Dissertations / Theses on the topic 'Reflux index'

Orientador: Elizete Aparecida Lomazi da Costa Pinto
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: Na faixa etária pediátrica, a apresentação clínica da doença do refluxo gastroesofãgico é bastante inespecífica, dificultando o diagnóstico clínico da doença. A monitorização prolongada do pH intra-esofágico determina a freqüência e duração dos episódios de refluxo ácido para o esôfago, mas, em crianças acima de 2 anos, a relação entre os valores do índice de refluxo e as diferentes apresentações clinicas da doença de refluxo gastroesofãgico tem sido pouco avaliada. O presente estudo pretendeu identificar os resultados dos estudos prolongados do pH intra-esofágico e associá-los ao quadro clinico dos pacientes. A apresentação clínica foi dividida em quatro grupos, de acordo com a sintomatologia predominante: regurgitador, digestivo, respiratório e portadores de paralisia cerebral. A pesquisa desenvolveu-se por meio de estudo transversal, retrospectivo e analítico, através do levantamento dos resultados de monitorizações prolongadas do pH intra-esofágico realizadas no Hospital de Clínicas da Unicamp, no período de janeiro de 1999 a dezembro de 2004. Análises descritivas e de associação foram realizadas, foi utilizado o teste Qui Quadrado de Pearson ou Exato de Fisher. Os dados clínicos de 131 pacientes (1 a 20,6 anos) e seus respectivos exames foram revisados. Os motivos que mais freqüentemente determinaram a investigação laboratorial foram: vômitos, anemia, baixo ganho ponderal e pneumonias de repetição. Encontrou-se que 89 (67,9%) dos pacientes tinham um estudo de pHmetria anormal, mas no grupo regurgitador, o exame foi alterado em apenas 4 de 18 pacientes. Nenhuma das queixas clínicas esteve associada a valores de índice de refluxo > 4. Não houve associação significativa entre presença de esofagite péptica diagnosticada pela endoscopia digestiva alta e o valor do índice de refluxo. A distribuição dos valores de índice de refluxo em MPE não guardou relação com a manifestação clínica ou a presença de esofagite num grupo de crianças avaliadas em hospital universitário
Abstract: A diversity of symptoms may be attributed to gastroesophageal reflux disease in children. A 24-h pH monitoring of the lower esophagus identifies frequency and duration of the acid reflux episodes, but the association between symptoms of gastroesophageal reflux and pH-monitoring data has been investigated in few studies involving children. This study aimed to identify data of the pH-monitoring studies in children and correlate them to the clinical picture. Data of pH-monitoring studies performed from January 1999 to December 2004 in a Medical School Hospital were analyzed. Patients were classified into four groups according to their predominant clinical symptom: infant regurgitation, digestive symptoms, respiratory symptoms and cerebral palsy. Clinical data and pH-monitoring reports from 131 patients (1 to 20.6 years) were analyzed. The most frequent reasons for laboratorial investigation were vomiting, anemia, poor weight gain and recurrent pneumonia. It was found that 89 (67.9%) patients had an abnormal pH-metry study, although only 4 of 18 patients in the regurgitation group. No clinical group was related to reflux index >4. There was no significant association between peptic esophagitis, confirmed by upper digestive endoscopy, and reflux index. In this group of children reflux inex were not associated to clinical presentation or to upper digestive endoscopy data
Mestrado
Pediatria
Mestre em Saude da Criança e do Adolescente

Thesis (Ph.D.)--University of Cincinnati, 2009.
Advisors: Lisa Kelchner PhD (Committee Co-Chair), Jean Neils-Strunjas PhD (Committee Co-Chair), Marshall Montrose PhD (Committee Member). Title from electronic thesis title page (viewed April 28, 2009). Keywords: Extraesophageal reflux; pH probe monitoring; Reflux Area Index; Reflux Symptom Index; Reflux Finding Score. Includes abstract. Includes bibliographical references.

The overall aims of our studies were to identify risk factors for respiratory symptoms and asthma in indoor environment but even to look at some personal risk factors such as body mass index and gastroesophageal reflux. The study population is based on participants of the European Community Respiratory Health Survey I and II.

