132 research outputs found

    Effects of isokinetic eccentric training on knee extensor and flexor torque and on gait of individuals with long term ACL reconstruction: A controlled clinical trial

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    Abstract-This study investigated the effects of the isokinetic eccentric training (IET) on the knee extensor and flexor torque and kinematic gait parameters in individuals with ACL reconstruction. Sixteen men with ACL reconstructed (ACLr) whose torque and the gait were evaluated, before and after 12 weeks of IET, was compared to a control group (14 individuals). Student t, MANOVA and ANOVA tests were performed with 5% of significance. The training increased the isometric, concentric at 30 and 120º/s (p < .05) and eccentric at 30º/s (p < .01) extensor torque on the affected limb (AL), and eccentric at 30 and 120º/s (p < .01), on the non-affected limb (NAL). In the flexors, there was an increase on the torque: isometric, concentric at 30º/s and eccentric at 30 and 120º/s (p < .01) in AL and in eccentric at 30 (p < .05) and 120º/s (p < .01) in NAL. With respect to the angular and spatio-temporal variables gait, there was no difference between pre-and post-training in LCAr group. Compared to control group, the cycle time, in two members, was lower in LCAr group, and stride length and cadence were higher in the AL of the LCAr (p < .05). Moreover, the knee flexion-extension angles (minimum and maximum) remained lower in LCAr, pre-and post-training (p < .01). The torque gain associated with eccentric isokinetic training did not affect the kinematic parameters of gait in patients undergoing ACL reconstruction. Keywords: gait, exercise, muscle strength, movement, anterior cruciate ligament reconstruction Resumo-"Efeitos do treinamento isocinético excêntrico de extensores de joelho e torque flexor na marcha de indivíduos com reconstrução do LCA: Um ensaio clínico controlado." Este estudo investigou os efeitos do treinamento isocinético excêntrico (TIE) sobre o torque extensor e flexor do joelho e parâmetros cinemáticos da marcha de indivíduos com reconstrução do LCA. Dezesseis homens com LCA reconstruído (LCAr), foram avaliados quanto ao torque e marcha, antes e após 12 semanas de TIE e comparados com um grupo controle (14 indivíduos). Testes t Student, MANOVA e ANOVA foram realizados com 5% de significância. O treinamento aumentou o torque extensor isométrico, concêntrico a 30 e 120º/s (p < 0,05) e excêntrico a 30º/s (p < 0,01) no membro afetado (MA), e excêntrico a 30 e 120º/s (p < 0,01), no membro não afetado (MNA). Nos flexores, houve um aumento no torque: isométrico, concêntrico a 30º/s e excêntrico a 30 e 120º/s (p < 0,01) no MA, e excêntrico a 30 (p < 0,05) e 120º/s (p < 0,01) no MNA. Com relação às variáveis espaço-temporais e angulares da marcha, não houve diferença entre as avaliações pré e pós-treino no grupo LCAr. Comparado ao controle, a duração do ciclo, nos dois membros, foi menor no LCAr, e comprimento da passada e cadência foram maiores no MA do grupo LCAr (p < 0,05). Além disso, os ângulos (mínimo e máximo) de flexão-extensão do joelho permaneceram menores no LCAr, pré e pós-treino (p < 0,01). O ganho de torque associado ao treinamento isocinético excêntrico não modificou os parâmetros cinemáticos da marcha nos indivíduos submetidos à reconstrução do LCA. Palavras-chave: marcha, exercício, força muscular, movimento, reconstrução do ligamento cruzado anterior H.H. Santos, C.O. Sousa, J.A. Barela, A.M.F. Barela & T.F. Salvini Motriz, Rio Claro, v.20 n.4, p. 431-441, Oct./Dec. 2014 432 Resumen-"Efectos del entrenamiento excéntrico isocinético en extensor de la rodilla y el par flexor y sobre la marcha de las personas con reconstrucción ACL: Un ensayo clínico controlado." Este estudio investigó los efectos del entrenamiento isocinético excéntrico (EIE) en el torque del extensor y del flexor de la rodilla y parámetros cinemáticos de la marcha de personas con la reconstrucción del LCA. Dieciséis hombres con LCA reconstruido (LCAr), fueron evaluados para el par y la marcha antes y después de 12 semanas de EIE y se compararon con un grupo control (14 personas). Prueba t Student, ANOVA y MANOVA se realizaron con 5 % de significación. La formación aumentó extensor torque isométrico, concéntrico 30 y 120°/s (p < 0,05) y la excéntrica 30°/s (p < 0,01) en el miembro afectado (MA), y la excéntrica 30 y 120°/s (p < 0,01) en el miembro no afectado (MNA). Flexor, hubo un aumento en el par motor: isométrica , concéntrica 30°/s excéntrica 30 y 120°/s (p < 0,01) en MA, excéntrico y 30 (p < 0,05 ) y 120°/ s (p < 0,01) en el MNA. Con respecto a las variables angulares y espacio-temporal de andar, no hubo diferencia entre pre y post-entrenamiento en grupo LCAr. En comparación con el grupo control, el tiempo de ciclo, em los dos miembros, fue menor en LCAr, y la longitud del paso y cadencia fueron mayores en el LCAr del MA (p < 0,05). Por otra parte, los ángulos de flexión-extensión de la rodilla (mínimo y máximo) se mantuvieron bajos en LCAr, pre y post-entrenamiento (p < 0,01). El aumento del torque asociado con el entrenamiento isocinético excéntrico no afectó los parámetros cinemáticos de la marcha en las personas sometidas a la reconstrucción del LCA

