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1.
Fisioter. Bras ; 22(6): 837-849, Fevereiro 7, 2022.
Article in Portuguese | LILACS | ID: biblio-1358278

ABSTRACT

Nos lactentes, o sistema imunológico ainda é imaturo, o que torna as crianças mais suscetíveis ao vírus sincicial respiratório, o principal causador da bronquiolite. O Reequilíbrio Toraco-abdominal (RTA) é um método de terapia manual que atua sobre o sistema respiratório por meio de uma leitura global em situações de doenças. Objetivos: Avaliar os efeitos do método RTA, comparado à fisioterapia tradicional (FT) em lactentes com bronquiolite. Metodologia: Pesquisa experimental e prospectiva, na qual 24 lactentes foram divididos em dois grupos, FT (n = 12) e RTA (n = 12). Parâmetros fisiológicos (frequência respiratória, frequência cardíaca, saturação de pulso de oxigênio e ausculta pulmonar), desconforto respiratório e desequilíbrio da biomecânica respiratória foram avaliados antes e após os manuseios. Resultados: A idade média foi de 13 (± 11,07) semanas no grupo FT e no grupo RTA 13,3 (± 8,41) semanas. Após os manuseios, obteve diferença estatística no grupo do RTA comparado ao da FT nos seguintes parâmetros: observamos uma diminuição significativa da frequência cardíaca (p = 0,02) e da frequência respiratória (p = 0,0002), no quesito esforço respiratório em tórax superior (p = 0,004) e tórax inferior (p = 0,017) e no escore de Wood-Downes em moderada com (p = 0,0001). Conclusão: O RTA mostrou-se mais eficaz que as técnicas da FT em relação aos benefícios ao lactente. (AU)


Subject(s)
Infant , Respiratory System , Biomechanical Phenomena , Bronchiolitis , Respiratory Syncytial Viruses , Musculoskeletal Manipulations , Infant
2.
Fisioter. Bras ; v.22(4): 502-515, Nov 2, 2021.
Article in Portuguese | LILACS | ID: biblio-1353367

ABSTRACT

A dinapenia da musculatura ventilatória relaciona-se com as complicações respiratórias pós-operatórias e aos óbitos de idosos submetidos a procedimentos cirúrgicos de etiologia toracoabdominal. Objetivo: Verificar o efeito crônico do treinamento cardiorrespiratório sobre a força dos músculos ventilatórios de idosas. Métodos: Amostra (n = 24) randomizada nos grupos: controle (n = 8), treinamento ventilatório (n = 7) e treinamento cardiorrespiratório (n = 9). O desfecho primário (PImáx e PEmáx) foi medido por um manovacuômetro digital MDV®300 (MDI/Brasil). Rodou-se a estatística descritiva (média e desvio padrão), seguida de uma ANOVA 3x3 e o testes post-hoc de Bonferroni, todos com significância de (P ≤ 0,05). Resultados: O teste Post Hoc atestou diferença estatisticamente significativa do grupo treinamento cardiorrespiratório no reteste 1 e 2 quando comparados ao teste inicial (PImáx; P = 0,000001 e P = 0,0000001 respectivamente) e (PEmáx; P = 0,000000 em ambas as comparações). Conclusão: O treinamento cardiorrespiratório proposto foi capaz de aumentar significativamente a PImáx, PEmáx, resistência aeróbica e a força de membros inferiores das participantes deste ECR. (AU)


Subject(s)
Aged , Aged, 80 and over , Respiratory Function Tests , Muscle Strength , Respiratory Tract Infections , Biomechanical Phenomena , Respiratory Muscles , Aged , Exercise , Exercise Test
3.
Rev. bras. ortop ; 56(6): 683-688, Nov.-Dec. 2021.
Article in English | LILACS | ID: biblio-1357142

ABSTRACT

Abstract Congenital clubfoot is one of the most common deformities at birth. The inadequacy or absence of treatment causes serious limitations for people with this condition. The initial treatment using the Ponseti method ensures functional results superior to other treatment modalities previously proposed. However, recurrences and neglected feet are still a challenge today. An understanding of the pathophysiology of the disease, as well as of the anatomy and local biomechanics and a thorough clinical and radiological evaluation of patients are essential to understanding the limits of the method and choosing the best treatment.


Resumo O pé torto congênito é uma das deformidades mais comuns ao nascimento. A inadequação ou ausência do tratamento provoca sérias limitações aos portadores desta condição. O tratamento inicial pelo método Ponseti garante resultados funcionais superiores a outras modalidades de tratamento propostas anteriormente, porém as recidivas e os pés negligenciados ainda são um desafio na atualidade. O entendimento da fisiopatologia da doença, da anatomia e biomecânica local e uma minuciosa avaliação clínica e radiológica dos pacientes são imprescindíveis para entendermos o limite do método e escolhermos o melhor tratamento.


Subject(s)
Congenital Abnormalities , Biomechanical Phenomena , Foot Deformities , Clubfoot , Talipes/therapy
4.
Arq. ciências saúde UNIPAR ; 25(3): 213-220, set-out. 2021.
Article in Portuguese | LILACS | ID: biblio-1348213

ABSTRACT

O teste funcional Timed Up and Go (TUG) é amplamente utilizado para avaliar o risco de queda, através do equilíbrio e mobilidade, por ser de fácil aplicação e boa reprodutibilidade na prática clínica. Porém, o TUG ainda possui algumas limitações, pois se concentra no tempo total em que o teste é realizado. Uma proposta de avaliação é através da utilização de sensores inerciais, baseados na tecnologia de sistemas microeletromecânicos, e vem sendo muito utilizados para análise do movimento humano. Logo, o objetivo desse estudo foi realizar uma revisão narrativa sobre o uso dos sensores inerciais nas medidas temporais e cinemáticas do TUG e suas subfases. Metodologia: Essa revisão narrativa foi realizada nas bases de dados PubMed, CENTRAL, BVS e PEDro, por meio do vocabulário MeSH entre o período de maio a junho de 2020. Os critérios de inclusão foram estudos que utilizaram sensores inerciais para avaliação de medidas temporais e cinemáticas do TUG e suas subfases. Resultados: Foram incluídos 11 artigos de um total de 2305 achados. Desses, 5 utilizaram os sensores de smartphones. Não houve padronização em relação à quantidade utilizada, nem à fixação e posicionamento. Os sensores conseguiram mostrar diferenças no TUG e suas subfases nas medidas temporais e cinemáticas nos diferentes grupos avaliados. Considerações Finais: Sensores inerciais são capazes de avaliar medidas temporais e cinemáticas do TUG e de suas subfases, mostrando serem ferramentas confiáveis. Entretanto, mesmo obtendo resultados satisfatórios, necessita-se de mais estudos abrangendo uma população maior.


