Comportamiento Mecánico de un Premolar Humano Sano Sometido a Fuerzas Funcionales y Disfuncionales en un MEF / Mechanical Behavior of a Healthy Human Premolar Subjected to Functional and Dysfunctional Forces in a FEM

El propósito de este estudio fue analizar el comportamiento mecánico de la estructura dental sana de un primer premolar inferior humano sometido a fuerzas funcionales y disfuncionales en diferentes direcciones. Se buscó comprender, bajo las variables contempladas, las zonas de concentración de esfuerzos que conllevan al daño estructural de sus constituyentes y tejidos adyacentes. Se realizó el modelo 3D de la reconstrucción de un archivo TAC de un primer premolar inferior, que incluyó esmalte, dentina, ligamento periodontal y hueso alveolar considerando tres variables: dirección, magnitud y área de la fuerza aplicada. La dirección fue dirigida en tres vectores (vertical, tangencial y horizontal) bajo cuatro magnitudes, una funcional de 35 N y tres disfuncionales de 170, 310 y 445 N, aplicadas sobre un área de la cara oclusal y/o vestibular del premolar que involucró tres contactos estabilizadores (A, B y C) y dos paradores de cierre. Los resultados obtenidos explican el fenómeno de combinar tres vectores, cuatro magnitudes y un área de aplicación de la fuerza, donde los valores de esfuerzo efectivo equivalente Von Mises muestran valores máximos a partir de los 60 MPa. Los valores de tensión máximos se localizan, bajo la carga horizontal a 170 N y en el proceso masticatorio en la zona cervical, cuando la fuerza pasa del 60 %. Sobre la base de los hallazgos de este estudio, se puede concluir que la reacción de los tejidos a fuerzas funcionales y disfuncionales varía de acuerdo con la magnitud, dirección y área de aplicación de la fuerza. Los valores de tensión resultan ser más altos bajo la aplicación de fuerzas disfuncionales tanto en magnitud como en dirección, produciendo esfuerzos tensiles significativos para la estructura dental y periodontal cervical, mientras que, bajo las cargas funcionales aplicadas en cualquier dirección, no se generan esfuerzos lesivos. Esto supone el reconocimiento del poder de detrimento estructural del diente y periodonto frente al bruxismo céntrico y excéntrico.

SUMMARY: The purpose of this study was to analyze the mechanical behavior of the healthy dental structure of a human mandibular first premolar subjected to functional and dysfunctional forces in different directions. It was sought to understand, under the contemplated variables, the areas of stress concentration that lead to structural damage of its constituents and adjacent tissues. The 3D model of the reconstruction of a CT file of a lower first premolar was made, which included enamel, dentin, periodontal ligament and alveolar bone considering three variables: direction, magnitude and area of the applied force. The direction was directed in three vectors (vertical, tangential and horizontal) under four magnitudes, one functional of 35 N and three dysfunctional of 170, 310 and 445 N, applied to an area of the occlusal and/or buccal face of the premolar that involved three stabilizing contacts (A, B and C) and two closing stops. The results obtained explain the phenomenon of combining three vectors, four magnitudes and an area of force application, where the values of effective equivalent Von Mises stress show maximum values from 60 MPa. The maximum tension values are located under the horizontal load at 170 N and in the masticatory process in the cervical area, when the force exceeds 60%. Based on the findings of this study, it can be concluded that the reaction of tissues to functional and dysfunctional forces varies according to the magnitude, direction, and area of application of the force. The stress values turn out to be higher under the application of dysfunctional forces both in magnitude and in direction, producing significant tensile stresses for the dental and cervical periodontal structure, while under functional loads applied in any direction, no damaging stresses are generated. This supposes the recognition of the power of structural detriment of the tooth and periodontium against centric and eccentric bruxism.

Diagnostic utility of 31 ECG criteria for predicting echocardiographic left ventricular geometry / Utilidad diagnóstica del ECG para predecir la geometría del ventrículo izquierdo por ecocardiograma

Abstract Objective: To explore the diagnostic utility of 31 electrocardiogram (ECG) criteria for detecting echocardiographic (Echo) left ventricular geometry using accuracy. Methods: This cross-sectional study included consecutive adults (> 18 years) that were classified by Echo left ventricular geometry as normal (NL), concentric remodeling (CR), concentric hypertrophy (CH), and eccentric hypertrophy (EH). Thirty-one state-of-the-art ECG criteria for Echo left ventricular hypertrophy were calculated. AUC 95%CI, accuracy, sensitivity, specificity, and positive and negative predictive value for detecting Echo left ventricular geometries were compared. Multivariable linear regression models were produced using the ECG criteria as the dependent variable. Results: A total of 672 adults were included in the study. From 31 ECG criteria, Cornell (ECG21, SV3 + RaVL) and modified Cornell (ECG 31, RaVL + deepest S in all leads) criteria have the best overall AUC in differentiating NL versus CH (0.666 and 0.646), NL versus EH (0.686 and 0.656), CR versus CH (0.687 and 0.661), and CR versus EH (0.718 and 0.676). In multivariable linear regression models, CH and EH had the strongest effect on the final voltage in Cor- nell (ECG21) and modified Cornell (ECG31). Conclusions: From 31 state-of-the-art criteria, Cornell and modified Cornell criteria have the best AUC and accuracy for predicting most left ventricular geometries. CH and EH had the strongest effect on the voltage of Cornell and modified Cornell criteria compared to body mass index, age, diabetes, hypertension, and chronic heart disease. The ECG criteria poorly differentiate NL from CR and CH from EH.

