Background: Though numerous studies have compared overground and treadmill walking there still exists a significant debate about whether the two modes of walking are equivalent. The present study provides a comprehensive evaluation of overground and treadmill walking at matched speeds and increasing treadmill speeds. Walking performance was compared in healthy adults, in people with stroke and between the groups. This is important to know because any differences may have implications for gait training in both groups. Methods: Ten healthy adults (50-73 years) and ten subjects with stroke (54-80 years) walked at their self-selected speed overground which was matched on a treadmill. Temporal parameters, angular kinematics and vertical ground reaction forces were recorded during walking once subjects were in steady state as determined from their heart rate and oxygen uptake, both of which were also recorded. Belt speed was then increased 10% and 20% above matched speed and steady state recordings obtained. Speed related adjustments were also evaluated and compared between the two groups of subjects. Results: For healthy adults, step, stride, and joint angular kinematics were similar for both modes of walking. Small reductions in double support time and decreased push-off force were evident on the treadmill. For subjects with stroke, step, stride, and stance times were longer when walking overground but the degree of symmetry was comparable for both surfaces. Kinematic data revealed interlimb asymmetry was more pronounced for all lower limb joint excursions during overground walking and vertical forces were higher. In comparison to healthy adults, stroke subjects walked with lower cadence, shorter strides, lower stance time, and smaller lower limb joint excursions than their healthy counterparts. When compared with overground walking the metabolic requirements of treadmill walking for healthy adults and subjects with stroke however were about higher by 23% and 15% respectively. All temporal-distance parameters, hip joint excursion, F1 and F2 forces and metabolic costs showed main effects of speed. An interaction between speed and group indicated that oxygen consumption increased at a greater rate in stroke than healthy subjects. Conclusions: The findings suggest that, although overground and treadmill gait patterns are similar for each group of subjects, people with stroke adopt a more symmetrical kinematic walking pattern on the treadmill that is maintained at faster belt speeds. Although there are differences in gait patterns between healthy and stroke subjects, both groups respond to the challenge of increased walking speed in the same way. One important difference is the abnormal elevation of energy demands associated with treadmill walking at faster speeds in stroke. Clinically, this warrants consideration as it may lead to premature fatigue and undesirable cardiorespiratory challenge in this group of individuals. / Thesis (Ph.D, Rehabilitation Science) -- Queen's University, 2009-08-27 06:41:19.999

„Hic sunt leones“ is a printed publication that represents the outcome of diploma thesis Map of Brno. It is a pocket-size map in a form of a book describing the dark side of Brno, fitting contextually within the scope of urban exploration. Locations described within the publication are far beyond the general interest of the majority, and even the alternative minority, of population within the city. These are locations whose visit may result not just in dirty pants or possible conflict with the police, but also in injuries or even death. The inaccessibility of these places is emphasized by the inaccessibility of the map itself, which is being tested at it's very edge of usability. Accurate cartographic mapping is not the intention of this project, neither it is the process of making these places easily accessible. Mediation of their unique atmosphere and providing the evidence of their mere existence is the primary intention here. More so because of the fact that such places are subjects to very fast perdition.

Indiana University-Purdue University Indianapolis (IUPUI) / Background: Ambulation is critical to a child’s participation, development of selfconcept, and quality of life. Children with cerebral palsy (CP) frequently exhibit limitation in walking proficiency which has been identified as the primary physical disability. Traditional rehabilitative treatment techniques to improve ambulation for children with CP reveal inconsistent results. Driven gait orthosis (DGO) training is a novel approach focusing on motor learning principles that foster cortical neural plasticity. Objective: The objectives are to determine if: (i) the lower extremity muscle activation patterns of children with CP are similar to age-matched TD children in overground (OG) walking, (ii) DGO training replicates muscle activation patterns in OG ambulation in TD children, (iii) the lower extremity muscle activation patterns in OG walking of children with CP are similar to their muscle activation patterns with DGO assistance, and (iv) DGO training promotes unimpaired muscle activation patterns in children with CP. Methods: Muscle activity patterns of the rectus femoris, semitendinosus, gluteus maximus and gluteus medius were recorded in the OG and DGO walking conditions of children with CP and age-matched TD. The gait cycles were identified and the data was averaged to produce final average gait cycle time normalized values. Results: In comparing the variability of the muscle activation patterns within the subject groups, CP DGO walking was considerably lower than CP OG. In comparing the muscle activation patterns in each condition, consistent differences (p < .05) were noted in terminal stance, pre-swing and initial swing phases of gait with the DGO condition consistently revealing greater muscle unit recruitment. Conclusion: The results indicate that training in the DGO provided the ability to practice with measurably repetitive movement as evidenced by decreased variability. Consistent differences were noted in muscle activation patterns in the terminal stance, pre-swing and initial swing phases of gait when most of these muscles are primarily inactive. The alteration in ground reaction force within the DGO environment may play a role in this variance. With the goal of normalizing gait, it is important that the effect of these parameters on ground reaction forces be considered in the use of DGO rehabilitation.

