SEPARATE TRUNK VOLUMES AND RIBS MOTION CORRELATIONS IN SWIMMERS

The purpose of this study was that to analyze the separate trunk volumes and ribs motion correlations aiming to verify swimmers present better motor coordination or control during breathing. The trunk was represented by 53 markers, attached to the ribs, vertebrae, thorax and abdomen of 13 male swimmers and 10 non-athletes. From the 3D coordinates of the markers, obtained by a kinematical analysis system equipped with 6 digital video cameras (60Hz), in function of time, the rotation angles of the 2nd to the 10th ribs around the quasi-transversal axis and the volumes of 4 separate compartments of the trunk were calculated (superior thorax, inferior thorax, superior abdomen and inferior abdomen). Correlating the curves of ribs rotation angles with the curves of the separate volumes, swimmers presented higher values during vital capacity manoeuvers when the correlation involved the inferior thorax and the superior and inferior abdomen. These results showed a better coordination between the trunk volumes and the ribs motion in the swimmers during vital capacity manoeuvers, suggesting that swimming practice leads to the formation of an optimized breathing pattern when larger efforts are required from the respiratory system

INFLUENCE OF YEARS OF SWIM TRAINING ON SEPARATE THORACOABDOMINAL VOLUMES DURING BREATHING

The purpose of this study was to verify the influence of the years of swim training on the separate thoracoabdominal volume variation during breathing using a kinematic analysis. Fifteen male swimmers were analyzed during tidal volume and vital capacity maneuvers. From the 3D coordinates of 30 markers fixed at the trunk the volumes of 4 separate compartments of the trunk (superior thorax, inferior thorax, superior abdomen and inferior abdomen) were calculated in function of time. During tidal volume, the coefficient of variation of the volumes of the superior and inferior abdomen increased with the years of swim training (

SEPARATE TRUNK VOLUMES AND RIBS MOTION CORRELATIONS IN SWIMMERS

The purpose of this study was that to analyze the separate trunk volumes and ribs motion correlations aiming to verify swimmers present better motor coordination or control during breathing. The trunk was represented by 53 markers, attached to the ribs, vertebrae, thorax and abdomen of 13 male swimmers and 10 non-athletes. From the 3D coordinates of the markers, obtained by a kinematical analysis system equipped with 6 digital video cameras (60Hz), in function of time, the rotation angles of the 2nd to the 10th ribs around the quasi-transversal axis and the volumes of 4 separate compartments of the trunk were calculated (superior thorax, inferior thorax, superior abdomen and inferior abdomen). Correlating the curves of ribs rotation angles with the curves of the separate volumes, swimmers presented higher values during vital capacity manoeuvers when the correlation involved the inferior thorax and the superior and inferior abdomen. These results showed a better coordination between the trunk volumes and the ribs motion in the swimmers during vital capacity manoeuvers, suggesting that swimming practice leads to the formation of an optimized breathing pattern when larger efforts are required from the respiratory system

CHEST WALL KINEMATICS OF ATHLETES WITH TETRAPLEGIA

The purpose of this study was to analyze the 3D dimensional kinematics of the chest wall to describe the respiratory movement of tetraplegic athletes. Wheelchair rugby players were filmed during respiratory maneuvers. Markers were affixed to the trunk of the volunteers. From the 3D coordinates of markers, four compartmental volumes of the trunk were calculated. We analyzed the coefficient of variation of volumes in different compartments of the trunk for each subject, and the results were compared among the compartments. It was possible to verify the contribution of each compartment during respiration. The lower abdomen compartment had the highest average coefficient of variation. The methodology was able to identify the volume variations of chest wall and can be efficient to evaluate the effects of sports on ventilatory mechanics of tetrapelgic

