentian margin has been interpreted as having experienced a collision-related dynamo-thermal event during the Middle Ordovician Taconic orogeny. In the western Newfoundland Appalachians, evidence for this collision is well-preserved in the Dashwoods subzone. Nevertheless, rocks of the neighbouring Corner Brook Lake block (CBLB), which is located in the heart of the Laurentian realm, did not show evidence for such an event. Instead, it was affected by Early Silurian Salinic deformation and associated peak metamorphism. Even though this difference in Early Palaeozoic tectonic history between the Dashwoods and the CBLB is widely known, it has not been satisfactorily explained. To better understand the Early Palaeozoic history of the region, in particular to test and better explain the lack of a Taconic dynamo-thermal event in the CBLB, field mapping, microscopic work, and U-Pb and 40Ar/39Ar geochronological studies were undertaken in the western and northern part of the Dashwoods subzone, and in the southern part of the CBLB. In addition, the kinematic history of the Baie Verte-Brompton Line - Cabot Fault Zone (BCZ), the tectonic zone that separates the two unique tectonic fragments, was studied. The western and northern parts of the Dashwoods subzone contain variably foliated igneous units of Middle Ordovician age (ca. 460 Ma) that are associated with the regionally voluminous Notre Dame continental arc. A ca. 455 Ma conjugate set of late syn-tectonic pegmatite dykes in the BCZ demonstrates a dextral sense of shear along the BCZ (DBCZ-1) during the Late Ordovician to earliest Silurian, and constrains the minimum age of the main phase of ductile deformation in the Dashwoods subzone. The fault-bounded CBLB has been affected by a single west-vergent deformational event, constrained between ca. 434 and ca. 427 Ma. More importantly, no evidence – neither petrographic nor geochronological – is present that would indicate that the CBLB was affected by a significant Taconic dynamo-thermal event. Hence, the CBLB and Dashwoods could not have been juxtaposed until after the late Early Silurian. Furthermore, the basement to the CBLB is devoid of any Grenville (sensu lato; ca. 1.0-1.3 Ga) U-Pb ages, which is in sharp contrast with crystalline basement elsewhere in the region, such as the Long Range Inlier. Therefore, it is highly unlikely that the CBLB represents the para-autochthonous leading edge of the Laurentian craton in the Newfoundland Appalachians, as commonly accepted. The CBLB is interpreted as a suspect terrane that has moved over 500 km parallel to the strike of the orogen. Docking to the external Humber Zone is likely to have occurred during the Early Silurian. Final juxtaposition with the Dashwoods took place after the late Early Silurian (post-Salinic) as a result of protracted dextral movement along the BCZ (DBCZ-2 and DBCZ-5). Current tectonic models for the Newfoundland Appalachians mainly focus on well-documented Early Palaeozoic orthogonal convergence of various terranes with the Laurentian margin, but large-scale orogen-parallel movements have rarely been considered. The possibility of large-scale strike-slip tectonics documented here, in addition to the convergent motions, may have significant implications for the tectonic interpretation of the Early Palaeozoic evolution of the Newfoundland Appalachians.

