No description available.

No description available.

No description available.

The Bereitschaftspotential (BP) is an event related potential believed to reflect motor planning and preparedness. Although the relationship between the BP and volitional movements of the distal limbs is well established, studies of the BP and speech have produced inconclusive findings. The most heavily debated of these findings were reports of left lateralized hemispheric asymmetry in the BP topography, shortly before speech onset. Several researchers argued that these shifts were artifacts produced by movements of the articulatory muscles. However, methodological differences between the studies could also explain why the asymmetry was not always found. In the present study it was proposed that articulatory complexity and semantic processing each contribute to observed variations in the speech BP topography. Eighteen healthy volunteers performed 3 speech tasks, designed to distinguish semantic and articulatory contributions to the BP topography. The findings suggested that articulatory complexity and semantic processing each uniquely contribute to the frontolateral and medial BP topographic distribution. The present study also introduced the use of Doppler imaging of the tongue as a means of eliminating potential artifactual tongue movements from the speech BP. / Ph. D.

Palatalization refers to a type of coarticulation in which the place of articulation of some sound is closer to the palate than otherwise expected, very often triggered by adjacent palatal segments. It has been known as one of the most dynamic phonological phenomena in phonetic and phonological research, but the articulatory nature of palatalization still merits further investigation. This dissertation investigates the articulatory patterns of palatalization in Korean, English, and Scottish Gaelic (Gàidhlig), all of which are typologically distinct from one another and exhibit both language-universal and language-specific palatalization processes. The main question asked in this dissertation is which articulatory properties of palatalization are universal across languages, and specific to languages or to individuals. Three production experiments using ultrasound imaging technology were conducted to capture tongue gestures of speakers from three different language groups. The results from 30 speakers in the three language groups show that both phonemic and phonetic plain vs. palatalized differences manifest gesturally. Furthermore, the results show that there is a significant amount of articulatory variability across languages and speakers, yielding no clear universal "palatal" gesture, but some articulatory strategies seem to be shared by speakers from different languages. The theoretical and empirical implications of the findings are discussed.

The objective of this work is to investigate whether the game physics based modelling is accurate enough to be used in modelling the motion of the human body, in particular musculoskeletal motion. Hitherto, the implementation of game physics in the medical field focused only on anatomical representation for education and training purposes. Introducing gaming platforms and physics engines into orthopaedics applications will help to overcome several difficulties encountered in the modelling of articular joints. Implementing a physics engine (PhysX), which is mainly designed for video games, handles intensive computations in optimized ways at an interactive speed. In this study, the capabilities of the physics engine (PhysX) and gaming platform for modelling and simulating articular joints are evaluated. First, a preliminary validation is carried out for mechanical systems with analytical solutions, before constructing the musculoskeletal model to evaluate the consistency of gaming platforms. The developed musculoskeletal model deals with the human joint as an unconstrained system with 6 DOF which is not available with other joint modeller. The model articulation is driven by contact surfaces and the stiffness of surrounding tissues. A number of contributions, such as contact modelling and muscle wrapping, have been made in this research to overcome some existing challenges in joint modelling. Using muscle segmentation, the proposed technique effectively handles the problem of muscle wrapping, a major concern for many; thus the shortest path and line of action are no longer problematic. Collision behaviour has also shown a stable response for colliding as well as resting objects, provided that it is based on the principles of surface properties and the conservation of linear and angular momentums. The precision of collision detection and response are within an acceptable tolerance controllable by varying the mesh density. An image based analysis system is developed in this thesis, mainly in order to validate the proposed physics based modelling solution. This minimally invasive method is based on the analysis of marker positions located at bony positions with minimal skin movement. The image based system overcomes several challenges associated with the currently existing methods, such as inaccuracy, complication, impracticability and cost. The analysis part of this research has considered the elbow joint as a case study to investigate and validate the proposed physics based model. Beside the interactive 3D simulation, the obtained results are validated by comparing them with the image based system developed within the current research to investigate joint kinematics and laxity and also with published material, MJM and results from experiments performed at the Brunel Orthopaedic Research and Learning Centre. The proposed modelling shows the advantageous speed, reliability and flexibility of the proposed model. It is shown that the gaming platform and physics engine provide a viable solution to human musculoskeletal modelling. Finally, this thesis considers an extended implementation of the proposed platform for testing and assessing the design of custom-made implants, to enhance joint performance. The developed simulation software is expected to give indicative results as well as testing different types of prosthetic implant. Design parameterization and sensitivity analysis for geometrical features are discussed. Thus, an integrated environment is proposed to link the real-time simulation software with a manufacturing environment so as to assist the production of patient specific implants by rapid manufacturing.

