Accelerometer data can be analyzed using a variety of methods which are effective in the clinical setting. Time-series analysis is used to analyze spatiotemporal variables in various populations. More recently, investigators have focused on gait complexity and the structure of spatiotemporal variations during walking and running. This study evaluated the use of time-series analyses to determine gait parameters during running. Subjects were college-age female soccer players. Accelerometer data were collected using GPS-embedded trunk-mounted accelerometers. Customized Matlab® programs were developed that included Gaussian continuous wavelet transform (CWT) to determine spatiotemporal characteristics, detrended fluctuation analysis (DFA) to examine gait complexity and autocorrelation analyses (ACF) to assess gait regularity. Reliability was examined using repeated running efforts and intraclass correlation. Proof of concept was determined by examining differences in each variable between various running speeds. Applicability was established by examining gait before and after fatiguing activity. The results showed most variables had excellent reliability. Test-retest R2 values for these variables ranged from 0.8 to 1.0. Low reliability was seen in bilateral comparisons of gait symmetry. Increases in running speed resulted in expected changes in spatiotemporal and acceleration variables. Fatiguing exercise had minimal effects on spatiotemporal variables but resulted in noticeable declines in complexity. This investigation shows that GPS-embedded trunk-mounted accelerometers can be effectively used to assess running gait. CWT and DFA yield reliable measures of spatiotemporal characteristics of gait and gait complexity. The effects of running speed and fatigue on these variables provides proof of concepts and applicability for this analytical approach. / Master of Science / Fitness trackers have become widely accessible and easy to use. So much so that athletic teams have been using them to track activity throughout the season. Researchers are able to manipulate data generated from the fitness monitors to assess many different variables including gait. Monitoring gait may generate important information about the condition of the individual. As a person fatigues, running form is theorized to breakdown, which increases injury risk. Therefore the ability to monitor gait may be advantageous in preventing injury. The purpose of this study is to show that the methods in this study are reproducible, respond reasonably to changes in speed, and to observe the changes of gait in the presence of fatigue or on tired legs. Three analyses are used in this study. The first method called autocorrelation, overlays acceleration signals of consecutive foot strikes, and determines the similarity between them. The second method utilizes a wave transformation technique that is able to determine foot contact times. The final method attempts to determine any pattern in the running stride. This method looks for changes in the structure of the pattern. Less structure would indicate a stride that is fatigued. The results showed that the methods of gait analysis used in this study were reproducible and responded appropriately with changes in speed. Small changes in gait were observed due to the presence of fatigue. Further investigation into the use of these methods to determine changes in gait due to the presence of fatigue are warranted.

As a valuable asset in human augmentation and medical rehabilitation, exoskeletons have become a major area for research and development. They have shown themselves to be effective tools for training and rehabilitation of individuals suffering from limited mobility. However, most exoskeletons are not capable of balancing without the assistance of crutches from the user. Leveraging technology and techniques developed for force controlled humanoid robots, a project was undertaken to develop a fully self-balancing, compliant lower-body robotic exoskeleton. Due to their many beneficial features, series elastic actuators were utilized to power the joints on the exoskeleton. This thesis details the development of four linear series elastic actuators (LSEA) as part of this project. All 12-degrees of freedom will be powered by one of these four LSEA's. Actuator requirements were developed by examining human gait data and three robot-walking simulations. These four walking scenarios were synthesized into one set of power requirements for actuator development. Using these requirements, analytical models were developed to perform component trade studies and predict the performance of the actuator. These actuators utilize high-efficacy components, parallel electric motors, and liquid cooling to attain high power-to-weight ratios, while maintaining a small lightweight design. These analyses and trade studies have resulted in the design of a dual-motor liquid-cooled actuator capable of producing a peak force 8500N with a maximum travel speed of 0.267m/s, and three different single-motor actuators capable of producing forces up to 2450N continuously, with a maximum travel speeds up to 0.767m/s. / Master of Science / Patients who suffer a severe back injury that results in paralysis from the waist down (paraplegia) commonly regain mobility in their daily lives by using a wheelchair. However, staying in a seated position for long periods can cause serious medical issues to arise. In order to address these issues, lower-body exoskeletons have been developed to help patients walk again. Exoskeletons are mechanical devices a person can wear to enhance their physical strength or endurance beyond their normal capability. These exoskeletons have shown themselves to be effective tools for training and rehabilitation of individuals suffering from limited mobility. However, most exoskeletons are not capable of balancing the user while they walk. In order to maintain balance, the user must hold themselves up with crutches. As with a wheelchair, heavy dependence on crutches can lead to new medical issues for the patient. To solve this problem, technology and techniques created for humanoid robots were used to develop a fully self-balancing exoskeleton. This exoskeleton is known as the Orthotic Lower-body Locomotion Exoskeleton. This thesis details the development of four actuators to power all twelve joints of the exoskeleton. These actuators utilize high-efficiency components, multiple electric motors, and liquid cooling to maintain a small lightweight design and while obtaining very high-power outputs.

