La préhension manuelle est une des habilités de l’homme la plus développée et la plus utilisée dans la vie de tous les jours. Cette capacité nous permet de saisir et de manipuler des objets dans des configurations aussi nombreuses que complexes. Malheureusement, la main est aussi le siège de nombreuses blessures qui, de par l’importance de la préhension, sont fortement handicapantes. Face à ce constat, comprendre les contraintes mécaniques qui sont exercées dans les muscles, les tendons, les articulations et les ligaments lors de gestes de la vie quotidienne apparaît comme un enjeu majeur pour la prévention, la réhabilitation et l’ergonomie. L’objectif de ce travail doctoral était de développer un modèle biomécanique de la préhension permettant une estimation de ces variables non mesurables. A titre d’exemple,le paradigme de la pince pouce-index a été utilisé. Dans une première étude, les modèles biomécaniques de la pince disponibles dans la littérature ont été développés et comparés.Suite à cette évaluation, il a été constaté que ces modèles, en particulier le pouce,nécessitaient des améliorations pour permettre une évaluation physiologiquement réaliste lors de la préhension. Dès lors, plusieurs améliorations ont été proposées. Premièrement, une procédure expérimentale a été développée afin d’évaluer et d’inclure les participations mécaniques passives (ligaments, tissus mous, butées osseuses) de l'articulation trapèzométacarpienne. Deuxièmement, des mesures effectuées par IRM ont été utilisées afin d’intégrer l’action mécanique du muscle First Dorsale Interosseous dans l’équilibre du pouce,ce muscle étant alors négligé malgré son importance dans les tâches de préhension.Troisièmement, une méthode expérimentale permettant d’évaluer plus facilement et plus précisément, in situ, les axes de flexion/extension et d’adduction/abduction de l’articulation trapèzométacarpienne a été proposée et évaluée. Enfin, le modèle biomécanique incluant ces améliorations a été mis en œuvre dans une dernière étude ergonomique visant à étudier l’effet de la taille de l’objet manipulé sur les forces musculaires et articulaires. / Manual precision grip is one of man's most developed and most used ability in everyday lifeactivities. The negative outcome is the high exposure of the hand to repetitive stress injurieswhich are often very disabling. Thus, the understanding of the mechanical stress exerted inmuscles, tendons, joints and ligaments during gripping tasks appears as a major issue forinjury prevention, rehabilitation and ergonomic considerations. This doctoral work aimed atdeveloping a biomechanical model of the grip to estimate the unmeasurable internal loads. Asan example, the classical paradigm of the thumb - index finger grip was used. In a first study,the biomechanical models of the thumb available in the literature were compared and severalimprovements proposed in order to obtain more physiologically realistic predictions. First, anexperimental method was developed to evaluate and include passive structures moment intothe equilibrium of the trapeziometacarpal joint (TMC). Secondly, MRI was used to integratethe mechanical action of the First Dorsal Interosseous muscle at the TMC, since this musclehas commonly been neglected in thumb models but seems essential during pinch grip.Thirdly, the kinematic model which has to be used with the anthropometric data of tendonmoment arms was evaluated and compared to our proposition of a functional method toassess, in situ, the axes of rotation of the TMC. Finally, the biomechanical model includingthese improvements was implemented in an ergonomic study. We investigated the effect ofobject width on grip forces and muscles/joints loads. This doctoral work finds its consistencyin its desire to develop and apply the biomechanical modelling of the hand in the fields ofclinical and ergonomics.