ACCURACY OF SPORT ACTION CAMERAS FOR 3D UNDERWATER MOTION ANALYSIS

The purpose of this study was to evaluate the accuracy of sport action cameras for 3D underwater motion analysis. Two cameras (GoPro) were fixed in the swimming pool. The image resolution was set to 1920 x 1080, the view angle was set to 127o and the frame rate was 60 Hz. A Wi-Fi remote was used to start the cameras. A wand calibration method based on radial distortion model was used to calibrate the cameras. The accuracy was evaluated in eight trials of dynamic rigid bar tests (working volume 4?1?1.5m3). The results revealed mean absolute error ranging from 1.23 mm to 1.93 mm. These values of accuracy for underwater analysis can be considered acceptable for the majority of 3D underwater motion analyses, in particular for swimming biomechanics

A CASE STUDY OF THE KICKING FOOT AND STANCE IN ROUNDHOUSE KICK: CONTROL AND COMBAT SITUATIONS

Once this work is part of a long term study, the aim was to show the preliminary results of the comparison of the kicking foot and stance in the roundhouse kick according to the onset condition (control vs. combat situation). One black belt athlete participated on this study. A motion capture system of 18 cameras (Optitrack© 360Hz) was used for the kinematic data acquisition. In order to obtain the maximum height and speed, execution and movement time of the kicking foot we used one marker. In order to represent the stance positions we used five markers. The preliminary analyses suggest that there are differences between control and combat situations: 1.the maximum height was smaller in combat situation since the athlete prefers to kick in the trunk of the opponent and 2.the stance positions highlight the influence of the movements of the opponent in combat

VALIDITY AND RELIABILITY OF THE MICROSOFT KINECT TO OBTAIN THE EXECUTION TIME OF THE TAEKWONDO’S FRONTAL KICK

The aim of this study was to verify the validity and reliability of the Microsoft Kinect® as a tool to analyze the time of the frontal kick of the Taekwondo (ap chagui). The volunteers performed 15 repetitions of this kick while the execution time data was been obtained, simultaneity, by the Microsoft Kinect® and the OptiTrack System (golden pattern). In order to verify the reliability of the durations of the kicks we calculated the Intraclass Correlation Coefficient (ICC3,k) between execution times found for each system. The Pearson Correlation was used to test the concurrent validity. The results of ICC and r Pearson presented in this study indicate that the Microsoft Kinect®, associated with a tracking algorithm, could be a feasible tool to evaluate the execution time of the frontal kick of the Taekwondo (ap-chagui)

Methodology for kinematic analysis of swimmer's trunks separate respiratory volumes

