Although most batoids (skates and rays) are benthic, only the skates (Rajidae) have been described as performing benthic locomotion, termed 'punting'. While keeping the rest of the body motionless, the skate's specialized pelvic fins are planted into the substrate and then retracted caudally, which thrusts the body forward. This may be advantageous for locating and feeding on prey, avoiding predators, and reducing energetic costs. By integrating kinematic, musculoskeletal, material properties, and compositional analyses across a range of morphologically and phylogenetically diverse batoids, this dissertation (i) demonstrates that punting is not confined to the skates, and (ii) provides reliable anatomical and mechanical predictors of punting ability. Batoids in this study performed true punting (employing only pelvic fins), or augmented punting (employing pectoral and pelvic fins). Despite the additional thrust from the pectoral fins, augmented punters failed to exceed the punting c apabilities of the true punters. True punters' pelvic fins had greater surface area and more specialized and robust musculature compared to the augmented punters' fins. The flexural stiffness of the main skeletal element used in punting, the propterygium, correlated with punting ability (3.37 x 10-5 - 1.80 x 10-4 Nm2). Variation was due to differences in mineral content (24.4-48-9% dry mass), and thus, material stiffness (140-2533 MPa), and second moment of area. The propterygium's radius-to-thickness ratio (mean = 5.52 +-0.441 SE) indicated that the propterygium would support true and augmented punters, but not non-punters, in an aquatic environment. All propterygia would fail on land. Geometric and linear morphometric analyses of 61 batoid pelvic girdles demonstrated that pelvic girdle shape can predict punting and swimming ability and taxonomic attribution to Order. / Characteristics of true punters' pelvic girdles, such as laterally facing fin articulations, large surface area formuscle attachment, and tall lateral pelvic processes are similar to characteristics of early sprawled-gait tetrapods' pelvic girdles. This dissertation demonstrates that punting is common in batoids, illustrates the convergent evolution of true punter and early tetrapod pelvic anatomy, and gives possible explanations for the restriction of elasmobranchs to aquatic habitats. / by Laura Jane Macesic. / Thesis ({Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

Wai Yin Yee = 遺傳演算法的應用連續影像之人體動作捕捉 / 韋燕儀. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 113-115). / Text in English; abstracts in English and Chinese. / Wai Yin Yee = Yi zhuan yan suan fa de ying yong lian xu ying xiang zhi ren ti dong zuo bu zhuo / Wei Yanyi. / Abstract --- p.ii / 摘要 --- p.iv / Acknowledgement --- p.vi / Content --- p.vii / List of Figures --- p.x / List of Tables --- p.xviii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Human Motion Capture --- p.1 / Chapter 1.1.1 --- Optical Motion Capture --- p.3 / Chapter 1.1.2 --- Monocular Motion Capture --- p.4 / Chapter 1.2 --- Proposed Human Motion Capture System --- p.6 / Chapter 1.3 --- Organization --- p.8 / Chapter Chapter 2 --- Introduction of Genetic Algorithms --- p.10 / Chapter 2.1 --- Traditional Search Methods & Genetic Algorithms --- p.11 / Chapter 2.2 --- Mechanism of Genetic Algorithms --- p.14 / Chapter 2.3 --- A Simple Genetic Algorithm --- p.16 / Chapter 2.3.1 --- Initialization --- p.16 / Chapter 2.3.2 --- Evaluation --- p.17 / Chapter 2.3.3 --- Selection --- p.18 / Chapter 2.3.4 --- Genetic Operation --- p.19 / Chapter 2.3.5 --- Termination --- p.23 / Chapter 2.4 --- Convergence Proof for GA --- p.24 / Chapter 2.5 --- Proposed Modified Genetic Algorithm --- p.26 / Chapter 2.6 --- Effectiveness of the Proposed Modified GA on Function Optimization --- p.28 / Chapter 2.6.1 --- Function 1 - Unimodal function --- p.28 / Chapter 2.6.2 --- Function 2 - Sine function --- p.35 / Chapter 2.6.3 --- Function 3 - Foxhole function --- p.39 / Chapter 2.6.4 --- Function 4 - Discrete function --- p.41 / Chapter Chapter 3 --- Pre-processing I - Articulated Stick Model --- p.44 / Chapter 3.1 --- Background Knowledge of Human Skeleton --- p.44 / Chapter 3.2 --- Simplified Humanoid Articulated Stick Model --- p.44 / Chapter Chapter 4 --- Pre-Processing II - Reference Lengths & 2-D Frame Scale --- p.48 / Chapter 4.1 --- Optimization Approach --- p.54 / Chapter 4.1.1 --- Parameters Range --- p.62 / Chapter 4.1.2 --- GA Formulation --- p.63 / Chapter 4.2 --- Triangulation approach --- p.63 / Chapter 4.3 --- Experiments & Discussion --- p.66 / Chapter 4.3.1 --- Experiment One: Synthetic sequences --- p.67 / Chapter 4.3.2 --- Experiment Two: Real image sequences --- p.71 / Chapter Chapter 5 --- Pre-Processing III - Possible Depths --- p.76 / Chapter Chapter 6 --- Resolving Depth Ambiguity by GA --- p.83 / Chapter 6.1 --- Smoothness Assumption --- p.83 / Chapter 6.2 --- Kinematic Constraint --- p.85 / Chapter 6.3 --- GA Formulation --- p.85 / Chapter 6.4 --- Proposed Constrained GA --- p.86 / Chapter 6.5 --- Implementation and Experiments --- p.87 / Chapter 6.5.1 --- Experiment One: Synthetic sequences --- p.88 / Chapter 6.5.2 --- Experiment Two: Real image sequences --- p.105 / Chapter Chapter 7 --- Conclusion --- p.111 / Bibliography --- p.113 / Appendix A Description of Rotating Angles --- p.116