Le tennis elbow est une pathologie fréquente affectant le membre supérieur. Cette pathologie s'observe également dans un large éventail d'activités manuelles allant de la manipulation d'outils de maçonnerie à la manipulation d'une souris d'ordinateur. Malgré son prévalence élevée, les mécanismes sous-jacents au développement du tennis elbow demeurent paradoxalement largement méconnus et n'offrent pas de consensus scientifique. Toutefois, les outils, les instruments ou les objets manipulés, formant une interface avec la main, sont soupçonnés d'être en partie responsables de l'apparition de cette affection. Cependant, le manque de moyens d'investigation biomécanique sur la main ramène cette assertion au statut d'hypothèse. Dans ce travail de thèse, l'idée que les caractéristiques physiques de la raquette (i.e. taille et forme du manche ; inertie de la raquette) puissent avoir une influence sur le risque d'apparition du tennis elbow a été testée. Pour cela, nous avons mené une démarche structurée en trois étapes. Tout d'abord, une approche expérimentale contrôlée nous a permis de quantifier les efforts exercés au niveau de l'interface main-manche lorsque l'on serre simplement ce dernier. Pour cela, un instrument de mesure des forces a été développé (i.e. ergomètre à 6 poutres couplé à une nappe de pression Tekscan). Cela nous a permis de définir une taille et une forme de manche optimale pour les forces de serrage. Dans un second temps, ce manche optimal (i.e. de section circulaire et de périmètre égal à 17,9% de la longueur de la main) a été testé au cours de frappes de tennis. / Lateral epicondylalgia (LE) have been reported to occur at least once in a range of 40% to 50% of tennis players and in a large number of workers using hand tools. Despite high prevalence, the mechanisms underlying the development of tennis elbow are paradoxically misunderstood and suffer from a lack of scientific consensus. The characteristics of the handled tools (e.g. the grip size and the shape) are believed to be partly responsible for the occurrence of these disorders. However, the available material and technique for investigation and the proceedings studies did not gave evidence for this hypothesis. In this work, the idea that the size and shape of a tennis racket handle can affect the risk of developing tennis elbow was tested in three main steps. First, a controlled experimental approach was performed in order to quantify the forces exerted at the interface hand / handle when squeezing simply a handle. A special force ergometer has been developed to measure the forces at the hand/handle interface. This study enabled us to define an optimal size and shape (i.e. circular perimeter equal to 18% of the length of the hand) to perform a maximal squeezing force. In a second step, the optimal handle was tested during tennis strokes. Our results show that with and without fatigue, the grip force was lower for the optimal handle compared to bigger or smaller handle. Finally, in a last step, a biomechanical model of the hand was used to assess the impact of the tennis racket grip size on the forces applied on muscles affected by tennis elbow during a simulation. Our results suggest that the optimal grip size reduces muscle tensions of hand extensor muscle.

Submitted by ADRIANA FRANCISCA DE ARAÚJO null (adrifranci@yahoo.com.br) on 2016-04-19T11:39:43Z No. of bitstreams: 1 Dissertação-Adriana Araujo.pdf: 1781999 bytes, checksum: b4418cc74a5cd142fa4696bd2b89d098 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-26T12:31:02Z (GMT) No. of bitstreams: 1 araujo_af_me_bauru.pdf: 1781999 bytes, checksum: b4418cc74a5cd142fa4696bd2b89d098 (MD5) / Made available in DSpace on 2016-04-26T12:31:02Z (GMT). No. of bitstreams: 1 araujo_af_me_bauru.pdf: 1781999 bytes, checksum: b4418cc74a5cd142fa4696bd2b89d098 (MD5) Previous issue date: 2016-02-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As atividades humanas e os artefatos utilizados para sua realização têm sido foco de estudos na área de Design Ergonômico. A interface homem/tecnologia é parte do escopo de pesquisa nos campos de design, ergonomia e saúde. O objetivo desse estudo foi a investigação sobre as diferenças no uso da força aplicada durante a escrita manual em pessoas com e sem rizartrose, bem como avaliar a influência do design do instrumento de escrita (caneta) na percepção de uso nas duas amostras. Trata-se de um estudo piloto, transversal e exploratório, em que foram desenvolvidas e aplicadas avaliações de percepção de esforço e conforto e força de preensão digital em 30 sujeitos, divididos em dois grupos de participantes do gênero feminino na faixa etária de 40 a 60 anos. Os dados coletados foram analisados através de testes estatísticos visando identificar diferenças (p≤0,05) entre os grupos. Os resultados mostraram que existem diferentes percepções sobre o uso da caneta pelos dois grupos e que não ocorrem ajustes na força de preensão digital durante o uso de diferentes instrumentos de escrita no grupo com rizartrose. Dentre as discussões apresentadas sobre o desempenho funcional das pessoas com e sem rizartrose destaca-se a importância do cuidado com as estruturas articulares durante o desempenho das atividades cotidianas e profissionais, considerando o uso dos instrumentos manuais e as intervenções terapêuticas. Portanto, é necessário aprimorar as reflexões entre aspectos fisiológicos e da neurociência que justificam parte desses resultados encontrados e discutidos acerca da percepção, força de preensão digital, rizartrose e atividades. / Human activities and artfacts used for its achievement have been study focus in the area of ergonomic design. The interface man/technology is part of the scope of research in the fields of design, ergonomy and health. The aim of this study was the investigation of the differences in the use of the applied force during handwriting in the people with and without “rizarthrosis”, as well as to evaluate the influence of the design of the writing instrument (pen) in the perception of use in both samples. It is a transversal and exploratory pilot study in which avaliations of perception of effort and comfort, and digital grip strength were developed and applied in 30 subjects divided into two groups of female participants between 40-60 years old. The collected data were analyzed through statistical tests aiming to identify differences (p≤0,05) between the groups. The results showed that there are different perceptions about the pen use by both groups and that adjustments do not occur in the digital grip strength during the use of different instruments of de writing in the “rizarthrosis” group. Among the discussions presented about the functional development of the people with and without “rizarthrosis”, it is highlited the importance of the care with the articular structures during the performance of the daily and professional activities, considering the use of the manual instruments and the therapeutic interventions. Therefore, it is necessary to improve the reflexions between physiological aspects and neuroscience which justify part of these results found and discussed about perception, digital grip strength, “rizarthrosis”and activities.

