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Plassman, Brenda L. 1957. "INSPIRATORY MUSCLE RESPONSES TO OCCLUSION (EMG)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/291244.
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Szöllösi, Tomáš. "Měření EMG a posouzení vlivu zátěže." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-374762.
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The task of this thesis was focused on influence of physical load on electrical activity of muscle. There are basic principals and terms from the problematic of measuring electric activity of muscle. Author suggested measuring protocol, got data from group of people, made an application and used this application to analyse measured signals. At the end of this work it was suggested statistical processing and evaluation of results.
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Gobert, Nathalie. "Etude des paramètres EMG de la fatigue musculaire du muscle trapèze supérieur dans l'extension de la tête." Bordeaux 2, 1992. http://www.theses.fr/1992BOR2M168.
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Young, Richard N. (Richard Norman). "The effect of muscle contractility on surface EMG /." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60423.
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This study was designed as an investigation of the role of changes in muscle force and changes in muscle length on the EMG for the Tibialis Anterior (TA).Using surface electrodes we examined the EMG for 4 contraction levels at 5 ankle positions over 60$ sp circ$ of ankle rotation. The change in median frequency with muscle length identified a significant shift in the power spectrum to lower frequencies with increasing muscle length.
To further investigate our results we performed three other experiments: First, using X-rays to identify the relative change in distance between two intramuscular wire electrodes we found the change in TA muscle length for this study to be 15% over the 60$ sp circ$ of ankle rotation. Second, to test for synergist contamination we used fine wire electrodes in the Extensor Digitorum Longus and the Peroneus. We found no evidence to support significant contamination. Third, we examined the role of smaller electrodes with a smaller interelectrode distance on our findings. The EMG showed drastic changes with even a slight shift in electrode position most likely due to the large number of innervation zones.
Therefore, the results indicate a shift in the power spectrum with a change in muscle length. In addition, surface EMG results are heavily dependent on the innervation zones and on the electrode geometry, all of which are important considerations in developing the EMG as an accurate diagnostic tool.
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Cutts, Alison. "Surface EMG as an indicator of muscle force." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328893.
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Bida, Oljeta. "Influence of electromyogram (EMG) amplitude processing in EMG-torque estimation." Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd--01295-140510/.
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Thesis (M.S.)--Worcester Polytechnic Institute.Keywords: system identification; EMG; optimal sampling rate; linear torque model; EMG-torque model; EMG amplitude; torque. Includes bibliographical references (p. 77-86).
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Portero, Pierre. "Adaptation du muscle humain à la microgravité simulée : apport de l'analyse spectrale du signal EMG." Compiègne, 1993. http://www.theses.fr/1993COMP566S.
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Les modifications des paramètres spectraux du signal électromyographique de surface (EMGS) des muscles Triceps Surae (T. S. ) et Tibialis Anterior (T. A. ), au cours d'une épreuve de fatigue isométrique, sont étudiées en relation avec une situation de microgravité simulée chez l'homme, c'est-à-dire lors d'une période de Bed Rest (B. R. ). La revue de la littérature a permis de montrer que : d'une part, lors d'une période de microgravité réelle ou simulée, les muscles à fonction antigravitaire (T. S) sont plus affectés que les muscles à fonction phasique (T. A. ) ; d'autre part, les paramètres spectraux EMGS évoluent différemment lors d'épreuves de fatigue et ceci en fonction de leurs caractéristiques métaboliques musculaires. L'étude a comporté deux phases principales : la première a consisté en la validation du protocole expérimental, la caractérisation des réponses des différents muscles en terme d'évolution des paramètres spectraux EMGS, et l'établissement d'une relation entre ces paramètres spectraux et certains paramètres du métabolisme musculaire exploré par spectroscopie RMN 31P ; la deuxième a été de caractériser l'évolution des paramètres spectraux EMGS en fonction du statut fonctionnel du T. S. Et du T. A. Lors d'une période de B. R. (4 semaines), avec et sans contre-mesures d'exercice musculaire. Les résultats montrent que : grâce à la méthode proposée (épreuve isométrique à 50% de la force maximale volontaire et analyse spectrale du signal EMGS), il est possible de différencier les évolutions des muscles en fonction de leur résistance à la fatigue grâce à l'établissement d'un débit de la fréquence moyenne (MPF) du spectre EMGS (% de diminution de la valeur initiale de la MPF par minute de temps de contraction). Ce débit constitue un index de fatigabilité d'un point de vue EMGS : il existe une relation entre le glissement spectral vers les basses fréquences de L'EMGS et la concentration musculaire en H2PO4 d'une part et H+ d'autre part ; il est possible de différencier ces évolutions par rapport à une situation de microgravité simulée, les différents chefs musculaires du T. S. (les gastrocnemii et le soleus) présentant une augmentation du débit de MPF contrairement au T. A. ; et enfin, lorsqu'un entraînement musculaire est non spécifique de la fonction des muscles étudiés, celui-ci n'est pas suffisant pour contrecarrer les effets du déconditionnement exprimés en terme EMGS. En conclusion, l'analyse spectrale du signal EMGS, lors d'épreuves de fatigue isométrique, apparaît comme étant un outil fiable pour discriminer les muscles par rapport à leur fonction antigravitaire (ou non) et en situation de microgravité simulée. L'aspect non invasif de cette méthode en fait une technique de choix pour le suivi de l'adaptation du muscle dans les domaines de la physiologie spatiale, sportive et de la médecine
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Rababy, Nada. "Estimation of EMG conduction velocity using system identification." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63819.
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Tortopidis, Dimitrios Steliou. "Bite force and EMG studies on the jaw-closing muscles." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361012.
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Liu, Ming Ming. "Dynamic muscle force prediction from EMG signals using artificial neural networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq20875.pdf.
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Sachs, Christina Michelle. "EMG analysis of type IIb muscle fibers correlated with blood lactate accumulation /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p1418061.
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Joubert, Michelle. "A finite element model for the investigation of surface EMG signals during dynami contraction." Pretoria : [s.n.], 2007. http://upetd.up.ac.za/thesis/available/etd-09042008-105943/.
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Zbořilová, Nicol. "Mobilní EMG modul pro využití v terapii." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-241999.
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This thesis explains structure of skeletal muscles, generation of action potencial and principle of muscle contraction. Further it shows types of electromyographic signal recording and its usage in therapy. Technical aspects of EMG signal and components required for electromyograph assemblage are next topic of this thesis. Another part presents design of simple EMG module for therapeutical application with bluetooth 4.0 interface.
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Santosa, Robert. "The influence of the leaf gauge on jaw muscles, EMG." Master's thesis, Faculty of Dentistry, 2001. http://hdl.handle.net/2123/4838.
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This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au
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Alibrahim, Anas. "The measurement of maximal bite force in human beings." Thesis, University of Dundee, 2015. https://discovery.dundee.ac.uk/en/studentTheses/73283c8a-eee6-468b-8300-b79c12ad9f51.
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Background: Registering a true maximum bite force on the most commonly-used force transducers is problematic. It is often believed that this is related mainly to discomfort and the fear of breaking teeth. Objectives: The aim of the project was to compare the suitability of different bite force measuring transducers including ones which were designed to improve subject comfort. The transducers used were a traditional strain-gauge transducer with and without covering with ethylene vinyl acetate (EVA) sheets, and a newly-developed pressure transducer. Methods: Five separate studies were performed in this project. The experiments were carried out on human volunteer subjects (aged 24 to 41 years). They were all dentate with no missing anterior teeth and with no crowns on these teeth. The following procedures were used in some or all of the studies: measurement of MVBF, electrical stimulation of the masseter muscle, and EMG recording from two pairs of jaw closing muscles. Results: The highest MVBF values were recorded on the pressure transducer, mean (± S.D.) 464 N ± 224 N; followed by the strain-gauge transducer with EVA sheets, 243 ± 80 N; and last of all the strain-gauge transducer with silicone indices, 165 ± 35 N; or acrylic indices, 163 ± 82 N. Significantly higher maximum potential bite forces were predicted by twitch interpolation for the pressure transducer (730 ± 199 N) than for the strain-gauge transducer with EVA sheets, 354 ± 67 N (Paired t test, P < 0.05). Significantly higher EMGs of the masseter and anterior temporalis muscles were found to be associated with MVBFs on the pressure transducer than with MVBFs on the strain-gauge transducer with EVA sheets (Paired t test, P < 0.05). Conclusions: It is concluded that: a) the pressure transducer system and to a lesser extent the strain-gauge transducer covered with EVA sheets seemed to overcome the fear associated with biting on the hard surfaces of the strain-gauge transducer alone; b) the pressure transducer may have some multi-directional capabilities which allow for total bite forces, or at least larger parts of them, to be recorded than on a uni-directional strain-gauge transducer.
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Hoeven, Johannes Harmen van der. "Conduction velocity in human muscle an EMG study in fatigue and neuromuscular disorders /." [S.l. : [Groningen] : s.n.] ; [University Library Groningen] [Host], 1995. http://irs.ub.rug.nl/ppn/142995223.
