Interaction techniques that use the layers above the display surface to extend the functionality of pen-based digitized surfaces continue to emerge. In such techniques, stylus movements are constrained by the bounds of a layer inside which the interaction is active, as well as constraints on the direction of movement within the layer. The problem addressed in this thesis is that designers currently have no model to predict movement time (MT) or quantify the difficulty, for movement (steering) in layers above the display surface constrained by thickness of the layer, its height above the display, and the width and length of the path. The problem has two main parts: first, how to model steering in layers, and second, how to visualize the layers to provide feedback for the steering task. The solution described is a model that predicts movement time and that quantifies the difficulty of steering through constrained and unconstrained paths in layers above the display surface. Through a series of experiments we validated the derivation and applicability of the proposed models. A predictive model is necessary because the model serves as the basis for design of interaction techniques in the design space; and predictive models can be used for quantitative evaluation of interaction techniques. The predictive models are important as they allow researchers to evaluate potential solutions independent of experimental conditions.<p>Addressing the second part of the problem, we describe four visualization designs using cursors. <p>We evaluated the effectiveness of the visualization by conducting a controlled experiment.

This thesis reports on a multi-phased research project conducted to evaluate the use of the Cognitive Orientation to daily Occupational Performance (CO-OP) approach with adults with stroke. Current approaches to motor recovery, called systems approaches, suggest that movement arises from a dynamic interaction among several different systems, including perception, cognition, and action, all within the context of the individual and his or her environment. CO-OP is an established treatment approach for children with motor-based performance problems that takes into account interactions among several systems, as well as individual needs and environmental factors. CO-OP is a client-centred, problem solving approach based on the theoretical foundations of learning and motor learning theory. The objectives of this project were: to examine the efficacy of CO-OP to improve motor skill acquisition and performance in adults living with chronic stroke; to explore other benefits of the approach; and to identify adaptations for use with adults with stroke. Two series of single case experimental studies were conducted, with three participants completing each. In addition, semi-structured interviews were conducted. Findings from the single case experiments provide evidence that CO-OP is associated with performance improvements in both trained and untrained self-selected goals in adults more than one year post stroke. As well, pre-post measures suggest there may be changes in performance satisfaction, motor control, generalized use of the affected upper extremity, and self-efficacy. Interview findings provided valuable information about the experiences of participants with the approach; the interview respondents enjoyed the increased sense of responsibility that came with problem solving on their own, but expressed a desire to have ongoing professional support. Suggestions for modifications to CO-OP for use adults with stroke are made. CO-OP is a promising approach to improve functional independence in adults with stroke. Future research is warranted.

Interaction techniques that use the layers above the display surface to extend the functionality of pen-based digitized surfaces continue to emerge. In such techniques, stylus movements are constrained by the bounds of a layer inside which the interaction is active, as well as constraints on the direction of movement within the layer. The problem addressed in this thesis is that designers currently have no model to predict movement time (MT) or quantify the difficulty, for movement (steering) in layers above the display surface constrained by thickness of the layer, its height above the display, and the width and length of the path. The problem has two main parts: first, how to model steering in layers, and second, how to visualize the layers to provide feedback for the steering task. The solution described is a model that predicts movement time and that quantifies the difficulty of steering through constrained and unconstrained paths in layers above the display surface. Through a series of experiments we validated the derivation and applicability of the proposed models. A predictive model is necessary because the model serves as the basis for design of interaction techniques in the design space; and predictive models can be used for quantitative evaluation of interaction techniques. The predictive models are important as they allow researchers to evaluate potential solutions independent of experimental conditions.<p>Addressing the second part of the problem, we describe four visualization designs using cursors. <p>We evaluated the effectiveness of the visualization by conducting a controlled experiment.