No description available.

No / The importance of peripheral visual cues in the control of minimum-foot-clearance during overground locomotion on a clear path was investigated. Eleven subjects walked at their natural speed whilst wearing goggles providing four different visual conditions: upper occlusion, lower occlusion, circumferential–peripheral occlusion and full vision. Results showed that under circumferential– peripheral occlusion, subjects were more cautious and increased minimum-foot-clearance and decreased walking speed and step length. The minimum-foot-clearance increase can be interpreted as a motor control strategy aiming to safely clear the ground when online visual exproprioceptive cues from the body are not available. The lack of minimum-foot-clearance increase in lower occlusion suggests that the view of a clear pathway from beyond two steps combined with visual exproprioception and optic flow in the upper field were adequate to guide gait. A suggested accompanying safety strategy of reducing the amount of variability of minimum-foot-clearance under circumferential–peripheral occlusion conditions was not found, likely due to the lack of online visual exproprioceptive cues provided by the peripheral visual field for fine-tuning foot trajectory.

„Nun sag, wie hast du’s mit der Messung im Labor?“ So oder ähnlich lautet die sich anhand dieser Arbeit ergebende Gretchenfrage bezüglich biomechanischer Auswertungen und Studien des Laufsports, welche unter Laborbedingungen durchgeführt werden. Hierbei wird angenommen, dass eine Messung im Labor eine valide experimentelle Operationalisierung des Ausdauerlaufens darstellt. Aufgrund der räumlichen Begrenzung kann lediglich eine vergleichsweise geringe Anzahl an einzelnen Versuchen aufgezeichnet werden. Für die statistische Auswertung werden dann zumeist einzelne Parameter der Zeitreihen berechnet, welche wiederum zusammengefasst durch Mittelwerte den Probanden repräsentieren müssen. Bei der Verwendung von diskreten Parametern reduziert sich die aufgenommene Information der Zeitreihe dabei erheblich. Damit einhergehend muss die Frage geklärt werden, ob die Variabilität eines Probanden anhand diskreter Werte oder anhand der gesamten Kurve Beachtung finden muss. Des Weiteren stellt sich die Frage inwieweit das arithmetische Mittel über eine große Anzahl an Versuchen als die den Probanden repräsentierende Kennzahl verwendet und dessen Variabilität mittels einer endlichen Anzahl an Wiederholungen charakterisiert werden kann. Für die Untersuchungen wurden zunächst zwei Studien durchgeführt, wobei die Aufzeichnung von Bodenreaktionskräften und der Winkelgeschwindigkeit bei 100 Läufen an je zwei Messtagen im Labor erfolgte. Die statistischen Auswertungen umfassen sowohl die Betrachtung der Konvergenz von Folgen kumulierter Mittelwerte, Standardabweichungen und Root Mean Square Errors für diskrete Parameter und die gesamten aufgezeichneten Signale der Bodenreaktionskräfte und Winkelgeschwindigkeit als auch die Untersuchung von Prädiktionsbändern. Zudem wurden unterschiedliche Algorithmen zur Bestimmung der minimalen Anzahl an aufzuzeichnenden Versuchen entwickelt. Diese beinhalten nichtlineare Regressionsmodelle für die Anpassung der kumulierten Fläche der Prädiktionsbänder gesamter Kurven und die Analyse der Differenzen aufeinanderfolgender Standardabweichungskurven. Zusammenfassend geht aus dieser Arbeit hervor, dass die postulierte ausreichende und stabile Charakterisierung eines Probanden anhand des arithmetischen Mittels sowie der vollständigen und soliden Beschreibung der Variabilität für diskrete Parameter nicht nachgewiesen werden konnte. Für gesamte Kurven ergab sich ein anderes Bild. Die Probanden konnten anhand der mittleren vertikalen Bodenreaktionskräfte sowie der Bodenreaktionskräfte in anterior-posterior Richtung stabil und ausreichend charakterisiert werden. Für die Bodenreaktionskräfte in mediolateraler Richtung und die Kurve der Winkelgeschwindigkeit wurde dies nicht bestätigt. Die Möglichkeit der Charakterisierung der Variabilität eines Probanden konnte zudem verifiziert werden. Durch Beibehaltung der ursprünglichen Messprozedur ist die Wahrscheinlichkeit sehr hoch, dass der begangene Fehler den Ausgang der statistischen Auswertung beeinflusst und damit Eigenschaften der vorliegenden Grundgesamtheit unter Umständen falsch widerspiegelt. Von einer Verwendung des Mittelwertes diskreter Parameter sollte daher abgesehen werden. Der Fehler sowie dessen unbekanntes Ausmaß sind zum Teil unkontrollierbar und dessen Auswirkungen auf weitere biomechanische Kenngrößen nicht überprüfbar. Die Annahme, dass eine Labormessung als valide experimentelle Operationalisierung des Ausdauerlaufens angesehen werden kann, ist damit hinfällig. Es ist zukünftig notwendig, die Erforschung neuer Aufnahme- und Auswerteprozeduren, die alternative Verwendung gesamter Kurven und die Entwicklung neuer Testverfahren zu forcieren.