The Timed Up and Go (TUG) functional test is widely used to assess the risk of falling through balance and mobility since it is easy to apply and presents good reproducibility in clinical practice. However, the TUG test still has some limitations, as it focuses on the total time the test is performed. A proposal for evaluation is the use of inertial sensors, based on the microelectromechanical system technology, which has been widely used for the analysis of human movement. Therefore, the objective of this study was to carry out a narrative review on the use of inertial sensors in the temporal and kinematic measurements of TUG and its subphases. Methodology: This narrative review was carried out in the PubMed, CENTRAL, BVS, and PEDro databases using the MeSH vocabulary between the period of May to June 2020. The inclusion criteria were studies using inertial sensors to evaluate temporal and kinematic measurements of the TUG and its subphases. Results: A total of 11 articles were selected from 2305 hits. From these, five (5) used smartphone sensors. There was no standardization regarding the quantity used, nor their fixation and positioning. The sensors were able to show differences in the TUG and its subphases in the temporal and kinematic measurements in the different groups evaluated. Final Considerations: Inertial sensors are capable of evaluating temporal and kinematic measurements of the TUG and its subphases, showing that they are reliable tools. Nevertheless, although satisfactory results were obtained, further studies are needed covering a larger population.


Subject(s)
Technology/statistics & numerical data , Remote Sensing Technology/statistics & numerical data , Smart Materials , Biomechanical Phenomena , Accidental Falls/statistics & numerical data , Postural Balance , Mobility Limitation , Smartphone/statistics & numerical data
5.
Rev. bras. med. esporte ; 27(4): 381-385, Aug. 2021. tab, graf
Article in English | LILACS | ID: biblio-1288606

ABSTRACT

ABSTRACT Background: Objective: The study of sports biomechanics in sports medicine usually requires a special image analysis system (software) to obtain 3D kinematics data. Taking the swimming project in sports medicine as an example, 3D water images in water have always been relatively complicated and difficult. As light travels in different media, it will refract and reflect. When testing underwater movements, if only a land camera or an underwater camera is used for testing, the error caused by light refraction will be larger, which will affect the accuracy of the test data even more. Methods: Taking breaststroke movement as an example, a three-dimensional measurement method based on the Kwon3D movement analysis system is introduced. This method is different from the simple underwater camera test. It is a three-dimensional test method combining a land camera and an underwater camera. Two underwater cameras and two land cameras were used to simultaneously calibrate the water and underwater space with the same calibration frame in the experiment after analyzing and verifying the accuracy of 3D reconstruction. Results: The comprehensive reconstruction error is small, and the average relative error is less than 1%. Conclusions: The application of three-dimensional image analysis technology of vision systems in sports medicine is reasonable and worth promoting. Level of evidence II; Therapeutic studies - investigation of treatment results.


RESUMO Antecedente: Objetivo: O estudo da biomecânica do esporte na medicina esportiva geralmente requer o uso de um sistema especial de análise de imagens (software) para a obtenção de dados cinemáticos 3D. Tomando o projeto de natação na medicina esportiva como exemplo, a análise de imagens 3D da água na água sempre foi um teste relativamente complicado e difícil. À medida que a luz viaja em diferentes meios, ela refratará e refletirá. Ao testar movimentos subaquáticos, se apenas uma câmera terrestre ou subaquática for usada para o teste, o erro causado pela refração da luz será maior, o que afetará a precisão dos dados de teste ainda mais. Métodos: Tomando o movimento de nado peito como exemplo, um método de medição tridimensional baseado no sistema de análise de movimento Kwon3D é introduzido. Este método é diferente do teste simples de câmera subaquática. É um método de teste tridimensional que combina uma câmera terrestre e uma câmera subaquática. No experimento, duas câmeras subaquáticas e duas câmeras terrestres foram usadas para calibrar simultaneamente a água e o espaço subaquático com o mesmo quadro de calibração. Depois de analisar e verificar a precisão da reconstrução 3D. Resultados: O erro de reconstrução abrangente é pequeno e o erro relativo médio é inferior a 1% Conclusões: A aplicação da tecnologia de análise de imagem tridimensional do sistema de visão na medicina esportiva é razoável e vale a pena promover. Nível de evidência II; Estudos terapêuticos- investigação dos resultados do tratamento.


RESUMEN Antecedente: Objetivo: El estudio de la biomecánica del deporte en la medicina deportiva generalmente requiere el uso de un sistema de análisis de imágenes especial (software) para obtener datos de cinemática 3D. Tomando como ejemplo el proyecto de natación en medicina deportiva, el análisis de imágenes de agua en 3D en el agua siempre ha sido una prueba relativamente complicada y difícil. A medida que la luz viaja en diferentes medios, se refractará y reflejará. Al probar los movimientos bajo el agua, si solo se utiliza una cámara terrestre o una cámara submarina para realizar la prueba, el error causado por la refracción de la luz será mayor, lo que afectará aún más la precisión de los datos de la prueba. Métodos: tomando como ejemplo el movimiento de la brazada, se introduce un método de medición tridimensional basado en el sistema de análisis de movimiento Kwon3D. Este método es diferente de la simple prueba de cámara subacuática. Es un método de prueba tridimensional que combina una cámara terrestre y una cámara submarina. En el experimento, se utilizaron dos cámaras submarinas y dos cámaras terrestres para calibrar simultáneamente el agua y el espacio submarino con el mismo marco de calibración. Después de analizar y verificar la precisión de la reconstrucción 3D. Resultados: el error de reconstrucción integral es pequeño y el error relativo promedio es inferior al 1%. Conclusiones: La aplicación de la tecnología de análisis de imágenes tridimensionales del sistema de visión en la medicina deportiva es razonable y vale la pena promoverla. Nivel de evidencia II; Estudios terapéuticos- investigación de los resultados del tratamiento.


