Orientador: Delaine Rodrigues Bigaton / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-24T08:10:00Z (GMT). No. of bitstreams: 1 Lizardo_FredericoBalbino_D.pdf: 16140755 bytes, checksum: 1d5ad2aa2e68c3fefee3bd783200426d (MD5) Previous issue date: 2013 / Resumo: O core é um segmento do corpo relacionado com o tronco ou, mais especificamente, com a região lombar-pélvica, e sua estabilidade é fundamental para proporcionar uma base durante movimentos dos membros superior e inferior em atividades da vida diária ou gestos esportivos, bem como suportar cargas, prevenir disfunções como lombalgia, desenvolver força e proteger a medula espinal e suas raízes neurais. Exercícios de estabilização do tronco são frequentemente utilizados em programas de prevenção/reabilitação ou treinamento esportivo e muitos destes consistem na manutenção da posição "neutra" da coluna com aplicação de diferentes tipos de sobrecarga. Assim sendo, esse trabalho composto por três artigos, teve como objetivo: 1) analisar os efeitos na atividade eletromiográfica dos músculos do core com a utilização de diferentes estratégias de sobrecarga progressiva (apoio unilateral com e sem superfícies instáveis e variação de movimentos dos membros, com e sem resistência) durante exercícios de estabilização de prancha ventral e lateral; 2) avaliar a atividade eletromiográfica dos músculos do core nos exercícios de estabilização prancha ventral e lateral com e sem utilização de diferentes superfícies instáveis; 3) analisar os índices de cocontração geral e local dos músculos flexores e extensores do tronco nos exercícios de estabilização de prancha ventral e lateral com e sem superfícies instáveis. A amostra foi composta por 22 voluntários do gênero masculino (23,65 + 4,49 anos), saudáveis e fisicamente ativos. A coleta do sinal eletromiográfico foi realizada com eletrodos de superfície diferenciais simples. O sinal eletromiográfico foi analisado no domínio temporal (RMS e Envoltório Linear) e normalizado pela Contração Isométrica Voluntária Máxima. Os dados obtidos foram submetidos à análise estatística paramétrica, empregando-se teste de análise de variância de medidas repetidas (ANOVA). Os resultados mostraram que a incorporação de movimentos do membro produz maior atividade dos músculos abdominais locais e glúteo médio (GM), enquanto a utilização de superfícies instáveis e movimento do membro intensificam o recrutamento dos músculos abdominais globais e a adição de sobrecarga externa influencia o recrutamento do GM. Observou-se ainda que a utilização isolada da superfície instável não aumenta o recrutamento dos músculos do core na prancha lateral, no entanto, a instabilidade simples no membro superior com bola de ginástica e a instabilidade dupla na prancha ventral intensificam o recrutamento dos músculos abdominais globais. Não foram demonstradas diferenças significativas nos índices de cocontração durante os exercícios de estabilização de prancha ventral e lateral com e sem a utilização de superfície instável. A compreensão dessas respostas é importante para profissionais da área da saúde determinarem a progressão apropriada nos programas de prevenção e reabilitação do core, ou treinamento esportivo / Abstract: The core is a segment of the body related to the trunk or more specifically to the lumbopelvic region. The core stability is essential to provide a basis for movements of upper and lower limbs in daily activities or sports, as well as to support loads, prevent disorders as back pain, develop strength and protect the spinal cord and nerve roots. Trunk stabilization exercises are often used in programs of prevention/rehabilitation or sports training and many of these are performed to maintain the "neutral" position of the spine by applying different types of load. For that reason, this work consisted of three articles and, aimed: 1) to analyze the effects of the core muscles on electromyographic (EMG) activity using different strategies of progressive loads (unilateral support with and without unstable surfaces and variation in limb movements, with and without resistance) in prone and side bridges exercises of trunk stabilization; 2) to evaluate the EMG activity of the core muscles in stabilization exercises in prone and side bridges with and without use of different unstable surfaces; 3) to analyze the rates of general and local cocontraction of the trunk flexor and extensor muscles in stabilization exercises in prone and side bridges with and without unstable surfaces. Twenty-two male, healthy and physically active volunteers (age, 23.65 ± 4.49 years), were recruited for this study. EMG data were collected using single differential surface electrodes. The EMG signal was analyzed in the time domain (RMS and linear envelope) and normalized by the maximum voluntary isometric contraction. The data were subjected to parametric statistical analysis, using the analysis of variance (ANOVA) for repeated measures. The results showed that incorporating limb movements produces greater activity of the gluteus medius (GM) and local abdominal muscles, whereas the use of unstable surfaces and limb movements enhances the recruitment of the global abdominal muscles, and the addition of external load influences the GM recruitment. Also, the isolated use of unstable surfaces did not increase the recruitment of the core muscles in the side bridge; however, the upper limb single instability with fitness ball and the double instability in the prone bridge intensified the recruitment of the global abdominal muscles. No significant differences were found in rates of cocontraction during stabilization exercises in prone and side bridges with and without the use of unstable surfaces. Understanding these responses will be important for healthcare professionals to determine the appropriate progression in programs of prevention/ rehabilitation of the core, or sports training / Doutorado / Anatomia / Doutor em Biologia Buco-Dental