No description available.

Σκοπόςτης παρούσας εργασίαςείναι αρχικά η δημιουργία ενός μοντέλου με τα χαρακτηριστικά ενός μονωτήρα υψηλής τάσης.Το μοντέλο αυτό θα ενσωματωθεί στο μοντέλο μιας γραμμής υψηλής τάσης διπλού κυκλώματος των 400kV, για να υπολογιστούν οι επαγόμενες υπερτάσεις σε παρακείμενο υπέργειο αγωγό μεταφοράς υδρογονανθράκων. Τα παραπάνω επιτυγχάνονταιμε τη μοντελοποίηση πραγματικών πυλώνων και γραμμών του Ελληνικού συστήματος μεταφοράς καθώς και υπέργειου αγωγού υδρογονανθράκων.Η εξομοίωση υλοποιείται μέσω του προγράμματος ATP-EMTP. Για τον σχεδιασμό του μοντέλου του μονωτήρα χρησιμοποιήθηκε το μοντέλοVolt-TimeCurve. Επίσης χρησιμοποιήθηκαν δύο τύποι κεραυνού για τις προσομοιώσεις, για γρήγορο και αργό σήμα, με τιμές ρεύματος 100kA. Για το γρήγορο, οι τιμές χρόνων μετώπου και ουράς 1.2/50μs και για το αργό σήμα 10/350μs. Σε αυτή τη διπλωματική εργασία υπάρχουν 8 κεφάλαια. Στα πρώτα 5 κεφάλαια έγινε μια παράθεση πληροφοριών και θεωρητική προσέγγιση όλων των επιμέρους τμημάτων που συνθέτουν τη συνολική διάταξη της μελέτης. Στο 5ο κεφάλαιο γίνεται λεπτομερής αναφοράστο πρόγραμμα ATP-EMTP στο οποίο πραγματοποιήθηκε η προσομοίωση.Στο 6o κεφάλαιο γίνεται η μοντελοποίηση όλων των στοιχείων της διάταξης και η ενσωμάτωσή τους στοATP-EMTP. Στο 7ο κεφάλαιο γίνεται παρουσίαση του μοντέλου του μονωτήρα που αναπτύχθηκε και στο 8ο κεφάλαιο γίνεται παρουσίαση των αποτελεσμάτων της προσομοίωσης και εξάγονται κάποια συμπεράσματα σχετικά με τη διάταξη. / The purpose of this paper is , at first, to create a model with the features of a high voltage insulator. This model will be incorporated into the model of a high-voltage line double circuit 400kV, to calculate the induced transients in adjacent aboveground pipeline hydrocarbons. These goals are achieved by modeling real pillars and lines of Greek transport system and overground pipeline hydrocarbons. The simulation is implemented through the ATP-EMTP. The model Volt-Time Curve is used for the modeling of the insulator. Also, two types of lightning are used for the simulations, for fast and slow signal, with current values 100kA. For fast signal, the prices of front and tail time are 1.2 / 50ms and for slow signal 10 / 350ms. In this thesis there are 8 chapters. In the first five chapters was a quote and information theoretical approach to all individual parts that make up the overall layout of the study. The 5 chapter is a detailed reference to the ATP-EMTP program which performed the simulation. The 6 chapter is the modeling of all elements of the layout and the incorporation into the ATP-EMTP. In chapter 7 we present the model of the insulator developed and in chapter 8 we present the simulation results and draw inferences about the layout.

