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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.
51

Identification des propriétés hyperélastiques des muscles de la cuisse à l'état passif : couplage des techniques de corrélation d'images aux techniques d'imagerie médicale / Identification of the hyperelastic properties of the passive thigh muscles : coupling of the image correlation with medical imaging techniques

Affagard, Jean-Sébastien 14 October 2013 (has links)
La compréhension du comportement musculaire est un champ d’investigation primordial dans divers domaines tels que le sport, le crash automobile et la médecine. Peu de techniques in vivo permettent aujourd’hui de caractériser les propriétés mécaniques du muscle. Aussi, l’objectif de ce travail est de développer une méthode d’identification in vivo à partir demesures de champs de déplacement. La méthode d’identification est composée de 3 étapes interdépendantes. La première consiste à réaliser une IRM de la cuisse pour segmenter manuellement différents tissus musculaires (quadriceps, ischios, gracilis et sartorius) et le tissu adipeux. Un comportement Néo-Hookéen est choisi pour modéliser le comportement hyperélastique (C10, D). Dans un second temps, un dispositif expérimental de compression est développé pour mesurer le champ de déplacement in vivo à partir des techniques d’imagerie échographique et de Corrélation d’Images Numériques. Finalement, une méthode inverse est mise en œuvre pour identifier les paramètres C10 et D de chaque tissu. Par le biais d’un exemple numérique, l’erreur sur les paramètres identifiés est évaluée. Les cartographies des champs de déplacement expérimentaux confirment les observations qualitatives obtenues sur les images échographiques et sont validées par les champs de déformation obtenus par approximation diffuse. Une faible erreur d’identification (C10<3%, D<7%) est obtenue à partir de l’exemple numérique, et les paramètres mécaniques identifiés sont en accord avec la littérature. Ces résultats valident la démarche inverse mise en œuvre qui permettra, à terme, de suivre l’évolution des pathologies et de mener des simulations prédictives. / The understanding of the mechanical behavior of the muscle tissue is an important field of investigation with different applications in medicine, car crash and sport. Currently, few in vivo imaging techniques are able to characterize the mechanical properties of muscle. Thus, this study aims at developing an in vivo identification method based on displacement fieldmeasurements. The identification approach is composed of 3 dependent steps. The first step consists in performing a 2D MRI acquisition of the thigh in order to segment manually the muscle (quadriceps, ischio, gracilis and sartorius) and fat tissues. A Neo-Hookean model is chosen to characterize the hyperelastic behavior (C10, D). Secondly, an experimental compressiondevice is developed to measure the in vivo displacement field using ultrasound and Digital Image Correlation (DIC) techniques. Finally, an inverse method is implemented to identify the C10 and D parameters of each soft tissue. A numerical example is used to quantify the identification error on each parameter. Displacement field measurements confirm the ultrasound observations. They are also validated by the cartographies of the strain fields, which are obtained by the diffuse approximation method. Using the numerical example, the identification leads to low errors on the C10 (< 3%) and D (< 7%) parameters. Identified values of the mechanical parameters are in good agreement with the literature. All results validate the implemented identification method. In the long term, this protocol will allow to follow the evolution of pathologies and to conduct predictive simulations.
52

Identifying a Test to Monitor Weightlifting Performance in Competitive Male and Female Weightlifters

Travis, S. Kyle, Goodin, Jacob R., Beckham, George K., Bazyler, Caleb D. 23 May 2018 (has links)
Monitoring tests are commonly used to assess weightlifter’s preparedness for competition. Although various monitoring tests have been used, it is not clear which test is the strongest indicator of weightlifting performance. Therefore, the purpose of this study was to (1) determine the relationships between vertical jump, isometric mid-thigh pull (IMTP) and weightlifting performance; and (2) compare vertical jumps to IMTP as monitoring tests of weightlifting performance in a large cohort of male and female weightlifters. Methods: Fifty-two competitive weightlifters (31 males, 21 females) participated in squat and countermovement jump testing (SJ, CMJ), and IMTP testing performed on force plates. All laboratory testing data was correlated to a recent competition where the athletes had attempted to peak. Results: Squat jump height (SJH) was the strongest correlate for men and women with the Sinclair Total (r = 0.686, p ≤ 0.01; r = 0.487, p ≤ 0.05, respectively) compared to countermovement jump height (r = 0.642, p ≤ 0.01; r = 0.413, p = 0.063), IMTP peak force allometrically scaled to body mass (r = 0.542, p ≤ 0.01; r = −0.044, p = 0.851) and rate of force development at 200 ms (r = 0.066, p = 0.723; r = 0.086, p = 0.711), respectively. Further, SJH was a stronger correlate of relative weightlifting performance compared to IMTP peak force in females (p = 0.042), but not male weightlifters (p = 0.191). Conclusions: Although CMJ and IMTP are still considered strong indicators of weightlifting performance, SJH appears to be the most indicative measure of weightlifting performance across a wide-range of performance levels. Thus, SJH can be used as a reliable measure to monitor weightlifting performance in male and female weightlifters.
53