In the first study, water damage and visible moulds were reported in 7.4% and 17% of the homes respectively. The combination of water damage and visible moulds was independently associated with attacks of breathlessness when resting and after activity and also to long term cough. In the second study, the prevalence of nocturnal GER increased with higher BMI and the same pattern could be seen for habitual snoring. Reported onset of asthma, wheeze and night-time symptoms increased in prevalence along with the BMI gradient. In the multivariable analysis, obesity and nocturnal GER were independent risk factors for onset of asthma, wheeze and night-time symptoms. Habitual snoring was an independent risk factor for onset of wheeze and night-time symptoms, but not for onset of asthma. In the third study, a total of 18% of the subjects reported indoor dampness in the last 12 months and 27% of the subjects reported indoor dampness since the previous survey. Respiratory symptoms and asthma were significantly more prevalent in individuals exposed to indoor dampness and indoor dampness was a risk factor for respiratory symptoms and asthma after adjusting for possible confounders. Indoor dampness was an independent risk factor for onset of respiratory symptoms but not for asthma onset. Remission of respiratory symptoms was less likely to occur if subjects reported indoor dampness. In the fourth study, the lowest prevalence of atopy and the lowest levels of all indoor allergens, bacteria and moulds were found in Iceland. A positive association was found, between cat allergen exposure and asthma symptoms and between bronchial hyperresponsiveness and the amount of viable mould in indoor air.

Athletic potential is one of the most complex human traits. An elite athlete is produced from a complex interaction of an innumerable number of traits exhibited by the athlete. However, it’s not clear whether these traits are innate, allowing the athlete to excel, or, alternatively, are a consequence of practice. To be successful, athletes rely heavily on sensory information from the visual and vestibular systems. This study investigated the relationship eye movement control has with innate athleticism by comparing the saccadic and Vestibulo-Ocular Reflex (VOR) responses of former, no longer practicing, elite athletes against their age and gender matched counterparts who were non-elite or non-athletes. Results showed subjects who participated in athletic activities longer (regardless of type or level achieved), showed both significantly better VOR suppression capabilities, as well as higher head velocities while suppressing their VOR. Although, these results are correlative in nature, they do not support the potential that VOR suppression is a learned trait of athletes. A longitudinal study would be required to assess this relationship fully.

Thesis (Ph. D.)--Dept. of Psychology. University of Missouri--Kansas City, 2005.
"A dissertation in psychology." Advisor: Diane L. Filion. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed March 12, 2007. Includes bibliographical references (leaves 115-120). Online version of the print edition.

