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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Svalová síla při chůzi: vliv morfologie kostry / Muscle force during walking: effect of skeletal morphology

Tomášová, Kateřina January 2020 (has links)
The muscle force determines the energy costs of locomotion and the loading of the musculoskeletal system. As the body size increases, the muscle force increases too. The observed less joint flexion in larger individuals could be a moderating mechanism to reduce muscle force when walking. To date, there is a lack of knowledge about the effect of body size and joint angles on muscle force. The aim of this study was to investigate how body size affects muscle force in the stance phase of walking and whether larger individuals can effectively compensate for the increase in muscle force through postural changes. We acquired kinematic, kinetic and electromyographic data for 19 men during normal walking and carrying additional 20 % of body weight. We estimated muscle force using the method of musculoskeletal modeling. We emploeyd the multiple linear regression to asses independent effect of body mass, lower limb length, biiliac breadth and joint flexion angle on total (iF) and maximum (maxF) lower limb muscle force. The body mass had a great positive effect on the gluteus medius muscle force (maxF and iF) but did not affect the iliopsoas muscle force (maxF and iF) nor the vasti muscles force (iF). The lower limb length had a positive effect on the gluteus maximus muscle force (maxF) and a negative effect...
82

Adaptive Feedback Regulator for Powered Lower-Limb Exoskeleton under Model Uncertainty

Thakkar, Kirtankumar J. January 2021 (has links)
No description available.
83

Prosthetic Control using Implanted Electrode Signals

Hákonardóttir, Stefanía January 2014 (has links)
This report presents the design and manufacturing process of a bionic signal messagebroker (BSMB), intended to allow communication between implanted electrodes andprosthetic legs designed by Ossur. The BSMB processes and analyses the data intorelevant information to control the bionic device. The intention is to carry out eventdetection in the BSMB, where events in the muscle signal are matched to the events ofthe gait cycle (toe-o, stance, swing).The whole system is designed to detect muscle contraction via sensors implantedin residual muscles and transmit the signals wireless to a control unit that activatesassociated functions of a prosthetic leg. Two users, one transtibial and one transfemoral,underwent surgery in order to get electrodes implantable into their residual leg muscles.They are among the rst users in the world to get this kind of implanted sensors.A prototype of the BSMB was manufactured. The process took more time thanexpected, mainly due to the fact that it was decided to use a ball grid array (BGA)microprocessor in order to save space. That meant more complicated routing and higherstandards for the manufacturing of the board. The results of the event detection indicatethat the data from the implanted electrodes can be used in order to get sucient controlover prosthetic legs. These are positive ndings for users of prosthetic legs and shouldincrease their security and quality of life.It is important to keep in mind when the results of this report are evaluated that allthe testing carried out were only done on one user each.
84

Which prosthetic foot to prescribe? Biomechanical differences found during a single session comparison of different foot types hold true one year later

De Asha, Alan R., Barnett, C.T., Struchkov, Vasily, Buckley, John January 2017 (has links)
Yes / Introduction: Clinicians typically use findings from cohort studies to objectively inform judgements regarding the potential (dis)advantages of prescribing a new prosthetic device. However, before finalising prescription a clinician will typically ask a patient to ‘try out’ a change of prosthetic device while the patient is at the clinic. Observed differences in gait when using the new device should be the result of the device’s mechanical function, but could also conceivably be due to patient related factors which can change from day-to-day and can thus make device comparisons unreliable. To determine whether a device’s mechanical function consistently has a more meaningful impact on gait than patient-related factors, the present study undertook quantitative gait analyses of a trans-tibial amputee walking using two different foot-ankle devices on two occasions over a year apart. If the observed differences present between devices, established using quantitative gait analysis, were in the same direction and of similar magnitude on each of the two occasions, this would indicate that device-related factors were more important than patient-related factors. Methods: One adult male with a unilateral trans-tibial amputation completed repeated walking trials using two different prosthetic foot devices on two separate occasions, 14 months apart. Walking speed and sagittal plane joint kinematics and kinetics for both limbs were assessed on each occasion. Clinically meaningful differences in these biomechanical outcome variables were defined as those with an effect size difference (d) between prosthetic conditions of at least 0.4 (i.e. ‘medium’ effect size). Results: Eight variables namely, walking speed, prosthetic ‘ankle’ peak plantar- and dorsi- flexion and peak positive power, and residual knee loading response flexion, peak stance-phase extension and flexion moments and peak negative power, displayed clinically meaningful differences (d > 0.4) between foot devices during the first session. All eight of these showed similar effect size differences during the second session despite the participant being heavier and older. Conclusions: Findings suggest that a prosthetic device’s mechanical function consistently has a more meaningful impact on gait than patient-related factors. These findings support the current clinical practice of making decisions regarding prosthetic prescription for an individual, based on a single session evaluation of their gait using two different devices. However, to confirm this conclusion, a case series using the same approach as the present study could be undertaken.
85