Bilateral Muscle Oxygenation Kinetics In Response To Repeat Sprint Cycling In Strong And Weak Individuals

Abbott, John 01 May 2020 (has links)
Repeat sprint ability has been investigated thoroughly, however optimal training methodology to improve RSA remains elusive. Both kinetic and physiological viewpoints have been used to scrutinize aspects of RSA including, initial sprint performance (anaerobic power), maximal cardiorespiratory fitness (VO2max), lactate threshold, anaerobic capacity (mean power), muscle activation (EMG), and local muscle oxygenation kinetics. To our knowledge no study has utilized maximal strength levels as a separate factor among a homogenous group of cardiorespiratory fitness individuals (as determined by peak VO2 during RSA). The purpose of this study was to better understand the relationship between maximal strength, muscular characteristics, and cycling RSA- respective to muscle oxygenation responses. Fifteen participants completed fifteen 10-second maximal effort sprints on a cycle ergometer interspersed with 30-seconds passive recovery. Respiratory, muscle oxygenation, and kinetic responses were monitored continuously and evaluated relationships with maximal strength and muscular architecture as determined by isometric mid-thigh pull and ultrasonography respectively. A series of 2 x 15 mixed design, group x time, ANOVA’s were used to evaluate the effects of group and or sprint on muscle oxygenation kinetics. Strong individuals were found to have significantly greater levels of muscle oxygenation usage, recovery and the respective rates; p = 0.01, p = 0.02, p
54

Maximum Strength, Rate of Force Development, Jump Height, and Peak Power Alterations in Weightlifters across Five Months of Training

Hornsby, W. Guy, Gentles, Jeremy A., MacDonald, Christopher J., Mizuguchi, Satoshi, Ramsey, Michael W., Stone, Michael H. 13 October 2017 (has links)
The purpose of this monitoring study was to investigate how alterations in training affect changes in force-related characteristics and weightlifting performance. Subjects: Seven competitive weightlifters participated in the study. Methods: The weightlifters performed a block style periodized plan across 20 weeks. Force plate data from the isometric mid-thigh pull and static jumps with 0 kg, 11 kg, and 20 kg were collected near the end of each training block (weeks 1, 6, 10, 13, 17, and 20). Weightlifting performance was measured at weeks 0, 7, 11, and 20. Results: Very strong correlations were noted between weightlifting performances and isometric rate of force development (RFD), isometric peak force (PF), peak power (PP), and jump height (JH). Men responded in a more predictable manner than the women. During periods of higher training volume, RFD was depressed to a greater extent than PF. JH at 20 kg responded in a manner reflecting the expected fatigue response more so than JH at 0 kg and 11 kg. Conclusions: PF appears to have been more resistant to volume alterations than RFD and JH at 20 kg. RFD and JH at 20 kg appear to be superior monitoring metrics due to their “sensitivity.”
55

"Estudo anatômico do retalho perfurante ântero-lateral da coxa" / Anatomic study of the anterolateral thigh flap