La surveillance du bien-être fœtal pendant le travail repose essentiellement sur l’enregistrement du rythme cardiaque fœtal (RCF). Celui-ci, même continu pendant le travail, ne permet pas d’évaluer parfaitement l’oxygénation du fœtus ni le risque d’asphyxie néonatale. En effet, cet outil est imparfait et son évaluation subjective avec une importante variabilité d’interprétation inter et intra opérateur. Des examens dits de seconde ligne sont utilisés en pratique courante pour caractériser l’état fœtal : le prélèvement de sang fœtal au scalp pour l’étude de l’équilibre acido-basique du fœtus (pH ou lactates) ou la pose d’électrode au scalp pour étudier l’ECG fœtal (analyse du segment ST). Ces techniques sont néanmoins invasives et sont soumises à des contraintes techniques. Il y a donc un intérêt à développer des moyens d’évaluation du bien être fœtal à la fois objectifs et non invasifs afin de diminuer la survenue d’une asphyxie périnatale. En effet, celle-ci touche 3 à 8 nouveaux nés pour 1000 naissances. La mortalité en période post-natale est de 25 à 50% des cas et ceux qui survivent développeront des troubles sévères (épilepsie, retard neuro-cognitif et comportemental, paralysie cérébrale…). Au cours de l’accouchement, l’asphyxie périnatale se caractérise par une diminution du pH artériel ombilical. Cette mesure du pH sanguin est donc la mesure de référence pour déterminer la sévérité de l’asphyxie.Une des voies étudiées pour améliorer le dépistage des fœtus à risque d’acidose est l’analyse des modifications du système nerveux autonome (SNA) par analyse de la variabilité du rythme cardiaque fœtal. En effet, la fréquence cardiaque fœtale est en permanence sous l’influence du système nerveux autonome et sa variabilité (VFC) est un reflet de la balance sympathique / parasympathique. Le CHU de Lille a développé une nouvelle méthode d’analyse continue de la VFC ayant montré son efficacité chez l’adulte et chez le nouveau né pour l’évaluation du SNA. L’objectif de ce travail de Thèse est d’adapter cette technologie à l’analyse du SNA fœtal pour obtenir un nouvel indice appelé Fetal Stress Index (FSI) et d’évaluer sa pertinence en situation d’acidose.Cette preuve de concept a été effectuée de manière expérimentale chez le fœtus de brebis. Elle s’est réalisée en 2 temps. Nous avons tout d’abord évalué la performance du FSI par rapport aux méthodes classiques d’analyse de la VFC en termes d’aptitude à détecter les variations du SNA. Après injection d’Atropine, parasympatholytique, ou de Propranolol, sympatholytique, nous avons montré que le FSI était une méthode efficace et spécifique d’évaluation des variations du tonus parasympathique du SNA. Cette étude a également montrée la supériorité du FSI par rapport aux méthodes classiques d’analyse de la VFC en termes de sensibilité et de spécificité. Dans un second temps, nous avons évalué ce nouvel indice comme facteur prédictif de l’état acido basique du fœtus dans 2 modèles expérimentaux d’occlusion cordonale. Dans le premier modèle, l’acidose était obtenue par une occlusion continue du cordon avec une réduction de partielle du débit ombilical. Dans le second, nous réalisions des occlusions totales répétées à intervalles réguliers afin de mimer les contractions utérines lors du travail. Dans les 2 études, nous avons observé une hausse du FSI en cas d’acidose avec une corrélation significative entre le FSI et le pH, mais aussi entre le FSI et les lactates dans le second modèle.En conclusion, le FSI constitue un bon reflet de l’activité parasympathique fœtale. Cet indice permet d’étudier les variations du SNA fœtal avec une meilleure sensibilité et une meilleure spécificité que les méthodes usuelles d’analyse de la VFC et semble bien corrélé à l’état acido basique fœtal. Il s’agit donc d’un indice prometteur qu’il sera intéressant d’incorporer dans une analyse multi paramétrique du rythme cardiaque fœtal
The monitoring of fetal well being during labor is essentially based on fetal heart rate (FHR) analysis. The recording of FHR, even continuously during labor, does not fully assess fetal oxygenation or neonatal risk of asphyxia. Indeed, this tool is imperfect and subjective with an important inter and intra-operator variability. Second-line examinations to characterize the fetal state are currently used in routine practice, i.e. scalp fetal blood sampling to study the fetal acid-base balance (pH or lactates) or scalp electrode placement to study the fetal ECG (ST segment analysis). These techniques are nevertheless invasive and subject to technical constraints. There is therefore an interest in developing both objective and non-invasive means of evaluating fetal wellbeing to reduce neonatal encephalopathy. Indeed, its prevalence is about 3 to 8 per 1000 births. Post natal mortality is about 25 to 50% and survivors will hav severe diseases (epilepsy, neurologic impairment, cerebral palsy…).One of the possibilities studied to better identify fetuses at risk for acidosis is the analysis of changes in the autonomic nervous system (ANS) in response to hypoxia.Indeed, the regulation of heart rate is dependent on the ANS and thus, its variability is a reflection of the sympathetic / parasympathetic balance. Analysis of heart rate variability (HRV) is a recognized non-invasive tool that is used to assess ANS regulation. The CHU Lille has developed a new continuous tool for the analysis of HRV, which demonstrated its efficacity in adults and neonates to evaluate the ANS. The objective of this thesis was to develop its index, called Fetal Stress Index (FSI), in the fetus and to evaluate it in conditions of acidosis.The study was experimental in a sheep model chronically instrumented and was in 2 steps. First, we evaluate the performance of our method compared to commonly used HRV analysis, regarding the ability to detect the variation of variations of the ANS. After injection of atropine, to inhibit parasympathetic tone, or propranolol to block sympathetic activity, we shown that our method appeared to be effective in detecting parasympathetic inhibition and, moreover, was superior to classical analysis of HRV in terms of sensibility and specificity.In a second time, we evaluated this new index as a predictive factor of the fetal acid-base state in 2 experimental models of fetal hypoxia by occlusion of the cord. In the first one, acidosis was obtained through a partial occlusion of the umbilical cord and in the second one, though repetitive complete occlusion as uterine contractions during labor. In those two studies, we observed a raise of our index in case of acidosis with a correlation beetween FSI and pH and also FSI and lactates in the second model.In conclusion, the FSI reflects fetal parasympathetic activity, has a better detection than others usual methods, and seems well correlated to fetal acid-base status. It is a promising index and it will be interesting to incorporate it in a multi parametric analysis of fetal heart rate to predict acidosis