Resumen Objetivo: Explorar la utilidad diagnóstica de 31 criterios de ECG para detectar la geometría ecocardiográfica del ventrículo izquierdo usando la exactitud, área bajo la curva, sensibilidad, especificidad, y valor predictivo positivo y negativo. Métodos: Este estudio transversal incluyó adultos (> 18 años) que se sometieron a ECG y ecocardiograma transtorácico. Los pacientes fueron clasificados según la geometría del ventrículo izquierdo: normal (NL), remodelado concéntrico (RC), hipertrofia concéntrica (HC) e hipertrofia excéntrica (HE). Se calcularon 31 criterios clásicos de ECG para detectar hipertrofia ventricular izquierda y se comparó el rendimiento diagnóstico en cada geometría. Creamos un modelo de regresión lineal múltiple usando los criterios de ECG como variable dependiente. Resultados: Se incluyeron 672 adultos. Los criterios de Cornell (ECG 21, SV3 + RaVL) y Cornell modificado (ECG31, RaVL + S mas profunda de las 12 derivaciones) tienen el mejor AUC para diferenciar NL versus HC (0.666 y 0.646), NL versus HE (0.686 y 0.656), RC versus HC (0.687 y 0.661) y RC versus HE (0.718 y 0.676). En el análisis multivariado la geometría del ventrículo izquierdo (HC e HE) fue la variable que mas influyó en el resultado final del criterio de Cornell y de Cornell modificado. Conclusión: De los 31 criterios clásicos explorados, los criterios de Cornell y Cornell modificado tienen el mejor AUC y exactitud para predecir la mayoría de las geometrías del ventrículo izquierdo. Los criterios del ECG no diferencian bien la geometría NL del RC ni HC de la HE.

Avaliação isocinética da força de contração excêntrica dos músculos isquiotibiais no período pré-operatório de pacientes com lesão de ligamento cruzado anterior / Isokinetic assessment of eccentric hamstring strength in the preoperative period of patients with anterior cruciate ligament injury

Introdução: A força de contração excêntrica é uma moderna medida para definir diferentes parâmetros no estudo da Ortopedia moderna, sendo considerada uns dos recentes temas mais discutidos no quesito ganho de força muscular. O objetivo do trabalho foi analisar o estado da musculatura flexora da coxa (isquiotibiais), através da avaliação de sua força de contração excêntrica, por meio do dinamômetro isocinético no período pré-operatório nos pacientes com lesão de ligamento cruzado anterior. Métodos: Estudo retrospectivo observacional entre agosto e dezembro de 2018 de uma clínica especializada em atendimento em Criciúma/SC. Resultados: A média do pico de torque excêntrico da musculatura posterior da coxa em flexão do membro afetado foi de 27,60 ± 10,56 kg, e do membro contralateral atingiu 27,47 ± 6,91 kg. O déficit de força entre os membros teve uma mediana de 9,14 % (0,0 - 61,45), e o tempo médio entre a lesão e o exame isocinético foi de 10,0 (1,0 - 48,0) meses. Observou-se que os maiores déficits de força foram encontrados naqueles indivíduos que tinham maior intervalo de tempo entre a lesão e a realização da avaliação isocinética. Conclusão: Nos indivíduos submetidos ao teste de dinamometria isocinética após lesão do ligamento cruzado anterior, evidenciou-se um déficit na força de contração excêntrica da musculatura isquiotibial entre o membro afetado e contralateral, o que ratifica achados da literatura a respeito da biomecânica articular do joelho. Além disso, maiores déficits foram encontrados naqueles pacientes com maior intervalo de tempo para realização do exame isocinético.

Introduction: Eccentric strength is a modern measurement for defining different parameters in the study of modern orthopaedics, being considered one of the most widely discussed topics in recent times within the subject of muscle strength gain. The aim of this work was to analyze the state of flexor muscles in the thigh (hamstring muscles) by evaluating their eccentric strength with an isokinetic dynamometer during the preoperative period of patients with anterior cruciate ligament injury. Methods: This is a retrospective observational study performed between August and December 2018 at a specialized clinic in Criciúma/SC. Results: The mean eccentric peak torque of the hamstring muscles during flexion of the affected limb was 27.60 ± 10.56 kg and that for the contralateral limb was 27.47 ± 6.91 kg. The strength deficit between limbs had a median value of 9.14% (0.0­61.45) and the mean time between the injury and isokinetic testing was 10.0 (1.0­48.0) months. Higher strength deficits were observed in individuals who had longer periods between the injury and isokinetic testing. Conclusion: In individuals who underwent isokinetic testing after an anterior cruciate ligament injury, there was a deficit between the eccentric hamstring strength of the affected limb and that of the contralateral limb, which corroborates findings in the literature regarding the biomechanics of the knee joint. Moreover, larger deficits were found in patients with longer periods between the injury and isokinetic testing.