Ishida, Luiz Carlos 17 August 2006 (has links)
INTRODUÇÃO: O retalho ântero-lateral da coxa é baseado em vasos perfurantes do ramo descendente da artéria circunflexa lateral femoral. Este retalho tem características muito interessantes para a cirurgia reparadora, como a pequena espessura, pedículo longo e excelente área doadora. No entanto, existem muitas controvérsias na literatura quanto aos vasos perfurantes e ao trajeto do pedículo deste retalho. Neste trabalho procurou-se estabelecer alguns parâmetros anatômicos e esclarecer estas controvérsias. MÉTODO: Estudaram-se 100 coxas de 50 cadáveres quanto aos seguintes aspectos: 1- Número e localização de perfurantes encontrados, 2- Trajeto do pedículo perfurante, 3- Trajetória intramuscular, 4- Comprimento do trajeto intramuscular, 5- Comprimento total do pedículo, 6- Diâmetro dos vasos e 7- Espessura do retalho. RESULTADOS: 1- Encontraram-se de 0 a 4 perfurantes por coxa estudada, todas em um raio de até 6cm do ponto médio entre a espinha ilíaca ântero-superior e a borda lateral da patela. 2- Os vasos perfurantes tinham trajeto músculo-cutâneo em 75,76% das coxas e septo-cutâneo em 24,24%. 3- Dos pedículos perfurantes com trajeto músculo-cutâneo, 86,67% possuíam trajetória indireta contra 13,33% com trajetória direta. 4- O comprimento médio do trajeto intramuscular dos pedículos foi de 3,67 ± 2,01 cm. 5- O comprimento médio do pedículo total foi de 11,31 ± 3,12 cm. 6- O diâmetro médio da artéria na origem do ramo descendente da artéria circunflexa femoral foi de 2,21 ± 0,85 mm e para as veias no mesmo local de 2,66 ± 1,33 mm e 2,10 ± 1,11 mm. 7- A espessura da tela subcutânea foi de 8,98 ±6,23 mm e da pele de 1,60 ± 0,76 mm. CONCLUSÕES: 1- Existiu uma pequena possibilidade de não haver pedículos perfurantes. 2- Quando presentes, os pedículos perfurantes do ramo descendente da artéria circunflexa lateral femoral eram encontrados em numero de 1 a 4, sempre em um raio de 6 cm a partir do ponto médio entre a espinha ilíaca ântero-superior e a borda lateral da patela. 3- Os trajetos dos pedículos perfurantes eram predominantemente músculo-cutâneos. 4- A trajetória intramuscular encontrada foi predominantemente indireta. 5- O comprimento do trajeto intramuscular correspondeu a 31,69% do comprimento total do pedículo. 6- O comprimento total do pedículo se mostrou adequado tanto para transferências locais como à distancia por técnicas microcirúrgicas. 7- Os diâmetros dos vasos, tanto da artéria quanto das veias, se mostraram adequados para a realização de anastomoses microcirúrgicas. 8- A espessura do retalho encontrada foi significantemente maior nas coxas de indivíduos femininos, mas tanto nos homens quanto nas mulheres a espessura foi relativamente fina. / INTRODUCTION: The anterolateral thigh flap is based on the perforator vessels of the descending branch of the lateral circumflex femoral artery. This flap has very interesting characteristics for the reconstructive surgery, like the small thickness, long pedicle and excellent donor site. On the other hand, there are many controversial data on the literature about the perforator vessels and the pedicle course of this flap. The aims of this study are to establish some anatomical parameters and clear some controversies. METHOD: A hundred thighs of 50 cadavers were studied for: 1- The number and location of the perforator vessels. 2- The course of the perforator pedicles. 3- The intramuscular course. 4- The length of the intramuscular course. 5- The total length of the vascular pedicle. 6- The diameter of the vessels. and 7- The thickness of the flap. RESULTS: 1- There were found from 0 to 4 perforators per thigh, all in a 6cm radius from the mid point between the anterosuperior iliac spine and the lateral border of the patella. 2- The pedicles was musculocutaneous in 75,76% of the thighs and septocutaneous in 24,24%. 3- Among the musculocutaneous pedicles, 86,67% had a direct intramuscular course, and 13,33% had indirect course. 4- The mean length of the intramuscular course was 3,67 ± 2,01 cm. 5- The mean total pedicle length was 11,31 ± 3,12 cm. 6-The mean artery diameter on the origin of the descending branch of the lateral circumflex femoral artery was 2,21 ± 0,85 mm and the mean vein diameter on the same spot was 2,66 ±1,33 mm and 2,10 ± 1,11 mm. 7- The mean subcutaneous fat tissue thickness was 8,98 ± 6,23 mm and the mean skin thickness was e 1,60 ± 0,76 mm. CONCLUSIONS: 1- There was a possibility of finding no perforators of the descending branch of the lateral circumflex femoral artery. 2- When present, the perforators pedicles were found in numbers between 1 to 4, always in a 6cm radius from the mid point between the anterosuperior iliac spine and the lateral border of the patella. 3- The perforators pedicles courses were predominantly musculocutaneous. 4- The intramuscular courses were mainly indirect. 5- The intramuscular length was responsible for 31,69% of the total length of the vascular pedicle. 6- The total length of the pedicle was adequate for either local or microsurgical transfers. 7- The arterial and venous diameters were adequate for microsurgical anastomosis. 8- The female cadavers had significantly thicker flaps, but both in the male and the female cadavers the flap was considerably thin.
56

"Estudo anatômico do retalho perfurante ântero-lateral da coxa" / Anatomic study of the anterolateral thigh flap