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Bene, Cheryl Renee. "Visually displayed-EMG biofeedback : training muscle relaxation in hearing impaired children :a thesis." Scholarly Commons, 1988. https://scholarlycommons.pacific.edu/uop_etds/505.
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The purpose of the present study was to test the use of visually displayed EMG biofeedback as a means for training hearing impaired adolescents to reduce anterior temporalis or frontalis muscle tension . Five male and four female hearing impaired students between the ages of 13 and 15 were chosen from the California School for the Deaf, Fremont, CA to serve as participants. Each participant was randomly assigned to either an experimental or control condition. Participants in the experimental groups were given five 15 minute EMG biofeedback training sessions. An additional group of 4 adolescents with normal hearing from Marshall Junior High School, Stockton, CA served as a hearing control group. The dependent measure was a 5 minute pretest and post-test measurement of muscle tension (in microvolts).
Split-plot analyses were performed to determine if there were significant differences between a ) the .hearing impaired experimental and the hearing impaired control groups, b) the hearing impaired control and the hearing control groups, and c) the hearing impaired experimental group and the hearing control group.
Results of the analyses showed that at post-test both the hearing impaired experimental group and the hearing control group showed a significant decrease in muscle tension F(1,7)=5.85 p< .05. The interaction was nonsignificant. Comparison of the two control groups showed that at post-test the two groups were not significantly different in levels of muscle tension. The comparison between the hearing impaired experimental and the hearing control groups resulted in a significant interaction (Group X Time of Testing) F( 1,6)=9.47, p=.02, and the main effect for time of testing approached significance.
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Szabó, Balázs. "High density EMG based estimation of lower limb muscle characteristics using feature extraction." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-289859.
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Electromyography (EMG) is a common tool in electrical muscle activity measurement and can be used in multiple areas of clinical and biomedical applications, mainly in identifying neuromuscular diseases, analyzing movement or in human machine interfaces. Traditionally a pair of electrodes were used to measure the signals, but in recent years the use of high density surface EMG (HD-sEMG) gained more popularity as it can sample myoelectric activities from multiple electrodes in an array on a single muscle and provide more information. In this thesis a measurement setup and protocol is proposed that can provide a reliably measurement, furthermore multiple features are extracted from the collected signals to characterise the major muscles around the ankle. 5 healthy subjects were tested using an ankle dynamometer with 5 HD-sEMG placed on the Tibialis Anterior, the Gastrocnemius Medialis, the Soleus, the Gastrocnemius Lateralis, and on the Peroneus Longus. Several tests were conducted using different initial angle of the ankle joint and different percentages of the maximum voluntary contraction. The reliability of the setup was assessed by comparing the variance between the collected signals of the same subject in a repeated test, and by comparing different subjects to each other. Results show a reasonably good reliability with less than $10\%$ variance, and adequate selectivity as well. To examine the muscle characteristics, 7 features were extracted from the collected and processed signals, then the features were plotted and compared to signs for muscle characteristics such as muscle fatigue, activation, and spatial distribution of activation. Correlations between features of mean average value (MAV) and zero crossing (ZC), and different muscle characteristics could be observed.
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Keating, Jennifer. "Relating forearm muscle electrical activity to finger forces." Digital WPI, 2014. https://digitalcommons.wpi.edu/etd-theses/580.
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The electromyogram (EMG) signal is desired to be used as a control signal for applications such as multifunction prostheses, wheelchair navigation, gait generation, grasping control, virtual keyboards, and gesture-based interfaces [25]. Several research studies have attempted to relate the electromyogram (EMG) activity of the forearm muscles to the mechanical activity of the wrist, hand and/or fingers [41], [42], [43]. A primary interest is for EMG control of powered upper-limb prostheses and rehabilitation orthotics. Existing commercial EMG-controlled devices are limited to rudimentary control capabilities of either discrete states (e.g. hand close/open), or one degree of freedom proportional control [4], [36]. Classification schemes for discriminating between hand/wrist functions and individual finger movements have demonstrated accuracy up to 95% [38], [39], [29]. These methods may provide for increased amputee function, though continuous control of movement is not generally achieved. This thesis considered proportional control via EMG-based estimation of finger forces with the goal of identifying whether multiple degrees of freedom of proportional control information are available from the surface EMG of the forearm. Electromyogram (EMG) activity from the extensor and flexor muscles of the forearm was sensed with bipolar surface electrodes and related to the force produced at the four fingertips during constant-posture, slowly force-varying contractions from 20 healthy subjects. The contractions ranged between 30% maximum voluntary contractions (MVC) extension and 30% MVC flexion. EMG amplitude sampling rate, least squares regularization, linear vs. nonlinear models and number of electrodes used in the system identification were studied. Results are supportive that multiple degrees of freedom of proportional control information are available from the surface EMG of the forearm, at least in healthy subjects. An EMG amplitude sampling frequency of 4.096 Hz was found to produce models which allowed for good EMG amplitude estimates. Least squares regularization with a pseudo-inverse tolerance of 0.055 resulted in significant improvement in modeling results, with an average error of 4.69% MVC-6.59% MVC (maximum voluntary contraction). Increasing polynomial order did not significantly improve modeling results. Results from smaller electrode arrays remained fairly good with as few as six electrodes, with the average %MVC error ranging from 5.13%-7.01% across the four fingers. This study also identified challenges in the current experimental study design and subsequent system identification when EMG-force modeling is performed with four fingers simultaneously. Methods to compensate for these issues have been proposed in this thesis.
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Peña, Guido Gómez. "Controle de impedância adaptativo dirigido por EMG para reabilitacão robótica." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-19032019-144320/.
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Esta tese trata da estimativa de torque e rigidez do paciente dirigida por EMG e sua utilização para adaptar a rigidez do robô durante a reabilitação assistida por robôs. Os sinais eletromiográficos (EMG), obtidos de músculos que atuam durante os movimentos de flexão e extensão de um usuário utilizando uma órtese de joelho ativa, são processados para obter as ativações dos músculos. Inicialmente, um modelo musculoesquelético simplificado e otimizado é usado para calcular as estimativas de torque e rigidez da junta do paciente. A otimização do modelo é realizada comparando o torque estimado com o torque gerado pela ferramenta de dinâmica inversa do software OpenSim, considerando um modelo musculoesquelético escalonado. Como uma solução complementar, é proposta uma rede neural perceptron multicamada (NN) para mapear os sinais EMG para o torque do paciente. Também é apresentado um Ambiente de Estimativa de Torque Gerado por EMG criado para analisar os dados obtidos a partir da aplicação das abordagens propostas considerando a aplicação de um protocolo criado para a análise de interação usuário-exoesqueleto. Um banco de dados de indivíduos saudáveis também foi disponibilizado neste trabalho. Além disso, uma estratégia de controle de impedância adaptativa é proposta para ajustar a rigidez do robô com base na estimativa de rigidez do paciente por EMG. A estratégia inclui uma solução ideal para a interação paciente-robô. Finalmente, são apresentados os resultados obtidos aplicando o controle de impedância adaptativo proposto durante os movimentos de flexão e extensão do usuário que usa a órtese ativa.This thesis deals with EMG-driven patient torque and stiffness estimation and its use to adapt the robot stiffness during robot-aided rehabilitation. Electromyographic (EMG) signals, taken from selected muscles acting during flexion and extension movements of an user wearing an active knee orthosis, are processed to get the muscles activations. First, a simplified and optimized musculoskeletal model is used to compute the estimate of patient joint torque and stiffness. The model optimization is performed by comparing the estimate torque with the torque generated by the inverse dynamics tool of the OpenSim software, considering a scaled musculoskeletal model. As a complementary solution, a multilayer perceptron neural network (NN) is proposed to map the EMG signals to the patient torque. It is also presented an EMG-driven Torque Estimation Environment created to analyze the data obtained from the application of the proposed approaches considering a protocol created for user-exoskeleton interaction analysis. A database with data from 5 healthy subjects is also made available in this work. Additionally, an adaptive impedance control strategy is proposed to adjust the robot stiffness based on the EMG-driven patient stiffness estimation. The strategy includes an optimal solution for the patient-robot interaction. Finally, the results obtained by applying the proposed adaptive impedance control during flexion and extension movements of the user wearing the active orthosis are presented.
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Benoit, Daniel L. "Motion analysis of the knee : kinematic artifacts, EMG normalisation and joint forces /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-357-4/.
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Kaya, Ryan D. "Muscle Strength, Motor Units, and Aging." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1365769270.
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Zulkiply, Hapiz. "Postural sway and electromyography (EMG) muscle activation of the lower body on surfaces with varying stability." Thesis, Wichita State University, 2007. http://hdl.handle.net/10057/1529.