Effects of eccentric exercise on muscle architecture in adults: a systematic review / Efectos del ejercicio excéntrico en la arquitectura muscular en adultos: una revisión sistemática

SUMMARY: The purpose of this systematic review was to determine the effects of eccentric training on muscle architecture in the adult population. Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statements were followed using keywords associated with architecture muscular and eccentric training. Four databases were used: PubMed, Scopus, SPORTDiscus and Web of Science. Methodological quality was assessed using the PEDro scale. A total of 1260 articles were retrieved, 18 included in this review. The parameters most frequently evaluated in the studies consulted were pennation angle (PA), fascicle length (FL), and muscle thickness (MT). These were assessed mainly in lower limb muscles such as biceps femoris long head (BFlh), vastus lateralis (VL), medial gastrocnemius (MG) and lateral gastrocnemius (LG), respectively. Eccentric training for at least four weeks generates adaptations in these parameters, mainly by increasing MT with FL and decreasing PA, determining muscle function. These results provide evidence on the effects of eccentric training on muscle architecture, which could be helpful to prevent injuries and favor muscle recovery processes.

RESUMEN: El propósito de esta revisión sistemática fue determinar los efectos del entrenamiento excéntrico sobre la arquitectura muscular en la población adulta. Se siguieron las recomendaciones del Ìtems de referencia para publicar Revisiones Sistemáticas y Metaanálisis (PRISMA) utilizando palabras clave asociadas con la arquitectura muscular y el entrenamiento excéntrico en cuatro bases de datos: PubMed, Scopus, SPORTDiscus y Web of Science. La calidad metodológica se evaluó mediante la escala PEDro. Se encontró un total de 1260 artículos, del los cuales, 18 fueron incluidos en esta revisión. Los parámetros más frecuentemente evaluados en los estudios fueron el ángulo de penación (AP), la longitud del fascículo (LF) y el grosor muscular (Gm). Estos fueron evaluados principalmente en músculos de los miembros inferiores como la cabeza larga del bíceps femoral (CLBf), el vasto lateral (VL), el gastrocnemio medial (GM) y el gastrocnemio lateral (GL), respectivamente. El entrenamiento excéntrico durante al menos cuatro semanas genera adaptaciones en estos parámetros, principalmente aumentando el GM con la LF y disminuyendo el AP, determinando de esta manera la función muscular. Estos resultados aportan evidencias sobre los efectos del entrenamiento excéntrico en la arquitectura muscular, que podrían ser útiles para prevenir lesiones y favorecer los procesos de recuperación muscular.

La fase excéntrica-concéntrica y el índice de fuerza reactiva en el salto con contra movimiento en voleibolistas / A fase excêntrica-concêntrica e o índice de força reativa no salto de contra-movimento nos jogadores de vôlei / The eccentric-concentric phase and the index of strength reactivates in the jump with counter movement in volleyball players

RESUMEN El trabajo que se presenta tiene como objetivo analizar la relación existente entre la fase excéntrica-concéntrica y el índice de fuerza reactiva en el salto vertical con contra movimiento del equipo de voleibol, de la primera categoría de La Habana. Para ello, se hace referencia al significado de los diferentes componentes de la contracción muscular en la actividad deportiva, así como otros tipos de contracciones musculares para el trabajo dinámico. Los métodos empleados fueron de nivel teórico y empírico, tales como histórico-lógico, inductivo-deductivo, análisis-síntesis, revisión documental, la medición y los matemáticos-estadísticos; estos últimos para la tabulación y arribo de resultados. Se utilizó el método de puntuación de McCall para determinar la evaluación de los indicadores seleccionados, donde se tiene en cuenta los valores observados por encima de la media, los cuales tienen puntuaciones estándar positivas, mientras que los valores por debajo de la media tienen puntuaciones estándar negativas. Se realiza una comparación con otras investigaciones, sobrepasando en el caso de los varones por 0.8 cm. Con respecto a la media cubana, hay una diferencia de 0.7 cm. con respecto a la media española de 0.13 cm. y al analizar la referencia internacional, la diferencia está entre 8 y 13 cm. La información alcanzada facilitó la correcta planificación y su intensificación en las cargas con pesas en la zona de fuerza máxima, rápida y explosiva para el incremento del salto vertical en los atletas de voleibol, reflejado en el resultado competitivo del equipo.

RESUMO O objetivo deste trabalho é analisar a relação entre a fase excêntrica-concêntrica e o índice de força reativa no salto vertical com contra-movimento da equipe de vôlei da primeira categoria de Havana. Para este fim, é feita referência ao significado dos diferentes componentes da contração muscular na atividade esportiva, assim como outros tipos de contrações musculares para o trabalho dinâmico. Os métodos utilizados foram de nível teórico e empírico, tais como histórico-lógico, indutivo-dedutivo, análise-síntese, revisão documental, medição e matemática-estatística; este último para a tabulação e chegada dos resultados. O método de pontuação de McCall foi usado para determinar a avaliação dos indicadores selecionados, onde os valores observados acima da média são levados em consideração, que têm pontuação padrão positiva, enquanto os valores abaixo da média têm pontuação padrão negativa. É feita uma comparação com outras pesquisas, superando em 0,8 cm no caso dos homens. Em relação à média cubana, há uma diferença de 0,7 cm. em relação à média espanhola de 0,13 cm. e quando se analisa a referência internacional, a diferença está entre 8 e 13 cm. As informações obtidas facilitaram o planejamento correto e sua intensificação nas cargas com pesos na zona de força máxima, rápida e explosiva para o aumento do salto vertical em atletas de vôlei, refletido no resultado competitivo da equipe.