A hérnia perineal é uma das afecções cirúrgicas frequentemente observadas na rotina da clínica cirúrgica de pequenos animais e acometem na sua maioria, cães machos, não castrados e acima de cinco anos. Apresenta elevado índice de recidivas e complicações pós-cirúrgicas, e devido a este fato, muitas técnicas foram preconizadas e utilizadas para a sua correção. Os objetivos do presente estudo foram avaliar a locomoção cinética dos cães com hérnia perineal bilateral, submetidos à técnica de transposição do músculo semitendinoso antes e após a sua transposição; verificar a capacidade de adaptação do membro pélvico operado, após a transposição do semitendinoso, até 90 dias de pós-operatório e analisar a viabilidade dessa técnica de reparação em casos de hérnia perineal bilateral. Foram operados onze cães com diagnostico de hérnia perineal bilateral, no Serviço de Cirurgia de Pequenos Animais junto ao Hospital Veterinário da Faculdade de Medicina Veterinária da Universidade de São Paulo (HOVET-FMVZ / USP). Todos foram submetidos à técnica de transposição do músculo e avaliados com exames baropodométricos antes e após a cirurgia, nos períodos de 30, 60 e 90 dias pós-operatório. As variáveis pico de força vertical (PFV) e impulso vertical (IV) foram utilizadas como parâmetros para a análise de mudanças na locomoção. A PFV e IV não mostraram diferença estatística (p> 0,05) entre os membros operados e não operados, respectivamente (18,62 0 &plusmn 4,93 e 18,51 &plusmn 3,75), indicando que não houve alteração na locomoção dos cães após a transposição do músculo semitendinoso. A diferença no comportamento dessas variáveis no período pré-operatório nos permitiu aferir que o desconforto provocado pela hérnia perineal possa interferir na locomoção do animal gerando assimetria, considerando que após o procedimento operatório a simetria da locomoção apresentou valores mais compatíveis dentro do normal. As diferenças em PFV e IV, embora não significativas, nos dá uma idéia da recuperação desses cães e sugere que a transposição não afeta a função locomotora do membro operado. / A perineal hernia is a surgical lesion frequently observed in surgical clinic for small animals, affecting mainly dogs neutered over five years. Has a high recurrence rate and postoperative complications, and due to this fact, many techniques have been proposed and used for its correction. The objectives of this study were to evaluate the kinetic movement of dogs with bilateral perineal hernia, submitted to the technique of transposition of the semitendinosus muscle before and after its implementation and verify the adaptability of the pelvic limb surgery, after transposition of the semitendinosus 90 days of postoperatively and analyze the feasibility of this technique of repair in cases of bilateral perineal hernia. Eleven dogs were operated with diagnosis of bilateral perineal hernia, on the Surgery Service of the animal small of the Veterinary Hospital of the Faculty of Veterinary Medicine, University of São Paulo (HOVET-FMVZ / USP). All patients underwent the technique of muscle transposition and evaluated baropodometric examinations before and after surgery, in periods of 30, 60 and 90 days postoperatively. The variables peak vertical force (PFV) and vertical impulse (VI) were used as parameters for the analysis of changes in locomotion. The PFV and IV showed no statistical difference (p> 0.05) between the operated and non operated limbs, respectively (18.62 &plusmn 4.93 and 18.51 &plusmn 3.75), indicating that there was no change in locomotion dogs after the transposition of the semitendinosus muscle. The difference in behavior of these variables in the preoperative period allowed us to infer that the discomfort caused by perineal hernia can interfere with the locomotion of the asymmetry animal generating, whereas after the operative procedure, the symmetry of locomotion showed more next values of the normal. The difference in PFV and IV, although not significant, gives us an idea of the recovery of these dogs and suggests that the transposition does not affect the motor function of the limb.