Subject(s)
Humans , Swimming/physiology , Video Recording/methods , Imaging, Three-Dimensional/methods , Biomechanical Phenomena/physiology , Algorithms , Calibration , Water
6.
Rev. bras. med. esporte ; 27(2): 218-224, Apr.-June 2021. tab, graf
Article in English | LILACS | ID: biblio-1280073

ABSTRACT

ABSTRACT Introduction: The use of ankle braces reduces the risk of ankle injuries in basketball players. However, the mechanisms of injury protection provided by the ankle braces in the basketball game are still unknown. Objectives: To analyze the effects of wearing a lace-up ankle brace, and to conduct an exercise protocol that simulated the intensity of the basketball game on ground reaction force (GRF) during basketball-specific vertical jumps. Methods: Eleven male younger basketball players aged under 18 completed 48 vertical jumps, with and without ankle braces, during an exercise protocol composed of four 10-minute periods, simulating the activity profile and intensity of the basketball game as well as the typical intervals between periods. Mediolateral (variables: the greatest medial and lateral peaks) and vertical (variables: vertical peak, impulse peak, impulse at 50 ms of landing, loading rate and jump height) GRF were measured during takeoff and landing for all the jumps performed in the exercise protocol. Results: The use of the ankle brace reduced mediolateral GRF in all periods of the exercise protocol during takeoff and landing ( P < 0.05), without affecting the vertical GRF ( P > 0.05). Mediolateral and vertical GRF (takeoff mediolateral vertical peaks, landing mediolateral peaks, landing impulse peak, takeoff and landing loading rate) increased significantly during four subsequent 10-minute periods ( P < 0.05). However, for mediolateral GRF, the increase overtime was higher without braces. Conclusions: The use of the ankle brace reduced the mediolateral GRF on the lower limb, while there was a progressive increase in the external load applied to the body during the vertical jumps in the subsequent periods of the exercise protocol performed at the same intensity of the basketball game. Level of evidence I; Randomized clinical trial .


RESUMEN Introducción: El uso de órtesis de tobillo reduce el riesgo de lesiones en el tobillo en jugadores de baloncesto. Sin embargo, los mecanismos de protección de lesión proporcionados por las órtesis durante el juego de baloncesto aún son desconocidos. Objetivos: Analizar el efecto del uso de órtesis de tobillo lace-up (con cordón) y de un protocolo de ejercicio que simuló la intensidad del juego de baloncesto sobre la fuerza de reacción del suelo (FRS) durante saltos verticales específicos del baloncesto. Métodos: Once jugadores de baloncesto del sexo masculino con menos de 18 años realizaron 48 saltos verticales, con y sin órtesis de tobillo, durante un protocolo de ejercicios compuesto por cuatro períodos de 10 minutos, que simularon el perfil de actividad e intensidad del juego de baloncesto, así como los intervalos típicos entre los períodos. Las FRS mediolaterales (variables: mayores picos medial y lateral) y verticales (variables: pico vertical, pico de impulso, impulso en 50 ms de aterrizaje, tasa de sobrecarga y altura del salto) fueron medidas durante las fases de despegue y aterrizaje de todos saltos realizados en el protocolo de ejercicio. Resultados: El uso de órtesis redujo la FRS mediolateral en todos los períodos analizados, durante las fases de despegue y aterrizaje (P < 0,05), sin afectar la FRS vertical (P > 0,05). La FRS mediolateral y vertical (picos mediolateral y vertical de despegue, picos mediolaterales de aterrizaje, pico de impulso de aterrizaje, tasa de sobrecarga en el despegue y aterrizaje) aumentaron significativamente durante cuatro períodos subsiguientes de 10 minutos (P < 0,05). Sin embargo, para la FRS mediolateral, el aumento a lo largo del tiempo fue mayor sin el uso de órtesis. Conclusiones: El uso de órtesis de tobillo redujo la FRS mediolateral en el miembro inferior, mientras que hubo un aumento progresivo de la carga externa aplicada al cuerpo durante los saltos en los períodos subsiguientes del protocolo de ejercicios con la misma intensidad del juego de baloncesto. Nivel de evidencia I; Ensayo clínico aleatorizado.


RESUMO Introdução: O uso de órtese de tornozelo reduz o risco de lesões no tornozelo em jogadores de basquetebol. No entanto, os mecanismos de proteção de lesão fornecidos pelas órteses durante o jogo de basquetebol ainda são desconhecidos. Objetivos: Analisar o efeito do uso de órtese de tornozelo lace-up (com cordão) e de um protocolo de exercício que simulou a intensidade do jogo de basquetebol sobre a força de reação do solo (FRS) durante saltos verticais específicos do basquetebol. Métodos: Onze jogadores de basquetebol do sexo masculino com menos de 18 anos realizaram 48 saltos verticais, com e sem órtese de tornozelo, durante um protocolo de exercícios composto por quatro períodos de 10 minutos, que simularam o perfil de atividade e intensidade do jogo de basquetebol, assim como os intervalos típicos entre os períodos. As FRSs mediolaterais (variáveis: maiores picos medial e lateral) e verticais (variáveis: pico vertical, pico de impulso, impulso em 50 ms da aterrissagem, taxa de sobrecarga e altura do salto) foram medidas durante as fases de decolagem e aterrissagem de todos os saltos realizados no protocolo de exercício. Resultados: O uso de órtese reduziu a FRS mediolateral em todos os períodos analisados, durante as fases de decolagem e aterrissagem (P < 0,05), sem afetar a FRS vertical (P > 0,05). A FRS mediolateral e vertical (picos mediolateral e vertical de decolagem, picos mediolaterais de aterrissagem, pico de impulso de aterrissagem, taxa de sobrecarga na decolagem e aterrissagem) aumentaram significativamente durante quatro períodos subsequentes de 10 minutos (P < 0,05). No entanto, para a FRS mediolateral, o aumento ao longo do tempo foi maior sem o uso de órtese. Conclusões: O uso de órtese de tornozelo reduziu a FRS mediolateral no membro inferior, enquanto houve um aumento progressivo da carga externa aplicada ao corpo durante os saltos nos períodos subsequentes do protocolo de exercícios com mesma intensidade do jogo de basquetebol. Nível de evidencia I; Estudo clínico randomizado .