Utilization of an external focus of attention has been proved to be beneficial in the motor learning literature. When people focus on the effects of the movement (i.e., external focus of attention), the motor skill is enhanced compared to directing attention to the body movements (i.e., internal focus of attention). Previous studies that have examined the effect of focus of attention on learning a motor skill often used visible or imagined objects to elicit an external focus of attention. However, the effects of these different types of external focus instruction have not been investigated thoroughly. It was unclear prior to this thesis how the focus of attention effect is influenced by the use of imagery. The purpose of the present study was to investigate the difference between directing attention to a visible object and an imagined object when performing and learning the standing long jump. It was hypothesized the group of participants who practiced with an imagery instruction would perform similarly in the post-test with or without an object that was used to elicit an external focus of attention. It was also hypothesized the group of participants who practiced with a visible object would perform similarly during the post-test with the same visible object; but the performance would decline in the post-test with no object. The results indicated there was no difference in the effect of the two different types of instructions. That is, performance during the practice and post-test were similar for the participants who imagined an object during the practice phase compared to the participants who practiced with an object. The post-test with and without an object were also similar within the same group as well as between the two groups. The results of the study provided additional evidence vision does not influence the focus of attention effect. Participants that practiced the standing long jump with a visible cone did not change the performance on the transfer test when the cone was removed. Also, participants that were instructed to direct their attention toward an imaginary cone performed just as well as participants that focused their attention on a visible cone on both the retention and transfer test. Therefore, the primary finding of the present experiment is that the focus of attention effect can be induced through the use of imagery.

Os resultados do desempenho motor (DM) na adolescência podem ser imprecisos quando os fatores de crescimento, idade biológica e idade cronológica (IC) não são considerados. A idade óssea (IO) é reconhecida como um eficiente indicador biológico, assim, a identificação da IO em função do crescimento e o DM resultante foi o objeto de estudo em 233 escolares de 9 a 16 anos de ambos os sexos (fem=109; masc=114). A IO foi determinada por radiografia do punho e mãos e o DM medido em testes de aptidão física. A IO foi maior (0,7 anos) e mais abrangente que a IC, com maiores efeitos no sexo feminino. As moças estavam mais maduras que os rapazes em todas as idades, todavia eles apresentaram maiores médias de DM, estatura, peso corporal e menor valor de gordura. O crescimento foi mais concordante com IO enquanto o DM com IC, sem significância estatística para ambos os sexos. Concluiu-se que ao classificar adolescentes segundo o crescimento, a maturação é indispensável, porém quando o DM está envolvido, as informações de IC e sexo são suficientes. / The results of the motor performance (MP) in adolescence can be inaccurate if the growth factors, biological age and chronological age (CA) are not considered. The bony age (BA) is recognized as an efficient biological indicator, like this, the identification of BA in function of the growth and results upon MP was here the object of study in 233 from 9 to 16 years of both sexes students (femme=109; male=114). BA was determined by x-ray of the wrist and hands, and the MP was measure in physical fitness tests. BA was larger (0.7 years) and including than CA, with larger effects in the female sex. The girls were more mature than boys in all the ages, though they presented larger averages of MP, height, weight and smaller fat value. The growth was more concordant with BA while MP with CA, without statistical significance for both sexes. In conclusion, when classifying adolescents according to the growth, the maturation is indispensable, however when the MP is involved, the information of IC and sex are enough.

Background: Numerous multidimensional assessment tools have been developed to measure frailty; however, the clinical feasibility of these tools is limited. We previously developed and validated an upper-extremity function (UEF) assessment method that incorporates wearable motion sensors. The purpose of the current study was to: 1) cross-sectionally validate the UEF method in a larger sample in comparison with the Fried index; 2) develop a UEF frailty index to predict frailty categories including non-frail, pre-frail, and frail based on UEF parameters and demographic information, using the Fried index as the gold standard; and 3) develop a UEF continuous score (points scores for each UEF parameter and a total frailty score) based on UEF parameters and demographic information, using the Fried index as the gold standard. Methods: We performed a cross-sectional validation and index development study within the Banner Medical Center, Tucson, and Banner Sun Health Research Institute, Sun City, Arizona. Community-dwelling and outpatient older adults (>= 60 years; n = 352; 132 non-frail, 175 pre-frail, and 45 frail based on Fried criteria) were recruited. For the UEF test, each participant performed a 20-s elbow flexion, within which they repetitively and rapidly flexed and extended their dominant elbow. Using elbow motion outcomes two UEF indexes were developed (categorical and score). The Fried index was measured as the gold standard. Results: For the categorical index, speed of elbow flexion, elbow range of motion, elbow moment, number of flexion, speed variability and reduction within 20 s, as well as body mass index (BMI) were included as the pre-frailty/frailty predictor parameters. Results from 10-fold cross-validation showed receiver operator characteristic area under the curve of 0.77 +/- 0.07 and 0.80 +/- 0.12 for predicting Fried pre-frailty and frailty, respectively. UEF score (0.1 to 1.0) was developed using similar UEF parameters. Conclusions: We present an objective, sensor-based frailty assessment tool based on physical frailty features including slowness, weakness, exhaustion (muscle fatigue), and flexibility of upper-extremity movements. Within the current study, the method was validated cross-sectionally using the Fried index as the gold standard and the UEF categorical index and UEF frailty score were developed for research purposes and potentially for future clinical use.

