Equilíbrio estático e dinâmico em bailarinos: revisão da literatura

A dança envolve integração de movimento, equilíbrio postural e aspectos relacionados ao controle postural. Informações sobre o equilíbrio em bailarinos são de grande importância, pois eles são considerados modelos de controle postural. O objetivo foi revisar estudos sobre equilíbrio postural estático e dinâmico em bailarinos, caracterizando o controle e a dependência visual desses atletas para a manutenção do equilíbrio. Para isso, foi realizada uma revisão nas bases de dados PubMed, SciELO, Lilacs e Science Direct, considerando o período entre 1997 a 2013, utilizando os descritores equilíbrio, controle postural, plataforma de forças, ballet, bailarinos clássicos e aferência visual. Foram selecionados 18 artigos capazes de fornecer dados quantitativos para avaliação do equilíbrio nesses atletas classificados pelo nível de evidência científica Oxford. A literatura revisada mostra completa concordância quanto ao efeito da retirada da informação visual sobre a estabilidade postural de bailarinos considerados como executantes altamente treinados. Estudos mostrando a comparação do equilíbrio de bailarinos com outras técnicas desportivas confirmaram um padrão específico de equilíbrio nesses indivíduos. Entretanto, associando-se à restrição visual, bailarinos apresentaram maior deslocamento do centro de pressão comparado a outras modalidades desportivas, sugerindo maior dependência visual para a manutenção do equilíbrio. Bailarinos apresentam menor oscilação postural em relação a indivíduos não treinados e indivíduos treinados em outras práticas desportivas, com maior dependência visual para manutenção do equilíbrio.La danza envuelve integración de movimiento, equilibrio postural y aspectos relacionados al control postural. Informaciones sobre el equilibrio en bailarines son de gran importancia, pues ellos son considerados modelos de control postural. El objetivo fue revisar estudios sobre equilibrio postural estático y dinámico en bailarines, caracterizando el control y la dependencia visual de esos atletas para la manutención del equilibrio. Para eso, fue realizada una revisión en las bases de datos PubMed, SciELO, Lilacs y Science Direct, considerando el período entre 1997 y 2013, utilizando los descriptores equilibrio, control postural, plataforma de fuerzas, ballet, bailarines clásicos y aferencia visual. Fueron seleccionados 18 artículos capaces de proveer datos cuantitativos para evaluación del equilibrio en esos atletas clasificados por el nivel de evidencia científica Oxford. La literatura revisada muestra completa concordancia en cuanto al efecto de la retirada de la información visual sobre la estabilidad postural de bailarines considerados como ejecutantes altamente entrenados. Estudios mostrando la comparación del equilibrio de bailarines con otras técnicas deportivas confirmaron un estándar específico de equilibrio en esos individuos. Entre tanto, asociándose a la restricción visual, bailarines presentaron mayor desplazamiento del centro de presión comparado a otras modalidades deportivas, sugiriendo mayor dependencia visual para la manutención del equilibrio. Bailarines presentan menor oscilación postural en relación a individuos no entrenados e individuos entrenados en otras prácticas deportivas, con mayor dependencia visual para manutención del equilibrio.Dance involves integration between movement, postural balance and the multiple aspects involved with postural control. Information regarding the balance of ballet dancers is of great importance, as they are considered models of great postural control. The aim was to review studies about static and dynamic postural balance of ballet dancers, characterizing visual dependency in the postural control of these athletes to maintain balance. A review of literature was performed on PubMed, SciELO, Lilacs, and Science Direct databases considering the period between 1997 and 2013, and using the descriptors balance, postural control, force plates ballet dancers, classical ballet dancers and visual afferences. Eighteen articles were considered able to provide the quantitative and qualitative data to assess the balance among those athletes, and were thus, selected. These papers were classified by Oxford level of evidence. The reviewed literature shows full consensus regarding the effect of removing visual information over postural stability according to the experience of subjects considered highly trained dancers. Studies comparing the balance of ballet dancers to other sporting techniques confirmed that they have a specific postural balance pattern. Nevertheless, in association with visual restriction, ballet dancers show a greater center of pressure dislocation and instability compared to other sports, which suggests that they have higher visual dependence to maintain balance. Ballet dancers have better static balance compared to non-trained subjects and other types of athletes, but greater visual dependence to maintain balance

Patellar Kinematics analysis by magnetic resonance imaging in individuals with patellofemoral pain