Graduation thesis is specialized on dilemma of the integrated circuits with ball grid array. Chapter two describes several types of packages and confrontation of their characteristics. Chapter three considers possibilities of corrections these boards bedded with packages, mounting and demounting of these packages, method of camera control and also inspection of the soldering process. Chapter four attend to practical measuring of thermal profiles and their optimalization.

Abstract Morbid obesity is the most rapidly increasing health threat of developed countries, and the costs caused by it are already higher than those of smoking. In an increasing number of developing countries both starvation and morbid obesity are increasing simultaneously. Obesity in children and adolescents is also increasing rapidly. Conservative treatment almost invariably fails when treating morbid obesity. Results of pharmacotherapy have been disappointing after great expectations. Laparoscopic gastric banding has been used in the treatment of morbid obesity since 1993. The method was first used mostly in Europe. In the USA either an open or laparoscopic gastric bypass have been the most common methods of surgery. The aim of this study was to investigate the operation results of 280 patients operated in Vaasa Central Hospital during the 11 years after March 1996. Of these patients, 123 have been followed at least 5 years. The results have been analyzed with BAROS that measures the quality of life. Quality of life was measured prospectively 1 year after surgery with the 15D questionnaire that is validated in the Finnish population. The effect of gastric banding in esophageal motility and reflux was studied prospectively in 31 patients. Late results were analyzed in 123 patients 11 years after the first operation. Mean excess weight loss (EWL) was 56% in patients who had their band in place 7 years after surgery, and 46% in all patients. There was no mortality related to the operation, and there was only one serious complication. Disease-specific quality of life improved in 78.8% of the patients in 28 months of follow-up. Health-related quality of life was significantly improved 12 months after surgery, but improvement was not connected to the amount of weight loss. The band inhibited reflux 19 months after surgery. Complications, failures, and reoperations increase with longer follow-up. Weight loss is moderate 9 years after a gastric banding operation, and in carefully selected patients this operation is still a good option in the treatment of morbid obesity.

Rationale: Laryngopharygeal reflux (LPR) is a controversial area of diagnosis and consequently management. Many patients suffering from voice and swallowing disorders may be suffering from LPR but decreased specificity of diagnosis makes management ineffective and impacts on quality of life as well as leading to overdiagnosis of LPR. Aims: (1) To establish the relationship between the Reflux Symptom Index (RSI) and the Reflux Finding Score (RFS) in participants who have attended the Wits University Donald Gordon Voice and Swallowing clinic. (2) To establish if there is a correlation between the total RFS and RSI scores. (3) To ascertain which test items of the RSI and the RFS are elevated in the participants. (4) To describe trends in RFS and RSI sub scores and (5) to determine if extraneous factors such as age, gender, professional voice use and smoking impact on the subscores of the RFS and RSI and to describe the trends based on these variables Method: A quantitative retrospective chart review of 105 patients who attended the Voice and Swallowing clinic was conducted. Each participant completed a self-rating scale for reflux severity (the RSI) as well as undergoing stroboscopic examination. Stroboscopic results were rated by a multidisciplinary team (2 otolaryngologists, a speech therapist and a voice coach) to ascertain the patient’s Reflux Finding Score (RFS). Inferential and descriptive statistics were employed to achieve the aims. Results: A weak negative significant correlation on totals of the RFS and RSI (r=0,20; p= 0,0395) was established. There were a number of intra-item correlations on the RSI and the RFS. Descriptive statistics revealed that hoarseness, excess mucus and throat clearing were the most frequently rated symptoms on the RSI and erythemia, posterior commisure hyperatrophy and diffuse laryngeal oedema most frequently rated signs on the RFS. Gender was the only variable found to have a significant effect on the total RFS and RSI ratings. Conclusion: There is specificity in the RSI and RFS as diagnostic materials for LPR. However, there may be an incidence of over diagnosis. Factors such as age, smoking, professional voice use and gender must be considered in diagnosis.