Ever since the first plate-tectonic model for the Appalachians was proposed, the Laurentian margin has been interpreted as having experienced a collision-related dynamo-thermal event during the Middle Ordovician Taconic orogeny. In the western Newfoundland Appalachians, evidence for this collision is well-preserved in the Dashwoods subzone. Nevertheless, rocks of the neighbouring Corner Brook Lake block (CBLB), which is located in the heart of the Laurentian realm, did not show evidence for such an event. Instead, it was affected by Early Silurian Salinic deformation and associated peak metamorphism. Even though this difference in Early Palaeozoic tectonic history between the Dashwoods and the CBLB is widely known, it has not been satisfactorily explained. To better understand the Early Palaeozoic history of the region, in particular to test and better explain the lack of a Taconic dynamo-thermal event in the CBLB, field mapping, microscopic work, and U-Pb and 40Ar/39Ar geochronological studies were undertaken in the western and northern part of the Dashwoods subzone, and in the southern part of the CBLB. In addition, the kinematic history of the Baie Verte-Brompton Line - Cabot Fault Zone (BCZ), the tectonic zone that separates the two unique tectonic fragments, was studied. The western and northern parts of the Dashwoods subzone contain variably foliated igneous units of Middle Ordovician age (ca. 460 Ma) that are associated with the regionally voluminous Notre Dame continental arc. A ca. 455 Ma conjugate set of late syn-tectonic pegmatite dykes in the BCZ demonstrates a dextral sense of shear along the BCZ (DBCZ-1) during the Late Ordovician to earliest Silurian, and constrains the minimum age of the main phase of ductile deformation in the Dashwoods subzone. The fault-bounded CBLB has been affected by a single west-vergent deformational event, constrained between ca. 434 and ca. 427 Ma. More importantly, no evidence – neither petrographic nor geochronological – is present that would indicate that the CBLB was affected by a significant Taconic dynamo-thermal event. Hence, the CBLB and Dashwoods could not have been juxtaposed until after the late Early Silurian. Furthermore, the basement to the CBLB is devoid of any Grenville (sensu lato; ca. 1.0-1.3 Ga) U-Pb ages, which is in sharp contrast with crystalline basement elsewhere in the region, such as the Long Range Inlier. Therefore, it is highly unlikely that the CBLB represents the para-autochthonous leading edge of the Laurentian craton in the Newfoundland Appalachians, as commonly accepted. The CBLB is interpreted as a suspect terrane that has moved over 500 km parallel to the strike of the orogen. Docking to the external Humber Zone is likely to have occurred during the Early Silurian. Final juxtaposition with the Dashwoods took place after the late Early Silurian (post-Salinic) as a result of protracted dextral movement along the BCZ (DBCZ-2 and DBCZ-5). Current tectonic models for the Newfoundland Appalachians mainly focus on well-documented Early Palaeozoic orthogonal convergence of various terranes with the Laurentian margin, but large-scale orogen-parallel movements have rarely been considered. The possibility of large-scale strike-slip tectonics documented here, in addition to the convergent motions, may have significant implications for the tectonic interpretation of the Early Palaeozoic evolution of the Newfoundland Appalachians.

Flow of traffic on freeways and limited access highways can be represented as a series of kinemetic waves. Solutions to these systems of equations become problematic under congested traffic flow conditions, and under complicated (real-world) networks. A simplified theory of kinematics waves was previously proposed. Simplifying elements includes translation of the problem to moving coordinate system, adoption of bi-linear speed-density relationships, and adoption of restrictive constraints at the on- and off-ramps. However, these simplifying assumptions preclude application of this technique to most practical situations. This research explores the limitations of the simplified theory of kinematic waves. First this research documents a relaxation of several key constraints. In the original theory, priority was given to on-ramp merging vehicles so that they can bypass any queue at the merge. This research proposes to relax this constraint using a capacity-based weighted fair queuing (CBWFQ) merge model. In the original theory, downstream queue affects upstream traffic as a whole and exiting traffic can always be able to leave as long as it gets to the diverge. This research proposes that this diverge constraint be replaced with a contribution-based weighted splitting (CBWS) diverge model. This research proposes a revised notation system, permitting the solution techniques to be extended to freeway networks with multiple freeways and their ramps. This research proposes a generalization to permit application of the revised theory to general transportation networks. A generalized CBWFQ merge model and a generalized CBWS diverge model are formulated to deal with merging and diverging traffic. Finally, this research presents computational procedure for solving the new system of equations. Comparisons of model predictions with field observations are conducted on GA 400 in Atlanta. Investigations into the performance of the proposed CBWFQ and CBWS models are conducted. Results are quite encouraging, quantitative measures suggest satisfactory accuracy with narrow confidence interval.