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The purpose of this study was to quantify muscle activation and body sway on a series of unstable surfaces. Surface electrodes were used to obtain muscle activation data from the tibialis anterior, gastrocnemius, gluteus medius, and gluteus maximus while body sway data (mean amplitude of A-P Sway, mean amplitude of M-L Sway, and Sway Index) was obtained using a force platform. Theraband stability trainers were used to provide a series of unstable surfaces. A total of fifteen participants (five females, ten males) volunteered in this study. It was determined that muscle activation increased as surfaces increased in instability. For example, peak tibialis anterior muscle activation when standing on the platform (one leg) was 34.5 %MVC while that for standing on the black surface was 64.9 %MVC. It was also determined that as body sway increased, muscle activation of the lower body increased as well. Several standing conditions (i.e. standing on one leg versus two legs, leaning in a particular direction) were also studied and it was determined that certain conditions significantly affect muscle activation as well as postural sway. This study provides objective muscle activity and postural sway data previously void in the literature which can be applied to a rehabilitation, health, or ergonomic setting.Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Industrial and Manufacturing Engineering
"July 2007."
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Zulkiply, Hapiz Jorgensen Michael. "Postural sway and electromyography (EMG) muscle activation of the lower body on surfaces with varying stability /." Thesis, A link to full text of this thesis in SOAR, 2007. http://hdl.handle.net/10057/1529.
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Karakostas, Tasos. "An EMG-Driven Model to Investigate Cocontraction of Lower Extremity Muscles During Gait." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392738209.
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Hewitt, G. "A study of developmental and intersubject differences in the use of EMG biofeedback to improve voluntary control of precise, directional contractions... frontalis muscles : Implications for clinical use." Thesis, Roehampton University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382549.
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Pettersson, Victor. "Repetitive climbing effect on muscle activation." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-42144.
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Background. Climbing is growing as a recreational sport worldwide. Climbing is a physically demanding sport requiring well developed strength and endurance. Plenty of studies have been made in the area of climbing in order to understand how the body adapts, which muscles are being used and how to prevent injury. A lot of these studies uses electromyography (EMG), a tool that measures electrical currents in muscles to detect muscle activity, as measurement method in order to do findings within the area. Aim. The aim was to study differences in muscle activation in arm and leg muscles in climbers before and after 40 repeated attempts over two weeks on a boulder problem. Furthermore, correlation between climbing level and change in total measured muscle activation after repeated attempts was assessed. Methods. 15 participants (five women and ten men) participated in this study. Standardized electrode placements and maximal voluntary isometric contractions (MVIC) were made for muscles; Flexor Carpi Radialis (FCR), Bicep Brachii (BB), Rectus Femoris (RF) and Gastrocnemius Lateralis (GL) before each measurement in order to maintain good reliability. Participants repeated a specific climbing route, adapted to the participants climbing ability, 40 times, divided into four sessions over two weeks. Before the first measured attempt the participant got to practice the route twice to get familiar with the moves. Average muscle activation was calculated by dividing the total muscle activation from each muscle with the time it took to complete the climbing route. Peak muscle values were calculated by dividing the highest muscle activation value with the MVIC values to get a %MVIC value. Results. A decrease in average muscle activation for FCR and BB were found (p=0.038, 0.023) whereas an increase in average activation for GL was found (p=0.027). Peak muscle activation showed significant decreases regarding upper extremities FCR and BB (p=0.008, p=0.011) but no significant changes to lower extremities RF and GL. Total average muscular activation regarding all muscles combined showed a general decreased activation (p=0.001). Moderate correlation was found between red-point level and decrease in total average muscle activation (r=0.53). Conclusion. When repeating a climbing route, the climbers muscle activation differs in upper and lower extremities, with a decrease in upper extremities peak and average muscle values, and an increase in GL average muscle values. Repetitions improves technique and muscle memory which could be the reason for the overall decrease in total muscle activation. Hopefully, this study could enrich the climbing world with further knowledge in how to train for climbing.
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Zhang, Xiang Qin. "Estimation du couple généré par un muscle sous SEF à la base de l’EMG évoquée pour le suivi de la fatigue et le contrôle du couple en boucle fermée." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20191/document.
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La stimulation électrique fonctionnelle (SEF) a le potentiel de fournir une amélioration active aux blessés médullaires en termes de mobilité, de stabilité et de prévention des effets secondaires.Dans le domaine des système SEF pour les membres inférieurs, le couple articulaire adéquat doit être fournie de façon appropriée pour effectuer le mouvement prévu et maintenir l'équilibre postural. Toutefois, les changements d'état du muscle tels que la fatigue musculaire est une cause majeure qui dégrade ses performances. En outre, la plupart des patients, dont la blessure médullaire est complète, n'ont pas le retour sensorielle qui permet de détecter la fatigue et les capteurs de couples in-vivo ne sont pas disponible à l'heure actuelle. Les systèmes conventionnels de commande SEF sont soit en boucle ouverte ou pas assez robustes aux changements d'état du muscle. L'objectif de cette thèse est le développement de la prédiction du couple articulaire et la commande en boucle fermée afin d'améliorer les performances de la commande SEF en termes de précision, de robustesse et de sécurité pour les patients.Afin de prédire le couple articulaire induit de la SEF, l'électromyographie (EMG) induit est utilisé pour corréler l'activité musculaire électrique et mécanique. Bien que la fatigue musculaire représente une variation dans le temps, une dépendance aux sujets et aux protocoles, la méthode proposée d'identification adaptative, basée sur le filtre de Kalman, est capable de prédire le couple articulaire variant dans le temps de manière systématique. La robustesse de la prédiction du couple articulaire a été évaluée lors d'une tâche de suivi de la fatigue en expérimentation chez des sujets blessés médulaires.Les résultats montrent une bonne performance de suivi des variations d'état des muscles en présence de fatigue et face à d'autres perturbations. Basé sur les performances de précision de la méthode prédictive proposée, une nouvelle stratégie de commande basée sur le retour EMG, «EMG-Feedback Predictive Control» (EFPC), est proposée afin de contrôler de manière adaptative les séquences de stimulation en compensant la variation dans le temps de l'état du muscle. De plus, cette stratégie de commande permet explicitement d'éviter d'appliquer une stimulation excessive aux patients, et de générer les séquences de stimulation appropriées pour obtenir la trajectoire désirée des couples articulairesFunctional electrical stimulation (FES) has the potential to provide active improvement to spinal cord injured (SCI) patients in terms of mobility, stability and side-effect prevention. In the domain of lower limb FES system, elicited muscle force must be provided appropriately to perform intended movement and the torque generation by FES should be accurate not to lose the posture balance. However, muscle state changes such as muscle fatigue is a major cause which degrades its performance. In addition, most of the complete SCI patients don't have sensory feedback to detect the fatigue and in-vivo joint torque sensor is not available yet. Conventional FES control systems are either in open-loop or not robust to muscle state changes. This thesis aims at a development of joint torque prediction and feedback control in order to enhance the FES performance in terms of accuracy, robustness, and safety to the patients.In order to predict FES-induced joint torque, evoked-Electromyography (eEMG) has been applied to correlate muscle electrical activity and mechanical activity. Although muscle fatigue represents time-variant, subject-specific and protocol-specific characteristics, the proposed Kalman filter-based adaptive identification was able to predict the time-variant torque systematically. The robustness of the torque prediction has been investigated in a fatigue tracking task in experiment with SCI subjects. The results demonstrated good tracking performance for muscle variations and against some disturbances.Based on accurate predictive performance of the proposed method, a new control strategy, EMG-Feedback Predictive Control (EFPC), was proposed to adaptively control stimulation pattern compensating to time-varying muscle state changes. In addition, this control strategy was able to explicitly avoid overstimulation to the patients, and conveniently generate appropriate stimulation pattern for desired torque trajectory
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Ozkaramanli, Deger. "Influence of Different Designs of High-Heeled Shoes on Kinematics, Kinetics, and Muscle EMG of Female Gait." Scholarly Repository, 2007. http://scholarlyrepository.miami.edu/oa_theses/109.
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Many studies have investigated the differences in gait patterns with increasing heel height. The purpose of this investigation is to study the differences in gait patterns when wearing stiletto and wedge type high-heeled shoes with different heel designs versus barefoot walking. A Vicon 512 Motion Analysis system and four Kistler force plates were used to record changes in lower-extremity joint kinetics and kinematics in three conventional planes of motion. Additionally, electromyography (EMG) was used to assess differences in the behavior of selected muscles under each condition. Results showed that wearing of the high-heeled shoes increased vertical ground reaction forces during both early and late stance. Ankle dorsiflexion moment was significantly greater in stiletto type high-heeled shoes compared to wedge and barefoot conditions. A reduction in ankle plantar flexor moment and ankle power was observed between high heeled shoe conditions and barefoot walking during late stance. An increase in the integrated EMG values of soleus and gastrocnemius lateralis muscles was noted during stance, while gastrocnemius medialis integrated EMG values decreased in both type of high heeled shoes. Integrated EMG of tibialis anterior was also decreased throughout swing phase due to more plantarflexed foot position. Knee extension moment during late stance increased significantly in both shoe conditions. Additionally, rotational hip moments were significantly different in high-heeled shoes compared to barefoot condition during both early and late stance. Peak plantar/dorsiflexion angles as well as maximum knee flexion angles differed significantly during stance phase of walking between all conditions. Quadriceps activity was increased and prolonged throughout stance and full gait cycle to control knee flexion. There was a trend towards more severe biomechanical changes occurring in stiletto type high-heeled shoes in majority of the dependent variables. Future research should focus on the biomechanics of female gait using different designs of high heeled shoes considering the weight, age, and experience of the wearer. Furthermore, utilizing multi-segmental foot models in order to assess kinematic changes occurring in the entire foot segment and recruitment of triceps surae muscle group will provide more insight to instability of high-heeled gait in different designs of high heeled shoes.