Les travaux réalisés lors de cette thèse ont porté sur le cortex moteur et les troubles de la marche de patients atteints de la maladie de Parkinson (MP). L’atteinte fonctionnelle des aires motrices corticales dans la MP et leur implication dans la physiopathologie des désordres moteurs a surtout été établie à partir de données issues des aires corticales des membres supérieurs. L’analyse électrophysiologique par stimulation magnétique transcranienne réalisée dans ces travaux de thèse a exploré les aires motrices corticales des membres inférieurs et révélé des troubles d’excitabilité différents de ceux classiquement décrits dans les aires corticales des membres supérieurs. En effet, il ressort principalement de l’étude sur le membre inférieur une diminution de la facilitation intracorticale (FIC) alors que la littérature décrit essentiellement pour les aires motrices corticales des membres supérieurs une altération des mécanismes inhibiteurs intracorticaux. Les anomalies corticales mises en évidence sont corrélées avec les paramètres locomoteurs affectés par la maladie, longueur d’enjambée et vitesse de marche. L’analyse des patients avec et sans traitement a permis de montrer que la supplémentation dopaminergique agit à la fois au niveau cortical et locomoteur normalisant partiellement les déficits observés. Les anomalies de FIC des aires corticales motrices des membres inférieurs paraissent donc être impliquées dans la physiopathologie des troubles de la marche dans la MP et pourraient de ce fait constituer un paramètre d’évaluation et un objectif thérapeutique de choix. L’utilisation de la stimulation magnétique transcranienne répétitive couplée à la neuronavigation permettrait d’explorer cette dernière piste. / This thesis aims to study the relationships between motor cortex impairment and locomotor disorders in Parkinsonian patients (PP). Most of the previous studies have focused on the upper limb cortical areas showing the existence of an imbalance in cortical excitability, which mainly evolves towards a state of impaired intracortical inhibition. However, just a few studies have been devoted so far to the exact cortical abnormalities responsible for Parkinsonians’ gait disorders. The transcranial magnetic stimulation (TMS) studies presented here demonstrate that the excitability abnormalities occurring in PP differ between the cortical areas associated with the lower and upper limbs, since defective intracortical facilitation (ICF) processes were mainly detected in the lower limbs cortical areas. Furthermore, these specific excitability abnormalities identified seem to be involve in the genesis of the hypokinetic locomotor component since correlations were established between the ICF level and the shortened stride length (and by correlates, with the reduced velocity). Patients were assessed with and without dopaminergic substitution treatment (DST). We found that DST modified significantly both the cortical excitability abnormalities and the defective locomotor parameters. Impaired facilitatory processes in lower limbs cortical areas may be involved in the pathophysiology of gait disorders in PD. This hypothesis should be addressed in an experiment coupling repetitive TMS and neuronavigation.

Human balance and locomotion control is highly complex and not well understood. To understand how the nervous system controls balance and locomotion works, we test how the body responds to controlled perturbations, the results are analyzed, and control models are developed. However, to recreate this system of control there is a need for a robot with human-like kinematics. Unfortunately, such a robotic testbed does not exist despite the numerous applications such a design would have in mobile robotics, healthcare, and prosthetics. This thesis presents a robotic testbed model of human lower legs. By using MRI and CT scans, I designed joints that require lower force for actuation, are more wear resistant, and are less prone to catastrophic failure than a traditional revolute (or pinned) joints. The result of using this process is the design, construction, and performance analysis of a biologically inspired knee joint for use in bipedal robotics. For the knee joint, the design copies the condylar surfaces of the distal end of the femur and utilizes the same crossed four-bar linkage design the human knee uses. The joint includes a changing center of rotation, a screw-home mechanism, and patella; these are characteristics of the knee that are desirable to copy for bipedal robotics. The design was calculated to have an average sliding to rolling ratio of 0.079, a maximum moment arm of 2.7 inches and a range of motion of 151 degrees. This should reduce joint wear and have kinematics similar to the human knee. I also designed and constructed novel, adjustably-damped hip and ankle joints that use braided pneumatic actuators. These joints provide a wide range of motion and exhibit the same change in stiffness that human joints exhibit as flexion increases, increasing stability, adaptability, and controllability. The theoretical behaviors of the joints make them desirable for use in mobile robotics and should provide a lightweight yet mechanically strong connection that is resistant to unexpected perturbations and catastrophic failure. The joints also bridge the gap between completely soft robotics and completely rigid robotics. These joints will give researchers the ability to test different control schemes and will help to determine how human balance is achieved. They will also lead to robots that are lighter and have lower power requirements while increasing the adaptability of the robot. When applying these design principles to joints used for prosthetics, we reduce the discomfort of the wearer and reduce the effort needed to move. Both of which are serious issues for individuals who need to wear a prosthetic device.