Vertebrate evolution has resulted in a diversity of feeding mechanisms. Cetaceans are secondarily derived tetrapods that have returned to a marine habitat. As a result, they display feeding modes that have converged with more basal aquatic vertebrates, but display a diversity of new solutions and adaptations. To begin to explore the diversity of feeding adaptations among odontocetes, kinematics of feeding modes and feeding adaptations for belugas (Delphinapterus leucas), Pacific white-sided dolphins (Lagenorhynchus obliquidens), and long-finned pilot whales (Globicephala melas) were characterized. In addition, direct measurements of intraoral pressure were collected to determine maximum suction performance. Characters from these analyses were combined with data for other odontocetes, and were mapped onto a phylogeny of Odontoceti to begin to explore where changes in feeding modes took place. Feeding modes were diverse in belugas, Pacific white-sided dolphins, and pilot whales and included suction, ram, and a combination of both. In general, four phases were observed: (I) preparatory, (II) jaw opening, (III) gular depression, and (IV) jaw closing. Suction was a large component of the prey capture method in belugas and subambient pressures in excess of 100 kPa were generated. Belugas were also capable of lateral lip gape occlusion and anterior lip pursing to form a small anterior aperture. Pacific whitesided dolphins relied on ram to capture prey. However, some degree of pursing and resultant subambient pressure was observed that was likely used to compensate for high ram speeds or for prey manipulation and transport to the esophagus. Pilot whales were more similar to belugas in kinematics, but maintained high approach velocities and did not generate significant suction pressures; suction and ram were used in combination. Belugas and pilot whales appeared to employ hyolingual depression as a primary suction generation mechanism, whereas Pacific white-sided dolphins relied on fast jaw opening. Ancestral state reconstructions indicated that suction feeding capability evolved independently at least six times within Odontoceti. These results indicate the diversity of feeding behaviors in odontocetes and provide directives for future studies on the diversity of feeding in secondarily aquatic mammals.

Einführung Der Pronation, als Bewegungsrichtung der Rückfußbewegung, ist in der biomechanischen Forschung in der Vergangenheit sehr viel Aufmerksamkeit geschenkt worden. In den unzähligen Veröffentlichungen zur Pronation wiederholen sich zwei Kernaussagen: Einerseits ist Pronation ein natürlicher Dämpfungsmechanismus, der andererseits bei übermäßiger Ausprägung zu Überlastungsschäden führen kann. Zu beiden Aussagen finden sich viele Untersuchungen, doch eindeutig belegt oder widerlegt sind beide nicht. Die vorliegende Arbeit möchte anhand von Untersuchungen zur Methodik der Bewegungsanalyse des Rückfußes dazu beitragen, den Diskrepanzen der verschiedenen Studienergebnisse auf den Grund zu gehen. Die Arbeit gliedert sich dazu in zwei Teile: Im ersten Teil werden diverse interne und externe Faktoren auf ihr pronationsbeeinflussendes Potential dargestellt. Für den zweiten Teil werden erstens das Elektrogoniometer, als gebräuchliches Messsystem der Rückfußbewegung, mit Hilfe der stereophotogrammetrischen Bewegungsanalyse (Goldstandard) validiert und zweitens innovative Messsysteme mit Schwerpunkt auf mobiler Bewegungsanalyse der Rückfußbewegung (Hall- und Drucksensoren, Gyrometer) entwickelt und ebenfalls validiert. Methodik Im Rahmen dieser Arbeit wurde eine Reihe von Einzelstudien durchgeführt, deren Methodik schwer zu verallgemeinern ist. Grundsätzlich kamen hauptsächlich Laborstudiendesigns zur Anwendung, in denen Gelenkwinkelamplituden, -ausmaße und -geschwindigkeiten der Rückfußbewegung analysiert wurden. In den Laborstudien der Einflussfaktoren wurde die Rückfußbewegung dabei entweder mit stereophotogrammetrischer Bewegungsanalyse oder mit dem Elektrogoniometer erfasst. Bei einer Ermüdungsstudie mit Feldtestdesign wurde die Rückfußbewegung mittels Gyrometer erfasst. Zur Validierung innovativer Messsysteme der Rückfußbewegung wurde entweder die stereophotogrammetrische Bewegungsanalyse oder das Elektrogoniometer verwendet. Ergebnisse Anhand der in der Arbeit vorgenommenen Analyse der pronationsbeeinflussenden Faktoren muss geschlussfolgert werden, dass Einflussfaktoren auf die Rückfußbewegung unzureichend verstanden sind. Die Einflussfaktoren lassen sich grundsätzlich jedoch in drei Gruppen einteilen: 1. kaum erforschte Faktoren (z.B. Alter, Geschlecht, Fußdimensionen, individueller Laufstil und generelle Bewegungsart), 2. kontrovers diskutierte Faktoren (z.B. Fußform, Gelenkkoppelung, genereller Schuheinfluss und Ermüdung) und 3. gesicherte Faktoren (z.B. USG-Achsenorientierung, varus / valgus-modifizierte Schuhgeometrie, Laufgeschwindigkeit). Für Laboruntersuchungen bieten, neben der stereophotogrammetrischen Bewegungsanalyse, zwei weitere Messsysteme, Elektrogoniometer und Gyrometer, vergleichbare Resultate bei der Bestimmung der Rückfußkinematik auf. Das Elektrogoniometer zeigte mittlere bis hohe, das Gyrometer nur mittlere Korrelationen bei den betrachteten Parametern. Hall- und Drucksensoren konnten zwar für eine gegebene Stichprobe rekursiv zur Bestimmung der Rückfußparameter verwendet werden, bei unbekannten Probanden oder alternativen Schuhmodellen lagen die Bestimmtheitsmaße jedoch nicht im akzeptablen