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Mulligan, Shaun R. "A Comparison of ICA versus genetic algorithm optimized ICA for use in non-invasive muscle tissue EMG." Master's thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/13149.
Full textAbstract:
Includes bibliographical references.The patent developed by Dr. L. John [1] allows for the the detection of deep muscle activation through the combination of specially positioned monopolar surface Electromyography (sEMG) electrodes and a Blind Source Separation algorithm. This concept was then proved by Morowasi and John [2] in a 12 electrode prototype system around the bicep. This proof of concept showed that it was possible to extract the deep tissue activity of the brachialis muscle in the upper arm, however, the effect of surface electrode positioning and effectual number of electrodes on signal quality is still unclear. The hope of this research is to extend this work. In this research, a genetic algorithm (GA) is implemented on top of the Fast Independent Component Analysis (FastICA) algorithm to reduce the number of electrodes needed to isolate the activity from all muscles in the upper arm, including deep tissue. The GA selects electrodes based on the amount of significant information they contribute to the ICA solution and by doing so, a reduced electrode set is generated and alternative electrode positions are identified. This allows a near optimal electrode configuration to be produced for each user. The benefits of this approach are: 1.The generalized electrode array and this algorithm can select the near optimal electrode arrangement with very minimal understanding of the underlying anatomy. 2. It can correct for small anatomical differences between test subjects and act as a calibration phase for individuals. As with any design there are also disadvantages, such as each user needs to have the electrode placement specifically customised for him or her and this process needs to be conducted using a higher number of electrodes to begin with.
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Li, Che Tin Raymond. "The stability of EMG median frequency under different muscle contraction conditions and following anterior cruciate ligament injury." Thesis, Queensland University of Technology, 2004. https://eprints.qut.edu.au/15968/1/Che_Tin_Raymond_Li_Thesis.pdf.
Full textAbstract:
Musculoskeletal injuries are commonly associated with muscle atrophy as a function of immobilization or change of normal function.
For example, injuries to the anterior cruciate ligament (ACL) which may involve ligament reconstruction, results in the "quadriceps
avoidance" gait which leads to atrophy of the knee extensormuscles. In these situations it is not clear whether or not the atrophy is associated with loss of specific muscle fibre types with accompanying functional deficits. Such knowledge would be helpful in implementing exercise regimes designed to compensate for loss of particular fibre types. It is believed that isokinetic exercise performed at speeds below 180° per second strengthens type I muscle fibres, and type II fibres at fast speeds. However, there is no evidence to indicate the specific muscle fibre response to different rates of muscle contraction. Identification of muscle fibre type is most directly determined by biopsy technique but is too invasive for a routine measurement. Electromyography median
frequency has been used as a non-invasive measure to infer muscle fibre composition in various studies. However, the reliability and
accuracy of this technique has been questioned and improvement is necessary.
This research was designed to provide a more accurate and reliable protocol for the determination of EMG median frequency which may
be used, after validation against more direct biopsy techniques, as a routine method for inferring muscle fibre composition. The
investigation also explored the muscular response as measured by EMG median frequency to varying speeds of muscle contraction,
fatiguing exercise and atrophy following ACL reconstruction. The ultimate aim of this research was to improve the reliability of the
determination of EMG median frequency to enhance its application as a predictor of muscle fibre composition. This provides information which may improve ACL rehabilitation programs designed to restore and prevent specific muscle fibre types loss that have not previously been targeted by current rehabilitation programs. This research was conducted in three studies.
Study one determined the stability of the EMG median frequency bilaterally for the quadriceps and hamstrings muscles and identified the mode of contraction associated with the greatest
reliability. The strength and EMG median frequency of the vastus lateralis, medial hamstrings and vastus medialis of 55 subjects was
determined across 5 speeds from 0° to 240° per second using a Kin-Com isokinetic dynamometer and an EMG data acquisition system. Isometric contraction was found to have the least bilateral discrepancy (4.01% ±3.06) and between trials standard deviation (4.50) in the vastus lateralis, medial hamstrings and vastus medialis.
Study two investigated the EMG median frequency changes in the vastus lateralis which occur immediately following different speeds of isokinetic exercise to the point of fatigue in normal subjects. Thirty-four subjects participated in the study, and performed a 90-second period of isokinetic exercise to activate the knee extensors at either 30° or 300° per second. EMG median frequency of the vastus lateralis was determined before, immediately
after and 7 minutes after the fatiguing exercise. The percentage drop in EMG median frequency of the vastus medialis was gnificantly (p<0.05) greater after slow speed (27.9%) than fast speed (20.25%) exercise, while no significant difference was found for the percentage drop in extension torque. Full recovery was found 7 minutes after the fatiguing exercise. By reference to previous research showing a relationship between EMG median
frequency and muscle fibre type, an increase in activation of type I muscle fibres with slow speed exercise and an increase in type II
muscle fibres with fast speed exercise was observed.
Study three identified the changes in EMG median frequency following ACL reconstruction and evaluated the bilateral differences in EMG median frequency of the knee muscles. The relationships between EMG median frequency and the measures of knee functional ability, knee muscle strength, age and time since surgery were also investigated. Twelve subjects who had undergone ACL reconstruction using a semitendinosus and gracilis graft 6 to 12
months earlier, participated in the study. EMG median frequency was determined from an 8-second isometric contraction and knee functional ability was assessed using the Cincinnati Rating Scale. Bilateral EMG median frequency shifts were inconsistent among subjects. On the basis of previous research which indicated a
relationship between EMG median frequency and fibre type, no consistent pattern of muscular fibre type atrophy subsequent to ACL reconstruction occurred within 6 to 12 months (ranged from -43 to 57 Hz). Additionally, no significant correlations were found between
the EMG median frequency and the knee functional score and knee extension and flexion torques, age, time since operation and the bilateral differences in EMG median frequency. The results of this investigation will serve to improve the reliability of EMG median frequency across a range of conditions in which it has been
evaluated. Further research is needed to confirm the relationship between EMG median frequency and direct observations of muscle fibre composition to improve the predictive value of this measure. Following this validation it will be possible to evaluate the bilateral EMG median frequency shift to infer the type of muscle fibre atrophy, and use this measure in determining the efficacy of specific rehabilitation programs.
In conclusion
* An 8-second isometric contraction is recommended for determining EMG median frequency.
* EMG median frequency of a muscle decreases significantly more after slow fatiguing exercise than after fast speed fatiguing exercise.
* There was no generalised bilateral EMG median frequency shift found in a group of subjects 6 to 12 months following semitendinosus and gracilis graft ACL reconstruction.
* The results of this study will serve to improve the reliability of procedures used to determine EMG median frequency under a range of different contractile conditions. The EMG median
frequency changes in response to these conditions require further validations with muscle biopsy in future.
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Li, Che Tin Raymond. "The stability of EMG median frequency under different muscle contraction conditions and following anterior cruciate ligament injury." Queensland University of Technology, 2004. http://eprints.qut.edu.au/15968/.