Previous research has demonstrated that normally developing children are expected to have adult like control of their speech production skills by 10 years of age, as evidenced by increases in speed of production and decreases in performance variability. (e. g. Kent and Fortier 1980). There is also some evidence to suggest that phonologically disordered children may have poorer speech motor skills than their normally developing peers (e. g. Henry 1990, Edwards 1992, Waters 1992, Towne 1994). There are numerous techniques that can be used to measure a number of different aspects of speech motor control. However, there are methodological difficulties in devising appropriate protocols for the collection and analysis of speed of speech production as used as an index of speech motor skill in young children. Some of the techniques that have had clinical application include measurement of rate in connected speech production and measurement of diadochokinetic (DDK) repetition rate. This investigation compared normally developing and phonologically disordered preschool children on various indirect measures of speech motor skills, in imitated and spontaneous connected speech and in DDK tasks. The investigation also focused on refining the techniques of data collection and analysis appropriate to young children. While the results vary with regard to the statistical significance of the differences between the two groups of children on articulation rates and DDK rates, analysis of the error patterns in single word, spontaneous connected speech, imitated connected speech and DDK productions identified a sub group of phonologically disordered children who may present with an underlying speech motor deficit as the basis of their phonological disability. The results of the investigation are considered in terms of their implication for the speech motor skills of the two groups of children, techniques for measuring various aspects of speech motor skill and the clinical identification of phonologically disordered children who have an underlying speech motor deficit.

Orientador: Araildo Lima da Silva / Banca: Tamotsu Hirata / Banca: Luis Alberto Batista / Resumo: Os conseqüentes avanços na medicina esportiva incluem a busca por novos métodos tecnológicos que viabilizam uma melhor e mais eficaz avaliação muscular e articular no corpo humano. Associados a isso, a grande ocorrência de lesões de membros inferiores em especial aquelas da articulação do joelho, faz com que a procura por novos métodos de avaliação seja incentivada. Um recurso valioso consiste num método auxiliar de avaliação das lesões esportivas onde o exame deverá ser realizado através da aplicação de uma resistência constante. Na prática esportiva, há por um lado a importância da proporção do equilíbrio muscular agonista/antagonista, ou seja, do equilíbrio flexor/extensor representado, respectivamente, pelos isquiotibiais/quadríceps da coxa. De outro, a comparação dos valores absolutos da função muscular dos membros inferiores, quer seja para o quadríceps, ou para os isquiotibiais. Resultados alterados podem estar relacionados às lesões esportivas ou suas seqüelas. De interesse para o atleta e para a equipe multidisciplinar é poder dispor de um método de avaliação funcional muscular objetivo e seguro, que forneça dados confiáveis e reprodutíveis. Neste contexto um estudo foi desenvolvido objetivando-se a avaliação dos valores de torque bidirecional (flexão-extensão), potência, tempo e trabalho muscular do joelho quando submetido a uma resistência constante. Para tanto um dispositivo capaz de avaliar esses parâmetros foi desenvolvido no laboratório de biomecânica do Departamento de Mecânica da Unesp de Guaratinguetá, para gerar dados que caracterizem o estado físico e o desempenho dos indivíduos avaliados. Foram utilizados no estudo 19 voluntários do sexo masculino com idade entre 20-30 anos sem histórico de lesão na articulação do joelho, que foram submetidos a exercícios de flexão e extensão com amplitude de movimentos de 90 a 180° durante 40 segundos. / Abstract: The consequent advances in sports medicine include the search for new technological methods that permit a more efficient evaluation of the musculature and joints of the human body. The search for new methods of evaluation has been stimulated by the increased occurrence of injuries to inferior members and in particular knee articulation. A valuable approach consists of an auxiliary method of evaluation of sportive injuries. This examination is carried out through the application of a constant resistance. In sports practice, the agonist / antagonist muscle balance, that is, the flexor/extensor balance represented, respectively, by the hamstring muscle/quadriceps femuris, plays an important role. On the other hand, the comparison between the absolute values of the inferior members is also relevant. Changed results usually relate to sports lesions or their sequels. The development of an objective and safe method to evaluate muscular functionality will provide for reliable and reproducible results of the utmost importance to athletes and multidisciplinary teams. Therefore, a study was carried out proposing to evaluate values of bi-directional torque (flexion-extension), power, time and muscular effort of the knee when submitted to a constant resistance. To accomplish this, a device capable of evaluating these parameters was developed in the biomechanics laboratory of the Department of Mechanics at UNESP - Guaratinguetá. This device generated data that characterized the physical state and performance of the evaluated individuals. The apparatus was used in the study of 19 male volunteers, 20 - 30 years old without pathological history of joint injuries. These volunteers performed flexion and extension exercises during 40 seconds, with an amplitude of movements from 90 to 180°. From these results, a minimum performance standard was determined that characterized good performance among individuals evaluated by the system. / Mestre

No description available.

The purpose of this investigation was to determine if public school children with moderate and severe articulation disorders exhibit dyspraxic characteristics on a standardized developmental dyspraxia screening test.