Subject(s)
Humans , Male , Adolescent , Sprains and Strains/prevention & control , Basketball , Braces , Ankle Injuries/prevention & control , Biomechanical Phenomena , Ankle/physiology
7.
Rev. chil. ortop. traumatol ; 62(1): 46-56, mar. 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1342673

ABSTRACT

El manejo de la inestabilidad patelofemoral se basa en una adecuada evaluación de alteraciones anatómicas predisponentes. Patela alta es una de las causas más importantes de inestabilidad objetiva. La alteración biomecánica que ésta produce puede conducir a luxación patelar recurrente, dolor y cambios degenerativos focales. El examen físico es fundamental en la toma de decisiones. La evaluación imagenológica ha evolucionado desde métodos basados en radiografía hacia mediciones en resonancia magnética, que permiten una orientación más acabada de la relación existente entre la rótula y la tróclea femoral. El tratamiento se fundamenta en la corrección selectiva de los factores causales, donde la osteotomía de descenso de la tuberosidad anterior de la tibia y la reconstrucción del ligamento patelofemoral medial son herramientas que deben considerarse racionalmente. Este artículo realiza una revisión de la literatura, otorgando los fundamentos quirúrgicos que explican la importancia del tratamiento específico de patela alta en inestabilidad rotuliana.


Patellofemoral instability management is based on a thorough evaluation of predisposing anatomical factors. Patella alta is one of the utmost causes of objective instability. As a result, biomechanical disturbance can lead to recurrent patellar instability, pain, and focal degenerative changes. Physical examination is paramount in decision making. Imaging evaluation has evolved from X-rays based methods to magnetic resonance measurements, which allows a more accurate assessment of the patellotrochlear relationship. Treatment is based on a selective risk factors correction, where tibial tubercle distalization osteotomy and medial patellofemoral ligament reconstruction must be considered altogether. This article reviews the surgical rationale of patella alta treatment in patellofemoral instability.


Subject(s)
Humans , Osteotomy/methods , Patellar Dislocation/surgery , Patellofemoral Joint/surgery , Joint Instability/surgery , Osteotomy/adverse effects , Postoperative Care , Biomechanical Phenomena , Patellar Ligament/surgery , Knee Dislocation/diagnostic imaging , Patellofemoral Joint/diagnostic imaging , Joint Instability/diagnostic imaging
8.
Rev. bras. oftalmol ; 80(1): 71-76, jan.-fev. 2021. tab, graf
Article in Portuguese | LILACS | ID: biblio-1251315

ABSTRACT

RESUMO O artigo tem como objetivo descrever de forma prospectiva diferentes casos de ectasias altamente assimétricas (very asymmetric ectasia, VAE) para diferenciar formas subclínicas ou "frustas" do ceratocone (forme fruste keratoconus - FFKC) de casos de doença ectásica unilateral. O Caso 1 é um paciente de 39 anos, que admitiu ter coçado intensamente apenas o olho direito (OD) na juventude, se apresentando com ectasia unilateral tratada com sucesso por meio de implante de anel intraestromal em OD. O olho esquerdo (OE) apresentou-se normal ao exame completo por meio de propedêutica multimodal e acuidade visual não corrigida (AVsc) de 20/20, estável por mais de 5 anos, com TBI (tomography and biomechanical index) de 0.02. No Caso 2 é um paciente de 15 anos com ectasia clínica em OD, e OE com topografia normal, mas alterações tomográficas e biomecânicas, incluindo o TBI 0,56, caracterizarando a doença subclínica (FFKC). O Caso 3 é a mãe do paciente do Caso 2, de 46 anos, que se apresentou com presbiopia, sem qualquer histórico oftalmológico relevante. A AVsc foi de 20/20 em cada olho, topografia de Placido com leve encurvamento inferior, mas sem sinais definitivos de ectasia. A avaliação biomecânica e tomográfica revelou sinais de ceratocone em ambos os olhos, com TBI de 1,0 e 0,99. Esses três casos estão de acordo com a definição do consenso global e a hipótese de dois acertos (two-hit hypothesis), que ceratocone é uma doença bilateral, mas ectasia pode ocorrer por causa estritamente mecânica unilateralmente (ou em qualquer olho). A relevância da propedêutica multimodal é destacada, destacando-se a integração do estudo biomecânico e tomográfico com imagens de Scheimpflug.


ABSTRACT The article aims to prospectively describe different cases of highly asymmetric ectasia (very asymmetric ectasia, VAE) to differentiate subclinical or "frustrated" forms of keratoconus (forme fruste keratoconus - FFKC) from cases of unilateral ectatic disease. Case 1 is a 39-year-old patient with unilateral ectasia treated with an intrastromal ring implant. The contralateral eye was normal due to multimodal propaedeutics, stable for more than 3 years, with a TBI of 0.02. The patient admitted to having intensely scratched only his right eye in his youth. In Case 2, a 15-year-old patient with clinical ectasia in the right eye, had a left eye with normal topography and tomographic and biomechanical changes characterizing FFKC. Case 3 is the mother of the case 2 patient, aged 46, who presented with presbyopia, without any relevant ophthalmological history. Uncorrected visual acuity of 20/20 in each eye, Placido topography with slight lower curving, but without definitive signs of ectasia. The biomechanical and tomographic evaluation revealed signs of keratoconus in both eyes. These three cases are in accordance with the definition of the global consensus: keratoconus is a bilateral disease, but ectasia can occur because of strictly mechanical unilateral (in any eye). The relevance of multimodal refractive imaging is highlighted, with a focus on integrating biomechanical and tomographic assessments with Scheimpflug images.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Biomechanical Phenomena , Tomography/methods , Corneal Topography/methods , Dilatation, Pathologic , Keratoconus/diagnosis , Epidemiology, Descriptive
9.
Rev. Soc. Odontol. La Plata ; 31(61): 23-29, 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1354026

ABSTRACT

El reporte de este caso tiene como objetivo demostrar la utilidad de los anclajes esqueléticos temporarios como son las miniplacas cigomáticas y los microimplantes "buccal shelf" en el tratamiento ortodóncico, en una paciente de 17 años 10 meses de edad, clase II vertical, dólicofacial, con mordida abierta anterior y aumento de la altura facial inferior. Después de la primera fase de tratamiento, siguiendo la secuencia de arcos para completar la alineación, se utilizaron anclajes esqueléticos extrarradiculares con una mecánica de intrusión con fuerzas elásticas durante 10 meses. Se intruyeron sus piezas posteriores superiores e inferiores y se distalizó la arcada superior, corrigiéndose la oclusión. El mentón retrognático y su perfil convexo mejoraron con la autorrotación de la mandíbula (AU)