碩士
國立雲林科技大學
工業工程與管理系
105
Laryngopharyngeal Reflux (LPR) is an Extraesophageal Syndrome of Gastroesophageal Reflux Disease(GERD). LPR is more difficult to diagnostic accurately in the GERD. There is no objective of the current method. Therefore, the Patient-Reported Outcomes(PRO) had been develop in medicine. The health status of patinet be measure by PRO. PRO must be design completely, or it will measure by mistake. The Reflux Symptom Index(RSI) is a PRO of a well thought-out design, and it's the most complete among the PRO of LPR . It has been used in centers worldwide for many years. In this study, we modify the RSI in order to make it to be more completely. First, we evaluate the content validity of the RSI by focus group of qualitative research. Second, we evaluate quantitative psychometric properties of the RSI by, it includes both the reliability and the construct validity. Third, the area under the receiver operative characteristic cruve(AUC) as the objective function and we are required to maximize AUC to get optimization factor weight. The results show that a new theme appear in the fourth interview, and conceptual match is 92.1% on the focus group. "Throat discomfort" and "Eardrum pain" is not included in the RSI. Quantitative psychometric properties showed evidence of high internal consistency (Cronbach α: 0.72), good test-retest reliability (intraclass correlation coefficient: 0.64–0.81). Confirmatory factor analysis supported a 3-factor structure, named "Sound symptoms", "Nose and throat symptoms", "Tracheal and esophagus symptoms" respectively. Convergent validity was confirmed by moderate correlation assessments referencing the Reflux Questionnaire. The discriminant validity was supported by the ability to discriminate moderate-to-severe disease from mild disease. The result of the optimization of the weight is 0.4, 0.2, 0.4. Whether the optimization of the weight or the average weight, both are greater than unweight. Subsequent studies suggest to measure incidence rate of LPR by our themes, then we will obtain the symptoms that occur more frequently in Taiwan LPR patients. Finally, we can develop a PRO for patients with LPR in Taiwan.

Author: Bc. Anežka Zasadilová Title: The effect of physiotherapy on patients with gastroesophageal reflux disease Objectives: The aim of this thesis is to design a therapeutic unit and evaluate its effect on long-term treatment in the therapy of selected patients with gastroesophageal reflux disease Methods: The group of patients treated for esophageal reflux disease was examined using a standardized questionnaire, esophageal manometry and postural tests. This was followed by a two-month therapy aimed at stretching and strengthening the diaphragm using several physiotherapeutic methods. After completing the therapy, the probands were measured again as in the same way as in the initial examination. The obtained data were evaluated by statistical analysis using a nonparametric test for one selection (Wilcoxon test). Results: The evaluation of the questionnaire survey resulted in the value of p-value = 0.007265, ie less than the selected level of alpha significance (= 0.05). Based on the Wilcoxon test, it was confirmed that the input score was statistically significantly higher than the output score. The evaluation of the esophageal manometry gave the value of p-value = 0.6956, ie greater than the selected level of significance alpha (= 0.05). Based on the Wilcoxon test, it was not confirmed that the...

Thesis (M.P.H.)--University of Texas Health Science Center at Houston, School of Public Health, 2008.
Source: Masters Abstracts International, Volume: 46-06, page: 3259. Adviser: Charles E. Ford. Includes bibliographical references.