Parkinson’s disease (PD) is a common neurodegenerative movement disorder, characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta and the accumulation of aggregated alpha synuclein (aSyn). The disease often presents with early prodromal non-motor symptoms and later motor symptoms. Diagnosing PD based purely on motor symptoms is often too late for successful intervention, as a significant neuronal loss has already occurred. Furthermore, the lower prevalence of PD in females is not well understood, highlighting the need for a better understanding of the interaction between sex and aSyn, the crucial protein for PD pathogenesis. Here, we conducted a comprehensive phenotyping study in 1- to 5-month-old mice over- expressing human aSyn gene (SNCA) in a bacterial artificial chromosome (BAC-SNCA). We demonstrate a SNCA gene-dose-dependent increase of human aSyn and phosphorylated aSyn, as well as a decrease in tyrosine hy- droxylase expression in BAC-SNCA mice, with more pronounced effects in male mice. Phosphorylated aSyn was already found in the dorsal motor nucleus of the vagus nerve of 2-month-old mice. This was time-wise associated with significant gait altrations in BAC-SNCA mice as early as 1 and 3 months of age using CatWalk gait analysis. Furthermore, anxiety-related behavioral tests revealed an increase in anxiety levels in male BAC-SNCA mice. Finally, 5-month-old male BAC-SNCA mice exhibited a SNCA gene-dose-dependent elevation in energy expen- diture in automated home-cage monitoring. For the first time, these findings describe early-onset, sex- and gene- dose-dependent, aSyn-mediated disturbances in BAC-SNCA mice, providing a model for sex-differences, early- onset neuropathology, and prodromal symptoms of PD.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) and DBS of the pedunculopontine nucleus (PPN) have been shown to be effective surgical therapies for Parkinson’s disease (PD). To better understand the PPN and STN as DBS targets for PD, this research compares the anatomy, electrophysiology, and motor control roles of these nuclei. PPN and STN connections were examined in vivo in human subjects and in the non-human primate using probabilistic diffusion tractography. Both the PPN and STN were connected with each other and with the motor cortex (M1) and basal ganglia. After studying these anatomical connections in primates, their functional significance was further explored in an anesthetized rat model of PD. Examination of the electrophysiological relationship between the PPN and basal ganglia in the presence of slow cortical oscillatory activity suggested that excitatory input from the STN may normally modulate PPN spike timing but that inhibitory oscillatory input from the basal ganglia output nuclei has a greater effect on PPN spike timing in the parkinsonian brain. To examine transmission and modulation of oscillatory activity between these structures at higher frequencies, LFP activity was recorded from the PPN and STN in PD patients performing simple voluntary movements. Movement-related modulation of oscillatory activity predominantly occurred in the α (8-12 Hz) and low β (12-20 Hz) frequencies in the STN but in the high β (20-35 Hz) frequencies in the PPN, supporting observations from rodent studies suggesting that oscillatory activity is not directly transmitted from the STN to the PPN in PD. Finally, to better understand the roles of the STN and PPN in large-scale movement, the effects of STN and PPN DBS on gait abnormalities in PD patients were studied. DBS of the STN appeared to improve gait by optimising executive gait control while DBS of the PPN appeared to restore autonomic gait control. These results have several implications for DBS patient selection, surgical targeting, and for understanding the mechanisms underlying DBS efficacy.