Bereich. Dennoch sind für Messungen der Sohlendeformation mit Hilfe von Hallsensoren andere Anwendungsbereiche vorstellbar und auch realisierbar. Für Felduntersuchungen der Rückfußbewegung hat das Gyrometer das größte Potential. Es war im Rahmen dieser Arbeit bereits möglich, einzelne Parameter der Rückfußbewegung (Eversiongeschwindigkeit und -ausmaß) valide in mobilen Einsatzszenarien zu bestimmen. Schlussfolgerungen und Ausblick Die wichtigste Fragestellung für die biomechanische Forschung in Bezug auf die Rückfußbewegung ist die Klärung, ob ein Zusammenhang mit der Entstehung von Überlastungsschäden besteht. Aus den Erkenntnissen dieser Arbeit lassen sich fünf Kernzielstellungen skizzieren, die beachtet werden sollten, um dieser Frage nachzugehen: 1. Entwicklung von mobilen und direkten Messsystemen, zur Erfassung der Rückfußbewegung, nicht der des Schuhs, im natürlichen Bewegungsumfeld, 2. methodische und inhaltliche Diskussion und Standardisierung der Rückfußparameter, 3. Erweiterung der isolierten Betrachtung der Rückfußbewegung auf umliegende Segmente und Gelenke, 4. Kontrolle bzw. Einbeziehung von pronationsbeeinflussenden Faktoren in Untersuchungsdesigns und 5. Durchführung von großangelegten Längsschnittuntersuchungen. / Introduction In previous biomechanical research, a lot of effort has been put into the investigation of rearfoot pronation. In numerous publications, two main assumptions have been postulated: On the one hand, pronation is considered a natural damping mechanism; on the other hand, excessive pronation may lead to overuse injuries. Both assumptions have been intensively investigated; confirmed or negated is neither of the two assumptions so far. Within the frame of this thesis the author tries to contribute to the methodological analysis of rearfoot motion to solve current discrepancies regarding rearfoot motion. The thesis is devided in two parts: In the first part, the influences of various internal and external factors on rearfoot motion are investigated. In the second part, rearfoot motion measurement devices are being validated. Firstly, the elctrogoniometer, a common device used for rearfoot motion measurements, is being validated against the stereophotogrammetric motion analysis system (golden standard) and secondly, innovative devices with their main focus on mobile measurements are being developed and validated. Methods In the case of this thesis, numerous single studies were performed, whose methods vary in such a way, that it is difficult to generalize. Mainly laboratory settings have been used, in which joint angle excursions, ranges of motion and velocities were analysed. In laboratory settings, either a stereophotogrammetric motion analysis system or an electrogoniometer were used to determine rearfoot motion. A gyrometer was utilized in a field test investigating the influence of fatigue on rearfoot motion. Either a stereophotogrammetric motion analysis system or an electrogoniometer were chosen as the golden standard to validate the innovative measurement devices. Results The results of the studies within this thesis regarding pronation influencing factors lead to the conclusion, that factors influencing rearfoot motion are not well understood so far. However, it is possible to divide the investigated factors in three groups: 1. factors, that have received little research attention (e.g. age, gender, foot dimensions, individual running style, general type of movement), 2. factors, that are controversially discussed (e.g. foot shape, joint coupling, general shoe influence, fatigue), and 3. factors that have proven to influence rearfoot motion (e.g. orientation of subtalar joint axis, varus/valgus modified shoes geometry, running velocity). For laboratory investigations two innovative measurements devices, electrogoniometer and gyrometer, have shown similar results compared to the stereophotogrammetric motion analysis system. The correlations of the analyzed parameter were medium to high for the electrogoniometer and medium for the gyrometer. In a known subject sample, using the signals of hall resp. pressure sensors resulted in acceptable rearfoot motion values. However, applied on the data of unknown subjects or alternative shoe models, the calculated rearfoot motion values were way out of an acceptable range. Nevertheless, especially the measurement of midsole deformation by using hall sensors may be useful in further usage scenarios The gyrometer has the highest potential for rearfoot motion measurements within field testings. It was already possible to validly determine various rearfoot motion parameters (eversion velocity and excursion) in mobile testing scenarios. Conclusions and outlook The clarification of a possible correlation between various pronation parameters and the development of overuse injuries turns out to be the most important question for further biomechanical research concerning rearfoot motion. The findings of the thesis indicate five major objectives that should be considered in future research: 1. Development of mobile and direct measurement devices to determine rearfoot motion, not shoe motion, in a natural movement environment, 2. methodological and contentual discussion and standardization of rearfoot motion parameters, 3. extension of the isolated perspective of a single joint motion to adjoining segments and joints, 4. control or integration of rearfoot influencing factors in the testing design and 5. realization of comprehensive longitudinal studies.

