Orientador: Fausto Berzin / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-21T05:55:24Z (GMT). No. of bitstreams: 1 Zuccolotto_DeborahGatti_M.pdf: 1779011 bytes, checksum: 8c0c5c2a35b2c7c203d0461c594ec465 (MD5) Previous issue date: 1996 / Resumo: A proposta deste trabalho foi observar o comportamento eletromiográfico dos músculos Vasto Medial Oblíquo, Vasto Lateral, Semitendíneo e Bíceps da Coxa (porção longa) durante atividade no aparelho "STEPPING MACHINE", tomando-se as medidas de ângulo 0°, 30°, 60°, 90° para a flexão e extensão da perna na articulação do joelho. Foram analisados 10 voluntários adultos normais, utilizando-se um eletromiógrafo de 8 canais, mini-eletrodos de superfície do tipo BECKMAN e um eletrogoniômetro. O método estatístico empregado foi a análise de variância (ANOVA) e o teste de Tukey. Os resultados mostraram que no movimento de flexão, o músculo Vasto Medial Oblíquo apresentou diferença dos potenciais médios de ação ao nível de 5% de significância para as medidas de ângulo 90°, 30° e 0° e também diferença sifnificante entre 60° e 0°. O músculo Vasto Lateral apresentou diferença significante também em 5% no ângulo 90° em relação °a 60°, 30° e 0°, além de diferença entre 60° e 0°. Os músculos semitendíneo e bíceps da coxa não apresentaram diferença significativa nas diferentes medidas de ângulo. Durante o movimento de extensão do joelho, os músculos Vasto Medial Oblíquo e Vasto Lateral, apresentaram diferença entre as medidas de ângulo 90° e 60° em relação às medidas 30° e 0°. Os músculos semitendíneo e bíceps da coxa, não apresentaram diferença significante entre os potenciais de ação nas várias angulações analisadas. Os resultados sugerem que o aparelho "STEPPING MACHINE" pode ser indicado na reabilitação pós-operatória da articulação do joelho / Abstract: The purpose of this paper was to observe the electromyographyc behaviors of the Vastus Medialis, Vastus Lateralis, Semitendineous and Biceps Femoris Muscles during activity in the Stepping Machine equipament, taking the angle measurement 0°, 30°, 60° and 90° for the leg flexion and extension in the knee joint. Ten normal adults volunteers were analysed by using a 8 channels electromyographer, mini surface electrode Beckman type and electrogoniometer. The statistics method utilized was the variance analysis (ANOVA) and the Tukey test. The results showed that in the joint movement Vastus Medialis Muscle presented difference of the medius potencials of action in 5% level of significance for the angle 90° measurement, 30° and 0° and significant difference among 60° and 0°. The Vastus Lateralis muscle presented significant difference also in the angle 90° in 5% in relation of 60°, 30° and 0°, beyond the difference among 60° and 0°. The semitendineous and biceps femoris muscles didn't present significant . difference in different measures of the angles. During the knee joint extension, the Vastus Medialis and Vastus Lateralis muscles presented difference among the 90° and 60° angles in relation to 30° and 60° measurement. The Semitendineous and Biceps Femoris didn't show difference significant among the potencials action in several angled analysed. The results suggest that the Stepping Machine can be indicate in the post-operation rehabilitation / Mestrado / Fisiologia e Biofisica do Sistema Estomatognatico / Mestre em Odontologia

O objetivo deste estudo foi de analisar a confiabilidade teste reteste do posicionamento dos eletrodos na aquisição do sinal eletromiográfico dos músculos do antebraço na tarefa de preensão palmar, por meio de dois posicionamentos. O primeiro posicionamento proposto por Cram; Durie e o segundo proposto por Mogk; Keir. Foram recrutados 30 voluntários sendo divididos em 2 grupos com 15 indivíduos cada. O primeiro grupo era formado por indivíduos saudáveis, isto é, que não apresentavam qualquer patologia, trauma ou dor no membro superior. Este grupo era composto por 13 mulheres e 2 homens com idade média de 23,4 anos, sendo 13 destros e 2 canhotos. O segundo grupo era formado por indivíduos que apresentavam algum trauma no antebraço, punho ou mão, recrutados no centro de reabilitação e no ambulatório de cirurgia do membro superior do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo. A amostra era composta por 13 homens e 2 mulheres com idade média de 34,6 anos, sendo 14 destros e 1 canhoto. Todos os participantes assinaram o Termo de Consentimento Livre e Esclarecido. O procedimento foi realizado em dois dias com diferença de 24h entre as avaliações. A avaliação consistia em realizar a tarefa de preensão palmar com o dinamômetro analógico da marca Jamar® , realizando a máxima contração voluntária pelo período de 10 segundos com repouso de 3 minutos entre cada preensão, sendo