Luiz Carlos Ishida 17 August 2006 (has links)
INTRODUÇÃO: O retalho ântero-lateral da coxa é baseado em vasos perfurantes do ramo descendente da artéria circunflexa lateral femoral. Este retalho tem características muito interessantes para a cirurgia reparadora, como a pequena espessura, pedículo longo e excelente área doadora. No entanto, existem muitas controvérsias na literatura quanto aos vasos perfurantes e ao trajeto do pedículo deste retalho. Neste trabalho procurou-se estabelecer alguns parâmetros anatômicos e esclarecer estas controvérsias. MÉTODO: Estudaram-se 100 coxas de 50 cadáveres quanto aos seguintes aspectos: 1- Número e localização de perfurantes encontrados, 2- Trajeto do pedículo perfurante, 3- Trajetória intramuscular, 4- Comprimento do trajeto intramuscular, 5- Comprimento total do pedículo, 6- Diâmetro dos vasos e 7- Espessura do retalho. RESULTADOS: 1- Encontraram-se de 0 a 4 perfurantes por coxa estudada, todas em um raio de até 6cm do ponto médio entre a espinha ilíaca ântero-superior e a borda lateral da patela. 2- Os vasos perfurantes tinham trajeto músculo-cutâneo em 75,76% das coxas e septo-cutâneo em 24,24%. 3- Dos pedículos perfurantes com trajeto músculo-cutâneo, 86,67% possuíam trajetória indireta contra 13,33% com trajetória direta. 4- O comprimento médio do trajeto intramuscular dos pedículos foi de 3,67 ± 2,01 cm. 5- O comprimento médio do pedículo total foi de 11,31 ± 3,12 cm. 6- O diâmetro médio da artéria na origem do ramo descendente da artéria circunflexa femoral foi de 2,21 ± 0,85 mm e para as veias no mesmo local de 2,66 ± 1,33 mm e 2,10 ± 1,11 mm. 7- A espessura da tela subcutânea foi de 8,98 ±6,23 mm e da pele de 1,60 ± 0,76 mm. CONCLUSÕES: 1- Existiu uma pequena possibilidade de não haver pedículos perfurantes. 2- Quando presentes, os pedículos perfurantes do ramo descendente da artéria circunflexa lateral femoral eram encontrados em numero de 1 a 4, sempre em um raio de 6 cm a partir do ponto médio entre a espinha ilíaca ântero-superior e a borda lateral da patela. 3- Os trajetos dos pedículos perfurantes eram predominantemente músculo-cutâneos. 4- A trajetória intramuscular encontrada foi predominantemente indireta. 5- O comprimento do trajeto intramuscular correspondeu a 31,69% do comprimento total do pedículo. 6- O comprimento total do pedículo se mostrou adequado tanto para transferências locais como à distancia por técnicas microcirúrgicas. 7- Os diâmetros dos vasos, tanto da artéria quanto das veias, se mostraram adequados para a realização de anastomoses microcirúrgicas. 8- A espessura do retalho encontrada foi significantemente maior nas coxas de indivíduos femininos, mas tanto nos homens quanto nas mulheres a espessura foi relativamente fina. / INTRODUCTION: The anterolateral thigh flap is based on the perforator vessels of the descending branch of the lateral circumflex femoral artery. This flap has very interesting characteristics for the reconstructive surgery, like the small thickness, long pedicle and excellent donor site. On the other hand, there are many controversial data on the literature about the perforator vessels and the pedicle course of this flap. The aims of this study are to establish some anatomical parameters and clear some controversies. METHOD: A hundred thighs of 50 cadavers were studied for: 1- The number and location of the perforator vessels. 2- The course of the perforator pedicles. 3- The intramuscular course. 4- The length of the intramuscular course. 5- The total length of the vascular pedicle. 6- The diameter of the vessels. and 7- The thickness of the flap. RESULTS: 1- There were found from 0 to 4 perforators per thigh, all in a 6cm radius from the mid point between the anterosuperior iliac spine and the lateral border of the patella. 2- The pedicles was musculocutaneous in 75,76% of the thighs and septocutaneous in 24,24%. 3- Among the musculocutaneous pedicles, 86,67% had a direct intramuscular course, and 13,33% had indirect course. 4- The mean length of the intramuscular course was 3,67 ± 2,01 cm. 5- The mean total pedicle length was 11,31 ± 3,12 cm. 6-The mean artery diameter on the origin of the descending branch of the lateral circumflex femoral artery was 2,21 ± 0,85 mm and the mean vein diameter on the same spot was 2,66 ±1,33 mm and 2,10 ± 1,11 mm. 7- The mean subcutaneous fat tissue thickness was 8,98 ± 6,23 mm and the mean skin thickness was e 1,60 ± 0,76 mm. CONCLUSIONS: 1- There was a possibility of finding no perforators of the descending branch of the lateral circumflex femoral artery. 2- When present, the perforators pedicles were found in numbers between 1 to 4, always in a 6cm radius from the mid point between the anterosuperior iliac spine and the lateral border of the patella. 3- The perforators pedicles courses were predominantly musculocutaneous. 4- The intramuscular courses were mainly indirect. 5- The intramuscular length was responsible for 31,69% of the total length of the vascular pedicle. 6- The total length of the pedicle was adequate for either local or microsurgical transfers. 7- The arterial and venous diameters were adequate for microsurgical anastomosis. 8- The female cadavers had significantly thicker flaps, but both in the male and the female cadavers the flap was considerably thin.
57

