Test-retest, inter- and intra-rater reliability of the flexicurve for evaluation of the spine in children

Introduction: The early evaluation of the spine in children is desirable because it is at this stage of development that the greatest changes in the body structures occur. Objective: To determine the test-retest, intra- and inter-rater reliability of the Flexicurve instrument for the evaluation of spinal curvatures in children. Method: Forty children ranging from 5 to 15 years of age were evaluated by two independent evaluators using the Flexicurve to model the spine. The agreement was evaluated using Intraclass Correlation Coefficients (ICC), Standard Error of the Measurement (SEM), and Minimal Detectable Change (MDC). Results: In relation to thoracic kyphosis, the Flexicurve was shown to have excellent correlation in terms of test-retest reliability (ICC2,2=0.87) and moderate correlation in terms of intra-(ICC2,2=0.68) and inter-rater reliability (ICC2,2=0.72). In relation to lumbar lordosis, it was shown to have moderate correlation in terms of test-retest reliability (ICC2,2=0.66) and intra- (ICC2,2=0.50) and inter-rater reliability (ICC=0.56). Conclusion: This evaluation of the reliability of the Flexicurve allows its use in school screening. However, to monitor spinal curvatures in the sagittal plane in children, complementary clinical measures are necessary. Further studies are required to investigate the concurrent validity of the instrument in order to identify its diagnostic capacity.

Can the adapted arcometer be used to assess the vertebral column in children?

BACKGROUND: The adapted arcometer has been validated for use in adults. However, its suitability for use in children can be questioned given the structural differences present in these populations. OBJECTIVE: To verify the concurrent validity, repeatability, and intra- and inter-reproducibility of the adapted arcometer for the measurement of the angles of thoracic kyphosis and lumbar lordosis in children. METHOD: Forty children were evaluated using both sagittal radiography of the spine and the adapted arcometer. The evaluations using the arcometer were carried out by two trained evaluators on two different days. In the statistical treatment, the intraclass correlation coefficient (ICC), Pearson's product moment correlation, Spearman's rho, the paired t test, and Wilcoxon's test were used (α=.05). RESULTS: A moderate and significant correlation was found between the x-ray and the adapted arcometer regarding thoracic kyphosis, but no correlation was found regarding lumbar lordosis. Repeatability and intra-evaluator reproducibility of the thoracic kyphosis and lumbar lordosis were confirmed, which was not the case of inter-evaluator reproducibility. CONCLUSION: The adapted arcometer can be used to accompany postural alterations in children made by the same evaluator, while its use for diagnostic purposes and continued evaluation by different evaluators cannot be recommended. Further studies with the aim of adapting this instrument for use in children are recommended. .

Validation, repeatability and reproducibility of a noninvasive instrument for measuring thoracic and lumbar curvature of the spine in the sagittal plane / Validade, repetibilidade e reprodutibilidade de um instrumento não-invasivo para medição das curvaturas torácica e lombar da coluna vertebral no plano sagital

BACKGROUND: The need for early identification of postural abnormalities without exposing patients to constant radiation has stimulated the development of instruments aiming to measure the spinal curvatures. OBJECTIVE: To verify the validity, repeatability and reproducibility of angular measures of sagittal curvatures of the spine obtained using an adapted arcometer, by comparing them with Cobb angles of the respective curvatures obtained by using X-rays. METHODS: 52 participants were submitted to two procedures designed to evaluate the thoracic and lumbar curvatures: (1) X-ray examination from which the Cobb angles (CA) of both curvatures were obtained, and (2) measuring the angles with the arcometer (AA). Two evaluators collected the data using the arcometer, with the rods placed at T1, T12, L1 and L5 spinous processes levels in a way as to permit linear measurements which, with aid of trigonometry, supplied the AA. RESULTS: There was a very strong and significant correlation between AA and CA (r=0.94; p<0.01), with no-significant difference (p=0.32), for the thoracic curvature. There was a strong and significant correlation for the lumbar curvature (r=0.71; p<0.01) between AA and CA, with no-significant difference (p=0.30). There is a very strong correlation between intra-evaluator and inter-evaluator AA. CONCLUSION: It was possible to quantify reliably the thoracic and lumbar curvatures with the arcometer and it can thus be considered valid and reliable and for use in evaluating spinal curvatures in the sagittal plane.