The challenges in automating the design of planar mechanisms are tremendous especially in areas related to computational representation, kinematic analysis and synthesis of planar mechanisms. The challenge in computational representation relates to the development of a comprehensive methodology to completely define and manipulate the topologies of planar mechanisms while in kinematic analysis, the challenge is primarily in the development of generalized analysis routines to analyze different mechanism topologies. Combining the aforementioned challenges along with appropriate optimization algorithms to synthesize planar mechanisms for different user-defined applications presents the final challenge in the automated design of planar mechanisms. The methods presented in the literature demonstrate synthesis of standard four-bar and six-bar mechanisms with revolute and prismatic joints. But a detailed review of these methods point to the fact that they are not scalable when the topologies and the parameters of n-bar mechanisms are required to be simultaneously synthesized. Through this research, a comprehensive and scalable methodology for synthesizing different mechanism topologies and their parameters simultaneously is presented that overcomes the limitations in different challenge areas in the following ways. In representation, a graph-grammar based scheme for planar mechanisms is developed to completely describe the topology of a mechanism. Grammar rules are developed in conjunction with this representation scheme to generate different mechanism topologies in a tree-search process. In analysis, a generic kinematic analysis routine is developed to automatically analyze one-degree of freedom mechanisms consisting of revolute and prismatic joints. Two implementations of kinematic analysis have been included. The first implementation involves the use of graphical methods for position and velocity analyses and the equation method for acceleration analysis for mechanisms with a four-bar loop. The second implementation involves the use of an optimization-based method that has been developed to handle position kinematics of indeterminate mechanisms while the velocity and acceleration analyses of such mechanisms are carried out by formulating appropriate linear equations. The representation and analysis schemes are integrated to parametrically synthesize different mechanism topologies using a hybrid implementation of Particle Swarm Optimization and Nelder-Mead simplex algorithm. The hybrid implementation is able to produce better results for the problems found in the literature using a four-bar mechanism with revolute joints as well as through other higher order mechanisms from the design space. The implementation has also been tested on three new challenge problems with satisfactory results subject to computational constraints. The difficulties in the search have been studied that indicates the reasons for the lack of solution repeatability. This dissertation concludes with a discussion of the results and future directions. / text

Correct muscular activation of the body segments during an overhand throw is achieved when movement originates in the larger and more proximal legs and trunk and moves sequentially to the smaller, distal segments of the shoulder and arm. This sequence permits angular velocity to transfer progressively through the throw as part of an open kinetic chain. The athlete can summate angular velocity and segmental forces only if he is able to create a separation between the body segments during the movement pattern, and this separation is thus essential to effective segmental sequencing for activation of the trunk muscles to occur separately from distal segment motion. Limited mobility of the shoulder and scapula during the kinematic sequence will limit the ability of that segment to receive and contribute to the angular velocity of its proximal neighbors and to apply its own muscle torque to the throwing implement. This may result in compensatory motion of the proximal muscle groups to meet the demands placed on the body. To establish a link between compensatory activation of the trunk muscles and mobility in the rotator cuff and to apply this relationship to the pattern of the overhand throw, activity in the latissimus dorsi and external oblique/quadratus lumborum muscles was measured using surface electromyography in 40 college-age participants during arm flexion and lateral shoulder rotation. Muscle activation was recorded both before and after mobilization of relevant throwing muscles through targeted functional exercise. Results showed no significant change but suggested a general decrease in the level of peak muscle activation after participants engaged shoulder exercises. This is indicative of a downward trend in compensatory trunk activation during the initiation of shoulder motion. An increase in overall trunk muscle activity was also observed after exercise, which may imply a simultaneous engagement of the proximal throwing muscles in response to shoulder motion.