"Comparação anatômica entre o retalho perfurante ântero-lateral da coxa e os retalhos cutâneos paraescapular e lateral do braço" / Anatomical comparison of the anterolateral thigh perforator flap and the parascapular and lateral arm skin flaps

Busnardo, Fabio de Freitas 01 September 2006 (has links)
A descrição de retalhos cutâneos pediculados em ramos perfurantes musculares é recente. O retalho ântero-lateral da coxa é vascularizado por vasos perfurantes musculares do ramo descendente da artéria circunflexa femoral lateral. Trata-se de retalho de pouca espessura, pedículo vascular longo e calibroso e baixa morbidade de área doadora. Entretanto, a dissecção do trajeto intramuscular de seu pedículo é tecnicamente difícil. Sua indicação é por vezes questionada por tratar-se de retalho de características semelhantes a outros vascularizados por artérias cutâneas diretas ou septocutâneas. Estes têm menor variação anatômica e dissecção mais simples. O presente estudo avaliou as características anatômicas do retalho ântero-lateral da coxa, através de dissecção em cadáveres frescos, comparando-as com as do retalho paraescapular e lateral do braço. Foram dissecados 60 retalhos (20 retalhos ântero-laterais da coxa, 20 paraescapulares e 20 retalhos laterais do braço) em 20 cadáveres frescos, não formolizados, com menos de 24 horas após o óbito. Todos os retalhos tiveram os seguintes parâmetros avaliados: comprimento do pedículo vascular, espessura do retalho, diâmetro do pedículo vascular arterial e venoso. Além disso, foi avaliada a presença de trajeto intramuscular do pedículo vascular (apenas nas dissecções do retalho ântero-lateral da coxa). A análise comparativa evidenciou que o pedículo vascular do retalho ântero-lateral da coxa é mais longo quando comparado aos dos retalhos paraescapular e lateral do braço (p<0,001). O retalho cutâneo lateral do braço apresenta a menor espessura (p<0,001) e o menor diâmetro arterial e venoso do pedículo vascular (p<0,001). Constatou-se a presença de trajeto intramuscular do pedículo do retalho ântero-lateral da coxa em 17 (85%) casos. O comprimento médio do segmento intramuscular do principal ramo perfurante foi de 4,13+2,02 cm. Os dados foram comparados e avaliados através de técnica de análise de variância com medidas repetidas. O nível de significância utilizado para os testes foi de 5%. As informações obtidas permitem concluir que o retalho ântero-lateral da coxa apresenta como vantagem o pedículo vascular de maior comprimento. Entretanto, apresentou em 85% dos casos a necessidade de dissecção intramuscular de um segmento deste pedículo. O retalho lateral do braço apresenta como principais características a pouca espessura e o menor diâmetro de seus pedículos vasculares. O retalho paraescapular tem características anatômicas semelhantes às do retalho ântero-lateral da coxa, não sendo evidenciada diferença significativa entre suas espessuras e diâmetros de seus pedículos vasculares. Apresenta pedículo vascular mais curto quando comparado ao do retalho ântero-lateral da coxa. Entretanto, trata-se de vaso septocutâneo, sem a necessidade de dissecção de trajeto intramuscular. / The description of the skin flaps based on perforator vessels is recent. The vascularization of the anterolateral thigh flap is based on perforator vessels coming from the lateral circumflex femoral artery. It has a thin skin paddle, a long and large vascular pedicle and low donor site morbidity. However, the dissection of the intramuscular path of its pedicle is technically difficult. Its indication is sometimes questionable since it is a flap with characteristics similar to others based on direct cutaneous or septocutaneous vessels, which have less anatomical variations and are easier to dissect. This study evaluated the anatomical characteristics of the anterolateral thigh perforator flap through the dissection of fresh cadavers, comparing them with those of the parascapular and lateral arm skin flap. Sixty flaps were dissected (20 anterolateral thigh, 20 parascapular and 20 lateral arm flaps) in 20 fresh cadavers, not perfused with formaldehyde, less than 24 hours after death. The following aspects were evaluated in all the flaps: length of the vascular pedicle, thickness of the flap and diameter of the arterial and venous vascular pedicle. Additionally, the presence of the intramuscular path of the vascular pedicle was evaluated (only in the dissections of the anterolateral thigh flap). The comparative analysis showed that the vascular pedicle of the anterolateral thigh perforator flap is longer when compared to those of the parascapular and lateral arm flaps (p<0,001). The lateral arm flap presented a pedicle with smaller arterial and venous diameter (p<0,001), in addition to being the thinner flap (p<0,001). It was verified that the vascular pedicle of the anterolateral thigh flap presented an intramuscular path in 17 (85%) cases. The average length of the intramuscular segment of the main perforator vessel was 4,13+2,02 cm. The data was compared and evaluated with variance analysis. The information obtained allows one to conclude that the advantage the anterolateral thigh perforator flap has over the other skin flaps is a longer vascular pedicle. However, the need for intramuscular dissection of a segment of this pedicle presented itself in 85% of the cases. The lateral arm flap is the thinnest flap, and the one with the smaller arterial and venous diameter of its vascular pedicle. The parascapular flap has anatomical characteristics similar to those of the anterolateral thigh flap, with no evidence of a significant difference between their thicknesses and diameters of vascular pedicles. Its vascular pedicle is shorter when compared to that of the anterolateral thigh flap. On the other hand, it is a fasciocutaneous vessel, without the need for intramuscular dissection.
58