Orientador:Ricardo Machado Leite de BarrosDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação FisicaResumo: Este trabalho consiste na análise de dois problemas relacionados à análise cinemática de volumes parciais de nadadores. O primeiro problema foi analisar os possíveis efeitos do treinamento e a influência dos anos de treinamento em natação nos volumes parciais do tronco em volume corrente e durante a manobra de capacidade vital usando análise cinemática. Foram selecionados dois grupos experimentais: Grupo de Nadadores e Grupo Controle. A partir das coordenadas 3D de 30 marcadores esféricos e retro-reflexivos fixados na superfície do tronco obteve-se as curvas dos volumes dos 4 compartimentos (tórax superior, tórax inferior, abdômen superior e abdômen inferior.) e foram calculados em função do tempo. A partir das curvas de volumes dos compartimentos foram calculados e comparados (ANOVA, p<0,05): o coeficiente de variação, o coeficiente de correlação entre os compartimentos do tronco para ambos os grupos. A regressão linear entre o coeficiente de variação dos volumes dos nadadores e os anos de treinamento em natação e a regressão linear entre o coeficiente de correlação e os anos de treinamento em natação (p<0,05) também foram calculados. Os resultados deste estudo mostraram que os nadadores sofrem efeitos do treinamento em natação obtendo maiores variações relativas dos compartimentos do abdômen, uma maior sincronia entre os compartimentos do tronco durante a manobra de capacidade vital e que anos de treinamento em natação afetam a variação relativa dos volumes parciais e a coordenação tóraco-abdominais durante respirações tranqüilas e quando maiores esforços respiratórios são exigidos, refletindo um aumento na utilização do diafragma. O segundo problema foi desenvolver um sistema para análise cinemática tridimensional submersa de volumes parciais do tronco (DvideoSub). O sistema consiste em 5 câmeras Basler (fc602A) protegidas por caixasestanques especialmente projetadas para as câmeras conectadas em um único desktop PC para aquisições online. Interfaces de softwares foram desenvolvidas para aquisição de dados, controle das câmeras, medição dos dados e reconstrução tridimensional baseados no sistema Dvideo. Para a avaliação do sistema foram realizados testes para analisar o efeito da lente de policarbonato, o efeito da correção óptica fora da água com a calibração do sistema fixo e móvel de calibração, o efeito da correção óptica dentro da água, o efeito da água, os erros de reconstrução de pontos conhecidos e a acurácia da distância de um corpo rígido em movimento. A partir do cálculo da distância do corpo rígido em função do tempo foram calculados: a média, o erro total, o RMS, o RMS%, o erro absoluto médio e a acurácia. Foi analisada também a aplicação do sistema proposto para a análise dos volumes parciais do tronco submerso a partir do cálculo do coeficiente de correlação entre os compartimentos do tronco na manobra de capacidade vital realizada fora e dentro da água. Os resultados mostraram que a lente de policarbonato influência no erro total da distância, a correção óptica proposta melhora o erro total da distância com a calibração do sistema fixo e com a utilização do sistema móvel para calibração os resultados não apresentaram melhora, sugerindo que este deve ser reformulado. O erro absoluto médio foi de 1,0mm fora da água e 2,8mm dentro da água, valores estes que estão dentro dos valores apresentados pela literatura (a partir 0,5mm até 11,6mm). Os valores de RMS obtidos fora da água (2,4mm ±0,01) e dentro da água (2.0mm ±0.01) foram similares e estes foram menores que os valores encontrados em Gourgoulis, et al., (2008) (4,6±0,5 fora da água, 5,9 ±1,5 dentro da água). Os coeficientes de correlação entre os compartimentos do tronco foram altos em ambas as situações. Os resultados mostraram a viabilidade do sistema para a análise cinemática tridimensional submersa e para a análise de volumes parciais com o tronco submerso. De maneira geral, as variáveis analisadas mostraram que a prática em natação pode causar um padrão respiratório diferenciado e a quantidade de anos de treinamento pode