Dual task performance and the interaction of tasks has been the subject of much research. When tasks are performed together they affect each other to varying degrees depending upon such factors as the similarity of the tasks, their difficulty, and whether one task is given preference over another. In this study, task preference was investigated under divided attention conditions in order to determine what effect preference had on task performance. Twenty young adults took part in this study and were randomly assigned into two groups. Each group was experimentally motivated to favor one of the two tasks – either speaking a "tongue-twister" or tracking a moving target on a screen with a computer mouse. Each participant performed the tasks in both an isolated and combined conditions. The measurements of task performance (tracking scores, utterance duration, lower lip and jaw displacement, lower lip and jaw velocity, upper lip-lower lip correlation, spatiotemporal index, and sound pressure level) were then analyzed to determine how task preference affected the participant's performance. It was expected that the preferred task's performance would not suffer when performed in the dual task situation. Although some trends were noted in the predicted direction, no statistically significant results were found as a function of task preference. There were, however, some gender effects. Men were found to have significantly higher intensity than women during the speaking tasks in both the dual and isolated task conditions, and they were also found to perform better than women on the motor tracking task in both the dual and isolated task conditions.

Rationale: Autism is a neurodevelopmental disorder with onset prior to the age of three years characterized by qualitative impairments in social interaction and communication skill, along with a restricted repetitive and stereotyped pattern of behavior, interests, and activities. In addition to these core diagnostic features, aberrant sensory responding has also been widely reported in the literature describing children and adolescents with autism spectrum disorders (ASD). Aberrant sensory processing has, however, been infrequently studied compared to communication and cognition in autism and existing studies have had multiple methodological deficiencies, especially with sampling procedures. Purpose. The purpose of this study is to describe patterns of sensory processing found in children with an ASD to test the relationship(s) of these patterns to diagnostic and developmental variables. Method. Retrospective data collection was used to collect developmental and sensory processing variables of 400 children with an ASD. Sensory processing abilities were measured by the SSP. Results. The majority of the sample (80.5%) had a diagnosis of autism. The average age of the sample was 49.58 months. The adaptive, social, language, and motor developmental variables were consistent with diagnostic patterns in that the children with Asperger Disorder demonstrated higher developmental levels than the children with autism and PDD-NOS. Eighty-nine percent of the sample demonstrated some degree of sensory processing dysfunction on the SSP Total Score with the greatest difficulties reported on the Underresponsive/Seeks Sensation, Auditory Filtering, and Tactile Sensitivity sections. Exploratory factor analysis identified 6 parsimonious factors: Low Energy/Weak, Tactile and Movement Sensitivity, Taste/Smell Sensitivity, Auditory and Visual Sensitivity, Sensory Seeking/Distractibility, and Hypo-responsivity. These factor variables contributed to explaining the differences in five of six developmental variables of the sample that are associated with the diagnosis of autism. Receptive language, adaptive and expressive language performance were significantly correlated with sensory processing factor scores. Conclusions. Together, the sensory processing findings noted in this study describe a pattern of dysfunctional sensory modulation. These findings have significant implications for intervention programs involving individuals with an ASD, given the potential impact of these findings on a childs ability to maintain active engagement.