coletados o sinal eletromiográfico de sete canais dos músculos do antebraço volar e dorsal, segundo cada método. Foi analisada a confiabilidade pelo índice de ICC e o SEM (Standard Error of Measurement). Os resultados obtidos mostram excelente correlação entre os dois posicionamentos em ambos os grupos. Quando verificado o valor de ICC do grupo de saudáveis verificou valores acima de 0.75 em todos os canais, o que demonstrou uma alta correlação entre as medidas em ambos os posicionamentos, com pequeno SEM. No grupo pacientes foi observado que nos músculos FUC, FSD e ERC uma correlação moderada para o posicionamento Mogk; Keir e somente no músculo FRC apresentou correlação moderada no posicionamento Cram; Durie. Os gráficos de Bland e Altman mostraram alta concordância entre as medidas, visto que, em ambos os posicionamentos, os valores ficaram entre o intervalo de confiança de 95% e próximos da linha média. Como conclusão pode-se inferir que ambos os posicionamentos apresentaram alta confiabilidade e alta correlação quando avaliado por meio do teste e re-teste, podendo ser utilizados para medida eletromiográfica dos músculos do antebraço / The objective of this study was to analyze test retest reliability of the electrodes placement in the acquisition of electromyography forearm muscles during a isometric hand grip task, through two different methods. The first method was proposed by Cram; Durie and the second by Mogk; Keir. We recruited 30 volunteers divided into 2 groups with 15 subjects each. The first group consisted of healthy subjects, who did not show any pathology, trauma or pain in the upper extremity. This group consisted of 13 women and 2 men with a mean age of 23.4 years, and 13 right-handed and 2 left-handed. The second group consisted of individuals who had previous trauma on the forearm, wrist or hand. They were recruited from the rehabilitation center and upper limb surgery clinic of the Medical School of Ribeirão Preto Clinical Hospital. The sample consisted of 13 men and 2 women with a mean age of 34.6 years, 14 right-handed and left-handed one. All participants signed the consent form. The procedure was performed in two days with 24 hours difference between assessments. The evaluation was to carry by a isometric handgrip task with a analog dynamometer Jamar®, with maximum voluntary contraction for 10 seconds with 3 minutes of rest and analised by CCI and SEM (Standard Error of Measurement) . The results obtained have a high correlation between the two methods in both groups. Analyzing the ICC value of the healthy group value noted above 0.75 in all channels, demonstrating a excelent correlation between the measurements in both positions and low SEM. Checking in group patients realize that the FUC, FSD and ERC muscles has a moderate correlation for Mogk; Keir positioning and only on FRC showed moderate correlation in Cram; Durie electrode placement method. Analyzing Bland and Altman method a high concordance was found between the measures, since in both positions, the values were between the confidence interval of 95% and close to the midline. Through this we can infer that both positions have high reliability and high correlation when measured by the test and retest

O objetivo deste estudo foi avaliar a confiabilidade intradia e interdias dos valores de amplitude da eletromiografia de superfície, dos músculos da cintura escapular e membro superior, durante a realização de 3 exercícios isométrico com a extremidade distal do segmento fixa em uma superfície estável e outra superfície instável, com descarga de peso axial controlada para o membro superior. Para tanto, 20 adultos saudáveis realizaram os exercícios push-up, bench-press e wall-press em diferentes níveis de carga (80 e 100% da carga máxima). Os valores de carga produzida por cada um dos exercícios foram registrados de maneira simultânea à eletromiografia. Os sujeitos realizaram três contrações voluntárias máximas (CVM) na posição de prova de função muscular de cada músculo, para obtenção do valor de referência para normalização dos valores de root mean square (RMS) e da integral do envoltório linear (?env). Os sujeitos foram instruídos, a realizarem de forma aleatória, 3 séries de contrações isométricas por 6 segundos em cada exercício, com intervalo de 2 minutos entre as séries e exercícios.Os sinais eletromiográficos dos músculos deltóide porção anterior e posterior, trapézio fibras superiores, serrátil anterior, peitoral maior porção clavicular, bíceps braquial porção longa e tríceps braquial porção longa foram captados por eletrodos de superfície ativos simples diferenciais, realizados em dois testes com intervalo de sete dias. Os dados foram coletados com freqüência de amostragem de 4000Hz e