Plasticity in spinal networks has been proposed as a means to permit motor skill learning and recovery after central nervous system disorders. This plasticity is significantly driven by input from the periphery (Wolpaw & Carp, 2006). For instance, attenuation of soleus Hoffmann (H) reflex can last beyond the period of different types of conditioning via putative presynaptic inhibition (Brooke et al., 1997). Interestingly, rhythmic arm cycling can also attenuate soleus H-reflex via interlimb connections and presynaptic pathways (Frigon, Collins, & Zehr, 2004). However, it remains to be studied if this attenuation is maintained beyond the period of arm cycling. In this study, we hypothesized that excitability of H-reflex pathway would remain suppressed after cessation of arm cycling. Subjects were seated with their trunk and feet fixed at a neutral position. Using an arm ergometer, they cycled at 1Hz for 30min. H-reflexes were evoked via stimulation of the tibial nerve in the popliteal fossa at 5 minute intervals. These intervals began prior to the cycling and continued during cycling and up to 30 minutes iv after termination of cycling (n=12). Besides soleus muscle, electromyography was recorded from tibialis anterior, vastus lateralis and biceps femoris. Stimulation was set to evoke an M-wave which evoked an H-reflex on the ascending limb of the recruitment curve (size was 75% Hmax) obtained prior to cycling. The M-wave amplitude was maintained throughout all trials by monitoring and adjusting the level of stimulation intensity. All H-reflex and M-wave data were normalized to the averaged Mmax to reduce inter –subject variability. The main result was that the suppression of H-reflex amplitude persisted beyond the period of arm cycling. H-reflex amplitudes were significantly (p<0.05) smaller up to 20 min after arm cycling had stopped. This suggests that arm cycling can induce plastic adaptation in the soleus H-reflex pathway that persists well beyond the period of conditioning. Also, in an additional experiment (n=8), the prolonged effect of arm cycling combined with superficial radial (SR) nerve stimulation was investigated. Interestingly, this cutaneous nerve stimulation cancelled out the prolonged suppression of H-reflex amplitude induced by arm cycling. Since SR nerve stimulation facilitates soleus H-reflex via reductions in the level of Ia presynaptic inhibition (Zehr, Hoogenboom, Frigon, & Collins, 2004), persistence in presynaptic inhibitory pathways is suggested as an underlying neural mechanism. These results have relevance for optimizing rehabilitation techniques in the treatment of spasticity which is known to be related to the H-reflex size (Levin & Hui-Chan, 1993).

Rhythmic locomotor activity involving the arms or the legs results in task and phase specific Hoffmann (H)-reflex modulation between the two arms or between the two legs. As well, specific ipsilateral and contralateral movement effects are observed. Recently it has been found that there is also interlimb (between arms and legs) task modulation of the H-reflex, using a rhythmic arm cycling paradigm. That is, the stationary Soleus H-reflex amplitude during arm cycling was attenuated when compared to a static condition (Frigon et al. 2004). The specific parameters of the arm cycling movement which may contribute to this attenuation however are unknown. The purpose of this research was to examine whether the interlimb Soleus H-reflex suppression is specific to: the phase of the arm movement; the movement of both arms; arm excursion; and, rate of arm cycling. Participants sat in a custom designed chair to prevent leg and trunk movement and performed bilateral arm cycling at frequencies of 1 and 2 Hz and with short and long crank lengths (to alter arm range of motion; ROM). As well. ipsilateral (relative to leg stimulated) and contralateral single arm cycling were performed at 1Hz with a long crank length. The Tibial nerve at the popliteal fossa was stimulated psuedorandomly at four phases of the arm cycle and changes in the Soleus H-reflex were recorded while maintaining a small, but stable motor (M)-wave for all trials. EMG was recorded from the Soleus, Tibialis Anterior. Vastus Lateralis and the Anterior Deltoid muscles. Peak to peak amplitudes of the H-reflex from each participant were determined off line and normalized to the M-max determined from individual M-H recruitment curves. Results indicate comparable suppressive effects in all phases of the arm movement, and with bilateral or unilateral cycling. The large ROM and the 2 Hz frequency of movement resulted in a stronger inhibition than with the small ROM and the 1 Hz arm cycling. This suggests that neural processes associated with generating both the rhythmic arm cycling pattern and the peripheral feedback from the arms, have an effect on the H-reflex modulation in the legs. We conclude that a general, rather than a specific, signal related to rhythmic arm muscle activity mediates the suppression of Soleus H-reflex during arm cycling.