Orientador: João Frnacisco Galera Monico / Banca: Paulo de Oliveira Camargo / Banca: Leonardo Castro de Oliveira / Nesta dissertação investiga-se o Posicionamento por Ponto Preciso (PPP), nos modos estático e cinemático, utilizando o Filtro de Kalman Estendido. Foram corrigidos os erros devido aos efeitos da refração troposférica, relatividade, movimento de rotação da Terra, variações das marés terrestres, correção do centro de fase da antena do satélite e fase Wind- up. Os efeitos devido à ionosfera foram minimizados através da combinação linear Ion-Free. A perda de ciclo foi detectada através da combinação linear widelane, envolvendo as duas observáveis: fase da onda portadora e pseudodistância. Quando a perda de ciclo é detectada, uma nova ambigüidade é inicializada no lugar da antiga. As implementações foram realizadas no software FILTER_FCT, em desenvolvimento na FCT/UNESP, o qual processava apenas a pseudodistância. Visando mostrar a acurácia que pode ser obtida com o PPP, foram realizados três experimentos: PPP no modo estático, PPP estático simulando o modo cinemático e PPP cinemático. No primeiro e no segundo experimentos foram utilizados dados das estações GPS: PPTE, VICO, RIOD e FORT, pertencentes à Rede Brasileira de Monitoramento Contínuo (RBMC), e da estação FRDN, localizada em Fredericton, no Canadá. No terceiro experimento foram utilizados dados do receptor GPS a bordo do satélite CHAMP. No PPP estático, utilizou-se como estratégia de processamento a modificação da variância das coordenadas e do relógio do receptor na matriz de variância-covariância do Filtro de Kalman Estendido. Verificou-se uma discrepância em relação às coordenadas consideradas verdadeiras na ordem de decímetros, com exceção das estações VICO e RIOD, que foram da ordem de centímetros. / In this dissertation the Precise Point Positioning (PPP), in static and kinematic modes, using Extended Kalman Filter is investigated. The errors due to troposphere refraction, relativity, movement of Earth's rotation, tide loading, satellite antenna phase center offset and phase wind-up were corrected. The effects due to ionosphere were minimized through the Ionospheric-Free linear combination. The widelane combination, involving phase and pseduorange, was used to detect cycle slips. When a cycle slip is detected, a new ambiguity is initialized in the place of the old one. The implementations were accomplished in the FILTER_FCT software. To show the accuracy in the PPP, three experiments were accomplished: PPP in the static mode, PPP in the static mode simulating the kinematic mode and PPP in kinematic mode. In the first and second experiments, data from PPTE, VICO, RIOD and FORT stations belonging to Brazilian Network for Continuous Monitoring (RBMC), and FRDN station located in Fredericton, Canada, were used. In the third experiment data from a GPS receiver on board of the CHAMP satellite were used. In static PPP, the modification of the coordinates variance and the receiver clock was used as processing strategy. The discrepanc ies obtained in the static positioning were on the order of decimeters, except for VICO and RIOD stations where they were on the order of centimeters. When the clock receiver variance was increased from (3.300)ø mø to (10.000)ø mø , the values of the discrepancies also increased, on the order of centimeters. Then, there is influence of the receiver clock variance in the estimated coordinates. The residual part of the tropospheric effects was estimated with the introduction of a scale factor in the processing. / Mestre

Après un accident vasculaire cérébral (AVC), l’utilisation de stratégies compensatoires dans les activités de la vie quotidienne peut freiner la récupération motrice du membre supérieur parétique. En effet, lors d’une tâche d’atteinte, les individus post-AVC présentant un déficit sévère limitant les mouvements épaule-coude, doivent utiliser la flexion du tronc afin de réaliser une tâche d’atteinte. Dans ce cas, il s’agit d’une compensation obligatoire-adaptative. D’autre part, certains individus post-AVC ayant suffisamment récupéré la motricité épaule-coude, continuent de solliciter une flexion du tronc, et cette compensation non-obligatoire du tronc est dite maladaptative car elle reflète la non-utilisation épaule–coude (proximal arm non-use - PANU) ayant