Différents dessins d’implants de prothèse totale de genou (PTG) sont utilisés en pratique clinique et chacun présente des caractéristiques biomécaniques spécifiques. Aucun implant n’a réussi à ce jour à reproduire parfaitement la biomécanique du genou naturel. Les objectifs de cette étude sont de comparer les résultats cliniques et biomécaniques tridimensionnels (3D) de deux types de PTG chez le même patient, puis de comparer la cinématique des PTG à celle d’un groupe de genoux asymptomatiques. Une cohorte de quinze patients avec un implant traditionnel dans un genou et un implant de nouvelle génération permettant un pivot dans le genou contralatéral a été étudiée. Le groupe contrôle était composé de trente-cinq genoux asymptomatiques. L’analyse de la cinématique 3D a été réalisée avec l’outil KneeKG (Emovi Inc. Canada) lors de la marche sur tapis roulant. L’évaluation clinique comprenait l’amplitude de mouvement ainsi que les questionnaires de perception articulaire, KOOS, Womac et SF-12. La comparaison de la cinématique des deux types de PTG a démontré quelques différences statistiquement significatives dans les plans sagittal et frontal alors que la comparaison des PTG et des genoux asymptomatiques a révélé plusieurs différences significatives dans les trois plans. Les scores cliniques des deux PTG ne comportaient pas de différence significative. Dans notre cohorte de patients, le design de l’implant a eu peu d’influence sur les résultats biomécaniques et cliniques. Les PTG n’ont pas reproduit une cinématique normale de genou. Beaucoup de travail et de recherche dans le développement de nouveaux implants sont encore nécessaires afin d’améliorer les résultats cliniques et de mieux reproduire la cinématique du genou naturel. / Various implants of total knee arthroplasty (TKA) are used in clinical practice and each presents specific biomechanical characteristics. No implant managed this day to reproduce perfectly the biomechanics of the natural knee. The objectives of this study are to compare the clinical and tridimensional (3D) biomechanical data of two different designs of TKA on the same patients and to compare the resulting 3D biomechanical data with those of asymptomatic knees. A cohort of fifteen patients with a traditional implant in one knee and an implant of new generation allowing a pivot in the contralateral knee was studied. The control group was composed of thirty-five asymptomatic knees. Assessment of 3D knee kinematics analysis was realized with the KneeKG (Emovi Inc. Canada) during treadmill gait. Clinical evaluation included range of motion as well as questionnaires of joint perception, KOOS, Womac and SF-12. Results showed some statistically significant differences in knee 3D kinematics of both TKAs in sagittal and frontal planes while comparison between TKAs and asymptomatic knees revealed several significant differences in all three planes. Clinical scores of both TKAs did not have significant difference. In our cohort of patients, TKA implant design had few measurable influences on kinematics during gait and on clinical results. TKA with these implants did not reproduce natural knee kinematics during gait. Significant research and development in new TKA designs are needed to improve clinical scores and reproduce natural knee kinematics.