ABSTRACT The aim of this work is to analyze the relationship between the eccentric-concentric phase and the reactive strength index in the vertical jump with countermovement of the first category volleyball team in Havana. For this purpose, reference is made to the meaning of the different components of muscular contraction in sports activity, as well as other types of muscular contractions for dynamic work. The methods used were theoretical and empirical, such as historical-logical, inductive-deductive, analysis-synthesis, documentary review, measurement and mathematical-statistical; the latter for the tabulation and arrival of results. McCall's scoring method was used to determine the evaluation of the selected indicators, where the values observed above the mean are taken into account, which have positive standard scores, while the values below the mean have negative standard scores. A comparison is made with other research, exceeding in the case of males by 0.8 cm. With respect to the Cuban average, there is a difference of 0.7 cm. with respect to the Spanish average of 0.13 cm. and when analyzing the international reference, the difference is between 8 and 13 cm. The information achieved facilitated the correct planning and its intensification in the loads with weights in the zone of maximum, fast and explosive strength for the increase of the vertical jump in volleyball athletes, reflected in the competitive result of the team.

Advance in Neural Control in Eccentric Exercise (review) / 中国康复理论与实践

The nervous system controls eccentric exercise in a special way. During eccentric exercise, excitability increases in cortex, and inhibition decreases, causing excitability decrease in spinal cords. In another hand, increased cortical excitability results in extra excitatory compensation for spinal inhibition. The excitability of the corticospinal pathway depends on the balance between excitability and inhibition of the spinal cord level finally, which usually decreases. Many factors, such as the intensity of contraction, can affect the balance of corticospinal excitability. There is a cross-over effect in eccentric exercise, which promotes corticospinal excitability in untrained limbs. However, the effects and mechanisms of muscle length, fatigue and training duration are still unclear, and current researches have focused in the healthy populations. More researches are needed to explore the effects of eccentric exercise on ill populations.

Effect of Eccentric Exercises on Knee Function and Neuromuscular Control of Patellofemoral Pain Syndrome / 中国康复理论与实践

Objective:To investigate the effect of eccentric exercise training on knee function and neuromuscular control in patients with patellofemoral pain syndrome. Methods:From September, 2016 to September, 2019, 39 outpatients with patellofemoral pain syndrome visiting our hospital were randomly divided into control group (n = 19) and experimental group (n = 20). Both groups received routine rehabilitation, while the experimental group received eccentric training of quadriceps femoris in addition, for eight weeks. They were assessed with Visual Analogue Scale (VAS) of pain, Lysholm score, while the acceleration time was measured with Isokinetic Testing and Training System, and stability index with Dynamic Balance Tester. Results:The VAS score, acceleration time of all the muscles, and overall, anterior-posterior and medial-lateral stability indexes decreased (t > 2.521, P < 0.05), and the Lysholm score increased (|t| > 13.628, P < 0.001) in both groups after treatment, while the VAS score, acceleration time of all the muscles, overall and anterior-posterior stability indexes were less (|t| > 2.174, P < 0.05), and the Lysholm score was more (t = 11.947, P < 0.001) in the experimental group than in the control group. Conclusion:Eccentric exercise training of quadriceps femoris is effective on pain, knee function and neuromuscular control for patients with patellofemoral pain syndrome.

Multifocal electroretinogram manifestation of strabismic amblyopia with eccentric central fixation / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To explore the characteristic changes of multifocal electroretinogram(mfERG)in strabismic amblyopia eyes with eccentric fixation.<p>METHODS: A total of 20 patients with strabismus amblyopia and eccentric fixation visited our hospital from January 2018 to December 2020 were collected as the study group(4 patients with exotropia and 16 patients with esotropia), while 20 patients with ametropic amblyopia were collected as the control group. The mfERG was examined under the state of mydriasis, and the amplitude density and incubation period of P1 wave were recorded.<p>RESULTS: Compared with the fellow eyes, the first ring(<i>P</i>=0.001), the second ring(<i>P</i><0.001), the third ring(<i>P</i>=0.001), the fourth ring(<i>P</i>=0.009)and the fifth ring(<i>P</i>=0.026)of strabismus amblyopia eyes were reduced significantly. Compared with the control group, the first ring(<i>P</i>=0.033), the second ring(<i>P</i>=0.002), the third ring(<i>P</i><0.001)and the fourth ring(<i>P</i>=0.014)of strabismus amblyopia eyes were reduced significantly. The incubation period of amblyopia eyes in the strabismus group showed significantly shortened in the first ring(<i>P</i>=0.017)and the second ring(<i>P</i>=0.001)compared with the fellow eyes, and in the second ring(<i>P</i>=0.007)compared with the control group.<p>CONCLUSION: The amplitude density of mfERG P1 wave in strabismic amblyopia eyes with eccentric fixation reduced more with the closer to macular fovea, and reduced more significantly than that in the ametropic amblyopia eyes.

Research progress of microstrabismus / 国际眼科杂志(Guoji Yanke Zazhi)

@#Microstrabismus is a kind of small angle strabismus, sometimes negative in cover test, accompanied by clinical characteristics such as abnormal retinal correspondence, eccentric fixation, amblyopia and rough stereopsis. Microstrabismus amblyopia treatment is very difficult, especially in eccentric fixation. In daily diagnosis and treatment, the microstrabismus often misdiagnosed due to the small squint degree and the negative coverage test, failed to be treated properly and in-time, the patient's eccentric fixation and fixation instability also been ignored, treated as normal amblyopia, while the result is not effective, sometimes even leads opposite effect, so it's important to recognize the microstrabismus.