LOWER LIMB MUSCLE ASSESSMENT USING DIFFUSION TENSOR AND BLOOD OXYGEN-LEVEL DEPENDENT IMAGING

Elzibak, Alyaa H. 31 January 2015 (has links)
<p>Diffusion tensor (DT) and blood oxygen-level dependent (BOLD) imaging are two noninvasive magnetic resonance (MR) techniques that have been used to probe skeletal muscle microstructure and microvasculature, respectively. Over a series of four studies, the work in this thesis aimed at furthering our understanding of baseline DT metrics and BOLD signals in lower limb muscles (calf and foot) of healthy young subjects. Since postural changes have been shown to alter numerous quantities, including fluid volumes and muscle cross sectional area, DT indices and BOLD signal characteristics were examined in response to movement from upright to supine position.</p> <p>Reductions of 3.2-6.7% and 3.4-7.5% were measured in calf DT eigenvalues and apparent diffusion coefficient (ADC) in the various muscles, following 34 and 64 minutes of supine rest, respectively (P</p> <p>Establishment of baseline diffusion metrics in the foot region was feasible (chapter 6). Examination of foot DT indices in response to positional change showed that the metrics decreased from 2.7-4.6% following 34 minutes of supine rest (P</p> / Doctor of Philosophy (PhD)
86

Tillförlitligheten hos kliniska tester vid diagnostisering av stressfrakturer i tibia : En narrativ litteraturöversikt

Nordstrom, Gustav January 2024 (has links)
Bakgrund: Stressfrakturer utgör 10–20 % av alla idrottsskador och 10% av alla ortopediska skador, av samtliga stressfrakturer lokaliseras upp till 49% i tibia. För att ställa diagnosen korrekt behövs en magnetröntgen, benskanning eller datortomografi. Syfte: Syftet med denna litteraturöversikt var att kartlägga tillförlitligheten hos kliniska tester för att diagnostisera stressfrakturer i tibia. Metod: En litteraturöversikt med narrativ design tillämpades, sökningen utfördes i Pubmed, Sportdiscus, Pedro &amp; Cinahl, inklusionskriteriet var att studierna skulle ha minst ett radiologiskt referenstest. Kvalitén av studierna bedömdes med Quadas mätinstrument. Resultat: 17 artiklar inkluderades i översikten, totalt var det åtta olika tester som undersöktes. Tre studier valde att kombinera flera tester vid diagnostiseringen av stressfrakturer i tibia. Inget ensamt test eller testkombination hade både en hög specificitet och sensitivitet. Flertalet studier fick en hög sensitivitet vid palpation, även kombinerade tester gav en hög sensitivitet. Konklusion: Enbart kliniska tester verkar inte kunna diagnostisera stressfrakturer i tibia då testerna har en låg specificitet. Eventuellt kan en kombination av tester utesluta stressfrakturer i tibia och därav minska behovet av röntgenundersökning. Flertalet studier hade metodologiska brister därför behövs mer forskning för att kunna dra säkrare slutsatser gällande testernas tillförlitlighet. / Background: Stress fractures make up 10-20% of all sports injuries and 10% of all orthopedic injuries, of all stress fractures up to 49% are in the tibia. To make the diagnosis correctly, an MRI, bone scan or computed tomography is needed.  Aim: The purpose of this study was to investigate the reliability of different clinical tests in the diagnosis of stress fractures of the tibia.  Method: A literature review with narrative design was applied, the search was performed in Pubmed, Sportdiscus Pedro and Cinahl, the inclusion criteria was that the studies had at least one radiological reference test. The quality of the studies was assessed with Quadas measuring instrument.  Results: 17 articles were included in the review, a total of eight different test examined. Three studies chose to combine multiple tests in the diagnosis of tibial stress fractures. No single test or test combination had both a high specificity and sensitivity. Most studies obtained a high sensitivity on palpation, even combined test gave a high sensitivity. Conclusion: Clinical tests alone do not seem to be able to diagnose stress fractures in the tibia as the tests have a low specificity. Possibly, a combination of tests can rule out stress fractures in the tibia and therefore reduce the need for radiological examination. Most studies had methodological flaws therefore, more research is needed to be able to draw safer conclusions regarding the ability of the tests.
87