Full textAbstract:
Musculoskeletal injuries are commonly associated with muscle atrophy as a function of immobilization or change of normal function. For example, injuries to the anterior cruciate ligament (ACL) which may involve ligament reconstruction, results in the "quadriceps avoidance" gait which leads to atrophy of the knee extensormuscles. In these situations it is not clear whether or not the atrophy is associated with loss of specific muscle fibre types with accompanying functional deficits. Such knowledge would be helpful in implementing exercise regimes designed to compensate for loss of particular fibre types. It is believed that isokinetic exercise performed at speeds below 180° per second strengthens type I muscle fibres, and type II fibres at fast speeds. However, there is no evidence to indicate the specific muscle fibre response to different rates of muscle contraction. Identification of muscle fibre type is most directly determined by biopsy technique but is too invasive for a routine measurement. Electromyography median frequency has been used as a non-invasive measure to infer muscle fibre composition in various studies. However, the reliability and accuracy of this technique has been questioned and improvement is necessary. This research was designed to provide a more accurate and reliable protocol for the determination of EMG median frequency which may be used, after validation against more direct biopsy techniques, as a routine method for inferring muscle fibre composition. The investigation also explored the muscular response as measured by EMG median frequency to varying speeds of muscle contraction, fatiguing exercise and atrophy following ACL reconstruction. The ultimate aim of this research was to improve the reliability of the determination of EMG median frequency to enhance its application as a predictor of muscle fibre composition. This provides information which may improve ACL rehabilitation programs designed to restore and prevent specific muscle fibre types loss that have not previously been targeted by current rehabilitation programs. This research was conducted in three studies. Study one determined the stability of the EMG median frequency bilaterally for the quadriceps and hamstrings muscles and identified the mode of contraction associated with the greatest reliability. The strength and EMG median frequency of the vastus lateralis, medial hamstrings and vastus medialis of 55 subjects was determined across 5 speeds from 0° to 240° per second using a Kin-Com isokinetic dynamometer and an EMG data acquisition system. Isometric contraction was found to have the least bilateral discrepancy (4.01% ±3.06) and between trials standard deviation (4.50) in the vastus lateralis, medial hamstrings and vastus medialis. Study two investigated the EMG median frequency changes in the vastus lateralis which occur immediately following different speeds of isokinetic exercise to the point of fatigue in normal subjects. Thirty-four subjects participated in the study, and performed a 90-second period of isokinetic exercise to activate the knee extensors at either 30° or 300° per second. EMG median frequency of the vastus lateralis was determined before, immediately after and 7 minutes after the fatiguing exercise. The percentage drop in EMG median frequency of the vastus medialis was gnificantly (p<0.05) greater after slow speed (27.9%) than fast speed (20.25%) exercise, while no significant difference was found for the percentage drop in extension torque. Full recovery was found 7 minutes after the fatiguing exercise. By reference to previous research showing a relationship between EMG median frequency and muscle fibre type, an increase in activation of type I muscle fibres with slow speed exercise and an increase in type II muscle fibres with fast speed exercise was observed. Study three identified the changes in EMG median frequency following ACL reconstruction and evaluated the bilateral differences in EMG median frequency of the knee muscles. The relationships between EMG median frequency and the measures of knee functional ability, knee muscle strength, age and time since surgery were also investigated. Twelve subjects who had undergone ACL reconstruction using a semitendinosus and gracilis graft 6 to 12 months earlier, participated in the study. EMG median frequency was determined from an 8-second isometric contraction and knee functional ability was assessed using the Cincinnati Rating Scale. Bilateral EMG median frequency shifts were inconsistent among subjects. On the basis of previous research which indicated a relationship between EMG median frequency and fibre type, no consistent pattern of muscular fibre type atrophy subsequent to ACL reconstruction occurred within 6 to 12 months (ranged from -43 to 57 Hz). Additionally, no significant correlations were found between the EMG median frequency and the knee functional score and knee extension and flexion torques, age, time since operation and the bilateral differences in EMG median frequency. The results of this investigation will serve to improve the reliability of EMG median frequency across a range of conditions in which it has been evaluated. Further research is needed to confirm the relationship between EMG median frequency and direct observations of muscle fibre composition to improve the predictive value of this measure. Following this validation it will be possible to evaluate the bilateral EMG median frequency shift to infer the type of muscle fibre atrophy, and use this measure in determining the efficacy of specific rehabilitation programs. In conclusion * An 8-second isometric contraction is recommended for determining EMG median frequency. * EMG median frequency of a muscle decreases significantly more after slow fatiguing exercise than after fast speed fatiguing exercise. * There was no generalised bilateral EMG median frequency shift found in a group of subjects 6 to 12 months following semitendinosus and gracilis graft ACL reconstruction. * The results of this study will serve to improve the reliability of procedures used to determine EMG median frequency under a range of different contractile conditions. The EMG median frequency changes in response to these conditions require further validations with muscle biopsy in future.
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Stensdotter, Ann-Katrin. "Motor control of the knee : kinematic and EMG studies of healthy individuals and people with patellofemoral pain." Doctoral thesis, Umeå : Dept. of Community Medicine and Rehabilitation, Physiotherapy, Umeå Univ, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-644.
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Geremia, Jeam Marcel. "Efeitos do treinamento excêntrico isocinético sobre as propriedades musculotendíneas de flexores plantares de indivíduos saudáveis." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/149070.
Full textAbstract:
O exercício excêntrico tem sido utilizado na prevenção/reabilitação de lesões e em programas de treinamento de força para melhorar o condicionamento físico de indivíduos saudáveis. O entendimento das adaptações causadas pelo treinamento excêntrico nos músculos flexores plantares se justifica: 1) pela importância desta musculatura na manutenção de posturas e no ciclo da marcha; 2) pela alta incidência de lesões do tendão de Aquiles; e 3) pelo uso sistemático deste tipo de treinamento em programas de prevenção e reabilitação do tríceps sural. Assim, a presente tese de doutorado busca verificar os efeitos do treinamento excêntrico nas propriedades neuromecânicas e morfológicas dos músculos flexores plantares. No capítulo I foram compiladas informações acerca das adaptações neuromusculares dos flexores plantares e do tendão de Aquiles de indivíduos saudáveis submetidos à programas de treinamento excêntrico. Os estudos encontrados indicam que o treinamento excêntrico pode aumentar a produção de força e ativação muscular, especialmente em testes excêntricos. No entanto, resultados conflitantes e lacunas identificadas na literatura motivaram a realização de dois estudos originais. Os objetivos dos estudos originais foram: 1) determinar a temporalidade das adaptações na ativação e massa muscular de flexores plantares, bem como sua contribuição para os ganhos de força em contrações excêntricas, isométricas e concêntricas ao longo do programa de treinamento (Capítulo II); e 2) avaliar os efeitos de 12 semanas de treinamento excêntrico nas propriedades morfológicas, mecânicas e materiais do tendão de Aquiles de indivíduos saudáveis (Capítulo III). Vinte participantes do sexo masculino realizaram um programa de treinamento excêntrico isocinético (duas vezes por semana, 3-5 séries de 10 repetições máximas). As avaliações das propriedades neuromecânicas e morfológicas dos flexores plantares foram realizadas a cada quatro semanas. Ao final de 12 semanas, o programa de treinamento excêntrico aumentou a produção de torque máximo excêntrico, isométrico e concêntrico; aumentou a atividade eletromiográfica máxima excêntrica e isométrica; e aumentou a espessura muscular. Além disso, os ângulos do pico de torque excêntrico e concêntrico foram deslocados para posições em que os músculos estavam mais alongados. O torque máximo e a espessura muscular aumentaram progressivamente até a oitava semana de treinamento. A ativação neural durante contrações excêntricas e isométricas aumentou após quatro semanas de treino e permaneceu constante até o final do treinamento, enquanto que a ativação neural durante contrações concêntricas permaneceu inalterada durante todo o período de treinamento. Além disso, houve aumento da área de secção transversa, da rigidez e do módulo de Young do tendão de Aquiles. Os incrementos na rigidez e no módulo de Young foram observados após quatro semanas de treinamento, enquanto que o aumento significativo da área de secção transversa tendínea ocorreu após oito semanas de treinamento. Quando tomados em conjunto, estes resultados nos possibilitam entender de que forma as adaptações neuromecânicas e morfológicas dos flexores plantares ocorrem. O aumento da força isométrica e excêntrica nas primeiras quatro semanas de treinamento parece ocorrer devido a adaptações neurais, musculares e tendíneas. No entanto, após maiores períodos de treinamento (i.e. acima de quatro semanas), o aumento da força ocorre devido a incrementos na massa muscular e na rigidez tendínea. Além disso, a ausência de adaptações neurais evidencia que os ganhos de força concêntrica podem estar relacionados apenas com adaptações musculares e tendíneas.Eccentric exercises are commonly used in prevention, rehabilitation and conditioning training programs. Understanding the adaptations caused by eccentric training on the plantar flexor muscles is justified by: 1) the importance of these muscles in maintaining posture and during gait cycle; 2) the high incidence of Achilles tendon injuries; and 3) the systematic use of this type of training in triceps surae prevention and rehabilitation programs. Thus, the present PhD thesis aims to verify the effects of eccentric training in neuromechanical and morphological properties of the plantar flexor muscles. Chapter I compiled information about the neuromuscular adaptations of the plantar flexors and Achilles tendon of healthy subjects undergoing eccentric training programs. The studies found indicate that eccentric training can increase the production of muscle strength and muscle activation, especially in eccentric tests. The studies found indicate that eccentric training can increase muscle strength and muscle activation, especially in eccentric tests. The purposes of the original studies were: 1) to determine the adaptations time course in plantar flexors activation and muscle mass, as well as their contribution to the strength gains in eccentric, isometric and concentric contractions during the training program (Chapter II); and 2) to evaluate the effects of 12 weeks of eccentric training on Achilles tendon morphological, mechanical and material properties in healthy subjects (Chapter III). Twenty male subjects performed an eccentric isokinetic training program (twice a week, 3-5 sets of 10 maximal repetitions). Plantar flexor neuromechanical and morphological evaluations were performed every 4 weeks. The 12-week training program led to increases in maximum eccentric, isometric and concentric torques; maximum eccentric and isometric electromyographic activity; and muscle thickness. The angles of peak torque in eccentric and concentric tests were shifted towards longer muscle lengths. Maximum torque and muscle thickness increased progressively until the 8th training week. Eccentric and isometric activation increased up to the 4th training week and remained constant until the 12th training week, while no change was found in concentric activation. In addition, Achilles tendon cross-sectional area, stiffness and Young's modulus were increased. The increases in stiffness and Young's modulus were observed after four weeks of training, while the significant increase in tendon cross-sectional area occurred after eight weeks of training. Taken together, these results allow us to understand how the neuromechanical and morphologic adaptations occur in the plantar flexors muscles subjected to a 12-week eccentric training program. The increase in isometric and eccentric strength in the first four weeks of training seems to be related to neural, morphological and tendinous adaptations. However, after longer training periods (i.e. up to four weeks), the strength increase is due to increases in muscle mass and tendon stiffness. Moreover, the absence of evidence in terms of neural adaptations during concentric contractions suggest that the concentric strength gains seem to be related only with muscle and tendon adaptations.