The objective of this report case is to demonstrate the usefulness of temporary skeletal anchors such as zygomatic miniplates and buccal shelf microimplants in orthodontic treatment, in a 17-year-old 10-month-old, vertical class II, dollicofacial patient with anterior open bite and increased lower facial height. After the first treatment phase, following the arch sequence to complete the alignment, extra-radicular skeletal anchors were used with intrusion mechanics with elastic forces for 10 months. Its upper and lower posterior pieces were intruded and the upper arch was distalized, correcting the occlusion. e retrognathic chin and its convex profile improved with autorotation of the jaw (AU)


Subject(s)
Humans , Male , Adolescent , Open Bite , Orthodontic Anchorage Procedures , Malocclusion, Angle Class II/therapy , Titanium , Tooth Movement Techniques , Biomechanical Phenomena , Dental Implants , Biotypology
10.
Conexões (Campinas, Online) ; 19: e021001, 2021.
Article in Portuguese | LILACS | ID: biblio-1292797

ABSTRACT

Objetivo: identificar as características e ações do goleiro de handebol diante de arremessos de longa (9m) e curta (6m) distâncias, a partir da opinião de treinadores brasileiros da categoria sub-16. Metodologia: foi utilizada uma abordagem qualitativa, a partir de entrevistas semiestruturadas com 19 treinadores de equipes masculinas e/ou femininas da categoria sub-16, que participaram de competições organizadas pelas duas maiores ligas de handebol do Estado de São Paulo. Os depoimentos foram tabulados e analisados com base no método do Discurso do Sujeito Coletivo (DSC). Resultados e Discussão: foram identificados quatro discursos: o DSC1 e o DSC3 apontaram a necessidade de o goleiro ser capaz de identificar as características técnico-táticas dos atacantes no momento do arremesso como forma de subsidiar a sua tomada de decisão; o DSC2 apontou a importância da colaboração entre goleiro e defensores; e o DSC4 apontou possíveis ações do goleiro que visam diminuir as possibilidades de arremesso do atacante. Considerações Finais: O estudo apresentou como considerações finais algumas diretrizes que os treinadores podem utilizar para planejar o treinamento dos goleiros de handebol durante o seu processo de formação esportiva.


Objective: The aim of this work was to identify the characteristics and actions of the handball goalkeeper for long (9m) and short (6m) pitches, based on the opinion of Brazilian coaches of the U-16 teams. Methodology: A qualitative approach was used, based on semi-structured interviews with 19 male and / or female team coaches in the sub-16 category, who participated in competitions organized by the two largest leagues in the State of São Paulo. The speeches were tabulated and analyzed based on the Collective Subject Discourse (CSD) method. Results and discussion: Four CSD were identified: CSD1 and CSD3 pointed out the need for the goalkeeper to be able to identify the technical-tactical characteristics of the attackers in the shot to support his decision making; CSD2 showed the importance of collaboration between goalkeepers and defenders; and CSD4 pointed out possible actions by the goalkeeper that aim to reduce the attacker's chances of shooting. Final considerations: The study presented as final considerations some guidelines that coaches can use to plan the training of handball goalkeepers during their sports training process.


Objectivo: El objetivo de esta investigación fue identificar las características y acciones del portero de balonmano para lanzamientos largos (9m) y cortos (6m), en base a la opinión de los entrenadores brasileños en la categoría cadete. Metodología: Se utilizó un enfoque cualitativo, basado en entrevistas semiestructuradas con 19 entrenadores de equipos masculinos y/o femeninos en la categoría cadete, que participaron en competiciones organizadas por las dos ligas más grandes del Estado de São Paulo. Las declaraciones fueron tabuladas y analizadas en base al método de Discurso del Sujeto Colectivo (DSC). Resultados y discusión: Se identificaron cuatro discursos: DSC1 y DSC3 señalaron la necesidad de que el portero pueda identificar las características técnico-tácticas de los atacantes en el tiro para apoyar su toma de decisiones; DSC2 señaló la importancia de la colaboración entre porteros y defensores; y DSC4 señaló posibles acciones del portero que tienen como objetivo reducir las posibilidades de disparo del atacante. Consideraciones finales: El estudio presentó como consideraciones finales algunas pautas que los entrenadores pueden usar para planificar el entrenamiento de los porteros de balonmano durante su proceso de entrenamiento deportivo.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Decision Making , Distance Perception , Athletic Performance , Youth Sports , Mentoring , Team Sports , Biomechanical Phenomena , Qualitative Research
11.
Rev. Asoc. Argent. Ortop. Traumatol ; 86(5) (Nro Esp - AACM Asociación Argentina de Cirugía de la Mano): 666-680, 2021.
Article in Spanish | LILACS, BINACIS | ID: biblio-1353974

ABSTRACT

El objetivo de este artículo es actualizar los conocimientos sobre la impactación cubitocarpiana y su tratamiento. Estudios clásicos sobre la biomecánica del borde cubital de la muñeca han demostrado que los cambios milimétricos en la relación de longitud entre el cúbito y el radio alteran significativamente la transferencia de cargas entre los huesos del carpo, el radio y el cúbito. Así, un aumento relativo en la longitud del cúbito generará una carga excesiva sobre la articulación cubitocarpiana que producirá un espectro de cambios degenerativos progresivos en el domo cubital, el semilunar, el piramidal y el complejo del fibrocartílago triangular que finalizarán con artrosis cubitocarpiana y radiocubital distal. La impactación cubitocarpiana, en sus diversos estadios degenerativos, se puede tratar mediante osteotomías que buscan descomprimir la carga cubitocarpiana. Las osteotomías pueden ser extrarticulares o intrarticulares. Entre las extrarticulares, están las diafisarias, las metafisarias sin exposición articular (subcapitales) y las metafisarias distales con exposición articular y, entre las intrarticulares, la cirugía de resección en oblea (wafer), que reseca cartílago y hueso subcondral del domo cubital, y puede ser un procedimiento abierto o artroscópico. Si hay artrosis radiocubital distal, solo se podrá tratar con cirugías de rescate, como Darrach, Sauvé-Kapandji, Bowers, o una prótesis radiocubital distal. Estas técnicas de osteotomía se han analizado detalladamente para lograr definir sus ventajas y desventajas. Finalmente se propone una forma de tipificar la impactación cubitocarpiana, cuyo objetivo es orientar al lector hacia el mejor tratamiento posible, avalado por la bibliografía actual. Nivel de Evidencia: V