aplicados filtros digitais de passa baixa de 500Hz e passa alta de 20Hz. Os valores de RMS e ?env foram normalizados pelo valor máximo da amplitude eletromiográfica obtida em 1 das 3 CVM do músculo correspondente. As confiabilidades intradia e interdias foram calculadas através do coeficiente de correlação intraclasse (ICC), erro padrão da medida (SEM) e coeficiente de variação (CV). Os resultados indicaram excelente confiabilidade intradia dos valores de amplitude eletromiográfica (ICC ?0,75). A confiabilidade interdias dos valores normalizados de RMS apresentou valores variando entre bom e excelente (ICC 0,52-0,98), já os valores normalizados de ?env apresentaram valores pobres a excelente de confiabilidade (ICC 0,06-0,93). Os valores de carga produzidos durante os exercícios apresentaram excelente confiabilidade intradia e interdias (ICC ?0,97). Por fim, os resultados do presente estudo sugerem que a confiabilidade dos valores normalizados de amplitude eletromiográfica dos músculos analisados apresentam valores mais confiáveis durante os exercícios realizados com superfície estável. Já os níveis de carga empregados (80 e 100%) durante os exercícios parecem não ter influenciado nos níveis de variabilidade, talvez por serem cargas muito próximas. / The objective of the present study was to evaluate the intra and interday reliability of surface electromyography amplitude values of the scapular girdle muscles and upper limbs during the performance of 3 isometric exercises of closed kinetic chain regarding the upper limbs with the fix distal segment extremity on one stable surface and the other one on one unstable surface. In this regard, 20 healthy adults realized the exercises push-up, bench-press and wall-press with different load levels (80 and 100% maximal load). The load values produced for each exercise were recorded simultaneously to the electromyography. The individuals performed three maximal voluntary contractions (MVC) in the muscular testing position of each muscle for the obtainment of the reference value for the root mean square (RMS) normalization values and for the integrated of the linear envelope (?env). The individuals were instructed to realize at random, 3 isometric contraction series taking each exercise 6 seconds with a rest of 2 minutes between the series and the exercises. The electromyographic signals of the anterior and posterior deltoid, upper trapezius, anterior serratus, pectoralis major, biceps and triceps brachial muscle were captured by simple active differential surface electrodes, in two tests with a 7-day interval. Data were collected with a sampling frequency of 4000Hz and 500Hz low and 20Hz high passage digital filters. The RMS and ?env values were normalized by the maximal electromyographic amplitude value obtained in 1 of the 3 MVC of the corresponding muscle. The intra and interday reliabilities were calculated through the intraclass correlation coefficient (ICC), standard error measure (SEM) and coefficient of variation (CV). The results indicated an excellent intraday reliability of the electromyographic amplitude values (ICC ?0.75). The interday reliability of the RMS normalized values presented values varying between good and excellent (ICC 0.52-0.98), whereas the ?env normalized values presented poor to excellent reliability values (ICC 0.06-0.93). The load values produced during the exercises presented excellent intra and interdays reliability. Finally, the results of the present study suggest that the reliability of the electromyographic amplitude normalized values of the analyzed muscles present better values during the performance of the exercises with stable surface. However the load levels utilized during the exercises do not seem to have influenced the variability levels, eventually in view of being very close levels

Orientador: Marcelo Ferraz Mesquita / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T05:56:39Z (GMT). No. of bitstreams: 1 Ferreira_DanielFilgueiras_M.pdf: 1227737 bytes, checksum: 8574e46d80b04a8d94d10a74cac5fef3 (MD5) Previous issue date: 2005 / Resumo: O objetivo desta pesquisa foi avaliar eletromiograficamente o padrão de atividade muscular resultante da utilização de duas técnicas de montagem de dentes artificiais para obtenção de equilíbrio em prótese total dupla. Vinte e quatro pacientes totalmente edêntulos, livres de sinais e sintomas de Desordem Temporomandibular (DTM) com no mínimo cinco anos de uso de próteses totais, foram separados em dois grupos de 12 pacientes: (G1 e G2). Para o G1, utilizou-se a técnica Convencional, onde o equilíbrio foi obtido através de contatos interferentes entre dentes artificiais. Para o G2, utilizou-se a técnica das Rampas Posteriores de Nóbilo, que proporciona