A Síndrome da Dor Femoropatelar (SDFP) é uma das disfunções mais freqüentes do joelho, que acomete adultos jovens do sexo feminino. Embora os fatores etiológicos da SDFP ainda não estejam bem estabelecidos, autores apontam as alterações da cinemática patelar como o principal fator causal. A intervenção conservadora é freqüentemente indicada para o tratamento destes indivíduos, abrangendo exercícios em cadeia cinética aberta (CCA) e cadeia cinética fechada (CCF). O objetivo deste trabalho foi analisar a cinemática patelar durante o repouso e exercícios em indivíduos saudáveis e com SDFP. Participaram deste trabalho, 20 voluntários clinicamente saudáveis e 19 com SDFP submetidos a exames de ressonância nuclear magnética (RNM) durante o repouso, contração isométrica voluntária máxima (CIVM) em CCA e CCF com o joelho posicionado a 15º, 30º e 45º de flexão. As imagens de RNM foram avaliadas pelo programa e-film medical na obtenção dos ângulos do sulco (AS), ângulo de congruência (AC), ângulo de tilt patelar (ATP), ângulo patelar lateral (APL), deslocamento lateral patelar (DLP) e o bisect offset (BO). O coeficiente de correlação intraclasse (ICC) foi aplicado para verificar a confiabilidade intra-examinador e o modelo linear de efeitos mistos aplicado para as comparações inter e intra-grupo, sendo estabelecido nível de significância de 5%. Os resultados do ICC revelaram níveis excelentes de confiabilidade (ICC> 0,75) para todas as medidas de ambos os grupos. De acordo com os dados analisados, pode-se constatar que o grupo SDFP apresenta um maior deslocamento lateral da patela durante o repouso, CIVM em CCA e CCF com o joelho posicionado a 15º de flexão em relação ao grupo controle. Na comparação entre os posicionamentos do joelho e entre as cadeias, para ambos os grupos verificou-se um melhor equilíbrio patelar com o joelho fletido a 30º e a 45º com a CIVM em CCA e CCF. Com o joelho posicionado a 15º de flexão, a patela apresenta-se em sua posição de maior instabilidade, mesmo durante a CIVM em CCF e CCA para ambos os grupos. Desta maneira pode-se concluir que exercícios em CCA e CCF com o joelho posicionado a 30º e a 45º apresentam uma melhor estabilidade patelar em relação aos exercícios com o joelho posicionado a 15º de flexão.Patellofemoral Pain Syndrome (PPS) is one of the most common knee dysfunctions affecting young adult women. Although PFPS etiologic factors remain uncertain, authors have reported that changes in patellar kinematics as the main cause. Conservative interventions are frequently indicated, which includes open kinetic chain (OKC) and closed kinetic chain (CKC) exercises. This study had the objective to analyze patellar kinematics on individuals with PFPS and health controls, at rest position and while performing exercises. Thirty-nine volunteers participated in this study (20 healthy individuals and 19 with PFPS) and were subjected to nuclear magnetic resonance (NMR) at the following conditions: at rest, maximal voluntary isometric contraction (MVIC) in OKC and CKC with the knee flexed at 15º, 30º, and 45º. NMR images were evaluated using e-film medical for the following angles: sulcus angle (SA), congruence angle (CA), patellar tilt angle (PTA), lateral patellar angle (LPA), lateral displacement of the patella (LDP), and bisect offset (BO). The interclass coefficient correlation (ICC) was applied to verify intra-rater reliability and the linear mixed effects model for inter- and intra-group comparisons, with level of significance at 5%. ICC results revealed excellent reliability levels (ICC> 0.75) for all measurements in both groups. The analyzed data reveal that, compared to the control group, the PFPS group presents greater lateral displacement of the patella at rest, MVIC in OKC and CKC with the knee flexed at 15º. Comparisons among knee positions and kinetic chains, in both groups, it was observed that better patellar balance was obtained with the knee flexed at 30º and 45º with MVIC in OKC and CKC. For both groups, the position with most instability of the patella is with the knee flexed at 15º, even during MVIC in CKC and OKC. Hence, it is concluded that OKC and CKC exercises with the knee flexed at 30º and 45º promote better stability of the patella with regards to exercises performed with the knee flexed at 15

Patellar Kinematics analysis by magnetic resonance imaging in individuals with patellofemoral pain