The purpose of this article is to provide updated knowledge about ulnocarpal impaction syndrome (UCIS) and its treatment. Classic studies on biomechanics of the ulnar side of the wrist have shown that millimetrical changes in the relative lengths of the ulna and the radius significantly alter the load transmission between the carpal bones, the radius and the ulna. Thus, an increase in the relative length of the ulna will generate an excessive load on the ulnocarpal joint, which will produce a spectrum of progressive degenerative changes in the ulnar dome, lunate, triquetrum, and the triangular fibrocartilage complex (TFCC), that will lead to ulnocarpal and distal radioulnar joint (DRUJ) osteoarthritis. In its various degenerative stages, UCIS can be treated with osteotomies that seek to decompress the ulnocarpal load. These can be extra-articular or intra-articular. Within the extra-articular osteotomies, we find the diaphyseal, metaphyseal without joint exposure (subcapital), and the distal metaphyseal with joint exposure. Within the intra-articular ones, we find the wafer procedure, which resects the cartilage and subchondral bone of the ulnar dome, and can be performed either openly or arthroscopically. If there is associated DRUJ osteoarthritis, it can only be treated with salvage surgeries such as the Darrach, Sauvé-Kapandji, and Bowers procedures, or a DRUJ arthroplasty. These osteotomy techniques will be analyzed in detail in order to define their advantages and disadvantages. Finally, we propose a way to typify the UCIS to guide the reader towards the best possible treatment supported by current literature. Level of Evidence: V


Subject(s)
Osteotomy , Ulna/surgery , Ulna/injuries , Wrist Injuries/surgery , Biomechanical Phenomena , Triangular Fibrocartilage
12.
Rev. Asoc. Argent. Ortop. Traumatol ; 86(5) (Nro Esp - AACM Asociación Argentina de Cirugía de la Mano): 681-695, 2021.
Article in Spanish | LILACS, BINACIS | ID: biblio-1353975

ABSTRACT

La reparación primaria de los tendones flexores en la zona II ha sido un desafío desde el surgimiento de la cirugía de la mano como especialidad luego de la Segunda Guerra Mundial. Desde Bunnell hasta hoy, la forma de operar y rehabilitar estos tendones ha evolucionado y cambiado considerablemente gracias a estudios anatómicos, biológicos y, sobre todo, mecánicos. Actualmente la técnica quirúrgica se basa en realizar una sutura fuerte y prolija, que no sufra fricción dentro de la vaina y que tolere la carga necesaria para la movilidad activa del dígito sin resistencia. Se han descrito múltiples configuraciones de puntos con diferentes materiales. Operando con anestesia local, la prueba de flexo-extensión activa intraoperatoria revela la resistencia del tipo de sutura elegida y ha cobrado importancia para definir el protocolo de rehabilitación. El tratamiento de los flexores en la zona II es, hasta el momento, un conjunto inseparable de técnica quirúrgica y rehabilitación asociada. La manipulación farmacológica del proceso biológico reparador es el principal campo de investigación actual


Primary flexor tendon repair in zone II has been a challenge since the emergence of hand surgery as a specialty after World War II. From Bunnell to today, the way of operating and rehabilitating these tendons has evolved and changed considerably thanks to anatomical, biological and --above all --mechanical studies. Currently, the surgical technique is based on performing a strong and neat suture, which does not suffer friction within the sheath and which tolerates the load necessary for the active motion of the finger without resistance. Multiple suture configurations with different materials have been described. Under local anesthesia, the intraoperative active flexion-extension test reveals the resistance of the type of suture chosen and has gained importance in defining the rehabilitation protocol. Treatment of flexors in zone II is, so far, an inseparable set of surgical technique and a suitable rehabilitation protocol. Biological strategies to enhance the tendon healing process are currently the main field of research


Subject(s)
Rehabilitation , Tendon Injuries/surgery , Biomechanical Phenomena , Reconstructive Surgical Procedures , Finger Injuries/surgery
13.
Braz. oral res. (Online) ; 35: e064, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1249380

ABSTRACT

Abstract: Sixty moderately curved canals of mandibular molars classified as Vertucci's type IV canal configuration were selected by micro-CT 1174. The teeth were divided into two groups according to the kinematics used, whether reciprocating or rotary motion (n=30, totaling 60 mesial root canals). The instruments used to perform the glide path procedures had identical features (0.15 mm of tip size, 0.04 mm/mm taper, thermal treatment, and square cross-section), but differed in the direction of the cutting blade. The duration of the procedure and the absolute and percentage frequency of the instruments to reach the full working length were recorded. The torsional test (3630-1; 1992) was performed on both used and unused instruments, to evaluate a possible reduction in the torsional resistance when using the glide path procedure. Statistical analysis was performed using the unpaired t-test and the chi-square test, and the level of significance was set at 5%. The type of kinematics used affected the duration of glide path procedures, and the reciprocating motion seemed to induce less torsional stress during glide path procedures.


Subject(s)
Root Canal Preparation , Dental Pulp Cavity , Biomechanical Phenomena , Equipment Design , X-Ray Microtomography , Molar/diagnostic imaging
14.
CoDAS ; 33(6): e20200102, 2021. tab, graf
Article in Portuguese | LILACS | ID: biblio-1286140

ABSTRACT

RESUMO Objetivo Sintetizar o estado do conhecimento científico sobre biomecânica da língua durante a deglutição após laringectomia total. Estratégia de pesquisa Formulou-se a questão PICO e combinações de descritores e termos livres para busca nas bases de dados PubMed/Medline, EMBASE, LILACS e SciELO. Critérios de seleção incluíram-se artigos nos idiomas português, inglês ou espanhol; sem limite de tempo; com resultados sobre a biomecânica da língua durante a deglutição em laringectomizados totais; e estudos do tipo ensaio clínico randomizado ou não randomizado, coorte, caso controle, transversal, série de casos e estudos de caso. Análise dos dados analisou-se ano, país, população, objetivo, delineamento do estudo, instrumentos de avaliação, principais desfechos e qualidade metodológica. Resultados Foram incluídos quatro estudos realizados nos Estados Unidos, um na Austrália e um no Brasil, publicados entre 1986 e 2014. Em todos os estudos incluídos a biomecânica da língua foi um desfecho secundário. A maioria dos artigos teve baixa qualidade metodológica, com amostras pequenas, predomínio do sexo masculino e desenho transversal prevalente. Os instrumentos de avaliação foram videofluoroscopia, manometria, acelerômetro ou dispositivo para captar pressão de língua. Resultados principais indicaram mais força de propulsão da base de língua para superar a alta resistência da neofaringe ao fluxo do bolo alimentar; redução do contato e pressão entre base de língua e parede posterior da faringe; resíduo em base de língua após deglutição; pressão aumentada e resistência reduzida da língua oral. Conclusão Existem indícios de movimentos compensatórios de língua durante a deglutição após laringectomia total, porém, as evidências científicas são insuficientes.