equilíbrio através de contatos deslizantes entre a superfície das rampas. O padrão de atividade muscular foi mensurado através da atividade eletromiográfica (EMG) dos músculos temporais porção anterior e masseteres nas posições de repouso (R) e na contração isométrica em máxima intercuspidação (CIMI), avaliado em quatro tempos: T0 - instalação; T1 - 1o mês; T2 - 2o meses; T3 - 3o meses de uso das próteses. Foi utilizado o eletromiógrafo Myosystem I® (Prosecon Ltda, Uberlândia, MG, Brasil) e o sinal eletromiográfico condicionado através de filtro digital passa faixa e analisado em relação RMS (Root Mean Square). Em ambos os grupos, observou-se pequenas alterações nos valores da atividade EMG para os músculos temporais anteriores e masseteres na posição de R. Na posição de CIMI, no G1 os músculos temporais anteriores apresentaram valores finais menores que os iniciais, e situação inversa foi observada para os masseteres, com valores finais maiores que os iniciais; no G2 observou-se inversão dos valores para os músculos temporais anteriores e aumento para os masseteres com ligeiro equilíbrio no terceiro mês de avaliação. O teste Wilcoxon-Mann-Whitney entre as técnicas e o de Friedman nos tempos avaliados não mostraram diferenças estatísticas significativas (p<0.05). Conclui-se que as técnicas estudadas clinicamente não apresentaram diferença entre si, e que as avaliações nos tempos não proporcionaram o equilíbrio dos músculos mastigatórios estudados. Dessa forma, ambas técnicas podem ser utilizadas com performances clínicas semelhantes / Abstract: The aim of this study was to evaluate by the electromyography muscular activity pattern resulting of two prosthetic teeth arrangement techniques that promote balance in double complete dentures. Twenty-four subjects totally edentulous, free from signs and symptoms of TMJ disorders and with at least five years complete dentures use were divided in two groups of 12 subjects: G1 and G2. In the Group 1, the Conventional technique was used and the interference contacts between artificial teeth were responsible for the balance. In the Group 2, the Nóbilo's Balancing Ramps technique, slippery contacts between ramps surfaces provided balance. The muscular activity pattern was measured by electromyographic (EMG) activity of anterior temporal and masseter muscles in the mandibular rest (R) and maximal biting in the intercuspal position (CIMI) at four times: T0 - installation; T1 - 1st month; T2 - 2nd month; T3 - 3rd month of prostheses use. The electromyographic sign was collected with Myosystem I® conditioned through of digital filter pass band and analyzed in relation to RMS (Root Mean Square). In both groups, in the mandibular rest of the anterior temporal and masseter muscles was observed small alterations in the EMG activity values. In CIMI position, in the Group 1, anterior temporal muscles showed final values smaller than the initial, differently of masseter muscles that showed final values greater than the initial; in the Group 2 inversion values were observed in the temporal muscles and increase in the masseter with light balance in the third month evaluation. Wilcoxon-Mann-Whitney test between the techniques and the Friedman test in the evaluated times did not show significant statistical differences (p<0.05). The techniques clinically studied did not show differences between themselves and the times evaluation did not provide balance in the masticatory muscles studied. In this way, both techniques can be used with similar clinic performance / Mestrado / Protese Dental / Mestre em Clínica Odontológica

Orientador: Fausto Berzin / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T11:20:07Z (GMT). No. of bitstreams: 1 Nagae_MirianHideko_M.pdf: 1078280 bytes, checksum: ba397a779b3d141835ce4bdd7491c631 (MD5) Previous issue date: 2005 / Resumo: O comportamento da musculatura peribucal diante de alterações dento esqueletais sempre foi objeto de interesse tanto no meio clínico como entre os pesquisadores. No entanto , sua ação ainda é pouco compreendida , particularmente o músculo bucinador que , segundo Mayoral (1977), por ter como função manter o equilíbrio na cavidade bucal , necessita que as estruturas dento cranianas que a circundam estejam corretamente posicionadas . Assim , este estudo teve por finalidade avaliar e comparar o padrão de atividade exercido pelo músculo bucinador em relação ao músculo masseter em voluntários Classe I e III de Angle , durante o ciclo mastigatório. Dois grupos de voluntários foram estudados: Grupo controle ¿ 16 voluntários , Classe I de Angle ; Grupo experimental ¿ 16 voluntários , Classe III de Angle , com faixa etária entre 18 e 40 anos , de ambos os sexos. Para análise eletromiográfica desses músculos foi