CONTEXTUALIZAÇÃO: A necessidade de identificação precoce de alterações posturais, sem expor as pessoas à radiação constante, tem estimulado a construção de instrumentos para medir as curvaturas da coluna vertebral. OBJETIVO: Verificar a validade, repetibilidade e reprodutibilidade dos ângulos das curvaturas sagitais da coluna vertebral, obtidos por meio de um arcômetro adaptado, comparando-os com os ângulos de Cobb (AC) das respectivas curvaturas, obtidos por meio de exames radiográficos. MÉTODOS: Cinquenta e dois indivíduos foram submetidos a dois procedimentos destinados a avaliar as curvaturas torácica e lombar: (1) exame de raios-X, a partir do qual os AC de ambas as curvaturas foram obtidos e (2) medição dos ângulos das curvaturas com o arcômetro (AA). Dois avaliadores coletaram os dados usando o arcômetro com as hastes sobre os processos espinhosos T1, T12, L1 e L5, de modo a permitir medidas que, com auxílio de trigonometria, forneceram os AA. RESULTADOS: Encontrou-se correlação muito forte e significativa entre AA e AC (r=0,94, p<0,01), sem diferença significativa (p=0,32) para a curvatura torácica, enquanto, para a curvatura lombar, encontrou-se uma forte e significativa correlação (r=0,71, p<0,01) entre AA e AC, sem diferença significativa (p=0,30). Existe uma correlação muito forte intra-avaliador e inter-avaliador nos AA. CONCLUSÃO: O arcômetro permitiu quantificar as curvaturas torácica e lombar, podendo-se considerar as medições válidas, fidedignas e objetivas para uso na avaliação de curvaturas da coluna vertebral no plano sagital.

Análise do torque de resistência e da força muscular resultante durante exercício de extensão de quadril no Pilates e suas implicações na prescrição e progressão / Assessment of resistance torque and resultant muscular force during Pilates hip extension exercise and its implications to prescription and progression

CONTEXTUALIZAÇÃO: A análise da mecânica externa dos exercícios de Pilates e da biomecânica das articulações pode subsidiar a prescrição de exercícios na reabilitação. OBJETIVOS: Avaliar o comportamento do torque de resistência (ΓR) do exercício de extensão de quadril (EQ) realizado no Cadillac; realizar uma análise biomecânica a partir do comportamento do ΓR e das distâncias perpendiculares médias ponderadas (DPMPs) para estimar a força muscular resultante (FM R) dos extensores e flexores e propor critérios mecânicos para progressão do exercício de EQ realizado no Cadillac. MÉTODOS: Catorze praticantes de Pilates realizaram EQ no aparelho Cadillac em quatro situações em ordem aleatorizada - usando duas molas (vermelha e azul) fixadas em duas posições (alta e baixa). As posições angulares foram coletadas por meio de eletrogoniometria. Para o cálculo do ΓR, torque muscular (ΓM) e da FM R foram usados diagramas de corpo livre e equações de movimento. Os valores de DPMP dos músculos flexores e extensores do quadril foram quantificados usando dados da literatura. RESULTADOS: O ΓR e a FM R apresentaram comportamentos semelhantes em todas as situações, entretanto os valores máximos de ΓR não ocorrem na mesma posição articular que a FM R máxima. A DPMP dos flexores de quadril apresentou um comportamento crescente-decrescente, com máximo próximo aos 55º de flexão, enquanto os extensores de quadril apresentaram comportamento semelhante, com máximo próximo aos 25º de flexão. CONCLUSÃO: A análise biomecânica do exercício e a avaliação das características mecânicas associadas à articulação do quadril podem ser usadas como critérios objetivos de prescrição e progressão do exercício de EQ no Pilates.

BACKGROUND: The understanding of the external mechanics of Pilates exercises and the biomechanics of the joints may guide the prescription of rehabilitation exercises. OBJECTIVES: To evaluate the resistance torque (ΓR) during hip extension (HE) exercises performed on the Pilates Cadillac. To perform a biomechanic analysis of the ΓR and the weighted mean moment arm (WMMA) in order to calculate the resultant muscle force (FM R) of the hip extensors and flexors. To present a mechanical criteria for progression of HE exercise on the Pilates Cadillac. METHODS: Fourteen participants performed HE exercises on the Cadillac in four randomly assigned situations - using two springs (blue and red), which were attached in two positions (high and low). Angular positions were measured using an electrogoniometer. In order to calculate ΓR, the muscle torque (ΓM) and FM R, free-body diagrams and movement equations were used. The WMMA of the hip extensors and flexors were estimated from the literature. RESULTS: The ΓR and FM R presented a similar behavior during all situations; however, the maximum ΓR values did not occur at the same joint position as the FM R maximum values. The WMMA of the hip flexors presented an increased- decreased behavior with greatest values around 55º of flexion, while the hip extensors presented a similar behavior with greatest values around 25º of flexion. CONCLUSION: Biomechanic analysis of HE exercises and the evaluation of mechanical features in relation to the hip joint may be used as an objective criteria for the prescription and progression of HE exercise in Pilates.