Réalisé en cotutelle avec le laboratoire M2S de Rennes 2 / Cette thèse s’intéresse à définir de nouvelles méthodes cliniques d’investigation permettant de juger de l’impact de l’avance en âge sur la motricité. En particulier, cette thèse se focalise sur deux principales perturbations possibles lors de l’avance en âge : la chute et l’altération de la marche.Ces deux perturbations motrices restent encore mal connues et leur analyse en clinique pose de véritables défis technologiques et scientifiques. Dans cette thèse, nous proposons des méthodes originales de détection qui peuvent être utilisées dans la vie courante ou en clinique, avec un minimum de contraintes techniques. Dans une première partie, nous abordons le problème de la détection de la chute à domicile, qui a été largement traité dans les années précédentes. En particulier, nous proposons une approche permettant d’exploiter le volume du sujet, reconstruit à partir de plusieurs caméras calibrées. Ces méthodes sont généralement très sensibles aux occultations qui interviennent inévitablement dans le domicile et nous proposons donc une approche originale beaucoup plus robuste à ces occultations. L’efficacité et le fonctionnement en temps réel ont été validés sur plus d’une vingtaine de vidéos de chutes et de leurres, avec des résultats approchant les 100% de sensibilité et de spécificité en utilisant 4 caméras ou plus. Dans une deuxième partie, nous allons un peu plus loin dans l’exploitation des volumes reconstruits d’une personne, lors d’une tâche motrice particulière : la marche sur tapis roulant, dans un cadre de diagnostic clinique. Dans cette partie, nous analysons plus particulièrement la qualité de la marche. Pour cela nous développons le concept d’utilisation de caméras de profondeur pour la quantification de l’asymétrie spatiale au cours du mouvement des membres inférieurs pendant la marche. Après avoir détecté chaque pas dans le temps, cette méthode réalise une comparaison de surfaces de chaque jambe avec sa correspondante symétrique du pas opposé. La validation effectuée sur une cohorte de 20 sujets montre la viabilité de la démarche. / This thesis is concerned with defining new clinical investigation method to assess the impact of ageing on motricity. In particular, this thesis focuses on two main possible disturbance during ageing : the fall and walk impairment. This two motricity disturbances still remain unclear and their clinical analysis presents real scientist and technological challenges. In this thesis, we propose novel measuring methods usable in everyday life or in the walking clinic, with a minimum of technical constraints. In the first part, we address the problem of fall detection at home, which was widely discussed in previous years. In particular, we propose an approach to exploit the subject’s volume, reconstructed from multiple calibrated cameras. These methods are generally very sensitive to occlusions that inevitably occur in the home and we therefore propose an original approach much more robust to these occultations. The efficiency and real-time operation has been validated on more than two dozen videos of falls and lures, with results approaching 100 % sensitivity and specificity with at least four or more cameras. In the second part, we go a little further in the exploitation of reconstructed volumes of a person at a particular motor task : the treadmill, in a clinical diagnostic. In this section we analyze more specifically the quality of walking. For this we develop the concept of using depth camera for the quantification of the spatial and temporal asymmetry of lower limb movement during walking. After detecting each step in time, this method makes a comparison of surfaces of each leg with its corresponding symmetric leg in the opposite step. The validation performed on a cohort of 20 subjects showed the viability of the approach.

L’analyse de la marche a émergé comme l’un des domaines médicaux le plus im- portants récemment. Les systèmes à base de marqueurs sont les méthodes les plus fa- vorisées par l’évaluation du mouvement humain et l’analyse de la marche, cependant, ces systèmes nécessitent des équipements et de l’expertise spécifiques et sont lourds, coûteux et difficiles à utiliser. De nombreuses approches récentes basées sur la vision par ordinateur ont été développées pour réduire le coût des systèmes de capture de mou- vement tout en assurant un résultat de haute précision. Dans cette thèse, nous présentons notre nouveau système d’analyse de la démarche à faible coût, qui est composé de deux caméras vidéo monoculaire placées sur le côté gauche et droit d’un tapis roulant. Chaque modèle 2D