utilizado eletromiógrafo Myosystem I e para o processamento e análise dos dados software MatlabÒ (versão 5.3). Como transdutores , foram utilizados eletrodos de superfície passivos bipolares MedtraceÒ , acoplados a pré-amplificadores LynxÒ , formando um circuito correspondente a um eletrodo diferencial . Para análise estatística dos dados utilizou-se o sistema computacional Statistical Analysis System - SAS . Após a Análise de Variância foi aplicado os Testes de Tukey para comparação das médias e t de Student para 2 amostras independentes. Para todas as Análises de Variância considerou-se o nível crítico de 5% (p<0,05). As variáveis foram analisadas qualitativamente e quantitativamente. Qualitativamente , analisou-se a comparação da curva em si com relação aos voluntários Classe I e III de Angle . Quantitativamente , foram analisados argumentos que fornecessem sustentação aos achados qualitativos , ou seja , a razão entre o período do Root Mean Square - RMS inativo sobre o período do RMS ativo de cada músculo ; instante máximo - -IMAX e duração do período ativo - ON dos ciclos mastigatórios referente às classes e músculos. Qualitativamente a atividade EMG do músculo bucinador durante os ciclos mastigatórios foi claramente demarcada , embora a correspondência das atividades cíclicas com o músculo masseter , nem sempre apresentasse as mesmas proporções. Nos voluntários Classe I , o músculo masseter apresentou dois períodos claramente demarcados, de atividade e inatividade. O músculo bucinador , por sua vez , exerceu um padrão semelhante na fase de elevação mandibular do músculo masseter alcançando inclusive , seu ápice no mesmo instante e cessando sua atividade durante o abaixamento mandibular. No entanto após 0,24ms de inatividade , reiniciou sua atividade em amplitudes mínimas . Já os voluntários Classe III , apresentaram padrão de atividade do músculo masseter semelhante aos dos voluntários Classe I , com períodos de atividade e inatividade equilibrados . O músculo bucinador , no entanto , apresentou padrão completamente diferenciado com períodos de ativação de longa duração e assincrônicos , em total descompasso com os ciclos do músculo masseter . O valor da razão do período inativo sobre o período ativo - RIA do músculo masseter , nos voluntários Classe I , foi de 7% e para a Classe III , 9% , comprovando a presença de dois períodos , de inatividade e atividade proporcionais . Com relação ao músculo bucinador , no entanto , houve uma ativação de 50% nos voluntários Classe I e de 90% nos voluntários Classe III durante o período de inatividade. . Para a análise das variáveis IMAX e ON , foram calculados os valores do Coeficiente de Variação ¿ CV em relação ao pico máximo e a média . Utilizou-se o CV com relação ao pico máximo como referência para as investigações , por apresentar o menor índice de dispersão . O IMAX de atividade entre os músculos dos voluntários Classe I e III não apresentaram diferenças significativas. Com relação a variável ON , o músculo bucinador nos voluntários Classe III apresentou um período ativo significativamente maior em relação aos voluntários Classe I / Abstract: Reactions of the perioral system of muscles in face of dental skeletal alterations have long been a concern to clinic practitioners as well as to researchers. However , its action is still poorly understood , notably that of buccinator muscle which , because of its function as balance upholder in mouth cavity , according to Mayoral (1977) , requires dental cranial structures surrounding it to be correctly placed . Therefore , this study aimed to assess and compare the pattern carried out by buccinator muscle compared to masseter muscle in volunteers Angle Class I and III , during mastication cycle. Two groups of subjects were studied : Control Group ¿ 16 volunteers , Angle Class I ; Experimental Group ¿ 16 volunteers , Angle Class III, age range between 18 and 40 years old . Electromyographical analysis of referred muscles was proceeded by use of Myosystem I electromyographer , and for data processing and analysis MatlabÒ software (version 5.3) was used . As to transducers , MedtraceÒ passive bipolar surface electrodes were used , joined to LynxÒ preamplifiers to create a circuit corresponding to a differential electrode . Computing System Statistical Analysis System ¿ SAS , was used in statistical analysis of data. After Variance Analysis , Tukey Tests were applied to compare means and Student-test t obtained from 2 independent samples . Critical level of 5% (p<0,05) was taken for all Variance Analyses . Variables were analyzed qualitatively and quantitatively . Qualitative analysis was completed comparing the curve itself related to Angle Class I and Class III volunteers . As for quantitative