acentuar ainda mais este padrão respiratório. O sistema proposto apresentou resultados satisfatórios podendo ser usado para a análise cinemática tridimensional submersa com diferentes objetivos.Abstract: This work consists on the analysis of two problems related to the kinematic analysis of the swimmer's separate volumes. The first problem was to analyze the effect of the swim training and the influence of the years of swim training on the separate volumes of the trunk, during tidal volume and vital capacity, maneuver using a kinematic analysis. Two groups were used: Control Group and the Swimmer Group. From the 3D coordinates of 30 land markers fixed on the trunk, the volumes of 4 separate compartments of the trunk (superior thorax, inferior thorax, superior abdomen and inferior abdomen) were calculated in function of time. From the curves of the separate volumes, the coefficient of variation and the correlation coefficient between the compartments were calculated for both groups and compared between groups (ANOVA, p<0.05). The linear regression between the coefficient of variation of the separate volumes and the years of swim training and the linear regression between the correlation coefficient and the years of swim training (p<0.05) were calculated. The results indicated that the swim training affects the separate volumes of swimmers causing higher relative variations of the abdomen compartments and a greater coordination between the compartments of the trunk during the vital capacity maneuver. These results suggest that the years of swim training affect the separate thoracoabdominal volumes during tidal volume and when higher respiratory efforts are required, reflecting the increased utilization of the diaphragm. The second problem was to develop a 3D underwater kinematic analysis system of separate volumes of the trunk (DvideoSub). The system consisted of up to five Basler cameras (fc602A) enclosed in housings specially designed and connected to a single desktop PC for online data acquisition. Software interfaces were developed for acquisition, camera controls, measurements and 3D reconstruction starting from a previously proposed system, named Dvideo. The system was evaluated according to the following analyzing tests: the effect of the polycarbonates lens (housing); the effect of the optic correction out of the water with the calibration of the fixed and mobile system of calibration; the effect of the optic correction underwater; the effect of the water; the errors of reconstruction of known points and a rigid body in movement accuracy. From the distance of rigid body in function of time we have calculated the mean, the total error, the RMS, RMS%, the absolute mean error and the accuracy. The application of the system for the analysis of the separate volumes of the submerged trunk was analyzed from the calculation of the correlation coefficient between the compartments of the trunk in vital capacity maneuver out and underwater. The results showed that the polycarbonates lens influence in the distance total error, the optic correction proposed improves the distance total error with the calibration of the fixed system and with the use of the mobile system for calibration the results have not presented improvement, suggesting that this must be reformulated. The RMS error values obtained out of the water (2.4mm ±0.01) and underwater (2.0mm ±0.01) were similar and they were lower than the values found in (Gourgoulis, , 2008) (4.6±0.5 out of water, 5.9 ±1.5 underwater). The absolute mean error was 1.0mm out of the water and 2.8mm underwater, which are in accordance to the values found in literature (from 0.5mm to 11.6mm). The results showed the reliability of the system for the underwater three-dimensional kinematic analysis. Concluding, the analyzed variables showed that the swim practice may lead to a respiratory pattern and the quantity of years of swim training may have an influence in stabilizing this pattern. The proposed system presented satisfactory results and can be used to underwater 3D kinematic analysis with different objectives.MestradoBiodinamica do Movimento HumanoMestre em Educação Físic