O movimento de alcançar e de pegar objetos é amplamente utilizado nas atividades diárias. Desta forma, diversos estudos têm analisado e descrito este padrão de movimento em função de diferentes aspectos que influenciam seu controle. Da mesma forma, o movimento de andar é uma habilidade fundamental nas atividades diárias e tem sido estudado e descrito amplamente na literatura. Entretanto, pouco se sabe sobre quais são as alterações que ocorrem nessas habilidades motoras quando elas são combinadas. A realização combinada de habilidades motoras (ex., andar e pegar um objeto) está muito presente no dia a dia das pessoas, mas o entendimento do controle desse tipo de tarefa combinada ainda não foi elucidado. Adicionalmente, ainda não está claro quais são as modificações que ocorrem nestes movimentos em função do processo de envelhecimento e do histórico de quedas recentes em idosos. Desta forma, três estudos foram conduzidos para investigar o desempenho motor de adultos jovens e idosos com e sem histórico de quedas na marcha combinada com o movimento de preensão em função do nível de dificuldade da tarefa manual. O primeiro estudo investigou o desempenho motor dos adultos jovens na marcha combinada com o movimento de preensão. O segundo estudo comparou o desempenho motor entre idosos com e sem histórico de quedas na marcha combinada com o movimento de preensão. Ainda, o terceiro estudo comparou o padrão de coordenação entre idosos (com e sem histórico de quedas) e adultos jovens na marcha combinada com o movimento de preensão. Participaram desta tese, 45 indivíduos distribuídos em três grupos (n=15): adultos jovens, idosos sem histórico de quedas e idosos com histórico de quedas. Os indivíduos foram convidados a alcançar e pegar um objeto em duas tarefas (manutenção da postura ereta e marcha) e para cada uma, seis condições experimentais foram realizadas com diferentes níveis de dificuldade. Para analisar o movimento de preensão, movimentos do corpo todo e os parâmetros espaço-temporais da marcha, um sistema tridimensional de análise de movimento foi utilizado. Modificações na marcha e no movimento de preensão foram identificados quando combinados, especialmente para as condições mais desafiadoras da tarefa manual. A adição da tarefa de pegar o objeto provocou uma adaptação na marcha, pois os participantes adotaram uma estratégia mais conservadora para aumentar a estabilidade dinâmica durante a fase de aproximação. Assim é possível sugerir que o movimento de preensão foi sobreposto ao da marcha, embora as adaptações no comportamento motor sejam globais, pois ambos os padrões motores (marcha e preensão) foram modificados para realizar com sucesso a tarefa em função dos diferentes níveis de dificuldade da tarefa manual. Os idosos com histórico de quedas apresentaram um desempenho motor inferior aos idosos sem histórico de quedas na marcha combinada com o movimento de preensão, como por exemplo, redução na velocidade do passo, aumento na duração do passo, redução na velocidade do punho e na abertura entre os dedos. Além disso, os idosos com histórico de quedas apresentaram maior redução na velocidade do COM AP em comparação com os idosos sem histórico de quedas. Assim, o paradigma de tarefas combinadas desenvolvido no presente estudo identificou mudanças nas estratégias de controle motor em idosos caidores, sendo que estas alterações foram ainda mais evidenciadas nas condições manuais mais difíceis. Ainda, a adição da tarefa de pegar o objeto na marcha modificou o padrão de coordenação entre membros superiores e inferiores para os movimentos de flexão/extensão e abdução/adução. Assim, para os movimentos de flexão e extensão, um padrão mais em fase e menos fora de fase foi identificado na condição de preensão comparado com a marcha livre quando o ombro direito foi analisado em relação ao ombro esquerdo e quadril direito. Para os movimentos de abdução e adução, quando o movimento de ombro direito foi analisado em relação ao ombro esquerdo e quadril direito, foi observado um padrão menos em fase. Além disso, um padrão menos fora de fase foi observado para os acoplamentos entre ombro direito-ombro esquerdo e ombro direito-quadril esquerdo. Entretanto, estas mudanças no padrão de coordenação não foram afetadas pelo nível de dificuldade manual. Este resultado sugere que as mudanças no padrão de coordenação são mais globais, enquanto mudanças específicas no movimento de membro superior são necessárias para acomodar as diferentes demandas da tarefa manual. Finalmente, idosos com histórico de quedas apresentaram um padrão diferente de coordenação quando comparados com os adultos jovens, como por exemplo, um padrão mais fora de fase para o acoplamento entre ombro direito e quadril direito e um padrão menos fora de fase para o acoplamento entre ombro direito e quadril esquerdo na marcha combinada com o movimento de preensão. Desta forma, parece que os idosos com histórico de quedas desacoplam