Rhythmic arm cycling is known to suppress the Hoffmann (H-) reflex in the soleus muscles of stationary legs; however, it is still unclear if this suppression is modulated by the phase of movement in the cycle path. In the present study we investigated phase-dependent modulation of the Sol H-reflex induced by rhythmic arm cycling. Modulation of the Soleus H-reflex was examined at 12 phases of the cycle path in 4 conditions; static arm positioning, as well as 3 arm cycling conditions, bilateral, ipsilateral and contralateral. H-reflexes were evoked and recorded at constant motor wave amplitudes across the conditions. Suppression of Sol H-reflex amplitude was dependent (main effect p<0.0001) upon the phase of movement during arm cycling, but not during static positioning. Results suggest that locomotor central pattern generators may contribute to the phasic reflex modulation observed in this study.

Evidence suggests that a flexible, task-dependent neuronal coupling of the upper and lower limbs exists, and this allows for coordinated rhythmic movement (e.g., locomotion). To further understand this coupling, muscle activity and reflex patterns can be examined by stimulating peripheral nerves during various tasks. In particular, cutaneous reflexes demonstrate task- and phase-dependent modulation, making them highly sensitive probes into neural activity during rhythmic movement. The purpose of this research was to use reflex modulation to probe the neuronal coupling between the arms and legs. This was done using a cycling paradigm that allowed for the separation of arm and leg movement, which is difficult to do in most forms of locomotion (i.e., walking). Participants (N=14) performed three cycling tasks: 1)arm cycling with stationary legs (ARM); 2)leg cycling with stationary arms (LEG); and 3)combined arm and leg cycling (ARM&LEG). The relative contributions from the arms and legs to reflex modulation in the legs were then determined throughout the movement cycle. It was hypothesized that the individual contributions from arm and leg movement to reflex amplitudes in the legs would summate during the combined arm and leg task. This hypothesis was tested explicitly by comparing the reflex amplitudes expressed during the combined arm and leg task to the algebraic summation of the reflex amplitudes expressed during the arm cycling and leg cycling tasks alone. Static trials were also collected at 4 positions within each task. Tasks were performed under two different cycling conditions: 1) Focused tibialis anterior (TA) contraction (FCC) (N=14); and 2) normal cycling (NC) (n=8). During all trials, stimulation was delivered pseudorandomly throughout the movement cycle to the superficial peroneal nerve at the ankle. EMG was recorded bilaterally from muscles in the arms and legs, and kinematic data were obtained from the elbow and knee joints. Results focused on the middle latency reflex amplitudes in TA (ipsilateral to the site of stimulation) during the FCC condition because the focused contraction did not significantly alter EMG or reflex activity in the other leg muscles studied. This also allowed for comparisons among tasks at comparable EMG levels. The main finding from this study was that reflex amplitudes expressed during the ARM&LEG task agreed with the predicted algebraic summation of reflex amplitudes expressed during the ARM and LEG tasks separately. Examination of the relative contributions from the arms and legs to the reflexes expressed during the combined task revealed that across all movement phases the legs accounted for 33% (p < .05) of the variance observed during the ARM&LEG task, while the arms accounted for an additional 5% (p < .05). The relative contributions from the arms and legs were also found to be phase dependent. That is, the relative contribution from the arms was dominant during the power phase of leg cycling while the leg contribution was dominant during the recovery phase. More specifically, the greatest contribution from the arms accounted for 57% of the variance in the ARM&LEG task when the leg was at 11 o'clock (p < .05) and the greatest contribution from the legs was 71% of the variance accounted for when the legs were at 9 o'clock (p < .05). Additionally, characteristic patterns of reflex amplitude modulation (i.e., phase- and task-dependent modulation) were observed during most of the cycling tasks. In conclusion, these findings suggest evidence for a neuronal coupling between the rhythm generators responsible for arm and leg movement which is functionally gated throughout the movement cycle of a combined arm and leg task.