Comparison of drop jump force-time profiles of team sport athletes and active controls

Abstract Aim: Lower-body non-contact injuries in team sport athletes (TSAs) are associated when absorbing force, during cutting and landing movements due to a lack of eccentric strength and decreased neuromuscular control leading to excessively higher joint forces. Thus, this project aimed to identify if TSAs had different acceleration and deceleration force profiles compared to a control group (non-TSA) when performing drop jumps (DJs). Methods: University TSAs (n = 15) and non-TSAs (n = 10) performed a series of DJs from a 39 cm box onto a force-plate. All data were normalized to the individual's body mass. Between-group differences in ground reaction force (GRF), rate of force development (RFD), and propulsive and breaking impulses were compared via t-tests and standardized differences. Results: TSAs had significantly, and meaningfully greater RFD than the non-TSAs (p < 0.01, Hedges' g (ES) = 1.24, 53%). While not statistically significant, the non-TSA group produced practically larger mean GRFs than TSAs (p = .09, ES = 0.72, 12.1%). No significant or meaningful between-group differences were detected for propulsive impulse (p = 0.08, ES = 0.41, 9.1%), braking impulse (p = 0.85, ES = 0.25, 4.6%), or impulse ratio (p = 0.35, ES = 0.21, 6.7%). Conclusions: This study shows the presence of significant RFD differences during the DJ in TSAs compared to non-TSAs. Furthermore, this investigation also showed there was no difference between TSA and students in GRF and impulse metrics. Implications from these findings suggest that TSAs can produce force rapidly, but deceleration metrics were not different from untrained students.

Effect of aquatic exercise after eccentric contraction-induced muscle injury / Efeito do exercício aquático depois de lesão muscular provocada por contração excêntrica / Efecto del ejercicio acuático después de una lesión muscular por contracción excéntrica

ABSTRACT Introduction: Muscle microlesions produced by eccentric contractions (EC) cause changes in strength, endurance, power and neuromuscular activity parameters for an extended period of time. Objectives: To investigate the effect of aquatic exercise after EC-induced muscle injury on strength, endurance, power and neuromuscular activity parameters. Methods: A cross-sectional experimental study with six subjects (age 25 ± 4 years, weight 77 ± 4kg and height of 162 ± 2 cm) with EC-induced muscle injury followed up during a recovery period (48h, 72h and 96h) without intervention (Group 1A) and involving aquatic exercises (Group 1B). Dynamic and isometric strength, muscular endurance, and vertical/horizontal power tests as well as vastus lateralis neuromuscular activity measurements were performed before, immediately after, and during the recovery period. Results: Our results indicate that the intervention in Group 1B, when compared to Group 1A, accelerated the recovery of dynamic (p <0.01) and isometric (p <0.03) strength at 48h and 72h, increased vertical power at 48h (p <0.05) and horizontal power at 48h and 72h (p <0.05), and reduced neuromuscular activity (p <0.05) at 48h and 72h after EC. Conclusions: According to our findings, performing aquatic exercises during the recovery period improves muscle efficiency and accelerates strength, power and neuromuscular activity recovery. Level of evidence l; Randomized clinical trial.

RESUMO Introdução: As microlesões musculares geradas por contrações excêntricas (CE) provocam alterações dos parâmetros de força, resistência, potência e atividade neuromuscular por período prolongado. Objetivos: Investigar o efeito do exercício aquático depois de lesão muscular provocada por CE sobre os parâmetros força, resistência, potência e atividade neuromuscular. Métodos: Estudo experimental cruzado com seis indivíduos (idade 25 ± 4 anos, peso 77 ± 4 kg e altura 162 ± 2 cm) com lesão muscular por CE e acompanhados durante um período de recuperação (48 h, 72 h e 96 h) sem intervenção (Grupo 1A) e envolvendo exercícios aquáticos (Grupo 1B). Antes, imediatamente e durante o período de recuperação foram realizados testes de força dinâmica, isométrica, resistência muscular, potência vertical/horizontal e mensuração da atividade neuromuscular do músculo vasto lateral. Resultados: Nossos resultados apontam que a intervenção no Grupo 1B, em comparação com o Grupo 1A, acelerou a recuperação da força dinâmica (p < 0,01) e isométrica (p < 0,03) nos tempos de 48 h e 72 h, aumentou a potência vertical no tempo de 48 h (p < 0,05) e a horizontal nos tempos de 48 h e 72 h (p < 0,05) e reduziu a atividade neuromuscular (p < 0,05) nos tempos de 48 h e 72 h depois de CE. Conclusões: De acordo com nossos achados, apontamos que os exercícios aquáticos durante o período de recuperação melhoram a eficiência muscular e aceleram a recuperação de força, potência e atividade neuromuscular. Nível de evidência l; Estudo clínico randomizado