Atividade elétrica dos músculos oblíquos externos e multífidos durante o exercício de flexoextensão do quadril realizado no Cadillac com diferentes regulagens de mola e posições do indivíduo / Electrical activity of external oblique and multifidus muscles during the hip flexion-extension exercise performed in the Cadillac with different adjustments of springs and individual positions

CONTEXTUALIZAÇÃO: Apesar do amplo uso do Pilates na Fisioterapia, há poucos estudos que avaliaram a ativação elétrica dos músculos nos exercícios. OBJETIVO: Verificar a influência de diferentes regulagens de mola e posições do indivíduo sobre a ativação elétrica dos multífidos (MU) e oblíquos externos (OE) durante a flexoextensão do quadril (FEQ) no Cadillac. MÉTODOS: Oito mulheres praticantes de Pilates por seis meses realizaram 10 repetições de FEQ nas situações: mola baixa (MB), mola fixada a 30 cm do nível em que estava o indivíduo; mola alta (MA), mola fixada a 90 cm do nível em que estava o indivíduo; posição próxima (PP), distância de 10 cm da fixação da mola; posição distante (PD), distância de 30 cm da fixação da mola. Dados cinemáticos e de eletromiografia (EMG) foram coletados sincronizadamente, e os músculos monitorados bilateralmente foram os OE e os MU. Cada movimento de FEQ foi recortado em duas fases (extensão e flexão). O sinal de EMG foi calculado e normalizado usando a contração voluntária máxima (CVM). O Wilcoxon test foi usado para investigar diferenças entre as situações (p<0,05). RESULTADO: Os músculos MU apresentaram valores de ativação muscular de 10 a 20 por cento da CVM, sendo os maiores valores observados na MA e na PD. Para os OE, valores de ativação de 20 a 45 por cento da CVM foram encontrados, com os maiores valores obtidos na MB e na PP. CONCLUSÃO: Os músculos OE e MU apresentaram uma ativação elétrica distinta durante as diferentes regulagens de mola e posições dos indivíduos avaliados.

BACKGROUND: Despite of the widepread use of Pilates in Physical Therapy, there are few studies that have assessed the muscle electrical activation during Pilates exercises. OBJECTIVE: Verify the influence of different spring adjustments and individual positions on the electrical activation of multifidus (MU) and oblique external (OE) muscles during hip flexion-extension (HFE) exercise on the Cadillac. METHODS: Eight women practicing Pilates exercises for at least six months performed 10 repetitions of HFE in the following situations: Lower Spring, spring fixed at 30 cm in relation to level which the individuals were positioned. Higher Spring, spring fixed at 90 cm in relation to level which the individuals were positioned. Near Position, distance of 10 cm from the fixed spring. Distant Position, distance of 30 cm from the fixed spring. Kinematic and eletromyographic data (EMG) were collected simultaneously and the MU and OE muscles were monitored. Each movement of HFE was splitted in two phases (extension and flexion). The EMG signal was calculated and normalized using the maximal voluntary contraction (MVC). The Wilcoxon test was used to investigate differences between the situations (p<0.05). RESULTS: MU muscle presented muscle activation values ranging from 10 to 20 percent MVC, and the highest muscle activation in the lower spring and in the near position. OE muscles presented muscle activation values ranging from 20 to 45 percent MVC, and the highest values in the higher spring and in the distant position. CONCLUSION: MU and OE muscles presented a distinct electrical activation during different available spring adjustments and individual positions.