A Síndrome da Dor Femoropatelar (SDFP) é uma das disfunções mais freqüentes do joelho, que acomete adultos jovens do sexo feminino. Embora os fatores etiológicos da SDFP ainda não estejam bem estabelecidos, autores apontam as alterações da cinemática patelar como o principal fator causal. A intervenção conservadora é freqüentemente indicada para o tratamento destes indivíduos, abrangendo exercícios em cadeia cinética aberta (CCA) e cadeia cinética fechada (CCF). O objetivo deste trabalho foi analisar a cinemática patelar durante o repouso e exercícios em indivíduos saudáveis e com SDFP. Participaram deste trabalho, 20 voluntários clinicamente saudáveis e 19 com SDFP submetidos a exames de ressonância nuclear magnética (RNM) durante o repouso, contração isométrica voluntária máxima (CIVM) em CCA e CCF com o joelho posicionado a 15º, 30º e 45º de flexão. As imagens de RNM foram avaliadas pelo programa e-film medical na obtenção dos ângulos do sulco (AS), ângulo de congruência (AC), ângulo de tilt patelar (ATP), ângulo patelar lateral (APL), deslocamento lateral patelar (DLP) e o bisect offset (BO). O coeficiente de correlação intraclasse (ICC) foi aplicado para verificar a confiabilidade intra-examinador e o modelo linear de efeitos mistos aplicado para as comparações inter e intra-grupo, sendo estabelecido nível de significância de 5%. Os resultados do ICC revelaram níveis excelentes de confiabilidade (ICC> 0,75) para todas as medidas de ambos os grupos. De acordo com os dados analisados, pode-se constatar que o grupo SDFP apresenta um maior deslocamento lateral da patela durante o repouso, CIVM em CCA e CCF com o joelho posicionado a 15º de flexão em relação ao grupo controle. Na comparação entre os posicionamentos do joelho e entre as cadeias, para ambos os grupos verificou-se um melhor equilíbrio patelar com o joelho fletido a 30º e a 45º com a CIVM em CCA e CCF. Com o joelho posicionado a 15º de flexão, a patela apresenta-se em sua posição de maior instabilidade, mesmo durante a CIVM em CCF e CCA para ambos os grupos. Desta maneira pode-se concluir que exercícios em CCA e CCF com o joelho posicionado a 30º e a 45º apresentam uma melhor estabilidade patelar em relação aos exercícios com o joelho posicionado a 15º de flexão.Patellofemoral Pain Syndrome (PPS) is one of the most common knee dysfunctions affecting young adult women. Although PFPS etiologic factors remain uncertain, authors have reported that changes in patellar kinematics as the main cause. Conservative interventions are frequently indicated, which includes open kinetic chain (OKC) and closed kinetic chain (CKC) exercises. This study had the objective to analyze patellar kinematics on individuals with PFPS and health controls, at rest position and while performing exercises. Thirty-nine volunteers participated in this study (20 healthy individuals and 19 with PFPS) and were subjected to nuclear magnetic resonance (NMR) at the following conditions: at rest, maximal voluntary isometric contraction (MVIC) in OKC and CKC with the knee flexed at 15º, 30º, and 45º. NMR images were evaluated using e-film medical for the following angles: sulcus angle (SA), congruence angle (CA), patellar tilt angle (PTA), lateral patellar angle (LPA), lateral displacement of the patella (LDP), and bisect offset (BO). The interclass coefficient correlation (ICC) was applied to verify intra-rater reliability and the linear mixed effects model for inter- and intra-group comparisons, with level of significance at 5%. ICC results revealed excellent reliability levels (ICC> 0.75) for all measurements in both groups. The analyzed data reveal that, compared to the control group, the PFPS group presents greater lateral displacement of the patella at rest, MVIC in OKC and CKC with the knee flexed at 15º. Comparisons among knee positions and kinetic chains, in both groups, it was observed that better patellar balance was obtained with the knee flexed at 30º and 45º with MVIC in OKC and CKC. For both groups, the position with most instability of the patella is with the knee flexed at 15º, even during MVIC in CKC and OKC. Hence, it is concluded that OKC and CKC exercises with the knee flexed at 30º and 45º promote better stability of the patella with regards to exercises performed with the knee flexed at 15

Braking and propulsive impulses in individuals with patellofemoral pain syndrome when walking up and down stairs

Patellofemoral pain syndrome (PFPS) is a prevalent clinical condition and it affects gait behavior. Braking and propulsive impulses are important biomechanical parameters obtained from ground reaction forces (GRF), which combine the amount of force applied over a period of time. The aim of this study was to evaluate these impulses while walking up and down stairs in healthy controls and PFPS individuals. The results did not reveal significant differences in braking and propulsive impulses between groups during these activities. Thus, the painful condition on a simple functional activity was insufficient to change the motor strategy to walking up or down the stairs