a tarefa da marcha combinada com o movimento de preensão, diferentes dos adultos jovens e idosos sem histórico de quedas. / Reaching-to-grasping an object is widely used in daily activities. Many studies have analyzed and described this movement pattern considering different aspects that influence how it is controlled. Likewise, walking is a fundamental skill in daily activities and has been studied and described widely in the literature. However, little is known about what are the changes that occur in these motor skills when they are combined. The combined performance of motor skills (e.g. walk and grasp an object) is very common in daily life activities, but the understanding of the control mechanisms of this type of task is lacking. In addition, it is not clear what are the changes that occur in these movements due to aging and changes in balance control as observed in older adults with history of falls. Thus, three studies were designed to investigate the motor performance of young adults and older adults with and without history of falls during walking combined with prehension. The first study investigated motor performance of young adults while performing the combined task of walk and prehension at different levels of difficulty of the manual task. The second study investigated the same combined task with different levels of manual task difficulty in older adults with and without history of falls. Yet, the third study investigated the interlimb coordination pattern in young and older adults with and without history of falls during the combined task of walking and prehension with different levels of manual task difficulty. Forty-five individuals, distributed in three groups (young adults; older adults without history of falls; older adults with history of falls), participated in this study. They performed the reach-to-grasp movement in two tasks (upright stance and gait) involving six experimental condition with different levels of manual difficulty. To analyze prehension, body movements and spatio-temporal gait parameters, a tridimensional movement analysis system was used. Modifications in gait and prehension were identified when they were combined, especially for the most difficult prehension conditions. The grasping task caused an adaptation in gait since participants preferred to adopt a more conservative strategy, increasing their dynamic stability during the approach phase and when grasping the dowel. Based on these results, it is possible to suggest that prehension was superimposed on gait, although the adaptations in motor behavior were global, since both motor patterns (i.e., walking and prehension) were changed to perform the task successfully with different levels of difficulty. It is possible to suggest that motor performance of fallers in the combined task of walking and grasping is more impaired than in no-fallers (for instance, decreased step velocity, increased step duration, decreased wrist velocity and peak grip aperture velocity). Moreover, older adults with history of falls presented a greater reduction in COM AP velocity when compared to older adults without history of falls. The combined task paradigm used in the present study showed some changes in motor control strategy of fallers older adults when performing walking and prehension combined. In addition, motor patterns (walking and grasping) of older adults (fallers and no-fallers) were modified in function of the level of manual task difficulty. The analysis of the relative motion allowed the quantification of the changes in the coordination pattern of the combined task involving walking and prehension for flexion/extension and abduction/adduction movements. For flexion/extension movements, a more in-phase and a less anti-phase pattern was identified in the grasping condition compared to walking through when right shoulder was analyzed relative to left shoulder and right hip. For adduction/abduction movements, when right shoulder was analyzed relative to left shoulder and right hip, it was observed less in phase pattern. In addition, we found a less anti-phase pattern for right shoulder-left shoulder and right shoulder-left hip couplings. However, the changes in motor coordination were not affected by the manual task difficulty for young adults and older adults with and without history of falls. This result suggests that changes in coordination are more general while specific changes in upper limb movement are necessary to deal with different task demands. Finally, older adults with history of falls presented a different pattern of coordination than young adults, such as, a more anti-phase pattern for right shoulder-right hip coupling and a less anti-phase pattern for right shoulder-left hip coupling during the combined task. Thus, it seems that older adults with history of falls decouple the walking and prehension tasks, differently of young adults and older adults without history of falls.