pour effet d’entraver la récupération du bras parétique.Dans la première étude, 45 sujets post-AVC et 45 sujets contrôles sains appariés en âge ont effectué une tâche d’atteinte, le tronc libre (utilisation spontanée du bras) et le tronc auto-fixé (utilisation maximale du bras). L’analyse a montré que les scores PANU des sujets post-AVC étaient compris entre 1,9% et 40,7% avec une médiane à 11,7%. La mesure du score PANU est reproductible, valide et représente la réserve motrice épaule-coude. Le seuil significatif du PANU a été fixé à 6,5% (limite supérieure chez les sujets sains). Enfin, le score PANU est complémentaire aux tests usuels de déficience et de fonction du membre supérieur (Box and Block test, Fugl-Meyer)La deuxième étude a montré la possibilité d’utiliser un système Kinect dans l’obtention du score PANU. Des mesures ont été effectuées simultanément avec les deux systèmes (Kinect et Zebris-CMS20s) chez 19 sujets post-AVC. Cette étude a montré que le score PANU mesuré avec la Kinect pourrait être utilisé comme un outil de diagnostic qui permettrait de proposer aux sujets post-AVC une rééducation spécifique d’utilisation forcée du bras par tronc bloqué ou bien par feedback.La troisième étude est une revue de la littérature sur les technologies innovantes appliquées à la rééducation sensorimotrice post-AVC suggérant que le score PANU puisse être intégré dans un traitement rééducatif par réalité virtuelle.En conclusion, ces travaux démontrent que quantifier objectivement la non-utilisation épaule-coude (score PANU) lors d’une tâche d’atteinte est possible et reproductible. Les scores PANU peuvent être déterminés également par un système très accessible (Kinect) ce qui permettrait d’intégrer le score PANU dans un jeu de rééducation par réalité virtuelle. / The use of compensatory strategies to perform activities of daily living after a stroke can reduce the upper limb recovery. In fact, post-stroke individuals with severe upper limb impairment that limits shoulder-elbow motion, have to use trunk compensation to achieve a reaching task within arms’ length, which is a form of mandatory/adaptive compensation strategy. Whereas, post-stroke individuals having adequately recovered shoulder-elbow motion, continue to use the trunk when they could use the proximal arm to achieve the reach; and this non-mandatory trunk compensation is considered maladaptive because it reflects proximal arm non-use or PANU, which is detrimental to true recovery of the paretic arm.In the first study, 45 post-stroke individuals and 45 age matched healthy controls performed a seated reaching task within arm’s length with the trunk free to move (spontaneous use) and trunk restrained (maximal use) to measure their PANU score. The analysis showed that PANU scores for the post-stroke individuals ranged between 1,9% and 40,7% with a median of 11,7%, and these PANU scores were a reliable and reproducible measure of the functional reserve of the upper limb. The PANU score threshold for clinical significance was set as 6.5% (upper limit in healthy subjects). The PANU score seems pertinent as a complement to usual clinical assessments of upper limb function and impairment (Box and Block test, Fugl-Meyer).The second study explored the applicability of the Kinect system to measure PANU scores in 19 post stroke individuals in comparison to the standard Zebris-CMS20s method. The analysis showed that the PANU score measured by the Kinect was valid and reliable, and therefore should be used as a tool to classify patients in order to propose specific upper limb rehabilitation with arm-forced use by trunk restraint or feedback.Study three was a review of innovative technologies applied to sensorimotor rehabilitation after a stroke suggesting that PANU scores could be implemented in virtual reality rehabilitation and be used as a tool to determine the efficacy of the specialised treatment.In conclusion, this thesis showed that i) objectively quantifying the proximal arm non-use (PANU score) during a reaching task using a 3D motion capture system is feasible and reliable, and ii) PANU scores are accurately determined also using a more widely available and less expensive Kinect-based motion sensor with the future aim of PANU being integrated in a Kinect-based upper limb virtual reality rehabilitation.