    O novo regime de contrato de trabalho em funções públicas e riscos psicossociais emergentes

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    Apresentação realizada no 3º Encontro Nacional de Riscos, Segurança e Fiabilidade em Lisboa, de 3-5 de novembro de 2009

    Talking About and Preparing for Death Among Older Adults

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    Experts on end-of-life issues recommend that individuals make preparations – living will, health care proxy, last will and testament, and memorial service – for their eventual death (Bischoff, Sudore, Miao, Boscardin, & Smith, 2013). While these experts further encourage a broader process of advance care planning, which includes conversations with loved ones, many individuals are reticent to engage in such end-of-life conversations (Brinkman-Stoppelenburg, Rietjens, & Heide, 2014). The purpose of this study was to investigate relationships between older adults’ comfort having end-of-life discussions with family members, death preparation, and comfort with their end-of-life plans. Community-dwelling older adults (N = 354) participated in an interview survey about end-of-life issues. Comfort with having end-of-life discussions with family was associated with greater death preparation and comfort with end-of-life plans. Death preparation mediated the relationship between comfort with end-of-life discussions and comfort with end-of-life plans. Overall, the results are consistent with the notion that individuals who are more comfortable discussing their end-of-life plans with loved ones engage in greater death preparation and thereby feel a greater sense of contentment with their plans for death

    Micrometeoroid Events in LISA Pathfinder

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    The zodiacal dust complex, a population of dust and small particles that pervades the Solar System, provides important insight into the formation and dynamics of planets, comets, asteroids, and other bodies. Here we present a new set of data obtained using a novel technique: direct measurements of momentum transfer to a spacecraft from individual particle impacts. This technique is made possible by the extreme precision of the instruments flown on the LISA Pathfinder spacecraft, a technology demonstrator for a future space-based gravitational wave observatory that operated near the first Sun-Earth Lagrange point from early 2016 through Summer of 2017. Using a simple model of the impacts and knowledge of the control system, we show that it is possible to detect impacts and measure properties such as the transferred momentum (related to the particle's mass and velocity), direction of travel, and location of impact on the spacecraft. In this paper, we present the results of a systematic search for impacts during 4348 hours of Pathfinder data. We report a total of 54 candidates with momenta ranging from 0.2 μNs\,\mu\textrm{Ns} to 230 μNs\,\mu\textrm{Ns}. We furthermore make a comparison of these candidates with models of micrometeoroid populations in the inner solar system including those resulting from Jupiter-family comets, Oort-cloud comets, Hailey-type comets, and Asteroids. We find that our measured population is consistent with a population dominated by Jupiter-family comets with some evidence for a smaller contribution from Hailey-type comets. This is in agreement with consensus models of the zodiacal dust complex in the momentum range sampled by LISA Pathfinder.Comment: 22 pages, 14 figures, accepted in Ap