Correlation Between Trochlear Groove Depth and Patellar Position During Open and Closed Kinetic Chain Exercises in Subjects With Anterior Knee Pain

The purpose of this study was to correlate the trochlear shape and patellar tilt angle and lateral patellar displacement at rest and maximal voluntary isometric contraction (MVIC) exercises during open (OKC) and closed kinetic chain (CKC) in subjects with and without anterior knee pain. Subjects were all women, 20 who were clinically healthy and 19 diagnosed with anterior knee pain. All subjects were evaluated and subjected to magnetic resonance exams during OKC and CKC exercise with the knee placed at 15, 30, and 45 degrees of flexion. The parameters evaluated were sulcus angle, patellar tilt angle and patellar displacement using bisect offset. Pearson's r coefficient was used, with p < .05. Our results revealed in knee pain group during CKC and OKC at 15 degrees that the increase in the sulcus angle is associated with a tilt increase and patellar lateral displacement. Comparing sulcus angle, patellar tilt angle and bisect offset values between MVIC in OKC and CKC in the knee pain group, it was observed that patellar tilt angle increased in OKC only with the knee flexed at 30 degrees. Based on our results, we conclude that reduced trochlear depth is correlated with increased lateral patellar tilt and displacement during OKC and CKC at 15 degrees of flexion in people with anterior knee pain. By contrast, 30 degrees of knee flexion in CKC is more recommended in rehabilitation protocols because the patella was more stable than in other positions.State of Sao Paulo Research Foundation-FAPESP [04/14097-7, 04/05086-1]State of Sao Paulo Research Foundation (FAPESP

Evaluating Patellar Kinematics Through Magnetic Resonance Imaging During Open- and Closed-Kinetic-Chain Exercises

Purpose: To evaluate patellar kinematics of volunteers Without knee pain at rest and during isometric contraction in open- and closed-kinetic-chain exercises. Methods: Twenty individuals took part in this study. All were submitted to magnetic resonance imaging (MRI) during rest and voluntary isometric contraction (VIC) in the open anti closed kinetic chain at 15 degrees, 30 degrees, and 45 degrees of knee flexion. Through MRI and using medical e-film software, the following measurements were evaluated: sulcus angle, patellar-tilt angle, and bisect offset. The mixed-effects linear model was used for comparison between knee positions, between rest and isometric contractions, and between (he exercises. Results: Data analysis revealed that the sulcus angle decreased as knee flexion increased and revealed increases with isometric contractions in both the open and closed kinetic chain for all knee-flexion angles. The patellar-tilt angle decreased with isometric contractions in both the open and closed kinetic chain for every knee position. However, in the closed kinetic chain, patellar tilt increased significantly with the knee flexed at 15 degrees. The bisect offset increased with the knee flexed at 15 degrees during isometric contractions and decreased as knee flexion increased during both exercises. Conclusion: VIC in the last degrees of knee extension may compromise patellar dynamics. On the other hand, it is possible to favor patellar stability by performing muscle contractions with the knee flexed at 30 degrees and 45 degrees in either the open or closed kinetic chain

Analysis of patellar stabilizers muscles and patellar kinematics in anterior knee pain subjects

Patella stabilizer muscle response and patellar kinematics were evaluated in 19 women with anterior knee pain (AKP) and 20 healthy women during maximum voluntary isometric contraction (MVIC) with the knee positioned at 15 degrees, 30 degrees and 45 degrees flexion during open (OKC) and closed (CKC) kinetic chain exercises. Patellar kinematics was evaluated through patellar tilt and displacement, and the electrical activity of patellar stabilizers through the root mean square normalized during MVIC and OKC with the knee at 90 degrees flexion. Data revealed that the vastus medialis oblique muscle (VMO) was more active in the control group compared to the AKP group during OKC exercises with the knee at 45 degrees flexion. However, no difference in the patellar kinematics was observed between these groups; nevertheless, the correlation between these parameters also showed, with the knee at 45 degrees flexion, that lateral patellar tilt increase was associated with a reduction in the activity of lateral patellar stabilizers in the control group and with an increase in the VMO activity in the AKP group. In conclusion, electrical activity is an important factor in evaluating AKP and in AKP treatment evolution. (C) 2010 Elsevier Ltd. All rights reserved.State of Sao Paulo Research Foundation - FAPESP[04/14097-7