Efektivita programu prevence zranění dolních končetin v házené / The effectiveness of program in lower limbs injuries in handball

Kropíková, Pavla January 2012 (has links)
Title of diploma's thesis: The effectiveness of program in lower limbs injuries in handball Abstract: The theoretical part of diploma's thesis contains detailed description of anatomy and kinesiology of knee and ankle joints. It also link injuries which affect this parts of body. This part contains accident occurrence in sports, causes and mechanism of injury. We could not forget the theoretical treatment for the prevention of injury. The practical part is the creation and application of a simple prevention motion program that will have a preventive effect in terms of lower limb injuries of female handball players. Research thesis therefore dealt efficiency of our original motion program. We checked the statistically processed data on the number and type of injuries in female players of handball in the first league of women. The effectiveness of our motion program was confirmed by reducing the number of injuries of the lower limbs in the intervention group. Key words: lower limb injury, injury prevention, accident occurrence, special prevention motion program
88

Effet de la croissance, du genre et de l'expertise sur les propriétés biomécaniques des membres inférieurs / Effect of growth, gender and expertise on the lower-limb biomechanical properties

Choukou, Mohamed Amine 12 December 2012 (has links)
L’objectif de cette thèse était d’appréhender les effets de la croissance et de l’expertise sur les propriétés biomécaniques des membres inférieurs de l’Homme. Pour ce faire, une série d’expérimentations se basant sur un modèle “masse-ressort” associé à des tâches de sauts verticaux ont été menées dans des conditions de terrain. Nous avons démontré dans un premier temps qu’un système accélérométrique transportable et autonome pourrait être utilisé, in situ, d’une manière fiable et valide afin d’estimer l’ensemble des paramètres mécaniques et indices neuromusculaires étudiés au cours de ce travail de recherche. Ensuite, au cours d’une étude croisée, nous avons identifié un âge d’or pour la maturation des paramètres neuromusculaires des membres inférieurs qui se situe autour de 15-16 ans, âge de début de différenciation fille/garçon et d’évolution des propriétés neuromusculaires du cycle étirement-renvoi vers l’âge adulte. Enfin, nous avons étudié l’effet de l’expertise sur les qualités physiques du sportif. Les résultats montrent clairement que le comportement neuromécanique des membres inférieurs évolue avec l’expertise sportive, d’une façon spécifique à l’activité. / The aim of this thesis was to apprehend the growth and expertise effects on the biomechanicalproperties of the human lower limb. For that aim, we basically used a “spring-mass” model whichwas associated to in-field vertical jump tasks. Firstly, we demonstrated that a transportable andautonomous accelerometric system was reliable and valid for assessing the whole mechanical andneuromuscular parameters which we studied in the current research work. Secondly, we identified agolden age for the maturation of the lower limb neuromuscular properties through a crossover study.That was the age of 15-16 years, which corresponds to a beginning of a gender differentiation and anevolution of the neuromuscular properties of the stretch-shortening cycle to the adulthood. Finally, westudied the effects of expertise on the sportsman physical abilities. The results clearly show that theneuromechanical behaviour of the lower limbs evolves with expertise by following an activity-relatedspecific way.
89