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Potes, Cristhian Mauricio. "Assessment of human muscle fatigue from surface EMG signals recorded during isometric voluntary contractions by using a cosine modulated filter bank." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Ahuja, Swati. "Immediate effect of complete denture occlusal errors on masticatory muscle EMG activity in denture wearers a pilot study /." View the abstract Download the full-text PDF version, 2009. http://etd.utmem.edu/ABSTRACTS/2009-011-Ahuja-index.htm.
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Thesis (M.S.)--University of Tennessee Health Science Center, 2009.Title from title page screen (viewed on July 23, 2009). Research advisor: Robert Brandt Document formatted into pages (vii, 42 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 37-39).
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Raghavendra, Jammalamadaka. "Optomyography: Detection of muscle surface displacement using reflective photo resistor." Thesis, KTH, Skolan för teknik och hälsa (STH), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-159204.
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A human body can carry out many physiological complex processes which can be mechanical, electrical or bio-chemical. Each mechanical activity generates a signal that describes the characteristics of the particular action in the form of pressure or temperature. Any irregularity in the process changes the usual functioning thus affecting the performance of the system. Several techniques were introduced to evaluate these muscular signals in order to get a deeper understanding of the medical abnormalities. Displacement sensors, laser optics, electrodes, accelerometers and microphones are some of the widely used devices in measuring the electrical and mechanical activities produced in the muscles. The aim of this thesis project was to find and implement a simple non-contact optical method to measure and monitor the displacements caused on the surface of the skin due to muscular movements. In this study, a device was developed using photo electric sensors that can record surface changes caused on the skin due to the movements forearm muscles.Människokroppens aktiviteter genererar olika mätbara signaler som kan vara biokemiska, elektriska, mekaniska. Naturligtvis är det viktigt att kunna mäta dessa signaler för att kunna veta om kroppens olika organ fungerar som de ska göra eller inte. När det gäller rent mekaniska aktiviteter genereras signaler av olika typer som beskriver denna aktivitet, såsom tryck, temperatur och förflyttning. Om en sådan process avviker från det normala fallet, kommer kroppssystemets prestanda att försämras. Ett antal tekniker utvecklades för att kunna mäta dessa signaler och uppnå djupare förståelse av möjliga icke-normala medicinska konsekvenser. Förflyttningssensorer, laser optik, elektroder, accelerometrar och mikrofoner är exempel på mättekniker som används för att studera elektrisk och mekanisk aktivitet i muskelvävnader. Målet med detta arbete är att hitta, utveckla och implementera en enkel, användarvänlig, beröringsfri, optisk teknik för att mäta och studera de ytliga förflyttningar som förändrar hudytans landskap och resulterar från muskelaktiviteter och rörelser. Detta projekt resulterade i en enkel prototyp för ett mätinstrument som ser ut som ett armband med två fotoelektriska sensorer som används för att mäta hudytans förändringar på grund av olika arm- och handrörelser.
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Grier, Finlay. "The Reduction of Tension Headache Using EMG Biofeedback and Locus of Control as Predictors." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc332051/.
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This study investigates the status of biofeedback treatment and locus of control (LOC) affiliation on the reduction of tension headache. Three LOC groups designated as internals, powerful-other externals and chance externals (using Wallston and Wallston's, 1978, Multidimensional Health Locus of Control Scale) were administered an eight week electromyogram (EMG) frontalis muscle biofeedback training program using an Autogen 1700 biofeedback unit. Subjects were 12 female and four male undergraduate students who had a history of tension headache. Results indicated no significant difference in frontalis muscle tension between the beginning and end of sessions in either a biofeedback or self-control condition for any of the LOC groups. Further, there was no significant difference among LOC groups in ability to reduce muscle tension in either the training or self-control condition. Finally, neither biofeedback training nor LOC groups were significant predictors of headache reduction. Extreme within-group variability and small sample size affected study findings and these and other implications for future research are discussed.
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Panahi, Ali. "MUSCLE FATIGUE ANALYSIS IN MINIMALLY INVASIVE SURGERY." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/dissertations/1320.
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Due to its inherent complexity such as limited work volume and degree of freedom, minimally invasive surgery (MIS) is ergonomically challenging to surgeons than traditional open surgery. Specifically, MIS can expose performing surgeons to excessive ergonomic risks including muscle fatigue that may lead to critical errors in surgical procedures. Therefore, detecting the vulnerable muscles and time-to-fatigue during MIS is of great importance in order to prevent these errors. In this research, different surgical skill and ergonomic assessment methods are reviewed and their advantages and disadvantages are studied. According to the literature review, which is included in chapter 1, some of these methods are subjective and those that are objective provide inconsistent results. Muscle fatigue analysis has shown promising results for skill and ergonomic assessments. However, due to the data analysis issues, this analysis has only been successful in intense working conditions. The goal of this research is to apply an appropriate data analysis method to minimally invasive surgical setting which is considered as a low-force muscle activity. Therefore, surface electromyography is used to record muscle activations of subjects while they performed various real laparoscopic operations and dry lab surgical tasks. The muscle activation data is then reconstructed using Recurrence Quantification Analysis (RQA), which has been proven to be a reliable analysis, to detect possible signs of muscle fatigue on different muscle groups. The results of this data analysis method is validated using subjective fatigue assessment method. In order to study the effect of muscle fatigue on subject’s performance, standard Fundamental of Laparoscopic Surgery (FLS) tasks performance analysis is used.
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Bernal, Cubias Guillermo Roman. "Learning from master's muscles : EMG-based bio-feedback tool for augmenting manual fabrication and crafting." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/91395.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Architecture, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 109-111).
Learning a novel skill is a time consuming process and can be frustrating at times. It may require hours of supervised training before a minimum level of proficiency can even be attained. For example in ceramics, centering the clay on the pottery wheel is a challenging task, which must be mastered before one can even begin to create an object. The objective of this thesis is to design and implement a wearable device that aids novices during the skill acquisition process of any such procedural motor task. The goal of the wearable device is to significantly reduce the amount of time needed to familiarize oneself with a new technique and medium, and to quickly attain a basic level of proficiency. This is achieved by providing students continuous visual feedback, which compares their on-going movements to that of a master craftsman performing the identical task recorded beforehand. Illuminated LEDs placed on the student's forearm relate movement kinematics, an accelerometer, magnetometer, gyroscope and muscle activity, all of which are recorded using electromyography (EMG) electrodes in real-time. The device thereby augments the sensory feedback available to the student during skill acquisition and enables them to correct their movements to match those of the master craftsman as an immediate reaction. In pilot studies, the device was evaluated within the context of pottery wheel-throwing; specifically, forearm kinematics and muscle activation during the centering of the clay were investigated. Movement feedback and data are discussed in relation to the current theories on sensorimotor control and learning. The initial results were evaluated with respect to the amount of time taken to become comfortable with the skill at hand. While there are a number of possible applications of the device, two main areas are discussed: 1) The device has the potential to become a disruptive technology, fundamentally changing traditional methods of learning and teaching arts and crafts, both in the studio/classroom environment and for autodidacts at home; 2) The device may have significant clinical impact in the field of neurorehabilitation and motor (re)education after a stroke or traumatic brain injury. Finally, an archive of expert performances for any given motor skill may be generated using the wearable device; an archive anyone could consult when learning a new skill whether it be out of curiosity or out of necessity.
by Guillermo Roman Bernal Cubias.
S.M.
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Harper, Allison Jessica. "Adequacy of Muscle Blood Flow During Handgrip Exercise." University of Toledo / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1260580537.
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Axelson, Hans. "Muscle Thixotropy : Implications for Human Motor Control." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5791.
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Torres-Oviedo, Gelsy. "Robust muscle synergies for postural control." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/22691.
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Thesis (Ph. D.)--Biomedical Engineering, Georgia Institute of Technology, 2007.Committee Chair: Ting, Lena H.; Committee Member: Chang, Young-Hui; Committee Member: Lee, Robert H.; Committee Member: Nichols, T. Richard; Committee Member: Wolf, Steve L.