<p dir="ltr">Ninety percent of humans are right-handed, and this is often construed to mean that the right hand is better than the left at all tasks, in the right-handed individuals. However, we often ignore the important role played by the left-hand when performing certain bimanual tasks. For instance, when slicing a bread loaf, stabilizing the bread with the left hand is as important as slicing it with the right hand. This implies that each hand is dominant in different types of tasks. The influential dynamic dominance theory posits that each hand’s specific dominance arises from the contralateral hemisphere specialization. The dominant (right) arm produces well-coordinated movements because the left hemisphere is superior at predictive control, and the non-dominant (left) arm shows better stabilizing performance because the right hemisphere is superior at impedance control. This theory has been proposed by studying arm movements. However, it is unclear whether the features of this theory extend to grip force control during object manipulation. This is an important gap in our knowledge; identifying the differences in hand-specific control of grip force would improve our understanding of sensorimotor control of skilled bimanual manipulations. Therefore, the goal of my dissertation was to investigate whether the features of dynamic dominance extend to the control of grip forces in bimanual object manipulation.</p><p dir="ltr">In this dissertation, I performed two studies to investigate the control of complex, bimanual object manipulation tasks. Participants held an object in each hand. The two objects were connected by a spring. The grip forces of each hand accounted not only for the dynamics of the object that the hand manipulated, but also for the destabilizing forces that arose from the actions of the other hand that were transmitted by the spring. This experimental design mimics ecological tasks like slicing bread to the first degree of approximation. The goals were to determine whether the features of hand-specific specialization of control observed in wrist movements is also evident in the movement of hand-held objects and in the control of grip forces during movement execution (study 1) and planning (study 2). Furthermore, I investigated how task uncertainty interacts with hemispheric specialization in modes of grip forces control in both studies.</p><p dir="ltr">In study 1, I investigated whether grip force characteristics differ between hands during an ongoing bimanual manipulation. The right hand produced accurate object movement performance accompanied by stronger modulations in grip force in response to dynamics of loads associated with object movement compared to the left hand. In contrast, the left hand stabilized the object’s position better by exerting a higher grip force on the object. The main contribution of this study is that it suggests that the left hemisphere specializes in predicting dynamics of loads associated with object movements whereas the right hemisphere specializes in ensuring object’s stability by increasing its impedance.</p><p dir="ltr">In study 2, I investigated anticipatory modulations in grip force before an impending bimanual object manipulation task. I studied how each hand prepared grip force for the expected increase in load force, thereby uncovering differences in underlying motor planning processes of each hand. Grip force increased in both hands; however, this increase was greater in the left hand. This result indicates that the right hemisphere relies more on impedance control during planning. The main contribution of this study is that it suggests that even the motor planning processes that prepare each hand for an impending motor action are specialized in a way consistent with the predictions of dynamic dominance theory.</p><p dir="ltr">This dissertation adds to the existing knowledge about hemispheric specialization of arm movement control and extends it to grip force control. Future studies should focus on how the control of arm movements and grip force interact in each hemisphere. Furthermore, building on this dissertation, future work on pathology- and age-related dexterity loss could potentially lead to better interventions that improve the quality of life in these populations.</p>

This thesis' focus is on the use of Alfred North Whitehead's concept of Actual Entities as a computational tool for computer science and the introduction of a novel usage of Actual Entities as learning agents. Actual Entities are vector based agents that interact within their environment through a process called prehension. It is the combined effect of multiple Actual Entities working within a Colony of Prehending Entities that produces emergent, intelligent behavior. It is not always the case that prehension functions for desired behavior are known beforehand and frequently the functions are too complex to construct by hand. Through the use of Artificial Neural Networks and a technique called Observational Intelligence, Actual Entities can extract the characteristic behavior of observable phenomena. This behavior is then converted into a functional form and generalized to provide a knowledge base for how an observed object interacts with its surroundings.