Clinical and Biochemical Features of Adult Diabetes Mellitus in Sudan

Abdelgadir, Moawia January 2006 (has links)
<p>The high prevalence of diabetes mellitus among the Sudanese population is linked to obesity, poor glycaemic control and a high rate of complications. This study investigated 1/ Leptin hormone and its correlations with different biochemical characteristics in Sudanese diabetic subjects, 2/ The impact of glycaemic control on pregnancy outcome in pregnancies with diabetes, 3/ The glycaemic response to Sudanese traditional carbohydrate foods, 4/ The influence of glucose self-monitoring on the glycaemic control among this population, 5/ The health related quality of life in Sudanese subjects with diabetes-related lower limb amputation. </p><p>Leptin was significantly lower in diabetic subjects compared with controls of same BMI in both females (P =0.0001) and males (P =0.019). In diabetic subjects, serum leptin correlated positively with the homeostatic assessment (HOMA) of both beta-cell function (P =0.018) and insulin resistance (P =.038). In controls, leptin correlated only with insulin resistance. Pregnancy complications were higher among diabetic compared with control women (P<0.0001) and varied with the type of diabetes. Infants of diabetic mothers had a higher incidence of neonatal complications than those of non-diabetic women (P<0.0001). In six Sudanese traditional carbohydrate meals over all differences in incremental AUCs were significant for both plasma glucose (P = 0.0092) and insulin (P = 0.0001). Millet porridge and wheat pancakes displayed significantly lower post-prandial glucose and insulin responses, whereas maize porridge induced a higher post-prandial glucose and insulin response. In type 2 diabetic subjects SMBG or SMUG was not related to glycaemic control. In type 1 diabetic subjects, SMBG was significantly associated with better glycaemic control, as assessed by HbA1c (P=0.02) and blood glucose at clinic visits (P=<0.0001), similar associations were found for SMUG respectively. Neither glycaemic control nor glucose self-monitoring was associated with education level. Diabetic subjects with LLA had significantly poorer HRQL compared to a reference diabetic group (P=<0.0001). Duration of diabetes and amputation had negative impact on HRQL in subjects with LLA (P=<0.0001) respectively. Diabetic subjects with LLA had decreased sense of coherence and high presence of symptoms. Improving health services at the primary level is important to reduce the complications and burden of disease in the Sudanese population.</p>
90

Clinical and Biochemical Features of Adult Diabetes Mellitus in Sudan

Abdelgadir, Moawia January 2006 (has links)
The high prevalence of diabetes mellitus among the Sudanese population is linked to obesity, poor glycaemic control and a high rate of complications. This study investigated 1/ Leptin hormone and its correlations with different biochemical characteristics in Sudanese diabetic subjects, 2/ The impact of glycaemic control on pregnancy outcome in pregnancies with diabetes, 3/ The glycaemic response to Sudanese traditional carbohydrate foods, 4/ The influence of glucose self-monitoring on the glycaemic control among this population, 5/ The health related quality of life in Sudanese subjects with diabetes-related lower limb amputation. Leptin was significantly lower in diabetic subjects compared with controls of same BMI in both females (P =0.0001) and males (P =0.019). In diabetic subjects, serum leptin correlated positively with the homeostatic assessment (HOMA) of both beta-cell function (P =0.018) and insulin resistance (P =.038). In controls, leptin correlated only with insulin resistance. Pregnancy complications were higher among diabetic compared with control women (P&lt;0.0001) and varied with the type of diabetes. Infants of diabetic mothers had a higher incidence of neonatal complications than those of non-diabetic women (P&lt;0.0001). In six Sudanese traditional carbohydrate meals over all differences in incremental AUCs were significant for both plasma glucose (P = 0.0092) and insulin (P = 0.0001). Millet porridge and wheat pancakes displayed significantly lower post-prandial glucose and insulin responses, whereas maize porridge induced a higher post-prandial glucose and insulin response. In type 2 diabetic subjects SMBG or SMUG was not related to glycaemic control. In type 1 diabetic subjects, SMBG was significantly associated with better glycaemic control, as assessed by HbA1c (P=0.02) and blood glucose at clinic visits (P=&lt;0.0001), similar associations were found for SMUG respectively. Neither glycaemic control nor glucose self-monitoring was associated with education level. Diabetic subjects with LLA had significantly poorer HRQL compared to a reference diabetic group (P=&lt;0.0001). Duration of diabetes and amputation had negative impact on HRQL in subjects with LLA (P=&lt;0.0001) respectively. Diabetic subjects with LLA had decreased sense of coherence and high presence of symptoms. Improving health services at the primary level is important to reduce the complications and burden of disease in the Sudanese population.

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