Notre objectif a été d'étudier l'apport d'une analyse temps-fréquence par transformée en ondelettes dans l'évaluation stabilométrique de la stabilité posturale de sujets présentant une pathologie neurologique. A partir d'un corpus de données incluant 199 patients présentant une pathologie neurologique et 41 sujets témoins, nous avons étudié la reproductibilité et la validité des paramètres stabilométriques. Nous avons déterminé les valeurs d'erreur de mesure de paramètres issus d'une analyse temps-fréquence, d'une analyse fréquentielle par méthode FFT et d'une analyse linéaire du signal, chez des patients hémiplégiques vasculaires. Pour la moyenne de 3 acquisitions de 30 secondes, nous proposons de privilégier l'utilisation de paramètres issus d'une analyse temps-fréquence qui sont les plus reproductibles. L'évaluation stabilométrique a montré un intérêt au moins équivalent aux critères cliniques dans la prédiction du risque de chute chez le patient hémiplégique vasculaire. Le modèle de prédiction reste cependant insuffisant pour être appliqué de manière isolé en pratique clinique, où une évaluation multi-modale du patient reste nécessaire. Une étude des déterminants neurologiques et biomécaniques de la distribution du contenu fréquentiel a été réalisée avec l'analyse en ondelettes. Nous avons montré qu'en l'absence de tremblement postural caractérisé, la distribution du contenu fréquentiel était essentiellement liée au degré d'instabilité posturale. Nos perspectives sont d'approfondir l'intérêt de l'analyse temps-fréquence par transformée en ondelettes, qui permet d'étudier à la fois la stabilité posturale et les mécanismes de contrôle sous-jacents. / Our objective was to study the interest of time-frequency analysis by wavelet transform in stabilometric assessment of postural sway in neurological patients. From a corpus of data including 199 patients with neurological disease and 41 control subjects, we studied the reliability and validity of stabilometric parameters. We determined the error measurement from a time-frequency analysis, a FFT analysis and a linear analysis of the stabilogram, in stroke patients. For the average of 3 acquisitions of 30 seconds, we propose to use the time-frequency parameters that are most reliable. Stabilometric assessment showed an interest at least equivalent to clinical criteria in predicting the risk of falls in the stroke patient. The prediction model remains insufficient to be applied alone in clinical practice, where a multi-modal patient assessment is still required. A study of the neurological and biomechanical determinants of the distribution of frequency content was carried out with the wavelet analysis. We have shown that in the absence of postural tremor, the distribution of frequency content was mostly related to the degree of postural instability. Our outlook is to deepen the time-frequency analysis by wavelet transform, which allows to study both postural stability and the underlying control mechanisms.

Thesis title: Evaluation of postural stability and postural strategy in obese people Objectives: The main objective was to evaluate postural stability using computer posturography in obese people and assess whether three-month exercise training with a focus on sensorimotor stimulation has an effect on postural stability. Methods: This is a cross-sectional experimental study. The research group consisted of 20 probands aged 30 to 62 years with BMI values of 31.1-53.5 kg / m2, from which the general posturography was evaluated. The effect of sensorimotor training was subsequently assessed of 13 probands, who were divided into two groups - interventional (n = 6) and control (n = 7). The measurement was performed using static computer posturography and computer goniometry processed by the freeStep software system. To compare the effect of sensorimotor training, measurements were performed twice in the intervention and control groups, over a period of approximately three months. Postural stability was evaluated based on the Sway test. Statistical analysis was performed using IBM SPSS Statistics 24 software. Statistical significance was determined at the level of α = 0.05, the result where p <0.05 was considered statistically significant. Results: General posturography in the research group showed a...

This diploma thesis deals with the measurement of the anti-roll bar characteristics. The target of this thesis is to design a device for measuring of torsional stiffness of the automobile stabilizer bars, design a measuring sequence for detection values subsequently used to calculate the stiffness, and calculate the total measuring error. The measuring device is designed for the needs of the Institute of Automotive Engineering of FME BUT.

No description available.