The Development of an Improved Finite Element Muscle Model and the Investigation of the Pre-loading Effects of Active Muscle on the Femur During Frontal Crashes

Mendes, Sebastian B 31 August 2010 (has links)
"Mammalian skeletal muscle is a very complicated biological structure to model due to its non-homogeneous and non-linear material properties as well as its complex geometry. Finite element discrete one-dimensional Hill-based elements are largely used to simulate muscles in both passive and active states. There are, however, several shortfalls to utilizing one-dimensional elements, such as the impossibility to represent muscle physical mass and complex lines of action. Additionally, the use of one-dimensional elements restricts muscle insertion sites to a limited number of nodes causing unrealistic loading distributions in the bones. The behavior of various finite element muscle models was investigated and compared to manually calculated muscle behavior. An improved finite element muscle model consisting of shell elements and Hill-based contractile truss elements in series and parallel was ultimately developed. The muscles of the thigh were then modeled and integrated into an existing 50th percentile musculo-skeletal model of the knee-thigh-hip complex. Impact simulations representing full frontal car crashes were then conducted on the model and the pre-loading effects from active thigh muscles on the femur were investigated and compared to cadaver sled test data. It was found that the active muscles produced a pre-load femoral axial force that acted to slightly stabilize the rate of stress intensification on critical stress areas on the femur. Additionally, the active muscles served to direct the distribution of stress to more concentrated areas on the femoral neck. Furthermore, the pre-load femoral axial force suggests that a higher percentage of injuries to the knee-thigh-hip complex may be due to the effects of active muscles on the femur. "
59

Estimativa do peso do recem-nascido por meio de medidas ultrassonograficas bidimensionais e do volume da coxa fetal / Birth weight precition by two-dimensional ultrasound measurements and fetal thigh volume