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Micski, Erik, and Ulrika Ottosson. "Calculation of Tidal Volume based on EMG-activity of the Diaphragm." Thesis, KTH, Skolan för teknik och hälsa (STH), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210547.
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The objective of the thesis was to evaluate the possibility to calculate the unloading distribution between a ventilator and a patient using a new mathematical modelling of the breathing patterns. The modelling used today is considered to lack sufficient precision for clinical use, and is a somewhat simplified model. To evaluate the possibility of a new model, a volunteer test was carried out - recording data such as Edi, pressure, volume and flow. Using this data, and by using a more complex model, tidal volume was estimated and compared to the measured data. The results did not imply any improvement compared to the simpler model regarding the accuracy and the variability. However, more work should be done in this area, as time deficiency prevented further analysis.
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Rönquist, Gustaf. "Relationship between knee joint angle and fine-wire EMG activity of the four quadriceps femoris muscles." Thesis, Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:gih:diva-4120.
Full textAbstract:
The purpose of the present study was to investigate the electromyography (EMG)-knee joint angle relationship and the differences in activity among the four quadriceps femoris (QF) muscles during maximal voluntary isometric knee extensions. Ten well-trained healthy male volunteers (mean ± 1 standard deviation (SD) age 33 ± 11 years, height 1.83 ± 0.07 m, body mass 79 ± 4.7 kg) performed maximal isometric knee extensions in a seated position at four different knee joint angles (90º, 65º, 40º, and 15º of knee flexion). Myoelectric activity was simultaneously recorded from rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), and vastus intermedius (VI) using fine-wire EMG. Root-mean-square (RMS) was calculated during a sustained phase of one second at each of the different knee joint angles tested. Results showed that the RMS value of the VM was significantly higher at 90º compared to 40º (P < 0.05). When comparing 90º-normalized RMS values among the four QF muscles collapsed across the three most extended positions (65º, 40º, and 15º of knee flexion), significantly lower normalized RMS value was observed for the VM compared to that of the RF (P < 0.01) and VL (P < 0.05), respectively. No significant differences in RMS values between knee joint angles were observed for any of the other QF muscles (RF, VL, and VI). These results suggest that VM muscle activity is highest at more flexed knee joint angles during a seated knee extension task. Further, as the knee gets more extended, muscle activity of the VM decreases and VM becomes less active than the VL and RF, respectively.Syftet med denna studie var att undersöka sambandet mellan elektromyografisk aktivitet (EMG) och vinkel i knäled, samt att jämföra skillnaden i aktiveringsgrad mellan quadriceps femoris (QF) fyra delmuskler vid maximala viljemässiga isometriska knäextensioner. Tio vältränade friska män (medelvärde ± 1 standardavvikelse, ålder 33 ± 11 år, kroppslängd 1,83 ± 0,07 m, kroppsvikt 79 ± 4,7 kg) deltog frivilligt i studien. Samtliga deltagare genomförde maximala isometriska knäextensioner i sittande position vid fyra olika vinklar i knäled (90º, 65º, 40º och 15º knäflexion). Myoelektrisk aktivitet registrerades samtidigt från rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM) och vastus intermedius (VI) med hjälp av intramuskulär EMG (trådelektroder). Det kvadratiska medelvärdet (engelska root-mean-square, RMS) beräknades under en en-sekundersperiod vid respektive ledvinkel. Resultaten visade att RMS-värdet för VM var signifikant högre vid 90º jämfört med 40º (P < 0,05). Vid en jämförelse av 90º-normaliserade RMS-värden mellan QF olika delmuskler för de tre mest extenderade positionerna (65º, 40º och 15º knäflexion) observerades signifikant lägre normaliserade RMS-värden för VM jämfört med RF (P < 0,01) respektive VL (P < 0,05). Inga signifikanta skillnader i RMS-värde mellan de olika ledvinklarna sågs för någon av de övriga delmusklerna (RF, VL och VI). Dessa resultat tyder på att VM är som mest aktiv vid mer flekterade knäledsvinklar under sittande knäextensioner. Vidare kommer aktiviteten i VM att minska allteftersom knäet blir mer extenderat, och dess aktivitet blir då lägre jämfört med VL respektive RF.
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Hans, Christian Tingelstad. "The Effect of Cold Acclimation on Changes in Muscle Activity." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26256.
Full textAbstract:
Human beings have been exposed to different cold conditions throughout time, and have through cold acclimation developed mechanisms to survive in these conditions. Cold acclimation can be elicited through exposure to natural cold climates, or artificially induced in a laboratory to study the body’s response to repeated cold exposures. Several studies looking at the effects of cold acclimation in humans have been conducted during the last 50 years, and have reported that cold acclimation can lead to a change in skin and core temperature, heat production and shivering. An accurate quantification of shivering thermogenesis (ST) during cold acclimation has not been done before, and most previous measurements of shivering during cold acclimation have been inaccurate and inadequate. In this study a Liquid Condition Suits (LCS) was used to elicit cold acclimation (10°C, 2hr daily, for 4 weeks) while an accurate measurement of the effect of cold acclimation on changes in muscle activity was conducted. In CHAPTER 2, results showed that four weeks of cold acclimation at 10°C did not change skin and core temperature, heat production or ST. The effects on shivering pattern and fuel selection were also analysed, but no effects of cold acclimation could be observed. These measurements were a part of a larger study, in which the effects of cold acclimation on changes in BAT were the main outcome measures. These data showed that an increase in BAT volume (45%) and activity (120%) were the only observed effects of cold acclimation. In CHAPTER 3, we set out to assess if changes in shivering from pre to post cold acclimation are associated with changes in BAT volume, and if the amount of BAT a participant possesses prior to cold acclimation can be used to predict changes in shivering intensity during cold acclimation. The interindividual variability in changes in thermal responses, heat production, shivering and BAT volume occurring between subjects during four weeks of cold acclimation was also addressed in this section.
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Dietrich, Ralf. "Zeitaufgelöste Frequenzanalyse von EMG-Signalen bei dynamischen Hebevorgängen mit zunehmenden Lasten." Doctoral thesis, Humboldt-Universität zu Berlin, Philosophische Fakultät IV, 2010. http://dx.doi.org/10.18452/16178.
Full textAbstract:
Die vorliegende Arbeit untersucht mit elektromyographischen und biomechanischen Methoden lokale muskuläre Ermüdung und die damit verbundenen Veränderungen in der Kinematik und Kinetik eines ausbelastenden Hebetests. Hierzu wurde der PILE-Test (Mayer et al., 1988) verwendet, der als Diagnostikverfahren in der Rehabilitation von Personen mit Rückenbeschwerden eingesetzt wird. In den letzten Jahren sind mathematische Verfahren entwickelt worden, um spektralanalytische Untersuchungen dynamischer Muskelkontraktionen durchführen zu können. In der vorliegenden Arbeit wurde einer dieser Ansätze im Rahmen eines Softwarepakets umgesetzt. Er beruht auf der Verwendung der ''Smooth-Pseudo-Wigner-Ville-Verteilung'', einer biquadratischen Transformation der Cohen-Klasse. Das Verfahren zeichnet sich durch eine hohe Zeit- und Frequenzauflösung aus. Die spektralanalytische Untersuchung von sechs bewegungsrelevanten Muskeln während des Hebetests zeigte für die 22 männlichen Sportstudierenden signifikante Verringerungen der Medianfrequenz lediglich für die Signale der Rumpfstrecker (M. erector spinae, M. gluteus maximus). Dies konnte für die Signale des Kniestreckers (M. vastus lateralis) nicht beobachtet werden. Diese Ergebnisse korrespondieren mit den kinematischen Änderungen im Verlauf der Testdurchführung. Zwischen der Frequenzänderung des M. erector spinae vom Startintervall (geringe Last) zum Schlussintervall (hohe Last) und der Verringerung der Bewegungsamplitude der Rumpfextension wurde eine signifikante Korrelation festgestellt. Aufgrund der daraus ableitbaren Insuffizienz des M. erector spinae kommt es in der Initialphase der Hebung, in der die maximalen Bodenreaktionskräfte auftreten, für nahezu die Hälfte der Probanden zu einem Absenken des Rumpfes. Da dieses Verhalten mit einer erhöhten Belastung im Bereich der lumbalen Wirbelsäule assoziiert wird, sollte die Bewegungsausführung während des PILE-Tests kontrolliert werden, um Gesundheitsrisiken zu vermeiden.Electromyographic and biomechanical methods were used to investigate localized muscle fatigue and changes in the kinematics during an exhausting lifting test. For this purpose the ''Progressive Isoinertial Lifting Evaluation'' (PILE) was utilized, which was published by Mayer (1988) as a method to quantify the lifting capacity of people with spinal disorders. Fatigue-related changes in the electromyographic signals of trunk and limb muscles were evaluated and compared to kinematic measures in order to determine whether fatigue influences motor behavior during the lifting test. Recent advances in the methodology of time-frequency analysis for electro- myographic signal processing provide a new way of studying localized muscle fatigue during dynamic contractions. One of these approaches was used to develop an algorithm for the analysis of highly dynamic muscle contractions. It is based on the ''smooth-pseudo-Wigner-Ville-distribution'', a biquadratic transformation of the Cohen class. The method is characterized by a high time and frequency resolution. Twenty-two male physical education students performed the lumbar PILE-test. During the lifting task, the median frequency significantly decreased over time in the trunk extensor muscles (erector spinae, gluteus maximus) but not in the limb muscles (vastus lateralis, gastrocnemius). This corresponds to changes in the kinematic. In the initial lifting phase, the range of motion of the knee joint increased from low to high loads, while the range of motion of the trunk decreased. Half of the subjects reached almost complete knee extension while the trunk was still in maximum flexion when lifting heavy loads. The change of median frequency of the erector spinae is significantly correlated with the reduction of trunk extension. These biomechanical changes are associated with increased peak torque at the lumbar spine. Therefore it is recommended to monitor the lifting technique during the PILE-Test to avoid health risks.