This thesis first explored the effects of concurrent spatial attention and working memory task performance on over-ground gait in healthy young and older adults. It then compared over-ground gait parameters and working memory performance in mild Alzheimer’s Disease (AD) and normal controls (NC) and investigated costs of dual-tasking on working memory performance and cadence during treadmill walking at preferred walking speed in the two groups. Furthermore, it explored these differences in AD and NC groups in relation to their subcortical hyperintensities (SH) that were rated using standardized scales on MRI. Reaction times and accuracy on working memory performance measures were collected under single and dual task conditions. Over-ground gait parameters were measured on an automated walkway. Costs of dual-tasking on gait parameters and working memory performance were measured at a constant velocity on a treadmill. The hypotheses that working memory influences gait performance and that a higher SH burden negatively influences over-ground gait and costs of dual-task conditions, were supported in a series of experiments. Gait slowed down while performing working memory and spatial attention tasks in young and older adults. Patients with mild AD, compared to NC, had a slower gait velocity, shorter stride length and lower cadence on the walkway. When the two groups were subdivided into higher and lower SH groups based on their median SH score, the NC group with lower SH burden walked significantly faster with a higher cadence and a longer stride length than the other three groups. Lastly, a higher SH burden negatively influenced working memory performance in NC while in mild AD patients, it had negative influences on adaptive changes in gait while dual-tasking. These results suggest that, in dual-task condition, SH interfere with processing speed in NC and on gait in AD. These findings provide new insights in to tradeoffs during dual tasking in relation to cerebrovascular disease. This has ecological implications because of the prevalence of small vessel disease in aging and dementia, may impact on predicting falls in AD.

This thesis first explored the effects of concurrent spatial attention and working memory task performance on over-ground gait in healthy young and older adults. It then compared over-ground gait parameters and working memory performance in mild Alzheimer’s Disease (AD) and normal controls (NC) and investigated costs of dual-tasking on working memory performance and cadence during treadmill walking at preferred walking speed in the two groups. Furthermore, it explored these differences in AD and NC groups in relation to their subcortical hyperintensities (SH) that were rated using standardized scales on MRI. Reaction times and accuracy on working memory performance measures were collected under single and dual task conditions. Over-ground gait parameters were measured on an automated walkway. Costs of dual-tasking on gait parameters and working memory performance were measured at a constant velocity on a treadmill. The hypotheses that working memory influences gait performance and that a higher SH burden negatively influences over-ground gait and costs of dual-task conditions, were supported in a series of experiments. Gait slowed down while performing working memory and spatial attention tasks in young and older adults. Patients with mild AD, compared to NC, had a slower gait velocity, shorter stride length and lower cadence on the walkway. When the two groups were subdivided into higher and lower SH groups based on their median SH score, the NC group with lower SH burden walked significantly faster with a higher cadence and a longer stride length than the other three groups. Lastly, a higher SH burden negatively influenced working memory performance in NC while in mild AD patients, it had negative influences on adaptive changes in gait while dual-tasking. These results suggest that, in dual-task condition, SH interfere with processing speed in NC and on gait in AD. These findings provide new insights in to tradeoffs during dual tasking in relation to cerebrovascular disease. This has ecological implications because of the prevalence of small vessel disease in aging and dementia, may impact on predicting falls in AD.