Bennini Junior, João Renato, 1978- 27 November 2018 (has links)
Orientadores: Cleisson Fabio Andrioli Peralta, Ricardo Barini / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-11-27T11:44:05Z (GMT). No. of bitstreams: 1 BenniniJunior_JoaoRenato_M.pdf: 1809698 bytes, checksum: 399e6ab502353af527e35953428d5e09 (MD5) Previous issue date: 2009 / Resumo: Introdução: Alguns estudos demonstram que a predição do peso fetal usando a volumetria dos membros fetais é mais precisa do que quando se usam medidas bidimensionais (2D). Até hoje, somente o método multiplanar foi utilizado para a volumetria dos membros fetais. Desta forma, a utilidade do método rotacional (VOCAL®) para este fim nunca foi testada. Objetivos: Avaliar as variabilidades intra e interobservadores e a concordância entre as medidas do volume da coxa fetal realizadas com os métodos multiplanar e VOCAL®. Comparar as acurácias das fórmulas com medidas do volume da coxa fetal com as acurácias das fórmulas com medidas 2D. Comparar as acurácias das fórmulas deste estudo com as acurácias das fórmulas já publicadas. Métodos: 210 pacientes foram avaliadas, formando um grupo para gerar as fórmulas (n = 150) e um grupo para validá-las (n = 60). Os pacientes utilizados para gerar as fórmulas também foram utilizados para avaliar as variabilidades intra e interobservadores e a concordância entre as medidas realizadas pelos métodos multiplanar e VOCAL®. Foram utilizadas análises de regressão polinomial para criar uma equação com medidas 2D, uma com o volume da coxa fetal medido pelo método multiplanar (CoxaM) e uma com o volume da coxa fetal medido pelo método VOCAL® (CoxaV). Utilizaram-se testes t de Student pareados para comparar as acurácias das equações deste estudo com as acurácias das fórmulas já publicadas. Foram utilizadas análises proporcionais de Bland e Altman para avaliar as variabilidades intra e interobservadores e a concordância entre as medidas realizadas pelos métodos multiplanar e VOCAL®. Resultados: A diferença média percentual entre as medidas pelos métodos multiplanar e VOCAL® foi de -0,04 com limites de concordância de 95% de -8,17 e 8,09. A diferença média percentual e os limites de concordância de 95% entre as medidas na avaliação das variabilidades intra e interobservadores foram -1,10 (-7,67 to 5,47) e 0,61 (-7,68 to 8,91) para o método VOCAL® e 1,03 (-6,35 to 8,41) e -0,68 (-11,42 to 10,06) para o multiplanar. As melhores fórmulas para cálculo do peso fetal estimado (PFE) foram: PFE = -562.824 + 11.962 x CA x CF + 0,009 x DBP² x CA² (CA: circunferência abdominal; CF: comprimento femoral; DBP: diâmetro biparietal); PFE = 1033.286 + 12.733 x CoxaM; PFE = 1025.383 + 12.775 x CoxaV. Tanto no grupo que gerou as fórmulas como no grupo utilizado para validá-las não houve diferença significativa entre as acurácias das fórmulas com medidas 2D ou tridimensionais (3D). Quando aplicadas nas pacientes deste estudo, as acurácias das fórmulas 2D e 3D já publicadas foram significativamente piores dos que as das novas fórmulas. Conclusões: Os métodos VOCAL® e multiplanar são intercambiáveis para a volumetria da coxa fetal. Possivelmente as maiores fontes de discrepâncias na estimativa do peso fetal são as diferenças fenotípicas entre as pacientes utilizadas para criar as fórmulas. Os dados deste estudo reforçam a necessidade de fórmulas específicas para cada população, independentemente do uso de medidas 2D ou 3D. / Abstract: Introduction: Some authors have demonstrated that the prediction of birth weight using fetal limb volumetry is more precise than with two-dimensional ultrasound (2DUS). To date, only the multiplanar method has been used for fetal limb volumetry, so the usefulness of the rotational technique (VOCALTM - Virtual Organ Computer- aided AnaLysis) for this purpose has never been tested. Objectives: To evaluate the repeatability, reproducibility and agreement of measurements performed with multiplanar and VOCALTM techniques for total fetal thigh volumetry. To compare the accuracies of birth-weight-predicting models with total fetal thigh volumetry with models derived from 2DUS parameters. To compare the performances of our new formulas with those of previously published equations. Methods: 210 patients were prospectively evaluated to compose a formula-generating group (n = 150) and a prospective-validation group (n = 60). The patients of the formula-generating group were also used to evaluate the repeatability, reproducibility and the agreement of the measurements of multiplanar and VOCALTM techiniques for fetal thigh volumetry. Polynomial regression analysis was performed in the formula-generating group to generate one equation with 2DUS measurements, one with fetal thigh volume measured by the multiplanar technique (ThiM) and one with fetal thigh volume obtained by the VOCALTM method (ThiV). Paired samples t-tests were used to compare the accuracies of our equations with those of previously published 2D and three-dimensional (3D) equations. Proportionate Bland and Altman analyses were performed to determine the agreement between the two methods and to evaluate intra- and inter-observer variability. Results: The mean percentage difference between measurements performed with the VOCALTM and multiplanar techniques was -0.04 and the 95% limits of agreement were -8.17 and 8.09. The mean percentage difference and 95% limits of agreement between paired measurements in the assessment of intra- and inter-observer variability were -1.10 (-7.67 to 5.47) and 0.61 (-7.68 to 8.91) for the VOCALTM technique and 1.03 (-6.35 to 8.41) and -0.68 (-11.42 to 10.06) for the multiplanar method. The formulas with the best fit for the prediction of birth weight (EFW) were: EFW = -562.824 + 11.962 x AC x FL + 0.009 x BPD² x AC² (AC: abdominal circumference; FL: femur length; BPD: biparietal diameter); EFW = 1033.286 + 12.733 x ThiM; EFW = 1025.383 + 12.775 x ThiV. For both the formula-generating and the rospective-validation groups, there was no significant difference between the accuracies of the new 2DUS and 3DUS models. When applied to our population, the accuracies of previously published 2DUS and 3DUS formulas were significantly worse than our models. Conclusions: The VOCALTM and multiplanar techniques can be used interchangeably for total fetal thigh volumetry. We believe that the greatest sources of discrepancies in estimation of birth weight are the phenotypic differences among patients used to create each of the formulas mentioned in this study. Our data reinforce the need for customized birth weight prediction formulas, regardless of whether 2DUS or 3DUS measurements are employed. / Mestrado / Tocoginecologia / Mestre em Tocoginecologia
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"Comparação anatômica entre o retalho perfurante ântero-lateral da coxa e os retalhos cutâneos paraescapular e lateral do braço" / Anatomical comparison of the anterolateral thigh perforator flap and the parascapular and lateral arm skin flaps