L’hypodynamie-hypokinésie est une situation correspondant à une diminution de l’activité motrice (hypokinésie) couplée à une diminution des charges corporelles (hypodynamie). Chez l’homme, cette situation est retrouvée lors d’une immobilisation, d’un alitement prolongé, d'un séjour en microgravité, ou lors du vieillissement (syndrome d’immobilité). L’hypodynamie-hypokinésie entraine une sévère altération de la performance motrice, notamment de l’équilibre, de la posture et de la locomotion. Cette altération est due à une dégradation du système musculaire (atrophie, changements phénotypiques), mais également à une modification des propriétés fonctionnelles du cortex sensorimoteur (réorganisation corticale, changements d’excitabilité corticale, modifications morphologiques). Si l’altération du système musculaire est bien décrite dans la littérature, les mécanismes impliqués dans la plasticité corticale restent mal connus. Une meilleure compréhension des systèmes mis en jeu dans l’hypodynamie-hypokinésie permettrait de développer des stratégies de prévention et/ou de récupération chez les patients soumis à cette situation. Dans cette optique, un modèle animal est communément utilisé au laboratoire. Il s'agit du modèle d'élévation du train postérieur pendant 14 jours chez le rat. Ainsi, les charges corporelles, s’exerçant habituellement sur les membres postérieurs, sont prévenues et l’activité musculaire limitée. Ce modèle animal reproduit la plupart des effets de l'hypodynamie-hypokinésie décrits chez l'homme.L’objectif de cette étude a été d’explorer les mécanismes de la réorganisation corticale induite par l’hypodynamie-hypokinésie. Notre intérêt s’est plus particulièrement porté sur l’insulin-like growth factor 1 (IGF-1), une protéine ubiquitaire possédant de nombreux rôles au niveau cérébral. En effet, en se fixant à son récepteur, l’IGF-1, parmi une multitude de phénomènes, stimule l’angiogenèse, la neurogenèse, et participe à la plasticité synaptique. De plus, il est reconnu comme étant un acteur central des effets bénéfiques de l’exercice physique au niveau cérébral.Aussi, dans un premier temps, nous avons déterminé les effets de cette hypoactivité sur l’IGF-1 et les voies de signalisation associées dans plusieurs structures impliquées dans la régulation de la performance motrice (cortex sensorimoteur, striatum, cervelet). Nos résultats montrent une sévère diminution des taux d’IGF-1 et de l’activation de la voie PI3K-AKT, et ce spécifiquement dans le cortex sensorimoteur.Dans un second temps, nous avons voulu déterminer si en maintenant le taux d’IGF-1 pendant toute la durée de l’hypodynamie-hypokinésie, il était possible de prévenir la réorganisation corticale et ses conséquences délétères sur le comportement moteur. Pour cela, dans une première partie, notre étude a porté sur le cortex somesthésique et la sensibilité tactile. Nos résultats montrent que l’IGF-1 prévient partiellement la réorganisation corticale et l’altération de la sensibilité tactile induites par l’hypoactivité. Dans une seconde partie, nous nous sommes intéressés à l’analyse du cortex moteur et de la performance motrice. Il apparait qu’un maintien des taux d’IGF-1 prévient une partie de l’altération du système moteur retrouvée en situation d’hypodynamie hypokinésie. Ainsi, l’ensemble de ces données suggère que la diminution des taux d’IGF-1 observée en condition d’hypoactivité joue un rôle clé dans la réorganisation corticale. De plus, notre étude montre qu’une prévention, même partielle, de cette réorganisation corticale peut induire une amélioration fonctionnelle de la performance motrice. / Hypodynamia-hypokinesia is a condition in which the motor activity (hypodynamia) as well as the weight exerted on the lower limbs (hypokinesia) are reduced. In humans, this condition is induced in immobilization, bed-rest, spaceflight or ageing (immobility syndrome) and is characterized by a chronic reduction in neuromuscular activity. This hypoactivity results in a profound alteration of motor task performances, in particular posture, gait and locomotion. These impairments are due to alterations in the muscular system (atrophy, phenotypic changes), but also to plastic changes in neural functions (cortical reorganization, alterations in cortical excitability, morphologic modifications). While degradation of the muscular system is described in the literature, the mechanisms involved in cortical plasticity are still unclear. A better understanding of the systems involved in hypodynamia-hypokinesia would allow the development of preventive and / or recovery strategies for patients affected by this hypoactivity. In this regard, hindlimb unloading is a disuse rodent model in which the elevation of the hindlimbs, during 14 days, prevents the weight to be normally exerted on the hindlimbs and reduces the normal muscular activity, finally causing hypoactivity. Studies performed on this model have shown that hindlimb unloading and human hypoactivity have similar effects. Today, our interest is turned towards insulin-like growth factor 1 (IGF-1), a ubiquitous protein involved in many cerebral functions. Indeed, IGF-1 is known to improve, inter alia, angiogenesis, neurogenesis and to be involved in synaptic plasticity in the whole brain. Moreover, several publications suggest that IGF-1 might mediate the beneficial effects of exercise on the brain.The aim of this study is to characterize the role of IGF-1 in cortical reorganization induced by hindlimb unloading as well as its functional consequences on motor performance. In the first part of the study, we have determined the effects of hindlimb unloading on IGF-1 level and the impact of its downstream main molecular pathways in motor control (sensorimotor cortex, striatum, cerebellum). Our results indicate that hindlimb unloading induces a decrease in IGF-1 level specifically in the sensorimotor cortex. This alteration is associated to a decrease in activation of the PI3K-AKT pathway. The second part of this study is dedicated to the effects of a restoration of IGF-1 levels, during the whole unloading period, on cortical reorganization and behavioral alterations focusing on sensory cortex and tactile sensory discrimination as well as motor cortex and motor performances. Our results show that treatment with IGF-1 partially prevents cortical reorganization and degradation of tactile sensory discrimination. Additionally, it appears that restoration IGF-1 levels prevent some of the effects of hindlimb unloading on the motor system.Taken together, ours results suggest that the decrease in the level of IGF-1 in the sensorimotor cortex during hindlimb unloading plays a key role in the cortical reorganization induced by hypoactivity. Moreover, our study shows that the prevention of this cortical reorganization, even when partial, can induce functional improvement in motor performance.