Determinação da força das linhas do kite sobre um praticante em terra, utilizando o trapézio e a cadeirinha do kitesurfing / Ascertainment of the kite’s lines forces on an athlete in land, using trapeze harness and seat harness of Kitesurfing

No Kitesurfing, o indivíduo utiliza o vento para deslizar com uma prancha sobre a água por meio de um kite, que pode ser preso ao praticante pelos equipamentos: trapézio (posicionado em volta da cintura) ou cadeirinha (posicionada em volta do quadril). A diferença entre eles consiste no ponto em que o kite exerce força sobre o indivíduo. O objetivo do presente estudo foi medir a força das linhas do kite (FLK) exercida sobre um praticante em terra, utilizando o trapézio e a cadeirinha em diferentes posições angulares entre o tronco do indivíduo e as linhas do kite. Um praticante foi preso às cordas de um kite, que foram fixadas à parede e ao teto de uma sala. Ele foi solicitado a manter por 8 s o corpo com certa inclinação em relação ao solo de modo a formar ângulos próximos de 35, 45, 60 e 90° entre a linha de ação da FLK e o seu corpo (medidos com um goniômetro manual), utilizando a cadeirinha e o trapézio. Com uma célula de carga foi registrado a FLK exercida sobre o indivíduo (normalizada pelo seu peso) e com uma câmera de vídeo foram verificadas a sua posição angular. Com o trapézio, a força avaliada foi 43,4±0,2%, 48,5±0,5%, 57,1±0,3% e 25,4±0,11% para os ângulos avaliados em ordem crescente; com a cadeirinha, a força foi 51,9±0,2%, 62,1±1,5%, 57,9±0,2% e 28,3±0,1% para os mesmos ângulos. A FLK sobre o praticante variou de 25 a 60% do peso corporal.

During kitesurfing, the athlete propels himself and his board across the water by transferring the energy of the wind into speed by a large controllable kite, which can be attached to the athlete by 2 equipment: the trapeze harness (placed around the waist) or the seat harness (placed around the hip). The difference between them consist on the point where the kite apply force on the athlete, changing the sailing conditions. However, measuring this force is not easy, due to the environment in which the sport is practiced, therefore to evaluate this force on earth is the first step towards the development of a methodology. To measure the Kite’s lines forces (KLF), applied on the athlete in land, using a trapeze harness and a seat harness in different angular positions between his trunk and the kite’s lines. One practitioner (22years old; 76kg; 1,79m) was attached to the kite’s lines, which were linked to the wall and to the ceiling of a room. The practitioner was asked to keep during 8 s the body with determined inclination in relation to the ground to form angles close to 35, 45, 60 and 90 ° between the line of action of KLF and his body (measured by a manual goniometer and similar to the angles that occur in the sport) using a trapeze harness and a seat harness. The KLF was recorded with a dinamometer. Later this force was normalized by the practitioner weight. And with a video camera the body position and angles desired were checked. With the trapeze harness, the forces evaluated were 43,4±0,2%, 48,5±0,5%, 57,1±0,3% e 25,4±0,11% for the angles measured in ascending range; with the seat harness the forces were 51,9±0,2%, 62,1±1,5%, 57,9±0,2% e 28,3±0,1% for the same angles. The KLF on the practitioner ranged from 25 to 60% of the practitioners weight. The next step will be evaluate the forces and practitioner’s the body position in land with the kite, to later perform measurements in terms of the sport.

Análise mecânica e estimativa da força muscular resultante no aparelho flexor dorsal do pé / Mechanical analysis and estimation of muscle strength resulting in apparatus flexor dorsal foot

Embora a importância do reforço dos dorsiflexores seja conhecida, muitas vezes esses músculos são negligenciados em um programa de treinamento. O objetivo desse estudo é analisar o comportamento do torque resistente do “aparelho flexor dorsal do pé” e analisar o comportamento da força muscular resultante durante o exercício. Para tanto, foram elaborados diagramas de corpo livre da parte móvel do aparelho e do segmento humano e, também, foram determinadas equações de equilíbrio de torque, em que a velocidade foi considerada constante. Os resultados indicam que o torque de resistência do aparelho é crescente até chegar à horizontal e decrescente a partir desse ponto. A força muscular resultante é crescente durante todo o movimento e mais notadamente após a horizontal.

Although the importance of the dorsiflexors muscle work is well known, very often these muscles are neglected in a workout-training program. The aim of this study is to analyze the behavior of the resistant torque on the “dorsiflexors machine” and, also, analyze how the muscle force output during the exercise is. For that, there were designed free body diagrams of the movable part of the machine and human segment. There were made torque equilibrium equations where the velocity was considered to be steady. Our results suggest the resistant torque increases till it gets at the horizontal line and it decreases from this spot on. As for the muscle force output it increases for all over the range of movement and it is more evident after the horizontal line.