Rhythmic arm cycling suppresses the soleus H-reflex amplitude in stationary legs in neurologically intact (NI) participants. It has been suggested that interlimb pathways connecting cervical and lumbosacral spinal cord are responsible for modulating the reflex excitability. After stroke, stretch reflex and its electrical analogue the H-reflex become hyperactive. The purpose of this study was to examine the effect of arm cycling on the H-reflex amplitude in the stationary legs after stroke. It was hypothesized that rhythmic arm movement would suppress the H-reflex amplitudes in the Iegs after stroke. Sixteen stroke participants performed bilateral arm cycling at 1Hz and at the highest frequency possible they could maintain. Additionally, thirteen age-matched neurologically intact individuals participated as a control group. Tibial nerves were stimulated to evoke H-reflexes simultaneously in both legs. M-wave, H-reflex (M-H) recruitment curves (RC) were collected during arm cycling and with arms stationary. Four variables (i.e.. M-H slope, H at threshold. Hmax, and 50% Hmax] obtained from the ascending limb of the M-H RC were compared across conditions. Results showed that the general effects of arm cycling in suppressing H-reflex size are preserved after stroke. However, effects after stroke were limited in that arm cycling did not affect the whole recruitment curve similarly, as it does in the NI population. Overall the results suggest that incorporation of rhythmic arm movement in rehabilitation paradigms after stroke might be helpful in suppression of hyperactive reflexes in the legs and therefore assist in locomotion.

The thesis presents a contribution to the topic of critical examination of various ways to evaluate and compare the level of press (media) freedom in countries throughout the world. It analyses the process of presentation the conclusions of press freedom indices to the public. The analysis is guided on two levels. First, the form in which the press freedom indices are published is investigated. And second, the media reflection of these publications is examined. The starting-point of this analysis focuses on theoretical view on various definitions of press freedom. First part of the thesis therefore provides the summary of important fields that should not be forgotten by any conceptualization of press freedom. Second chapter deals with the problems connected to evaluations and comparisons of press freedom in general and then in particular concerning the Freedom of the Press index by Freedom House and World Press Freedom Index by Reporters Without Borders. In the second part of the thesis, Czech media reflection of the two concerned indices is analyzed. First, the specifics of the Czech media landscape are dealt with. Next, the content analysis is applied that should approach the way Czech media use the data provided by the indices. The thesis then concludes the most serious weaknesses in the process through...

To assess acute performance-related effects of foam rolling, this study investigated the immediate effects of a standard foam rolling protocol on explosive strength of the plantarflexors and alpha motor neuron excitability in the soleus. Explosive strength was measured via vertical jump height (JUMP) and the Reactive Strength Index (RSI) obtained from a single leg drop jump. Alpha motor neuron excitability was measured by H reflex amplitude as H wave to M wave ratio (HM) obtained from the soleus muscle. JUMP and RSI measures were analyzed from nineteen subjects (12 male, 7 female) HM data were analyzed from 15 subjects (9 male, 6 female). Subjects attended one day of practice and instruction for the single leg drop jump and one day for data collection. One leg was randomly assigned to be the test leg (FL) and the other as the control (NL). The reported dominant leg and gender were also recorded for each subject. Subjects performed two single leg drop jumps per leg from a box height of 30 cm and then 10 soleus H reflexes were obtained. The intervention, which followed standard professional guidelines, consisted of 2.5 minutes of foam rolling for the FL and rest for the NL, followed by a 5 minute warm up on a cycle ergometer. The best jump and the average HM ratio were chosen for analysis. For each variable a post/pre ratio was calculated for statistical analysis. A 2x2x2 factor ANOVA with repeated measures on both factors was used for each variable. Analysis revealed no statistically significant differences for any of the variables, either as main effects or any of the interaction effects. Subjects trended towards a slightly larger post-intervention decrease in JUMP and RSI for the FL than the NL but this was not significant. It was concluded that a 2.5 minute intervention of foam rolling had no acute effect on explosive strength of the plantarflexors or alpha motor neuron excitability of the soleus.
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