analysis , statements providing support to qualitative findings were analyzed , namely : the ratio between inactive period of Root Mean Square - RMS and active period of RMS for each muscle ; maximum instant -IMAX and active period duration - ON. Qualitatively EMG activity for buccinator muscle during mastication cycle was clearly drawn , although correspondence of cyclic activities to masseter muscle did not always exhibit the same proportions . In volunteers Class I masseter muscle exhibited two clearly marked periods, of activity and inactivity . On its turn , buccinator muscle carried out a similar pattern during masseter muscle jaw elevation phase , even reaching its peak at the same moment , and ceasing its activity in wide correspondence to jaw depression. However after 0,24ms of inactivity it slightly re-started activity during masseter muscle inactivity period . On the other hand , Class III volunteers exhibited activity pattern of masseter muscle similar to those of Class I volunteers , showing balanced periods of activity and inactivity . Buccinator muscle , however , exhibited completely distinct pattern , with periods of long duration and desynchronized activation , completely out of pace with masseter muscle cycles . The result of ratio between inactive period and active period - RIA for masseter muscle was 7% in Class I volunteers , and 9% in Class III volunteers , proving the existence of two similar periods , of inactivity and activity . Regarding buccinator muscle , however , it was 50% in Class I volunteers , and 90% in Class III volunteers partially similar , marking off the existence of an inactivity period partially activity in volunteers Class I and much activity in volunteers Class III . To analyze IMAX and ON variables variation coefficient - CV values were calculated in relation to maximum peak and mean . The variation coefficient related to maximum peak was used as a reference for investigations, since it shows the smallest dispersion index . Activity IMAX between the muscles of Class I and III volunteers did not show significant differences . Regarding variable ON , buccinator muscle in Class I and III volunteers exhibited a significantly larger active period comparing to masseter muscle / Mestrado / Anatomia / Mestre em Biologia Buco-Dental

Whole body vibration (WBV) delivers a stimulus to the body via an oscillating platform and remains a relatively new area of research. Several applications of WBV stimuli have been developed as strength training and rehabilitation modalities, but inconsistent results have been published. There is little knowledge underpinning the mechanisms to explain the elicited neuromuscular responses to WBV and a wide range of WBV parameters across the literature. As a result, safe and effective protocols are yet to be established or validated. The aim of this current research was to investigate: the electromyography (EMG) and explosive performance responses to varying WBV frequencies; the effect of WBV data analysis techniques; and the influence of external factors on WBV stimulus and neuromuscular responses. Three main studies were completed: 1. An individualised response of both EMG and jump performance appears to exist dependent on vertical WBV frequency, in trained participants. This is in spite of no overall frequency dependent effect of EMG or performance responses across participants as a group. The influence of the role of expectancy effect appears minimal following this particular WBV protocol. 2. There was a significant effect of filter technique on EMG data recorded during vertical WBV. A tailored, WBV specific notch filter technique may offer an effective balance; excluding WBV noise artifacts without removing significant portions of valuable muscle signal EMG data. 3. The influence of external load on WBV acceleration output also appears minimal. Platform acceleration output was dependent on WBV frequency, as expected. Lower accelerations were recorded in superior body segments, suggesting a dampening mechanism, which was also proportionally dependent on frequency. EMG activity of upper and lower leg segments may differ in response to frequency, likely due to transmission distances involved. This may partially account for a potential dampening mechanism. In addition, a protocol to quantify WBV stimuli delivered by this particular WBV type illustrated significant differences in theoretical and actual parameters. This may explain not only the lack of overall explosive performance effect reported earlier; but also the inconsistent WBV literature. Future research should quantify WBV stimulus before investigating possible neuromuscular responses to individualised protocols, which may be assessed via EMG activity.