Two experiments were undertaken. The objective of Experiment One was to identify the lower limb muscles that were most frequently active during the early period of a step turning task for further testing in Experiment Two. In Experiment Two participants undertook multiple trials of a step-turning task, 30 and 60° to the left and right of midline, at a self-selected pace in response to a visual cue. There were five objectives to Experiment Two. Firstly, to identify the predominant order in the onset of foot movement so that anticipatory muscle activity could be defined for this task. Secondly, to identify whether there is a consistent temporal order in movement onset between the head and the feet. Thirdly, to identify whether and how consistently anticipatory lower limb muscle activity is present bilaterally. Fourthly, to assess whether there is a consistent sequence in the onset of anticipatory muscle activity among muscles active in at least 80% of trials. The final objective was to identity whether there was a consistent temporal relationship in the onset of the anticipatory muscle activity present in at least 80% of trials, with the onset of head and foot movement. Study Design: A repeated measures design was used. Background: Anticipatory lower limb muscle activity in gait initiation and forward stepping studies has been reported to be consistently present, and associated with initial and important balance responses. Falls during turning are associated with a high incidence of hip fractures in the elderly population. The presence of anticipatory lower limb muscle activity turning has not been previously reported. Participants: There were five participants in Experiment One, and ten in Experiment Two. All were between 18 and 40 years of age and did not have neurological or musculoskeletal disorders, or severe visual loss. Results: In Experiment One, four muscles were consistently active bilaterally, during the early period of step-turning and were: tibialis anterior, gastrocnemius, biceps femoris and gluteus medius. In Experiment Two the ipsilateral foot moved before the contralateral foot in 68% of trials towards the left, and 79% of trials towards the right. The onset of head movement consistently occurred before the onset of foot movement during turns towards both directions. The percentage of trials in which the four muscles were active in an anticipatory manner was low bilaterally, ranging from 12 to 38% of trials. Objectives that involved the further analysis of muscles active in at least 80% of trials were unable to be completed. Conclusions: During a step-turning task young healthy adults predominantly move their ipsilateral foot before their contralateral foot. The consistent onset of head movement prior to that of the feet, indirectly suggests that the visual system might influence the temporal onset of the feet. The low levels of anticipatory muscle activity during step-turning suggest that the lower limbs are not involved with the initial balance responses for this task thus making it inherently different to gait initiation and forward stepping.

Les animaux sont de plus en plus présents dans les effets spéciaux au cinéma et dans les films d'animation 3D. Les quadrupèdes en particulier, de par la richesse et de l'esthétique de leurs mouvement, sont souvent l'objet de création de personnages virtuels. L'objectif de cette thèse est d'utiliser la vidéo, et surtout des documentaires animaliers, pour créer des animaux virtuels capables de mouvements réalistes. Dans un premier temps, nous proposons de construire des squelettes d'animation de quadrupèdes à partir d'images. Nous montrons tout d'abord comment reconstruire un squelette réel à partir de plusieurs images. Ensuite, nous construisons un modèle déformable de squelette de quadrupède qui permet de de créer un squelette d'animation rapidement à partir d'une image ou d'un modèle 3D de l'animal à animer. Dans un second temps, nous proposons des méthodes permettant d'animer des quadrupèdes à partir de séquences vidéo. Nous présentons tout d'abord une technique d'animation de mouvements cycliques à partir de vidéo, qui permet notamment de choisir automatiquement les images-clés à partir d'une vidéo. Ensuite, nous proposons une nouvelle méthode d'analyse de vidéos qui permet d'identifier les différentes allures utilisées par l'animal, ainsi que les transitions entre allures.