Background. Although treatments for dizziness as a result of visual-vestibular mismatch (VVM) exist, the lack of prognostic information about this population affects the quality of their rehabilitation care. Despite numerous studies showing that individuals presenting with non-specific dizziness are likely to have VVM, and despite VVM being recognized by to the international classification of vestibular disorders by the Bárány Society, it remains unknown how prevalent this condition is. The VVM diagnostic questionnaire has not yet been generally accepted as a useful tool for diagnosis. There are inadequate criteria for prescribed vestibular rehabilitation for individuals with VVM, and little evidence to support the selection of treatment programs among this population. Treatment outcomes are not particularly successful because of a lack of guidelines. Studies have been performed that address dizziness severity, but no reliable biometric measurement has been developed yet. A potential measure of VVM could be responses of the autonomic nervous system (ANS) during vestibulo-visual challenges given the anatomical relationship between the vestibular system and the ANS. Individuals with both peripheral and central vestibular dysfunction exhibit symptoms and signs of autonomic dysfunction as a result of vestibulo-autonomic interactions. Moreover, changes in postural sway are a tangible indicator of the balance during any disturbance to the vestibular system. In this dissertation the use of measures of electrodermal activity (EDA) of the ANS and postural acceleration are explored in vestibular migraine (VM) individuals both with and without VVM. Purpose. The aims of this dissertation were to examine, in VM adults: 1) the presence of VVM and visual dependency in individuals presenting with complaints of dizziness using the VVM questionnaire and the Rod and Frame protocol, respectively; 2) the potential of EDA activity and postural responses to differentiate between VM and healthy individuals when accommodating for postural instability and visual-vestibular conflict; and 3) the effect of exposure to different visual contexts of VR environments on EDA phasic and tonic responses and postural responses in identified VM adults with VVM. Participants. Seventy-four participants with dizziness were enrolled in Aim 1 (70% female, mean age 45.4 ± 14.8 years), and a total of 45 participants (23 healthy, 45.5% female, mean age 34± 9 years) and (22 VM adults, 61% female, mean age 34.4 ± 8, including 12 VM adults with VVM, 77% female, mean age 34±9) were enrolled in the experimental studies for Aims 2 and 3. Methods. In Aim 1, the VVM questionnaire and the Rod and Frame protocol were used to test the presence of VVM and visual dependency, respectively. In Aims 2 and 3, a Shimmer 3 IMU sensor accelerometer was used to assess trunk acceleration in the anterior-posterior, medial-lateral, and vertical directions with different VR environments (STREET and SPACE). EDA measurements were assessed with a wireless wearable Shimmer 3 GSR+. Clinical measures of dizziness and mobility were concurrently tested. A linear mixed model was used to examine the effect of VM with and without VVM on standing balance and EDA activity. Results. The presence of VVM, headache, and visual dependency demonstrated a strong association. EDA activity and postural acceleration significantly differed between VM and healthy individuals. Specific subjective reporting tools, including ABC, VSS-SF, VVAS, and DHI, were reliable for distinguishing between VM and healthy individuals. Lastly, VM individuals with VVM exhibited significantly greater NPL of trunk accelerations in the vertical plane than VM individuals without VVM with the STREET environment compared to the SPACE environment. Conclusion. VVM and visual dependency could be risk factors for developing vestibular migraine and should be included in the examination protocol of those populations. Combining measures of EDA and trunk acceleration may provide objective measures of the severity of dizziness related to VVM. Results of this dissertation suggest that the use of EDA measures combined with NPL-Vert could provide potential neurophysiological biomarkers in identifying VVM in adults with vestibular migraines. Further, the correlation between the characteristics of the visual environment and the subjective dizziness outcome measure may contribute to establishing a threshold-tolerance basis for designing a vestibular rehabilitation program that will more precisely target symptom severity. / Physical Therapy

Virtual reality (VR) is becoming increasingly important in balance training. However, the influence of VR generated visual perturbation, through the novel virtual moving room paradigm, is unknown. Thirty healthy individuals had their static balance assessed on a BTrackS balance plate under eight different conditions: baseline eyes open and eyes closed with and without VR, unexpected toward and away moving VR perturbation, and expected toward and away moving VR perturbation. Multiple statistical analyses were conducted, and the results revealed significantly higher postural sway variables in the unexpected moving toward trials compared to the other moving room conditions; significantly higher postural sway variables in the eyes open no VR compared to VR; and significantly higher postural sway variables in the eyes closed no VR compared to VR. This study provides evidence that VR can be used as a safe and low-cost balance training tool by exposing individuals to fall-prone situations and increasing their balance confidence.

No description available.

No description available.

While it has been established that postural control is affected by executive function, research is lacking in identifying if specific executive function components are most responsible or if certain aspects of postural control are more affected than others (e.g., proprioception, vestibular, visual). The current study examined the role of inhibition, processing speed, and visuospatial ability in postural control under conditions affecting visual, proprioceptive, and vestibular sensory input. Cognitive assessments consisted of the Flanker Inhibitory Control and Attention Test, Digit Symbol Substitution Test, Clock Drawing Test, Trail Making Test – Part B, and simple reaction time. Standing Balance was used to assess postural sway. Analyses revealed that average balance was significantly associated with simple reaction time (r(88) = -0.31, p < .01) and the clock drawing test (r(88) = -0.25, p< .05). Further analyses revealed a significantly stronger relationship between pose #1 (eyes opened, firm) and average balance (r(88) = -0.845, p< 0.1) when compared to pose #2 (eyes closed, firm), and pose #3 (eyes opened, foam) and average balance r(88) = -0.8015, p< 0.1) when compared to pose #4 (eyes closed, foam). The significantly stronger relationship between these two measures demonstrates that visual input in both conditions #1 and #3 was associated with better postural control. The findings of this study demonstrate that reaction time and visuospatial abilities are associated with overall postural control in healthy older adults. Results suggest that reaction time should be more thoroughly researched to determine the extent of its influence on EF and physical function.

No description available.