de la moitié du squelette humain est reconstruit à partir de chaque vue sur la base de la segmentation dynamique de la couleur, l’analyse de la marche est alors effectuée sur ces deux modèles. La validation avec l’état de l’art basée sur la vision du système de capture de mouvement (en utilisant le Microsoft Kinect) et la réalité du ter- rain (avec des marqueurs) a été faite pour démontrer la robustesse et l’efficacité de notre système. L’erreur moyenne de l’estimation du modèle de squelette humain par rapport à la réalité du terrain entre notre méthode vs Kinect est très prometteur: les joints des angles de cuisses (6,29◦ contre 9,68◦), jambes (7,68◦ contre 11,47◦), pieds (6,14◦ contre 13,63◦), la longueur de la foulée (6.14cm rapport de 13.63cm) sont meilleurs et plus stables que ceux de la Kinect, alors que le système peut maintenir une précision assez proche de la Kinect pour les bras (7,29◦ contre 6,12◦), les bras inférieurs (8,33◦ contre 8,04◦), et le torse (8,69◦contre 6,47◦). Basé sur le modèle de squelette obtenu par chaque méthode, nous avons réalisé une étude de symétrie sur différentes articulations (coude, genou et cheville) en utilisant chaque méthode sur trois sujets différents pour voir quelle méthode permet de distinguer plus efficacement la caractéristique symétrie / asymétrie de la marche. Dans notre test, notre système a un angle de genou au maximum de 8,97◦ et 13,86◦ pour des promenades normale et asymétrique respectivement, tandis que la Kinect a donné 10,58◦et 11,94◦. Par rapport à la réalité de terrain, 7,64◦et 14,34◦, notre système a montré une plus grande précision et pouvoir discriminant entre les deux cas. / Gait analysis has emerged as one of the most important medical field recently due to its wide range of applications. Marker-based systems are the most favoured methods of human motion assessment and gait analysis, however, these systems require specific equipment and expertise, and are cumbersome, costly and difficult to use. Many re- cent computer-vision-based approaches have been developed to reduce the cost of the expensive motion capture systems while ensuring high accuracy result. In this thesis, we introduce our new low-cost gait analysis system that is composed of two low-cost monocular cameras (camcorders) placed on the left and right sides of a treadmill. Each 2D left or right human skeleton model is reconstructed from each view based on dy- namic color segmentation, the gait analysis is then performed on these two models. The validation with one state-of-the-art vision-based motion capture system (using the Mi- crosoft Kinect v.1) and one ground-truth (with markers) was done to demonstrate the robustness and efficiency of our system. The average error in human skeleton model estimation compared to ground-truth between our method vs. Kinect are very promis- ing: the joints angles of upper legs (6.29◦ vs. 9.68◦), lower legs (7.68◦ vs. 11.47◦), feet (6.14◦ vs. 13.63◦), stride lengths (6.14cm vs. 13.63cm) were better and more stable than those from the Kinect, while the system could maintain a reasonably close accu- racy to the Kinect for upper arms (7.29◦ vs. 6.12◦), lower arms (8.33◦ vs. 8.04◦), and torso (8.69◦ vs. 6.47◦). Based on the skeleton model obtained by each method, we per- formed a symmetry study on various joints (elbow, knee and ankle) using each method on two different subjects to see which method can distinguish more efficiently the sym- metry/asymmetry characteristic of gaits. In our test, our system reported a maximum knee angle of 8.97◦ and 13.86◦ for normal and asymmetric walks respectively, while the Kinect gave 10.58◦ and 11.94◦. Compared to the ground-truth, 7.64◦ and 14.34◦, our system showed more accuracy and discriminative power between the two cases.

Les modèles animaux d’arthrose permettent d’évaluer le potentiel d’agents thérapeutiques en phase préclinique de développement. Le présent ouvrage tient compte du chien comme modèle d’arthrose naturelle (chez l’animal de compagnie) ou expérimentale (par sectionnement chirurgical du ligament croisé crânial). Au sein des expérimentations, la force de réaction au sol verticale maximale, mesurée lors de l’analyse cinétique de la locomotion, est proposée comme témoin d’effets fonctionnels et structuraux sur ces modèles d’arthrose. Sur un modèle canin d’arthrose naturelle, le seuil de changement minimal détectable a été déterminé. Les changements au dysfonctionnement locomoteur peuvent désormais être cernés en s’affranchissant de la marge d’erreur inhérente à la mesure de la force verticale maximale. Il en découle l’identification de répondants lors d’essais cliniques entrepris chez le