Le travail présenté dans ce mémoire concerne le développement d’un système universel de manipulation de matériaux textiles souples. Il s’agit d’une pince de manipulation universelle qui se compose de trois techniques de manipulation, technique de vide, technique d’intrusion, technique de pincement. Cette pince universelle a été développée pour manipuler une surface textile de 100 x 100 mm². Les buts de cette pince sont les suivants: Acquérir une seule couche à partir d'un empilement de tissus.Tenir une seule couche, la transférer et la manipuler jusqu’au poste suivant.La technique de vide est la première technique développée dans notre recherche, elle se compose des organes de préhension qui sont « trois ventouses pneumatiques » dont les matériaux varient en fonction des matériaux textiles à manipuler, trois compensateurs de hauteur pour fixer les ventouses pneumatique et d'un générateur de vide pour créer le vide nécessaire grâce à un régulateur de pression. Les trois ventouses pneumatiques sont placées précisément sur les têtes d’un triangle équilatéral, au-dessus de la pièce textile. La technique d’intrusion est la deuxième technique développée dans notre recherche, cette technique est constituée de deux parties principales: Une partie qui donne le mouvement et l'actionnement des organes de préhension.Une partie de préhension qui contient des éléments de préhension qui sont des aiguilles.L’ensemble est commandé, au travers de vérins, par de l’air comprimée. La technique de pincement est la troisième technique développée dans notre recherche, elle comprend des organes de serrage opposés qui sont à mis en mouvement de façon alternative par deux vérins pneumatiques Deux types de validation des éléments constituant de la pince de préhension développée ont été réalisés avec succès, une validation statique en utilisant un support de fixation, une validation dynamique en utilisant un bras de robot. Pendant la validation statique, nous avons trouvé que la technique de vide fonctionnait très bien avec les matériaux imperméables à l’air et avec des matériaux ayant une porosité inférieure à 80% et/ou une perméabilité inférieure à 1500 L/m²/s sous 200 Pa.Pour les matériaux textiles ayant une porosité supérieure à 80% et/ou d’une perméabilité supérieure à 1500 L/m²/s sous 200 Pa, la consommation importante d’air comprimé interdit l’utilisation de cette technique et la force réelle d’attraction dépendant des propriétés du matériau manipulé suivant :La porosité, La perméabilité à l’air, La masse surfacique de matériau. Concernant la technique d’intrusion, nous trouvé que cette technique permet une manipulation efficace des matériaux textiles qui sont difficiles à manipuler par la technique de vide. Elle fonctionne très bien pour des matériaux perméables à l’air (tissus d’armure toile, tricots) alors qu’elle endommage les matériaux imperméables. Les risques liés à cette technique est le prélèvement de plusieurs couches à la fois si la profondeur de perçages des aiguilles n’est pas contrôlé précisément. Pendant la validation statique de la technique de pincement, nous avons trouvé que cette technique ne fonctionne pas bien seule.Pour résoudre ce problème, nous avons utilisé, la combinaison de deux technologies La technique d’intrusion technique La technique de pincement Et La technique de vide. La technique de pincement Les résultats trouvés pendant la validation de cette technique sont les suivants : la technologie de vide associée à la technique de serrage est la combinaison la plus efficace et la plus fiable, par contre un des inconvénients de cette technique est le contrôle de la force de serrage afin d’éviter l’endommagement de la surface de matériau manipulé. [...] / The work presented in this thesis concerns the development of a universal system for handling flexible textile materials. This is a universal gripper for manipulation, which consists of three technologies of manipulations, vacuum technology, intrusion technology, pinch technology. This new universal system was developed to handle a pieces of cut fabrics a square shape which had the dimensions of 100 mm×100 mm. The aims of this gripper are: Acquiring a single ply from a stack of woven fabrics Acquiring a single ply, handling and transfer it to the next station.The vacuum technology is the first technique developed in our research, it consists of a grippers which are « three pneumatic flat suction pads with stops » whose materials vary according to the manipulate textile materials, three level compensators for fixing the penumatic flat suction pads and a pneumatic vacuum generator to create the necessary vacuum thanks to a pressure regulator. The three pneumatic flat suction pads are precisely placed on the heads of an equilateral triangle, above the textile piece.The intrusion technology is the second technique developed in our research; this technique consists of two main parts: A party that gives movement and actuation of the gripper A party for gripping witch include the gripping elements that are needles The both parties are controlled, through a penumatic cylinder, by compressed air.The pinch technology is the third technique developed in our research; it comprises clamping grippers which are placed oppositely to moving alternately by two pneumatic cylinders.Two types of validation of the elements constituting of the gripper developed are performed, static validation by using a bracket, dynamic validation by