RESUMEN Introducción: Las microlesiones musculares generadas por contracciones excéntricas (CE) provocan alteraciones de los parámetros de fuerza, resistencia, potencia y actividad neuromuscular por período prolongado. Objetivos: Investigar el efecto del ejercicio acuático después de una lesión muscular provocada por CE sobre los parámetros fuerza, resistencia, potencia y actividad neuromuscular. Métodos: Estudio experimental cruzado con seis individuos (edad 25±4 años, peso 77±4kg y altura 162±2cm) con lesión muscular por CE y acompañados durante un período de recuperación (48h, 72h y 96h) sin intervención (Grupo 1A) e involucrando ejercicios acuáticos (Grupo 1B). Antes, inmediatamente después y durante el período de recuperación, fueron realizados tests de fuerza dinámica, isométrica, resistencia muscular, potencia vertical/horizontal y medición de la actividad neuromuscular del músculo vasto lateral. Resultados: Nuestros resultados apuntan que la intervención en el Grupo 1B, en comparación con el Grupo 1A, aceleró la recuperación de la fuerza dinámica (p<0,01) e isométrica (p<0,03) en 48h y 72h, aumentó la potencia vertical en el tiempo de 48h (p<0,05) y la horizontal en los tiempos de 48h y 72h (p<0,05) y redujo la actividad neuromuscular (p<0,05) en los tiempos de 48h y 72h después de la CE. Conclusiones: De acuerdo con nuestros hallazgos, apuntamos que los ejercicios acuáticos durante el período de recuperación mejoran la eficiencia muscular y aceleran la recuperación de fuerza, potencia y actividad neuromuscular. Nivel de evidencia l; Estudio ensayo clínico aleatorizado.

Modificaciones anatómicas del ventrículo izquierdo en deportistas de canotaje de alto rendimiento / Anatomical modifications of the left ventricle in high performance canoeing athletes

Introducción: La adaptación del corazón humano al acondicionamiento físico ha sido un tema de interés médico-científico, pues el remodelado cardíaco que comprende variación en el tamaño, forma, grosor de las paredes, y masa ventricular responde al tipo de actividad física. Objetivo: Determinar las modificaciones anatómicas del ventrículo izquierdo en kayacistas y canoístas femeninos y masculinos de alto rendimiento. Material y Métodos: Se realizó un estudio prospectivo, descriptivo de corte transversal en deportistas de canotaje de alto rendimiento que acudieron al Instituto de Medicina del Deporte durante la preparación especial con vistas a participar en los Juegos Olímpicos de Rio de Janeiro 2016. La muestra se conformó con 20 deportistas que cumplieron los criterios de inclusión establecidos, se recogieron los resultados de los diferentes parámetros ecocardiográficos que fueron estudiados para comprobar si existía modificación anatómica del ventrículo izquierdo (MAVI). Se empleó la estadística descriptiva e inferencial. Resultados: Edad promedio 20,9 ± 1,18 años, predominio del sexo masculino (65 por ciento); kayak (60 por ciento) y velocidad (55 por ciento) fueron las disciplinas deportivas y modalidades competitivas predominantes , fue frecuente la hipertrofia concéntrica en ambos sexos (65 por ciento), la edad deportiva de igual o menos de 10 años (60 por ciento), espesor relativo de la pared aumentado (65 por ciento), el índice AKS mayor se encontró en la hipertrofia excéntrica (1,3 por ciento) y el porciento de grasa predominante fue en la hipertrofia concéntrica para un (7,9 por ciento). Conclusiones: El espesor relativo de la pared ventricular tuvo una relación significativa con la modalidad competitiva(AU)

Introduction: The adaptation of the human heart to physical conditioning has been a medical and scientific topic of interest where cardiac remodeling involving changes in size, form, thickness of the walls and ventricular mass responds to the type of physical activity. Objective: To determine the anatomical modifications of the left ventricle in high performance male and female canoeing and kayaking athletes. Material and methods: A prospective, descriptive, cross-sectional study was conducted in high performance canoeing athletes that attended the Instituto de Medicina del Deporte during the special training in view of the preparation for the Olympic Games in Rio de Janeiro, 2016. The sample was composed of 20 athletes that fulfilled the established inclusion criteria. The results of the different echocardiographic parameters were collected and analyzed in order to check whether there were anatomical modifications of the left ventricle (AMLV). Differential and descriptive statistics were used. Results: The average age was 20, 9 ± 1, 18 years, the male sex predominated in the study (65 percent), kayak (60 percent) and velocity (55 percent) were the predominant sports disciplines and competitive modalities, respectively. Concentric hypertrophy in both sexes (65 percent), sporting age of 10 years or less (60 percent), and increase in relative wall thickness (65 percent) were frequent; the highest AKS index was found in eccentric hypertrophy (1,3 percent) and predominant fat percentage was observed in concentric hypertrophy (7,9 percent). Conclusions: The relative thickness of the ventricular wall had a significant relationship with the competitive modalities(AU)

Study Of Variations In Human Placental Attachment Of Umbilical Cord And Its Clinical Significance