Cameras calibration for underwater motion analysis

Orientador:Ricardo Machado Leite de BarrosTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação FísicaResumo: Para análises subaquáticas de movimentos tridimensionais é necessária uma calibração precisa de grandes volumes. Métodos baseados em modelos lineares de câmeras são comumente utilizados na biomecânica e para isso faz-se necessário a construção, o transporte e a medição de estruturas rígidas, o que se torna mais difícil quando volumes maiores estão envolvidos. Recentemente, métodos alternativos baseados em modelos não-lineares de câmeras, foram propostos para resolver este aspecto. Assim, os objetivos deste trabalho foram 1) avaliar a exatidão da reconstrução tridimensional fora e dentro da água utilizando o método proposto por Zhang (2000); 2) avaliar a exatidão dos métodos não-lineares para a calibração de câmeras propostos por Hatze, 1988, Cerveri, et al., 1998 e Zhang, 2000 para aplicações com câmeras submersas e os efeitos da variação da posição no volume de calibração sobre a exatidão de reconstrução tridimensional dos métodos e ressaltando, ainda as vantagens e desvantagens de cada método e 3) testar a aplicabilidade dos métodos não-lineares propostos por Cerveri et al., 1998 e Zhang, 2000 para a reconstrução da trajetória da mão de nadadores em diferentes nados. Para aquisição dos dados foi utilizado um sistema de análise cinemática (DVideo), que foi adaptado para aquisição de imagens submersa. O sistema consiste de computadores ligados em câmeras (Basler) para aquisição online de dados. Caixa-estanques especialmente desenvolvidas para o modelos das câmeras foram utilizadas para proteção e um genlocker trigger foi utilizado para a sincronização das câmeras. Tripés para sustentação e fixação das câmeras foram adaptados com ventosas para fixação no fundo da piscina. Para a correção da distorção foram implementados em Matlab os métodos não-lineares para a calibração de câmeras. Um teste de barra rígida foi usado para avaliação da exatidão e precisão. Os resultados mostraram que os métodos propostos por Cerveri et al., 1998 (1,16mm a 0,96mm) e Zhang, 2000 (0,73mm) são alternativas promissoras para análise tridimensional de movimentos subaquáticos. Ambas as metodologias apresentaram resultados com maior exatidão que os encontrados na literatura. Este fato ocorreu devido a uma melhor modelagem da distorção óptica que foi confirmada pela menor influência no erro relativo à posição do objeto no volume de aquisição. Quanto à flexibilidade e portabilidade em relação ao objeto de calibração, ambos os métodos usam objetos mais fáceis de construir e manipular do que os objetos tradicionalmente utilizados. O sistema para a análise tridimensional do movimento utilizando câmeras submersas mostrou-se ser adequado para aplicações subaquáticas. Uma vez que, os resultados aqui relatados podem ser imediatamente apreciados pelos treinadores, pois foi possível identificar simetria ou assimetria entre os dois lados, a variabilidade intra e inter-sujeitos em termos de padrões de movimento e concordância ou discordância com o modelo teórico. Importante ressaltar que existe a possibilidade de extensão da análise para os diferentes segmentos corporais e o sistema e os métodos para a calibração de câmeras apresentados neste trabalho podem ser utilizado para qualquer esporte ou atividade realizada na água, como por exemplo, hidroginásticas ou práticas de reabilitaçãoAbstract: In order to perform a three-dimensional motion analysis in underwater conditions is necessary to calibrate accurately large volumes. Methods based on linear camera models are commonly used in biomechanics and this requires to construct, to transport and to measurement rigid structures, which becomes more difficult when larger volumes are involved. Recently, alternative methods based on nonlinear camera models have been proposed to address this aspect. The aims of this study were 1) to evaluate the accuracy of 3D reconstruction out and underwater using the method proposed by Zhang (2000); 2) to evaluate the accuracy of nonlinear camera calibration methods proposed by Hatze, 1988, Cerveri, et al., 1998 and Zhang, 2000 for underwater applications using submerged cameras and the effects of object position in the acquisition volume on the accuracy of 3D reconstruction methods, highlighting the advantages and disadvantages of each method, and 3) to test the applicability of the nonlinear methods proposed by Cerveri et al., 1998 and Zhang, 2000 for the reconstruction of the swimmers hand trajectory in different swims styles. For data acquisition, we used a kinematic analysis system (DVideo), which was adapted for underwater conditions. The system consists of cameras (Basler) connected in computers for online data acquisition. Waterproof housings were specially designed to protect the cameras and a genlocker trigger was used to synchronize the cameras. Tripods to support and to fix the cameras were adapted with suction cups and were used to fix them on the swimming pool floor. In order to perform the distortion correction the nonlinear camera calibration methods were implemented in Matlab software. A rigid bar test was used to assess the accuracy and precision. The results showed that the methods proposed by Cerveri et al. 1 998 (1.16 mm to 0.96 mm) and Zhang, 2000 (0.73 mm) are promising alternatives for 3D underwater motion analysis. Both methodologies presented results with greater accuracy than those found in the literature. This occurred due to an improvement of the distortion modeling and that was confirmed by the smallest influence of the object position on the error values. Related to the flexibility and portability of the calibration object, both methods use objects easier to build and manipulate than the objects traditionally used. The 3D motion analysis system using submerged cameras showed to be suitable for underwater applications. The results reported here can be immediately appreciated by coaches, because it was possible to identify symmetry or asymmetry between the two sides, the variability within and between subjects in terms of movement patterns and agreement or disagreement with the theoretical model. Important to emphasize that there is the possibility of extending the analysis for different body segments and the system and the camera calibration methods presented in this work can be used for any sport or activity performed in water, such as hydro gymnastic or rehabilitation practicesDoutoradoBiodinamica do Movimento HumanoDoutor em Educação Físic