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Seburn, Kevin L. "The effect of the manipulation of blood lactate on the integrated EMG of the vastus lateralis muscle during incremental exercise." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28539.
Full textAbstract:
This study was designed to test the hypothesis that the electromyographic signal recorded from a working muscle reflects changes in blood lactate concentrations.
A group of trained cyclists performed two incremental exercise tests on a cycle ergometer. The Control Trial was a incremental test with power increments of 23.5 watts per minute. Cadence was monitored and maintained at 90+/-1 revolutions per minute. The Experimental Trial consisted of a high intensity arm exercise protocol designed to elevate blood lactate above 8 mmol/1. The arm protocol was followed by five minutes of rest and the incremental exercise protocol used in the Control Trial.
Expired gases were sampled every fifteen seconds and calculated values for oxygen uptake, ventilation, excess CO₂, and R.Q. were averaged to give a mean value for each minute in both trials. Heart rate was monitored and recorded every minute for both trials.
Electromyographic data were sampled from the vastus lateralis of the right leg for the final eight seconds of each workload in both trials. The data were integrated for each pedal cycle and averaged to give a mean integrated value for each cycle (CIEMG) for each workload.
During both trials blood samples were drawn from the cephalic vein of the left arm during the last ten seconds of each workload. The anaerobic threshold (Tlac) was determined using the log-log transformation as outlined by Beaver et al., (1985).
Control Trial lactate concentration showed a marked inflection point after an initial slow increase. The mean maximal lactate concentration was 18.21 +/- 5.54 in the Control Trials. This inflection point occurred at a mean lactate concentration of 5.58 +/- 1.05 mmol/1. The mean oxygen uptake at the inflection point was 2.28 +/- 0.37 1/min which represented a mean of 72.6 +/- 7.20 % of maximum. Experimental Trial mean plasma lactate at the beginning of incremental exercise was 26.61 +/- 8.86 mmol/1. The plasma lactate concentration decreased steadily for the initial loads to a mean low concentration of 10.78 +/- 5.78 mmol/1 at Tlac and then increased to a mean of 19.08 +/- 6.66 mmol/1 at test completion. Plasma lactate concentration was greater in the Experimental Trial at all workloads though the values tended to converge once Tlac was surpassed.
No visually identifiable inflection point in the plot of CIEMG vs Power could be determined in any of the plots. An analysis of the slope of the CIEMG vs. Power relationship was therefore performed. An analysis of variance demonstrated no significant difference in the slope of the relationship within or between trials in three different comparisons. The slope of the line was not statistically different when compared over: (a) the entire sample (b) pre Tlac and (c) post Tlac. Correlations performed between plasma lactate concentrations and CIEMG were significant in five of six subjects during the Control Trial (r = 0.57 to 0.97). During the Experimental Trial only three of the six subjects showed significant correlations and they were in the opposite direction (r = -0.62 to -0.96). Correlations between power output and CIEMG were for all subjects in both trials (r = 0.92 to 0.99 Control, r = 0.91 to 0.99 Experimental).
The increase seen in CIEMG with increased power output reflects poorly the changes in blood lactate concentrations under the conditions of this investigation. Plasma lactate showed a dramatic increase in the Control Trial and a steady decrease from an initial high concentration followed by a marked increase in the final workloads of the Experimental Trial. In contrast the CIEMG increased in a near linear fashion for all subjects in both trials. The changes in CIEMG showed highly significant correlations with changes in VO₂ or power output in both trials for all subjects. These results indicate that changes in the surface electromyogram are highly related to changes in power output. However the surface electromyogram changes are not driven by changes in lactate concentration under the conditions of this investigation and may not be a sensitive enough indicator of these changes to be employed in the determination of Tlac.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
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Sahlén, Adam. "Muscle activity in m.pectoralis major during bench press variations in healthy young males." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-29361.
Full textAbstract:
Background. The bench press is a commonly used resistance training exercise for targeting the chest musculature. During hypertrophy training, different variations of bench press are often used to isolate different segments (pars clavicularis, pars sternocostalis and pars abdominals) of the chest muscle m.pectoralis major. Commonly used variations of the bench press are decline bench press (less than 0° from horizontal) and incline bench press (more than 0° from horizontal). Some research has been done into these variations of bench angle and their effect on muscle activation; however other commonly used bench angles is yet to be investigated. Aim. The aim of this study was to examine if there were any difference in muscle activity in the three segments of m.pectoralis majors while performing three different barbell bench press variations with different bench angles to obtain a greater understanding of m.pectoralis major activation and possibly optimize hypertrophy training in above mentioned muscles segments. Method. 13 healthy male (age: 23± 3.8 year and BMI: 24.3 ±1.8 kg/m2) participated in this single group study. EMG was used to measure muscle activity in m.pectoralis major's three segments. Test subjects performed 1 set of 6 repetitions on each bench press variation at a relative load of 6RM. An maximal voluntary isometric contraction (MVIC) test was performed and set as 100 percent reference value for comparison muscle activity in various angles. Results. While performing the decline bench press and the incline bench press, the muscle activity in pars clavicularis displayed a strong trend of a lower muscle activity (decline: p= 0.055 and incline: p=0.052) in comparison to the flat bench press. Muscle activity in pars sternocostalis while performing the incline bench press was significantly lower in comparison to the flat bench press (flat: p<0.001 and decline: p<0.001). Muscle activity in pars abdominals while performing the decline bench press was significantly higher (p=0.013) in comparison to the flat bench press. Muscle activity in pars abdominals while performing the incline bench press were significantly lower than both the flat and decline bench press (incline: p<0.001 and decline: p<0.001). Conclusion. For a better isolation of the pars abdominals segment, the decline bench press should be used. Muscle activity in pars sternocostalis did not show any significant difference between flat and decline bench press and could be isolated with either of these two exercises. The muscle activity in pars clavicularis showed a strong trend of higher activity while performing the flat bench press compared to the decline and incline bench press, however findings regarding the pars clavicularis differs between studies.
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Iridiastadi, Hardianto. "Localized muscle fatigue during isotonic and nonisotonic isometric efforts." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/11095.
Full textAbstract:
Work-related musculoskeletal disorders (WMSDs) are prevalent in the workplace, and epidemiology studies show that these problems do not tend to diminish. While the use of new and advanced technology has substantially reduced the amount of physical workload, repetitive manual activities are still typically observed in various work settings. Despite their fairly low workload intensity, prolonged repetitive tasks have been associated with the development of musculoskeletal complaints and problems. Research on localized muscle fatigue (LMF) has been viewed as a viable endeavor toward understanding the processes and mechanisms associated with WMSDs. A mounting of evidence on local fatigue during sustained static work has been presented, but much less is known with respect to muscle fatigue during more complex activities.
A study was conducted with the primary objectives of determining the repeatability of several commonly used fatigue measures, and to evaluate the presence of long-lasting effects of fatigue from different recovery periods. Based on low-level intermittent arm abductions, findings from this study demonstrated that the use of perceptions of muscular discomfort and muscle strength as fatigue measures was satisfactory. In contrast, electromyography (EMG)-based measures were characterized by a fairly low repeatability. The study also suggested that, whenever practical, two days of recovery should be allotted in studies involving multiple exposures to fatiguing protocols. Long lasting effects of fatigue could be present when shorter amounts of recovery period were assigned.
A second study was also carried out to investigate the effects of work parameters (force-level, work-rest ratio, and work cycle) on muscular fatigue during intermittent static efforts. It was suggested that work conditions with muscular contraction level less than 12% MVE was non-fatiguing, irrespective of the values of the work parameters selected. Intermittent work with higher levels of muscle contraction might be acceptable, but it was dependent upon interactions of the other two parameters.
The effects of dynamic work conditions on muscle fatigue were investigated in another study. Findings from this third study suggested that muscles responded differently under dynamic conditions and the use of typical EMG measures (dynamic EMG) could be less sensitive. This study further demonstrated that fatigue evaluations during such conditions were difficult, and only a limited number of EMG-based measures could be potentially employed.Ph. D.