    Guided play and free play in an enriched environment: impact on motor development

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    The purpose of this study was to investigate the effects of guided play and free play in an enriched environment intervention programs using motor skill development in kindergarten children. Seventy-one children attending kindergarten classes were assigned to two experimental groups and one control group. Participants performed the Test of Gross Motor Development-2 before and after the intervention period. Results revealed that both boys and girls in the guided play group showed motor skill improvement, whereas no changes were observed in motor development in the boys and girls assigned to the free play in enriched environment group, nor in those in the control group. These findings indicate that the teacher’s role in the guided play intervention was crucial to help preschool children to improve their performance.CIEC – Research Centre on Child Studies, UM (FCT R&D 317

    Chondrocyte Deformations as a Function of Tibiofemoral Joint Loading Predicted by a Generalized High-Throughput Pipeline of Multi-Scale Simulations

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    Cells of the musculoskeletal system are known to respond to mechanical loading and chondrocytes within the cartilage are not an exception. However, understanding how joint level loads relate to cell level deformations, e.g. in the cartilage, is not a straightforward task. In this study, a multi-scale analysis pipeline was implemented to post-process the results of a macro-scale finite element (FE) tibiofemoral joint model to provide joint mechanics based displacement boundary conditions to micro-scale cellular FE models of the cartilage, for the purpose of characterizing chondrocyte deformations in relation to tibiofemoral joint loading. It was possible to identify the load distribution within the knee among its tissue structures and ultimately within the cartilage among its extracellular matrix, pericellular environment and resident chondrocytes. Various cellular deformation metrics (aspect ratio change, volumetric strain, cellular effective strain and maximum shear strain) were calculated. To illustrate further utility of this multi-scale modeling pipeline, two micro-scale cartilage constructs were considered: an idealized single cell at the centroid of a 100×100×100 μm block commonly used in past research studies, and an anatomically based (11 cell model of the same volume) representation of the middle zone of tibiofemoral cartilage. In both cases, chondrocytes experienced amplified deformations compared to those at the macro-scale, predicted by simulating one body weight compressive loading on the tibiofemoral joint. In the 11 cell case, all cells experienced less deformation than the single cell case, and also exhibited a larger variance in deformation compared to other cells residing in the same block. The coupling method proved to be highly scalable due to micro-scale model independence that allowed for exploitation of distributed memory computing architecture. The method’s generalized nature also allows for substitution of any macro-scale and/or micro-scale model providing application for other multi-scale continuum mechanics problems

    Effect of a Dual Task on Postural Control in Dyslexic Children

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    Several studies have examined postural control in dyslexic children; however, their results were inconclusive. This study investigated the effect of a dual task on postural stability in dyslexic children. Eighteen dyslexic children (mean age 10.3±1.2 years) were compared with eighteen non-dyslexic children of similar age. Postural stability was recorded with a platform (TechnoConcept®) while the child, in separate sessions, made reflex horizontal and vertical saccades of 10° of amplitude, and read a text silently. We measured the surface and the mean speed of the center of pressure (CoP). Reading performance was assessed by counting the number of words read during postural measures. Both groups of children were more stable while performing saccades than while reading a text. Furthermore, dyslexic children were significantly more unstable than non-dyslexic children, especially during the reading task. Finally, the number of words read by dyslexic children was significantly lower than that of non-dyslexic children and, in contrast to the non-dyslexic children. In line with the U-shaped non-linear interaction model, we suggest that the attention consumed by the reading task could be responsible for the loss of postural control in both groups of children. The postural instability observed in dyslexic children supports the hypothesis that such children have a lack of integration of multiple sensorimotor inputs
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