Ce travail porte sur l'incorporation de nanorenforts biosourcés, c'est-à-dire des nanofibrilles de cellulose (NFC), dans les matériaux composites à matrice polymère et les mousses. Ces nouveaux matériaux biosourcés peuvent par exemple être utilisés pour la conception de structures sandwich. L'étude à caractère expérimental, théorique et numérique s'articule autour de trois axes visant à optimiser tant les procédés d'élaboration que les propriétés en service de ces matériaux.Dans un premier temps, la rhéologie des suspensions concentrées de NFC, fluides à seuil thixotropes, a été étudiée aux échelles macro- et mésoscopiques en utilisant un dispositif original de rhéométrie couplé à des mesures de champs cinématiques par vélocimétrie ultra-sonore. Nous montrons ainsi que l'écoulement des suspensions de NFC est fortement hétéro-gène et présente des glissements aux parois, de multiples bandes de cisaillement couplés avec des écoulements de type « bouchon ». Sur la base de cette étude, un modèle rhéolo-gique multi-échelles est proposé. Ce modèle tient compte d'une part de l'architecture aniso-trope des réseaux connectés de NFC dans ces suspensions, et d'autre part des interactions mécaniques et physico-chimiques aux échelles nanométriques. Il permet de montrer que les interactions colloïdales et hydrodynamiques, ainsi que la tortuosité et l'orientation des NFC jouent un rôle majeur sur la contrainte seuil et sur le comportement rhéofluidifiant de ces suspensions.Dans un deuxième temps, des nanocomposites à matrice polymère ont été élaborés sous forme de films en faisant varier sur une très grande plage la fraction volumique de NFC. En utilisant d'une part des techniques de microscopie (AFM, MEB) et de diffraction aux rayons X, et d'autre part des essais mécaniques (traction, DMA) nous montrons (i) que les NFC ont une orientation plane et s'organisent en réseaux connectés par des liaisons hydro-gènes, (ii) que ces réseaux jouent un rôle majeur sur le comportement mécanique des nano-composites et (iii) que le comportement élastique des nanocomposites est bien en deçà des prévisions données par les modèles micromécaniques de la littérature. De là, nous proposons un modèle multi-échelles alternatif où les principaux nano-mécanismes de déformation sont ceux se produisant dans les parties amorphes des NFC et au niveau des très nombreuses interfaces entre NFC.Enfin, nous avons étudié l'influence des conditions d'élaboration, de la nature et de la con-centration des NFC sur les microstructures (microtomographie synchrotron à rayons X), les propriétés mécaniques (essais de compression) et les micro-mécanismes de déformation (essai in situ en microtomographie) de mousses préparées par cryodessiccation de suspensions aqueuses de NFC. / This study focuses on the use of cellulose nanofibrils (NFCs) as bio-based nano-reinforcement in polymer composites and foams. These renewable materials can be used in place of traditional materials such as for instance to produce sandwich panels. This experi-mental, theoretical and numerical work aims at optimizing the processing of these NFC-based materials as well as their use properties.In the first part of this work, the rheology of concentrated NFC suspensions, that behave as thixotropic yield stress fluids, is investigated at macro- and mesoscales using an original rheo-ultrasonic velocimetry (rheo-USV) setup allowing the local flow kinematic to be obtai-ned. We show that the flow of NFC suspensions is highly heterogeneous and exhibits com-plex situations with the coexistence of wall slippage, multiple shear bands and plug-like flow bands. Using this experimental database, we develop an original multiscale rheological model for the prediction of the rheology of NFC suspensions. The model takes into account the anisotropic fibrous nature of NFC networks as well as colloidal and mechanical interaction forces occurring at the nanoscale. The model predictions prove that colloidal and hydrody-namic interaction forces together with the orientation and the wavy nature of NFCs play a major role on the yield stress and shear thinning behaviour of the suspensions.In the second part of this work, NFC-reinforced polymer nanocomposite films are processed for a wide range of NFC contents. Using advanced microscopy techniques (AFM, SEM), X-ray diffraction and mechanical tests (tensile and DMA tests), we show (i) that NFCs form highly connected nanofibrous structures with in-plane random orientation, (ii) that these connected NFC networks play a leading role on the mechanical behaviour of the nanocompo-sites and (iii) that the elastic properties of nanocomposite films are much lower than those predicted from the micromechanical models of the literature. In light of these observations, we propose an alternative multiscale model in which the main involved deformation nano-mechanisms are those occurring both in the amorphous segments of the nanofibers and in the numerous nanofiber-nanofiber contact zones.Finally, in a third part we focus on the influence of the processing conditions, the suspension type and the NFC concentration on the microstructure (using X-ray synchrotron microto-mography), the mechanical properties (using compression tests) and the deformation micro-mechanisms (using in situ compression test with X-ray microtomography) of various foams prepared from NFC suspensions by freeze-drying.