Introduction: The word placenta comes from Latin - flat cake and Greek -”Plakous” which means “flat, slab like.”Only eutherian mammals possess placenta. The human placenta is discoid, hemochorial and deciduate whichfunctions as a fetomaternal organ. It is developed from chorion frondosum & decidua basalis. Abnormalities inthe development and site of insertion of the umbilical cord can affect maternal and fetal well-being. The umbilicalcord is usually attached near the centre of the placenta. The various types of umbilical cord attachment into theplacenta are: central, eccentric, battledore (marginal), velamentous (membranous) and furcate. Hence knowledgeabout the variations in the placental attachment of umbilical cord is important for clinicians.Aims and Objectives: The present study is undertaken to study various types of placental attachment of umbilicalcord.Materials and methods: The study was carried out on 10% formalin fixed 100 normal human placenta collectedfrom department of Obstetrics and Gynaecology, Cheluvamba Hospital for children & women, Mysore medicalcollege and research institute, Mysuru, Karnataka. The study was carried out in department of Anatomy, MMC&RI,Mysuru. Study of various types of placental attachment of umbilical cord was done by naked eye observation.The data obtained was tabulated & statistically analysed.Observations and Results: Out of 100 placenta observed 68 placenta had central attachment of umbilical cord,16 placenta had eccentric attachment, 12 placenta had battledore (marginal) attachment and 04 placenta hadmembranous (velamentous) attachment.Conclusion: Variation in the placental attachment of umbilical cord is associated with various congenitalanomalies. Therefore early prenatal ultrasonographic identification of anomalies helps in reducing risk inmaternal and perinatal outcome.

Knee Pain Presenting As Lumbar Radiculopathy: A Case Report

Background: Knee pain in general and if to be specific is the pain located anteriorly, and it is widespread among teenage, adults, and the old age population. Among the anterior knee pain etiologies, patellofemoral pain is one of the most common causes of knee pain. One of the significant issues with the patellofemoral pain is that most of the time it is misdiagnosed, or it is underrated for patients' problems, which in the long run lead to severe functional limitations and muscular atrophy. Right clinical diagnosis at an early phase in musculoskeletal conditions is vital. Case summary: The patient presented with chief complaints of diffused pain over right leg tracking it over to the lower back. She presented with a painful limping gait. No tenderness was noted over the lower back; the neural tension test was nonsignificant. Patellar compression test, Clark's test, eccentric step was positive. Severe disuse quadriceps muscular atrophy was noted over-involved limb. Tenderness over the retropatellar surface was significant. The patient was managed with cryotherapy at home, therapeutic ultrasound over the tender area along with Kinesio tapping, proprioception exercises, stretching, and strengthening exercises. Outcome measure: Pain, ROM, girth measurement, gait pattern. Significant improvement was noted in pain on NPS, ROM, and gait pattern in two weeks management. Conclusion: The Physiotherapy management in cases of anterior knee pain, specifically patellofemoral pain, mainly consisting of kinesiotaping, therapeutic ultrasound, cryotherapy, therapeutic exercises are very effective provided right clinical diagnosis, is made. The treatment outcome may be more fruitful if the correct clinical diagnosis is made at an early stage.

La inmersión en agua fría no reduce los marcadores de daño muscular en nadadores / Immersion in cold water does not reduce markers of muscle damage in swimmers / Efeito da imersão em água fria sobre os marcadores de dano muscular (CK; LDH) devidos ao exercício excêntrico em nadadores de Medellin

Objetivo: determinar el efecto de la inmersión en agua fría sobre los marcadores de daño muscular inducidos por el ejercicio excéntrico. Metodología: estudio cuasi-experimental, con 15 hombres nadadores, 10 en el grupo de tratamiento y 5 en el grupo control. Luego del protocolo excéntrico, con 2 series de 10 repeticiones en extensión de rodilla, el grupo de tratamiento tuvo 15 minutos de inmersión en agua fría, a 15 °C ± 1 °C, y el grupo control tuvo 15 minutos de inmersión en agua termoneutra, a 32 °C ± 1 °C. Las variables (CK, LDH, salto vertical, potencia y percepción del dolor) se registraron a las 24, 48 y 72 horas posteriores a la intervención. Resultados: la inmersión en agua fría no tiene efectos estadísticamente significativos en la reducción de los marcadores de daño muscular.

Objective: To determine the effect of immersion in cold water on markers of muscle damage induced by eccentric exercise. Methodology: Quasi-experimental study, with 15 male swimmers, 10 in the treatment group and 5 in the control group. After the eccentric protocol, with 2 series of 10 repetitions in knee extension, the treatment group had 15 minutes of immersion in cold water, at 15 °C ± 1 °C, and the control group had 15 minutes of immersion in thermoneutral water, at 32 °C ± 1 °C. The variables (CK, LDH, vertical jump, power and pain perception) were recorded at 24, 48 and 72 hours after the intervention. Results: Immersion in cold water has no statistically significant effects in reducing markers of muscle damage.

Objetivo: Determinar o efeito da imersão em água fria sobre os marcadores de dano muscular induzido por exercício excêntrico. Metodologia: Estudo quase experimental, 15 homens nadadores, 10 no grupo de tratamento e 5 no grupo de controle. Após o protocolo excêntrico (2 séries de 10 repetições na extensão do joelho), o grupo de tratamento teve 15 minutos de imersão em água fria a 15 ° C ± 1 ° C e o grupo controle teve 15 minutos de imersão em água termo-neutra a 32 ° C ± 1 ° C. As variáveis (CK, LDH, salto vertical, potência e percepção da dor) foram registradas nas 24, 48 e 72 horas após a intervenção. Resultados: A imersão em água fria não tem efeitos estatisticamente significativos na redução dos marcadores de dano muscular.