A presença de diferenças individuais no desempenho motor de crianças e jovens da mesma faixa etária é um aspecto relatado por grande parte da literatura. O presente estudo escolheu o modelo de capacidades perceptivo-motoras para explorar estas diferenças e focou na questão de níveis diferenciados de maturação do sistema nervoso central (SNC). Uma vez que a maioria dos estudos sobre capacidades perceptivo-motoras investiga adultos e não se conhece como o nível do SNC influencia a associação entre as capacidades e desempenho motor. Com isso, o presente estudo teve como objetivo investigar a associação entre as capacidades perceptivo-motoras e o desempenho de tarefas motoras em sujeitos de 7 e 13 anos de idade. A amostra refere-se aos sujeitos que fizeram parte do estudo de Crescimento e Desenvolvimento Motor Longitudinal Misto de Muzambinho-MG. Foram selecionados 110 sujeitos, contrabalanceados em termos de sexo e idade. As capacidades perceptivo-motoras analisadas foram a de coordenação multimembros (CM), timing coincidente (TC), tempo de reação (TR) e tempo de movimento (TM), por sua vez as tarefas motoras analisadas foram correr, rebater e receber. Para a análise da correlação foi utilizado o teste de Spearman, uma vez que não houve distribuição normal. Os resultados indicaram que o desempenho do correr se associou a CM tanto para os 7 anos (&rho;=-0,33) quanto para 13 anos (&rho;=-0,34). Por sua vez, o desempenho do receber se associou com a CM (&rho;=0,41) e TR (&rho;=-0,41) para os 7 anos, mas apenas com a CM (&rho;=0,29) para os 13 anos. E o desempenho do rebater não se associou com nenhuma das capacidades perceptivo-motoras analisadas. Com base nestes resultados, pode-se inferir que o desempenho em tarefas motoras típicas da infância é associado as capacidades perceptivo-motoras, mas o nível maturacional do sistema nervoso central pode ser um aspecto que interfere nesta associação. Estes resultados permitem identificar um campo de investigação promissor para entender as diferenças individuais que ocorrem no desempenho de crianças e jovens / The presence of individual differences in motor performance of children and teenagers of the same age group is a reported aspect for much of the literature. This study chose the model of perceptual-motor abilities to explore these differences and focused on issue of different central nervous system development levels (CNS). Since most of the studies investigate perceptual-motor abilities in adults and it is not known how the CNS level affects the association between ability and motor performance. This study aimed to investigate the association between perceptual-motor abilities and performance of motor tasks in individuals of 7 and 13 years old. The sample refers to subjects who participated in the study of mixed longitudinal motor growth and development in the city of Muzambinho - Minas Gerais/Brazil. It was selected 110 individuals, balanced in terms of gender and age. The perceptual-motor abilities analysed were the multilimb coordination (MC), coincident timing (CT), reaction time (RT) and movement time (TM) in turn analysed motor tasks were running, batting and receiving. For the correlation analysis it was used the Spearman\'s test, since there were no normal distribution. The results related to the running performances were associated with MC for both 7 years old (p = -0.33) and for 13 years old (p = -0.34). In turn, the receiving performances were associated with the MC (p = 0.41) and RT (p = -0.41) for 7 years old, but only with the MC (p = 0.29) for the 13 year old. Moreover, the batting performances were not associated with any of the perceptual-motor abilities analysed. Based on these results, we can infer that the performance in typical motor tasks of childhood is associated with the perceptual-motor abilities, but the maturity level of the central nervous system can be an aspect that interferes in this association. These results identify a promising field of research to understand individual differences occurring in the performance of children and teenagers