using the robot arm.During the validation static, we found that the vacuum technology performs well for non-permeable materials and with the materials whose their porosity less of the 80 % and their air permeability less than 1500 L/m²/s under 200 pa.For the materials textiles whose their porosity more than 80 % and their permeability more than 1500 L/m²/s under 200 pa, the high consumption of compressed air prohibits the use of this technique, and the real force of attraction dependent on the following material manipulated properties: • Porosity of the material• Air permeability• Weight of the material.Concerning the intrusion technique, we found that this technique allows realizing an effective handling of textile materials which are difficult to handle by the vacuum technique. It performs very well for air permeable materials (plain weave fabrics, knitted fabrics), while damaging waterproof materials. The risk associated with this technique is the manipulation multiplies of the layers at a time if the depth of the piercing of the needles is not precisely controlled.During the static validation of the pinch technique, we found that this technique does not function well alone. To solve this problem, we used, the combination of two technologies: Intrusion technology Pinch technology and Vacuum technology Pinch technologyThe results found during the validation of this technique are: the vacuum technology associated with the pinch technology is the most effective combination and more reliable, by against one disadvantage of this technique is the control of the clamping forces to prevent the damage of the material surface manipulated.For the dynamic validation of the gripper developed, we used the robot manipulation STÄUBLI. We fixed the gripper on the end of the arm of robot and after setting it, we varied the speed of manipulation to determine the limits of the manipulation by each technology.These validation procedures have in evidence the limits of our new gripper in terms of capacity of the gripping, consumption of the compressed air, characteristics and limitations of the flexible materials handled. [...]

L'arthrose de la main est une pathologie qui engendre des douleurs et des impotences fonctionnelles fortement handicapantes pour la vie quotidienne. Malheureusement, du fait de la complexité biomécanique de la main et du manque de quantification des forces subies par les articulations des doigts, la prévention et la réhabilitation de cette pathologie demeurent problématiques. L'objectif de ce travail doctoral a été de développer une modélisation musculo-squelettique de la main pour améliorer la compréhension de l'arthrose du point de vue biomécanique. Un modèle complet de la main, incluant les cinq doigts et le poignet, ainsi qu'un protocole expérimental de mesure de la cinématique et des forces externes appliquées à la main ont d'abord été développés pour estimer l'ensemble des forces musculaires et des forces articulaires durant la préhension. Ces outils méthodologiques ont permis de clarifier les risques d'arthrose associés aux types de préhension ainsi que ceux spécifiques aux articulations. Afin d'analyser plus précisément les facteurs de risques associés à chaque individu, une méthode d'individualisation des paramètres musculaires a été développée afin de mettre le modèle de la main à l'échelle des capacités réelles des individus. Cette méthode a été employée pour l'analyse de deux patientes et a permis de caractériser les adaptations et les conséquences biomécaniques associées à leurs affections spécifiques. Le modèle de la main et les protocoles expérimentaux développés ont ainsi fournit des données quantifiées qui représentent un intérêt concret pour l'amélioration de la prévention ainsi que pour l'élaboration et l'évaluation de programmes de réhabilitation. / Hand osteoarthritis is a pathology which results in pain and functional impotencies which are problematic for everyday life. Unfortunately, because of the complexity of hand biomechanics and the lack of quantification of finger joint loadings, the prevention and the rehabilitation of this pathology remain problematic. The objective of this doctoral work was to develop the musculoskeletal modelling of the hand to improve the understanding of hand osteoarthritis from a biomechanical point of view. A complete model of the hand, including the five fingers and the wrist, as well as an experimental protocol for measuring hand kinematics and grip forces were first developed to estimate all the muscle forces and joint forces during prehension tasks. These methodological tools have then been used to clarify the risk factors of hand osteoarthritis associated to prehension tasks and to specific joints. To investigate more precisely the risk factors associated to individuals, a method has been developed to individualise muscle parameters of the hand musculoskeletal model in order to provide a better representation of the real performances of each subject. This method has then been applied to the analysis of two osteoarthritis patients and allowed a complete characterization of the specific biomechanical adaptations and consequences associated to their specific affections. The hand musculoskeletal model and the experimental protocols developed during this doctoral work provided quantified data which represents a concrete interest to improve prevention but also to elaborate and evaluate rehabilitation programs.