La marche est un moyen de locomotion essentiel pour l'être humain. La marche en courbe fait partie des synergies motrices fondamentales qui permettent de se déplacer en sécurité lorsqu'un sujet tourne dans un couloir ou évite un obstacle. Ce travail vise à approfondir l'étude de la marche en courbe afin de définir des invariants locomoteurs fondamentaux pour l'explication biomécanique et neuroscientifique du mouvement mais aussi pour la génération de trajectoires réalistes en animation et en robotique humanoïde. L'originalité de ce travail est de considérer la trajectoire locomotrice humaine dans l'espace défini par la courbure et la vitesse de la trajectoire.Dans un premier temps, nous proposons une définition objective du virage qui s'appuie sur la relation discrète entre la courbure moyenne et la vitesse moyenne de la trajectoire à chaque pas du sujet en comparaison avec ces mêmes paramètres en ligne droite. Puis, nous nous intéressons aux relations de type loi de puissance entre vitesse et courbure au cours d'un virage. Nous démontrons l'existence d'une relation inter-individuelle au maximum de courbure. Enfin, nous nous intéressons au cas plus complexe de l'évitement de collision entre deux marcheurs afin d'identifier les stratégies mises en place. Ces stratégies dépendent de l'ordre de passage des sujets.

Les travaux présentés dans cette HDR visent à mieux comprendre le fonctionnement des mécanismes d'apprentissage qui sont liés au contrôle moteur bas niveau chez l'humain, pour les modéliser et les intégrer dans les contrôleurs des robots humanoïdes. L'objectif est de rendre ces derniers plus robustes face aux perturbations externes dues à l'environnement, ou à leur interaction avec l'humain (forces externes, glissement, pentes ou irrégularités du sol), ou aux dommages internes, soudains ou progressifs, qu'ils peuvent subir et qui mettent en péril leur mission (usures articulaires, amputation de membres moteurs, pertes sensorielles...). Pour ce faire, les capacités de généralisation offertes par les algorithmes d'apprentissage des réseaux de neurones et les synergies de leurs mécanismes adaptatifs (homéostasie, plasticité neuronale et synaptique) ont été étudiées. Les solutions ont été évaluées en soumettant les robots à des perturbations ou à des dysfonctionnements externes ou internes, lents ou brusques. Des réponses aux questions suivantes ont été apportées: comment la marche adaptative des robots peut elle être produite? Comment peut-elle être contrôlée? Quels types d'architecture permettent à la fois la production de rythmes locomoteurs et le contrôle de la posture? Quels sont les mécanismes adaptatifs sensori-moteurs qui régissent ces architectures pour les marches normales et déficientes des robots? Quelles sont les méthodologies possibles pour modéliser et reproduire ces architectures? Quelles sont les limites de ces approches ?.

Le but de ce travail de thèse a été d'analyser l'implication du tronc dans la locomotion, notamment sa commande rythmique, afin d'en comprendre les mécanismes de contrôle et les différentes activités segmentaires qui amènent ses mouvements. Ces m´ecanismes peuvent alors être modélisés pour reproduire les différentes synchronisations observées au niveau des activités de chaque segment vertébral considéré. Enfin, cette modélisation permet de spécifier les activités du tronc à observer pour suivre en continu le cycle de marche d'un individu se déplacant. Dans un premier temps nous rappellerons les données de la littérature sur la locomotion, et notamment l'activité du tronc, qui nous ont permis de définir les axes principaux dans lesquels nous allons orienter notre travail. Cet état de l'art nous a notamment amenés à étudier les structures de type ”générateurs de rythme centraux” (Central pattern generator, CPG, en anglais). Dans un second temps nous avons réalisé une série de mesures expérimentales pour analyser de facon systématique et précise l'activité musculaire et cinématique du tronc lors de diverses situations locomotrices (marche, course, bond, pédalage). Ces mesures nous ont permis de mieux comprendre la manière dont le tronc se mettait en mouvement et comment ses activités musculaires et cinématiques, notamment les synchronisations intersegmentaires, évoluaient afin de tirer le meilleur parti des mouvements du haut du corps lors de la locomotion proprement dite. Dans un troisième temps, les résultats obtenus par les mesures d'activités du tronc ayant mis en évidence l'utilité du tronc et les mécanismes de contrôle dans une locomotion efficace, nous avons exploré la modélisation de l'activité du tronc au moyen d'un réseau d'oscillateurs mimant un CPG. Le choix d'un modèle de CPG pour représenter l'activité du tronc fait suite à des considérations phylogénétiques qui semblent indiquer qu'une telle structure pourrait exister chez l'homme. Une des propriétés de ce type de réseaux est leur capacité à exprimer différentes synchronisations sans changer de structure, c'est ce que nous avons appliqué aux observations faites lors de la marche, la course... Une autre propriété de ces réseaux est leur aptitude à se synchroniser avec un signal externe, nous avons donc explor´e diff´erents moyens de commander ce réseau d'oscillateur en phase avec la locomotion, encore une fois à partir de l'activité du tronc, de son accélération pour être plus précis.