This study investigated effects of experimentally-induced subacromial pain, induced via hypertonic saline injection, on shoulder muscles activity. Electromyographic activity of 20 healthy participants was assessed for humeral elevation and descent for the control and experimental pain conditions, using fine wire electrodes for subscapularis and supraspinatus and surface electrodes for middle deltoid, upper trapezius, lower trapezius, infraspinatus, and serratus anterior. Normalized mean amplitudes were analyzed for each muscle for four phases for elevation and descent, respectively. Repeated measures analysis of variances (ANOVAs) were used to determine differences between muscle activity in the control and experimental condition for the four phases of elevation and descent. Differences for mean normalized amplitudes were not significant during humeral elevation. Increased activity was found for the pain condition for serratus anterior and middle deltoid during the first (120-90°) and third (60-30°) parts and decreased activity for infraspinatus in the second half of descent (60-0°). No significant differences were found during descent for upper and lower trapezius, subscapularis and supraspinatus. While increased serratus anterior activity during 60-30° of descent may be protective, increased middle deltoid and decreased infraspinatus activity during the same range may threaten subacromial tissues in that range. Overall the changes in muscle activation were individual specific, particularly during the concentric elevation phase.

京都大学 / 0048 / 新制・課程博士 / 博士(人間健康科学) / 甲第19640号 / 人健博第32号 / 新制||人健||3(附属図書館) / 32676 / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 黒木 裕士, 教授 坪山 直生, 教授 黒田 知宏 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM

Spinal motoneurons (MNs) relay neural commands from the brain to the muscles to produce functional movement. However, MNs are more than passive conduits of neural commands; they also shape motor output through alterations in their intrinsic excitability. These alterations allow MNs to modify (e.g., amplify and/or prolong) motor output even in the absence of descending motor commands. How MNs respond to this modulation, under various conditions, is not fully understood. In the scope of this dissertation, we leverage high-density electromyography and motor unit decomposition algorithms to investigate how human MNs behave in (Aim 1) different muscles under similar task demands; (Aim 2) the same muscle under different task demands; and (Aim 3) in response to exogenous neuromodulation. First, in Aim 1 we demonstrate that MN excitability varies across motor pools and, thus, may be functionally tuned to the task and its muscle-specific demands. The results indicate that the MN discharge rates were significantly higher in the first dorsal interosseous, a small hand muscle used for fine motor control. Conversely, higher MN excitability was observed within the tibialis anterior, a lower leg muscle involved in balance and locomotion. Next, in Aim 2 we show that a muscle (i.e., the biceps brachii) with multiple biomechanical functions (e.g., supination and flexion) receives differential synaptic input to perform each action while the MN discharge characteristics remain the same. Finally, in Aim 3 we demonstrate that a single cup of coffee can alter fundamental motor control mechanisms by increasing discharge rate, inter-pulse variability, and excitability through caffeine-induced neuromodulation. Collectively, findings from this dissertation demonstrate the human motor system’s tremendous ability to adapt to internal and external states. / Public Health

EMG classification is widely used in electric control of mechanically developed prosthesis, robots development, clinical application etc. It has been evaluated for years, but the main goal of this research is to develop an easy to implement and fast to execute pattern recognition method for classifying signals used for human gait analysis. This method is based on adding two new temporal features (form factor and standard deviation) for EMG signal recognition and using them along with several popular features (area under the curve, wavelength function-pathway and zero crossing rate) to come up with a low complexity suitable feature extraction. Results are presented for EMG data and a comparison with existing methods is made to validate the applicability of the foregoing method. It is shown that the best combination in terms of accuracy and time performance is given by spectral and temporal extraction features along with neural network recognition (NN) algorithm.

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