Corrección del queratocono con microlentes de alta excentricidad / Correction of keratoconus with highly eccentric microlenses

La adaptación de lentes de contacto en queratocono avanzado se torna compleja por la gran excentricidad de la zona apical. El lente de contacto rígido de diámetro pequeño con curva posterior parabólica o hiperbólica (diseño de alta excentricidad) es una excelente opción para el queratocono con ectasias de diámetro pequeño y alta elevación. Permite proteger la zona apical del cono y hace confortable la adaptación del lente en pacientes que aún no justifican una queratoplastia. El objetivo de este trabajo es mostrar cómo una adecuada adaptación permite retrasar o evitar una cirugía de alta complejidad para el paciente(AU)

The adaptation of contact lenses to treat advanced keratoconus is complex due to the great eccentricity of the apical area. The small diameter rigid contact lenses with parabolic or hyperbolic posterior curve (high eccentricity design) are an excellent choice for keratoconus with small diameter and highly elevated ectasias. It allows protecting the apical area of the cone and makes the adaptation of the lens more comfortable in those patients who do not require keratoplasty yet. The objective of this work is to show how an appropriate adaptation allows to retard or to avoid a surgery of high complexity for the patient(AU)

Application Progress of Eccentric Exercise Training in Rehabilitation(review) / 中国康复理论与实践

This article introduced the characteristics of eccentric contraction and its mechanism,as well as its application in the re-habilitation of chronic heart disease,chronic obstructive pulmonary disease,sports injuries,elderly sarcopenia,anterior cruciate ligament repair,cancer survivor,type 2 diabetes and nervous system diseases,etc.

Response of macrophages in rat skeletal muscle after eccentric exercise / 中华创伤杂志(英文版)

<p><b>PURPOSE</b>Macrophages are known to be important for healing numerous injured tissues depending on their functional phenotypes in response to different stimuli. The objective of this study was to reveal macrophage phenotypic changes involved in exercise-induced skeletal muscle injury and regeneration.</p><p><b>METHODS</b>Adult male Sprague-Dawley rats experienced one session of downhill running (16° decline, 16 m/min) for 90 min. After exercise the blood and soleus muscles were collected at 0 h, 6 h, 12 h, 1 d, 2 d, 3 d, 1 w and 2 w after exercise, separately.</p><p><b>RESULTS</b>It was showed that CD68 M1 macrophages mainly infiltrated into muscle necrotic sites at 1-3 d, while CD163 M2 macrophages were present in muscles from 0 h to 2 weeks after exercise. Using transmission electron microscopy, we observed activated satellite cells 1 d after exercise. Th1-associated transcripts of iNOS and Ccl2 were inhibited post exercise, while COX-2 mRNA was dramatically increased 12 h after running (p < 0.01). M2 phenotype marker Arg-1 increased 12 h and 3 d (p < 0.05, p < 0.01) after exercise, and Clec10a and Mrc2 were up-regulated in muscles 12 h following exercise (p < 0.05, p < 0.05).</p><p><b>CONCLUSION</b>The data demonstrate the dynamic patterns of macrophage phenotype in skeletal muscle upon eccentric exercise stimuli, and M1 and M2 phenotypes perform different functions during exercise-induced skeletal muscle injury and recovery.</p>

Design of longitudinal auto-tracking of the detector on X-ray in digital radiography / 生物医学工程学杂志

One algorithm is designed to implement longitudinal auto-tracking of the the detector on X-ray in the digital radiography system (DR) with manual collimator. In this study, when the longitudinal length of field of view (LFOV) on the detector is coincided with the longitudinal effective imaging size of the detector, the collimator half open angle ( ), the maximum centric distance ( ) between the center of X-ray field of view and the projection center of the focal spot, and the detector moving distance for auto-traking can be calculated automatically. When LFOV is smaller than the longitudinal effective imaging size of the detector by reducing , the can still be used to calculate the detector moving distance. Using this auto-tracking algorithm in DR with manual collimator, the tested results show that the X-ray projection is totally covered by the effective imaging area of the detector, although the center of the field of view is not aligned with the center of the effective imaging area of the detector. As a simple and low-cost design, the algorithm can be used for longitudinal auto-tracking of the detector on X-ray in the manual collimator DR.

Time to task failure of the contralateral untrained limb after high load-low repetition eccentric and low load-high repetition resistance training

Abstract Aims: Cross-training is the process whereby training of one limb gives rise to enhancements in the performance of the opposite, untrained limb and may be dependent on type of muscle contractions performed. The aim of this study was to investigate whether unilateral resistance training using eccentric contraction is more effective than concentric resistance training to improve time to task failure in the contralateral untrained limb. Methods:Subjects completed 12 weeks of resistance training consisting of 36 sessions, using unilateral leg exercise. Sustained isometric knee extension performed at 50% of maxmal force until task failure for the contralateral untrained leg. Surface electromyography (EMG) signals were simultaneously recorded from contralateral untrained quadriceps (vastusmedialis, rectus femoris, and vastuslateralis). Results: Time to task failure of the contralateraluntrained leg and associated EMG activitiessignificantly increased after 12 weeks ofunilateral resistance training(p<0.05). However, percent increase in time to task failure and EMG amplitude after eccentric resistance training was significantly higher than concentric resistance training (p<0.05). Conclusion: This study concluded that unilateral eccentric resistancetraining is superior to concentric resistance training to increase time to task failure in the contralateral untrained limb.(AU)