chien arthrosique. Une analyse rétrospective a, par la suite, déterminé un taux de répondants de 62.8% et d’une taille d’effet de 0.7 pour des approches thérapeutiques actuellement proposées aux chiens arthrosiques. Cette analyse détermina également que la démonstration d’une réponse thérapeutique était favorisée en présence d’un fort dysfonctionnement locomoteur. Sur un modèle canin d’arthrose par sectionnement chirurgical du ligament croisé crânial, la force verticale maximale a démontré une relation inverse avec certains types de lésions arthrosiques évaluées à l’aide d’imagerie par résonance magnétique. Également, la sensibilité de la force verticale maximale a été mise en évidence envers la détection d’effets structuraux, au niveau de l’os sous-chondral, par un agent anti-résorptif (le tiludronate) sur ce même modèle. Les expérimentations en contexte d’arthrose naturelle canine permettent de valider davantage les résultats d’essais cliniques contrôlés utilisant la force verticale maximale comme critère d’efficacité fonctionnelle. Des évidences cliniques probantes nécessaires à la pratique d’une médecine basée sur des faits sont ainsi escomptées. En contexte d’arthrose expérimentale, la pertinence d’enregistrer le dysfonctionnement locomoteur est soulignée, puisque ce dernier est en lien avec l’état des structures. En effectuant l’analyse de la démarche, de pair avec l’évaluation des structures, il est escompté de pouvoir établir la répercussion de bénéfices structurels sur l’inconfort articulaire. Cet ouvrage suggère qu’une plateforme d’investigations précliniques, qui combine le modèle canin d’arthrose par sectionnement chirurgical du ligament croisé crânial à un essai clinique chez le chien arthrosique, soit un moyen de cerner des bénéfices structuraux ayant des impacts fonctionnels. Le potentiel inférentiel de ces modèles canins d’arthrose vers l’Homme serait ainsi favorisé en utilisant la force verticale maximale. / Animal models of osteoarthritis are useful to evaluate the potential of osteoarthritis therapeutics at the preclinical stage of development. In this thesis, the dog is used as a model of naturally-occurring (i.e. companion animal) and experimentally induced (i.e. by surgical transection of the cranial cruciate ligament) osteoarthritis. The peak of the vertically-oriented ground reaction force, which is measured during kinetic gait analysis, is proposed to be an indicator of structural and functional benefits in these models of osteoarthritis. In a canine model of naturally-occurring osteoarthritis, the threshold of the minimal detectable change in peak vertical force was determined. An improvement in the locomotor disability can now be identified according to the measurement error (noise) of the peak vertical force. This allows the identification of responders when the peak vertical force is used as an outcome measure of functional benefits. A retrospective analysis later determined that current therapeutic approaches provided a responder rate of 62.8% with an effect size of 0.7 in dogs with naturally-occurring osteoarthritis. This analysis also determined that the therapeutic response is favored in cases of severe locomotor disability.   In a canine model of osteoarthritis induced by surgical transection of the cranial cruciate ligament, the peak vertical force demonstrated an inverse relationship with different types of structural changes, as evaluated upon magnetic resonance imaging. The sensitivity of the peak vertical force to detect structural benefits on the subchondral bone was also shown in this model using an antiresorptive agent (i.e. tiludronate). The experiments conducted in dogs with naturally-occurring osteoarthritis further validate findings from clinical trials in which the peak vertical force is used as an outcome measure of functional benefits. The practice of an evidence-based medicine is then expected. The experiments conducted in dogs with surgically-induced osteoarthritis support the recording of the locomotor disability, being in line with the level of the structural changes. By performing gait analysis in addition to structural evaluations, it is expected to establish the impact of structural benefits on joint discomfort This thesis suggests that a platform for preclinical investigations, which combines the canine model of osteoarthritis induced by surgical transection of the cranial cruciate ligament and a clinical trial in dogs with naturally-occurring osteoarthritis, offers the opportunity to discern structural benefits having functional impacts. A better prediction of outcomes for human clinical trials is expected by using the peak vertical force.