ABSTRACT Purpose To synthesize the state of scientific knowledge about biomechanics of the tongue during swallowing after total laryngectomy. Research strategy The PICO question and combinations of descriptors and single terms were formulated in the PubMed/Medline, EMBASE, LILACS, and SciELO databases. Selection criteria Articles in Portuguese, English, or Spanish were included, without time limit, with results on the biomechanics of the tongue during swallowing and total laryngectomy, and studies on randomized or non-randomized clinical trials, cohort, case control, cross-sectional, case series, and case studies. Data analysis year, country, population, objective, study design, assessment methods, main outcomes, and methodological quality were analyzed. Results There were four studies in the United States, one in Australia, and one in Brazil, all published between 1986 and 2014. In all studies, the biomechanics of the tongue was the secondary outcome. Most articles had low methodological quality, small samples, predominance of the male gender, and a prevalent cross-sectional design. The assessment instruments were fluoroscopy, manometry, accelerometer or a device to capture tongue pressure. Main results indicated a higher propulsion force of the tongue base to overcome the high resistance of the neopharynx to the bolus flow, reduced contact and pressure between the base of the tongue and the posterior pharyngeal wall, residues in the tongue base after swallowing, increased pressure, and reduced resistance of the oral tongue. Conclusion There are indications of compensatory tongue movements during swallowing after total laryngectomy; however, the scientific evidence is insufficient.


Subject(s)
Humans , Male , Deglutition Disorders/etiology , Deglutition , Pressure , Tongue , Biomechanical Phenomena , Brazil , Cross-Sectional Studies , Laryngectomy
15.
CoDAS ; 33(5): e20200203, 2021. tab
Article in Portuguese | LILACS | ID: biblio-1286129

ABSTRACT

RESUMO Objetivo Diversos comprometimentos da deglutição têm sido relatados em indivíduos com doença pulmonar obstrutiva crônica (DPOC), tendo como causa a desvantagem mecânica da musculatura respiratória devido à hiperinsuflação. Dentre as estratégias terapêuticas, até o momento, não foram encontrados relatos na literatura sobre o uso da terapia manual (TM) no manejo dos transtornos da deglutição nesta população. O objetivo do estudo foi verificar os desfechos de um programa de TM sobre a biomecânica da deglutição de indivíduos com DPOC. Método Foram avaliados 18 indivíduos com idade média 66,06±8,86 anos, 61,1% (11) homens e VEF1%médio 40,28±16,73 antes e após-programa de TM. As medidas analisadas foram: tempo de trânsito oral, tempo de trânsito faríngeo (TTF), número de deglutições, resíduos em valéculas (VL) e seios piriformes, penetração/aspiração e excursão hiolaríngea na deglutição das consistências líquida e pastosa. Resultados Houve diferença significativa no TTF (p=0,04), resíduos em VL (p=0,03), elevação máxima do hioide (p=0,003) e deslocamento do hioide (p=0,02) na deglutição da consistência pastosa. Na consistência líquida apenas redução de resíduos em VL (p=0,001). Conclusão O programa de TM interferiu na biomecânica da deglutição de indivíduos DPOC demonstrada pela redução do TTF, resíduos em VL e maior elevação e deslocamento do hioide na consistência pastosa. Na consistência líquida houve redução de resíduos em VL.


ABSTRACT Purpose Several swallowing disorders have been reported in chronic obstructive pulmonary disease (COPD) patients due to the mechanical disadvantage of the respiratory muscles caused by hyperinflation. To date, no reports have been found in the literature among the therapeutic strategies on the use of manual therapy (MT) to manage swallowing disorders in COPD. The aim of the study was to verify the outcomes of a TM program on the biomechanics of swallowing of individuals with COPD. Methods 18 individuals with a mean age of 66.06 ± 8.86 years, 61.1% (11) men, and a FEV1% mean of 40.28 ± 16.73 were evaluated before and after TM. The measures analyzed were: oral transit time, pharyngeal transit time (PTT), number of swallows, vallecular (VL) residue and pyriform sinuses, penetration/aspiration and hyolaryngeal excursion in liquid and pasty consistencies. Results A significant difference was found in PTT (p=0.04), VL residue (p=0.03), maximal hyoid elevation (p=0.003), and displacement of hyoid (p=0.02) in the pasty consistency. In the liquid consistency, we found a decrease in VL residue (p=0.001). Conclusion The MT program influenced the swallowing biomechanics of COPD patients demonstrated by a reduction in PTT and VL residue and increased hyoid elevation and displacement in the pasty consistency. In the liquid consistency, a decrease in VL residue was found.


Subject(s)
Humans , Male , Middle Aged , Aged , Deglutition Disorders/etiology , Deglutition Disorders/therapy , Pulmonary Disease, Chronic Obstructive/therapy , Musculoskeletal Manipulations , Biomechanical Phenomena , Deglutition , Middle Aged
16.
Braz. j. med. biol. res ; 54(5): e10693, 2021. tab, graf
Article in English | LILACS | ID: biblio-1153555

ABSTRACT

The present study compared the effects of a footwear designed to enhance energy return (thermoplastic polyurethane, TPU) vs minimalist shoes on running economy (RE) and endurance performance. In this counterbalanced and crossover design study, 11 recreational male runners performed two submaximal constant-speed running tests and two 3-km time-trials with the two shoe models. Oxygen uptake was measured during submaximal constant-speed running tests in order to determine the RE at 12 km/h and oxygen cost of running (CTO2) at individual average speed sustained during the 3-km running time-trials wearing either of the two shoes. Our results revealed that RE was improved (2.4%) with TPU shoes compared with minimalist shoes (P=0.01). However, there was no significant difference for CTO2 (P=0.61) and running performance (P=0.52) comparing the TPU (710±60 s) and the minimalist (718±63 s) shoe models. These novel findings demonstrate that shoes with enhanced mechanical energy return (i.e. TPU) produced a lower energy cost of running at low (i.e., 12 km/h) but not at high speeds (i.e., average speed sustained during the 3-km running time-trial, ∼15 km/h), ultimately resulting in similar running performance compared to the minimalist shoe.