La préhension modifiée après tétraplégie repose sur la ténodèse. Ses caractéristiques cinématiques sont : un transport poignet fléchi, étendant les doigts puis une saisie poignet étendu, fléchissant les doigts et produisant les prises palmaires et latérales passives. Les deux phases de la préhension sont réalisées successivement après tétraplégie contrairement au maintien du couplage des deux phases du sujet sain. Les caractéristiques cinématiques des autres mouvements du membre supérieur en chaîne cinétique ouverte sont la conservation des invariants de précision et d'économie pour la programmation des gestes malgré la réduction du nombre de degrés disponibles après tétraplégie mais au détriment d'une réduction de la vitesse d'exécution. Le temps de mouvement augmente probablement pour maintenir la précision finale ou consécutivement au déficit moteur. L'extension du coude sans triceps repose sur l'augmentation des mouvements des articulations proximales de l'épaule. Cependant cette compensation est incomplète comme l'atteste la réduction de l'espace de capture supérieur où le déficit moteur des muscles agonistes, synergiques stabilisateurs de la scapulothoracique et du coude mais également la raideur et les douleurs de l'épaule sont impliqués. L'imagerie motrice (i) améliore la préhension par ténodèse, (ii) conduit une plasticité d'adaptation, (iii) améliore qualité et structure temporelle de l'imagerie. Ainsi, la préhension gagne en reproductibilité avec une réduction de la variabilité du temps de mouvement. L'extension du poignet augmente lors de la saisie attestant le renforcement du mécanisme de compensation par ténodèse pour réaliser les prises. L'imagerie motrice favorise une plasticité cérébrale adaptative avec réduction des activations des cortex prémoteur et moteur primaire anormalement augmentées après tétraplégie. Enfin, les hauts scores de vivacité sont associés à une imagerie ralentie révélant un contrôle de la qualité de la représentation mentale au détriment de sa structure temporelle. Après imagerie, la qualité de la reconstruction mentale se renforce et la structure temporelle s'améliore / Tetraplegia alters active prehension which relies on tenodesis. Its kinematic characteristics are flexion of the wrist during transport and extension of the wrist during grasping eliciting lateral and palmar grips. Transport and grasping are two consecutive movements as opposed to healthy reach-to-grasp where transport and grasping are coupled. Others open chain upper limb movements showed that despite the degrees of freedom reduction, the central nervous system still plan movements using kinematic invariants like endmovements accuracy and movement economy but at the cost of velocity that decrease. The increase of movement time can be due to the requierement of endmovement accuracy, motor deficit like inability to generate cocontraction at the elbow level being due to triceps paralysis. Despite triceps brachii paralysis, shoulder movements trigger elbow extension. However, this compensation is incomplete as shown by the decrease of superior maximal reaching. This could be due to the deficit of agonist muscles along with proximal and distal synergic stabilizer, shoulder range of motion decrease and shoulder pain. Motor imagery results in (i) prehension improvement attesting that the compensation is strengthened (ii) cortical adaptive plasticity (iii) increase in quality and temporal structure of mental reconstruction. Thereby, consistency of prehension increases as shown by the reduction of movement time variability. Wrist extension increased during grasping attesting a strengthening of tenodesis compensatory mechanism to produce grips. Motor imagery elicited adaptive brain plasticity with reduction of premotor and primary motor cortex activations that are abnormally increased after tetraplegia. Finally, motor imagery control is based on movement quality to the detriment of temporal structure. In response to motor imagery, movement quality is further enhanced and temporal structure is improved. Thereby, prehension is improved in response to motor imagery. Thus, corrective and adaptive plasticity could be promoted