La prothèse totale du genou (PTG) est une chirurgie couramment pratiquée pour traiter les patients souffrant d’arthrose sévère du genou. Bien que cette technique chirurgicale soit efficace pour diminuer la douleur, améliorer la fonction du genou et rentable d’un point de vue socio-économique, un pourcentage non négligeable de patients n’est pas satisfait suite à la chirurgie, principalement due à une douleur persistante ou due à une perception d’avoir une mauvaise fonction articulaire, sans cause identifiée. Cependant, l’impact de cette chirurgie sur la cinématique tridimensionnelle (3D) du genou demeure mal compris. Dans le but de mieux comprendre pourquoi certains patients ressentent toujours de la douleur suite à cette chirurgie, cette étude analysera, dans un premier temps, l’effet prospectif de la chirurgie sur la cinématique 3D du genou. Puis dans un second temps, comparera la cinématique 3D de sujet souffrant de douleur à celle de sujets asymptomatiques suite à la prothèse. Pour parvenir à ces deux objectifs, deux études distinctes ont été entreprises. Une première étude prospective a porté sur l’évolution de la cinématique 3D du genou d’un groupe de 19 sujets, recrutés sur la liste d’attente pour prothèse totale du genou de deux chirurgiens du CHUM, hôpital Notre-Dame, puis la cinématique a été comparée avec un groupe contrôle de 17 sujets avec des genoux sains. Une seconde étude a comparé la cinématique 3D de 20 sujets souffrant de douleur post-PTG avec 20 sujets avec des genoux asymptomatiques suite à leur chirurgie. La première étude a permis de montrer que la cinématique dans le plan frontal suite à la prothèse totale du genou était corrigée vers celle des sujets sains. Contrairement à celle mesurée dans les autres plans (sagittal et axial) qui, malgré de petites corrections, demeure différente de la cinématique des sujets sains. La seconde étude a permis d’identifier un marqueur biomécanique de la douleur chez les sujets souffrant de douleur post-PTG. Effectivement, contrairement aux sujets asymptomatiques, suite à leur chirurgie, les patients souffrants de douleur marchent avec une contracture en flexion plus importante tout au long de la phase d’appui. Les résultats de ces deux études tendent à montrer que la prothèse totale du genou modifie la cinématique 3D du genou, sans toutefois redevenir semblable à celle d’un genou normal. De plus, certains marqueurs biomécaniques peuvent être associés à de la douleur suite à la chirurgie. Une meilleure compréhension de l’impact de la PTG sur la cinématique 3D du genou permettra d’offrir de meilleurs traitements en préparation et après la chirurgie et pourrait mener à de nouveaux designs de prothèses. / The total knee arthroplasty (TKA) is a common procedure in patients with severe knee osteoarthritis. This surgery has been proved to reduce pain, to improve knee function, and to be cost-effective. However, an important proportion of patients report insatisfaction, pain, and low articular function following the surgery. Moreover, even with this problem, the impact of the TKA on the tridimensional (3D) kinematics is not well understood. Therefore, two studies have been undertaken with the purpose of using the 3D kinematics to understand the post-TKA pain syndrome. During the first study, 19 subjects, recruited on a TKA waiting list of two surgeons of the CHUM, Hôpital Notre-Dame, were prospectively followed to measure the evolution of their 3D knee kinematics. A control group of 17 subjects with normal knees has also been recruited. The second study has compared 20 subjects with knee pain post-TKA with 20 subjects without pain post-TKA. The results of the first study tend to show an improvement in the frontal plan kinematics after the TKA toward the control group. However, the kinematics in the others plans still different of the control group. When the 3D kinematics of a group with pain is compared to a group without pain (second study), a biomechanical marker associated with pain was identified. The group with pain walk with a higher flexion contracture during the stance phase than the group without pain. Those results show that the total knee arthroplasty has an impact on the 3D kinematics; however, this impact is not necessarily toward the control group. Moreover, some biomechanical markers can be associated with the knee pain following the TKA. This show that we still doesn’t really understand the impact of the TKA on the kinematics, and that a better understanding of this impact could allow the surgeons to improve their care to their patients before and after the surgery.

Diploma thesis "Effect of gait school with prosthesis on stability and walking parameters of patients after transfemoral amputation deals with problems of patients after transfemoral amputation due to vascular etiology. It mentions elementary knowledge of rehabilitation after amputation of lower extremity. Furthermore, there are described main complications that amputation brings into the patient ́s life: pain associated with amputation, skin complications and psychological hardships. Emphasis is laid on gait and gait practice for patients with amputation. I further deal with deviations commonly observed on gait of these patients and with factors influencing the gait, including the influence of particular parts of the prosthesis on patients ́ gait. The practical part is dedicated to comparison of two different approaches to gait practice. The effect of these approaches is evaluated on the basis of results of two groups of patients. The results were gathered by examination on force plate, measurement of gait velocity, examination of gait cadence and evaluation of patients ́s gait videos. Furthermore, I use functional tests: LCI - 5, ABIS - R, ABC scale and PEQ. All of these examinations were performed at the beginning and in the end of patients ́ stay at the Clinic of rehabilitation in Hradec Králové. The...