Subject(s)
Male , Running , Oxygen Consumption , Shoes , Biomechanical Phenomena , Cross-Over Studies
17.
Clinics ; 76: e2358, 2021. tab, graf
Article in English | LILACS | ID: biblio-1249574

ABSTRACT

OBJECTIVES: In the present study, a novel single knot tenorrhaphy was developed by combining the modified Kessler flexor tendon suture (MK) with the loop lock technique. METHODS: A total of 48 porcine flexor digitorum profundus tendons were collected and randomly divided into six groups. The tendons were transversely cut and then repaired using six different techniques, the MK method, double knot Kessler-loop lock flexor tendon suture (DK), and single knot Kessler-loop lock flexor tendon suture (SK), each in combination with the epitendinous suture (P), and the same three techniques without P. Furthermore, by performing the load-to-failure tests, the biomechanical properties and the time taken to complete a repair, for each tenorrhaphy, were assessed. RESULTS: Compared to the MK+P method, DK+P was more improved, thereby enhancing the ultimate tensile strength. The SK+P method, which required fewer knots than DK+P, was easier to perform. Moreover, the SK+P repair increased the force at a 2-mm gap formation, while requiring lesser knots than DK+P. CONCLUSION: As opposed to the traditional MK+P method, the SK+P method was improved and exhibited better biomechanical properties, which may facilitate early mobilization after the repair.


Subject(s)
Animals , Sutures , Suture Techniques , Swine , Tendons/surgery , Tensile Strength , Biomechanical Phenomena
18.
Braz. oral res. (Online) ; 35: e003, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132743

ABSTRACT

Abstract: The present study investigated the intracanal decontamination and apical extrusion of bacteria and debris from root canals instrumented with rotary and reciprocating systems (ProDesign Logic or ProDesign R), with different file diameters and using conventional syringe irrigation (CSI) or passive ultrasonic irrigation (PUI). Eighty extracted mandibular premolars were contaminated with Enterococcus faecalis and randomly assigned to eight experimental groups according to the root canal instrumentation and irrigation technique employed (n = 10): G1: Prodesign Logic 25.06; G2: Prodesign R 25.06; G3 and G4 were instrumented with the same single-file systems, respectively, using 35.05 diameters and CSI. G5, G6, G7, and G8 were instrumented like the previous groups, but with PUI. Apically extruded debris during instrumentation was collected into pre-weighed microtubes. The weight of the empty microtube was subtracted from the final weight to establish the amount of extruded debris. Bacteria from root canals and extruded debris were collected for a microbiological evaluation of colony forming units (CFU/mL). For statistical analyses, the Mann-Whitney and Kruskal-Wallis followed by the Dunn's tests were used (α = 0.05). All instruments caused extrusion of debris. For irrigation techniques, PUI promoted greater debris and bacterial extrusion (p < 0.05). The CFU/mL count indicated that the instrumentation of the experimental groups were equally effective in the decontamination of the root canal (p > 0.05). The systems tested (regarding file diameter and kinematics) were associated with similar amounts of apically extruded debris and root canal decontamination. PUI was associated with greater debris and bacterial extrusion.


Subject(s)
Humans , Root Canal Preparation , Tooth Apex , Ultrasonics , Biomechanical Phenomena , Decontamination , Dental Pulp Cavity
19.
Clinics ; 76: e2803, 2021. tab, graf
Article in English | LILACS | ID: biblio-1278922

ABSTRACT

OBJECTIVES: To evaluate the clinical characteristics, ground reaction force (GRF), and function of the plantar muscles and dorsiflexors of the ankle in runners with and without Achilles tendinopathy (AT) and in non-runners. METHODS: Seventy-two participants (42 men, 30 women; mean age: 37.3±9.9 years) were enrolled in this cross-sectional study and divided into three groups: AT group (ATG, n=24), healthy runners' group (HRG, n=24), and non-runners' group (NRG, n=24). Both ankles were evaluated in each group. The American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale was used for clinical and functional evaluation. GRF was evaluated using force plates and muscle strength was evaluated using an isokinetic dynamometer. RESULTS: The AOFAS scores were lower in the ATG. The strike impulse was higher in the ATG than in the HRG and NRG. However, GRF was similar among the groups. The ATG exhibited lower total work at 120°/s speed than the HRG. The peak torque in concentric dorsiflexion was lower in the NRG than in the ATG and HRG. The peak torque and total work in concentric plantar flexion were lower in the NRG than in the ATG. The peak torque and total work in eccentric plantar flexion were lower in the NRG than in the ATG and HRG. CONCLUSION: Runners with AT showed higher strike impulse, lower muscle strength of the plantar flexors, and higher clinical and functional damage.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Achilles Tendon , Tendinopathy , Biomechanical Phenomena , Cross-Sectional Studies , Muscle, Skeletal , Torque , Muscle Strength , Ankle , Ankle Joint
20.
Journal of Biomedical Engineering ; (6): 1097-1102, 2021.
Article in Chinese | WPRIM | ID: wpr-921850

ABSTRACT

Atherosclerotic plaque rupture is the main cause of many cardiovascular diseases, and biomechanical factors play an important role in the process of plaque rupture. In the study of plaque biomechanics, there are relatively few studies based on fatigue fracture failure theory, and most of them mainly focus on the whole fatigue propagation process from crack initiation to plaque rupture, while there are few studies on the influence of crack on plaque rupture at a certain time in the process of fatigue propagation. In this paper, a two-dimensional plaque model with crack was established. Based on the theory of fracture mechanics and combined with the finite element numerical simulation method, the stress intensity factor (SIF) and related influencing factors at the crack tip in the plaque were studied. The SIF was used to measure the influence of crack on plaque rupture. The results show that the existence of crack can lead to local stress concentration, which increases the risk of plaque rupture. The SIF at the crack tip in the plaque was positively correlated with blood pressure, but negatively correlated with fibrous cap thickness and lipid pool stiffness. The effect of the thickness and angle of lipid pool on the SIF at the crack tip in the plaque was less than 4%, which could be ignored. This study provides a theoretical basis for the risk assessment of plaque rupture with cracks.


Subject(s)
Biomechanical Phenomena , Computer Simulation , Humans , Plaque, Atherosclerotic , Stress, Mechanical
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