The eggbeater kick is a skill used frequently in water polo and synchronized swimming to elevate the upper body for shooting, passing, blocking or compete with the opponent for position in the water. The hips, knees, and ankles are involved in creating favourable orientations of the feet so that propulsive forces in the vertical direction can be created. Literature reporting the technique of the eggbeater kick is scarce and limited to description of kinematics or muscle activity. The relationship of the kinematics to the demands on specific muscles has not been established. The purpose of this study was to analyze the kinematics and muscle activity of the water polo eggbeater kick in fatigued and unfatigued states to provide foundational knowledge on which training programs can be based. Twelve water polo players were tested executing the eggbeater kick in the vertical position while trying to maintain as high a position as possible for the duration of the test. The test was terminated when the player could not keep the top of the sternum marker above water. Anthropometric data were collected using the ‘eZone’ method. Three dimensional coordinates for the lower limbs and two dimensional coordinates of the above water top of the sternum marker were obtained. Surface electromyography recorded the muscle activity of the Tibialis Anterior, Rectus Femoris and Biceps Femoris muscles on both legs. Differences between fatigued and unfatigued conditions and between dominant and nondominant sides were tested using a two factor ANOVA with repeated measures. Differences within subjects were also investigated on a subject by subject basis with regard to muscle activity. Results indicated differences for kinematic and muscle activity variables between fatigue levels. The amplitude of anatomic angles and speed of the feet decreased with fatigue. Significant differences were found between dominant and non-dominant sides for the ankle motion. The non-dominant ankle was more inverted and adducted than the dominant ankle during the knee flexion phase of the cycle. The Rectus Femoris muscle had consistent patterns across subjects, while Tibialis Anterior and Biceps Femoris muscles were more subject specific in their responses. The Rectus Femoris and the Biceps Femoris have an agonist/antagonist relationship during knee flexion and extension. The Tibialis Anterior was active for long periods in the cycle while dorsiflexing and inverting the foot. As a consequence activity in these muscles decreased with fatigue. These findings point towards the necessity for players and coaches to address specific motions and muscles during the training of the eggbeater technique. Future work should focus on developing eggbeater kick training programs that address specific strength and flexibility.

No description available.

The aim of the study was to examine the muscle activities of fifteen male participants (23.44 ±2.63 years) during unilateral hockey bag load carrying of different weights (10%, 20%, and 30% bodyweight) and sizes (small and large). Walking without a hockey bag was the control condition. The results showed that increased peak and integrated EMG occurred with an increased load weight in the semitendinosus, gastrocnemius, rectus abdominis, and vastus medialis. The left rectus femoris and left semitendinosus were both significantly greater than the right corresponding muscle. Carrying the large hockey bag produced greater peak EMG in the right rectus abdominis and the right rectus femoris, whereas the right vastus medialis showed a larger peak EMG in the small hockey bag. It was concluded that the posterior-lateral carrying style of hockey bag load carriage explained the results being similar to both backpack and side pack load carriage studies.

Five studies were performed to explore the feasibility of treating severe chronic stuttering with EMG feedback. EMG spiking from the throat was found to correlate with stuttering, and to differentiate between stuttering and fluent speech. EMG spiking tended to disappear when stuttering was reduced by metronome-paced speech and by speech therapy. Likewise, when EMG spiking was reduced by feedback training, stuttering was concurrently reduced. Presentation of the feedback tone without instructions or information produced no reduction in stuttering or EMG spiking. Pseudofeedback was also generally ineffective. It was concluded that the feedback effect is apparently not an artifact of instructions, masking, distraction, adaptation, slowing of speech, or of a stutter-contingent aversive tone, nor is it a Hawthorne or placebo effect. Implications of the results are discussed. / Arts, Faculty of / Psychology, Department of / Graduate