Fabio de Freitas Busnardo 01 September 2006 (has links)
A descrição de retalhos cutâneos pediculados em ramos perfurantes musculares é recente. O retalho ântero-lateral da coxa é vascularizado por vasos perfurantes musculares do ramo descendente da artéria circunflexa femoral lateral. Trata-se de retalho de pouca espessura, pedículo vascular longo e calibroso e baixa morbidade de área doadora. Entretanto, a dissecção do trajeto intramuscular de seu pedículo é tecnicamente difícil. Sua indicação é por vezes questionada por tratar-se de retalho de características semelhantes a outros vascularizados por artérias cutâneas diretas ou septocutâneas. Estes têm menor variação anatômica e dissecção mais simples. O presente estudo avaliou as características anatômicas do retalho ântero-lateral da coxa, através de dissecção em cadáveres frescos, comparando-as com as do retalho paraescapular e lateral do braço. Foram dissecados 60 retalhos (20 retalhos ântero-laterais da coxa, 20 paraescapulares e 20 retalhos laterais do braço) em 20 cadáveres frescos, não formolizados, com menos de 24 horas após o óbito. Todos os retalhos tiveram os seguintes parâmetros avaliados: comprimento do pedículo vascular, espessura do retalho, diâmetro do pedículo vascular arterial e venoso. Além disso, foi avaliada a presença de trajeto intramuscular do pedículo vascular (apenas nas dissecções do retalho ântero-lateral da coxa). A análise comparativa evidenciou que o pedículo vascular do retalho ântero-lateral da coxa é mais longo quando comparado aos dos retalhos paraescapular e lateral do braço (p<0,001). O retalho cutâneo lateral do braço apresenta a menor espessura (p<0,001) e o menor diâmetro arterial e venoso do pedículo vascular (p<0,001). Constatou-se a presença de trajeto intramuscular do pedículo do retalho ântero-lateral da coxa em 17 (85%) casos. O comprimento médio do segmento intramuscular do principal ramo perfurante foi de 4,13+2,02 cm. Os dados foram comparados e avaliados através de técnica de análise de variância com medidas repetidas. O nível de significância utilizado para os testes foi de 5%. As informações obtidas permitem concluir que o retalho ântero-lateral da coxa apresenta como vantagem o pedículo vascular de maior comprimento. Entretanto, apresentou em 85% dos casos a necessidade de dissecção intramuscular de um segmento deste pedículo. O retalho lateral do braço apresenta como principais características a pouca espessura e o menor diâmetro de seus pedículos vasculares. O retalho paraescapular tem características anatômicas semelhantes às do retalho ântero-lateral da coxa, não sendo evidenciada diferença significativa entre suas espessuras e diâmetros de seus pedículos vasculares. Apresenta pedículo vascular mais curto quando comparado ao do retalho ântero-lateral da coxa. Entretanto, trata-se de vaso septocutâneo, sem a necessidade de dissecção de trajeto intramuscular. / The description of the skin flaps based on perforator vessels is recent. The vascularization of the anterolateral thigh flap is based on perforator vessels coming from the lateral circumflex femoral artery. It has a thin skin paddle, a long and large vascular pedicle and low donor site morbidity. However, the dissection of the intramuscular path of its pedicle is technically difficult. Its indication is sometimes questionable since it is a flap with characteristics similar to others based on direct cutaneous or septocutaneous vessels, which have less anatomical variations and are easier to dissect. This study evaluated the anatomical characteristics of the anterolateral thigh perforator flap through the dissection of fresh cadavers, comparing them with those of the parascapular and lateral arm skin flap. Sixty flaps were dissected (20 anterolateral thigh, 20 parascapular and 20 lateral arm flaps) in 20 fresh cadavers, not perfused with formaldehyde, less than 24 hours after death. The following aspects were evaluated in all the flaps: length of the vascular pedicle, thickness of the flap and diameter of the arterial and venous vascular pedicle. Additionally, the presence of the intramuscular path of the vascular pedicle was evaluated (only in the dissections of the anterolateral thigh flap). The comparative analysis showed that the vascular pedicle of the anterolateral thigh perforator flap is longer when compared to those of the parascapular and lateral arm flaps (p<0,001). The lateral arm flap presented a pedicle with smaller arterial and venous diameter (p<0,001), in addition to being the thinner flap (p<0,001). It was verified that the vascular pedicle of the anterolateral thigh flap presented an intramuscular path in 17 (85%) cases. The average length of the intramuscular segment of the main perforator vessel was 4,13+2,02 cm. The data was compared and evaluated with variance analysis. The information obtained allows one to conclude that the advantage the anterolateral thigh perforator flap has over the other skin flaps is a longer vascular pedicle. However, the need for intramuscular dissection of a segment of this pedicle presented itself in 85% of the cases. The lateral arm flap is the thinnest flap, and the one with the smaller arterial and venous diameter of its vascular pedicle. The parascapular flap has anatomical characteristics similar to those of the anterolateral thigh flap, with no evidence of a significant difference between their thicknesses and diameters of vascular pedicles. Its vascular pedicle is shorter when compared to that of the anterolateral thigh flap. On the other hand, it is a fasciocutaneous vessel, without the need for intramuscular dissection.

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