TRUNK SURFACE DEFORMATION AND VOLUME MEASUREMENT DURING RESPIRATION USING A LIGHT PROJECTION SYSTEM

This paper aim to measure trunk surface deformation and volume variation during respiration based on realistic 3D data obtained by means of a light projection system. For volume measurement, the trunk was represented as a polyhedron using QHULL method and the polyhedron volume was calculated for each instant of the respiratory cycle. Trunk surface deformation was obtained by means of contour maps and it variation during respiratory movement. The method was tested in one male health subject. Comparing the volume variation curve with the contour maps, it is possible to evaluate how the subject trunk deforms in order to produce this volume variation. In conclusion, the proposed method was able to measure trunk volumes and surface deformation during the respiration

EFFECT OF PILATES BASED EXERCISE ON BODY SWAY AND SHOOTING PERFORMANCE OF BRAZILIANS POLICE

This study investigated the effect of a 10-week Pilates practice on core stability, shooting performance and body sway in fifteen policemen (25.3 ± 3 years; 171 ± 9 cm; 71.6 ± 12.1 kg). The policeman performed 10 pistol shots and had the three dimensional ground reaction forces data (AMTI-OR-06, USA and gun target fluctuation point (SCATT USB Professional Trainer) registered during 5s prior shooting. Shooting score was also determined. Core stability was accessed by the double lowering limb (DLL) test. Although the Mann- Whitney U test showed that the Pilates practice significantly improve the core stability, no changes was observed on body sway or shooting performance. Ten weeks of Pilates practice was effective to improve core stability in policemen, but it was not able to decrease body sway during shooting or the ability of the shooter hit the target

CHANGES IN POSTURAL CONTROL POST AN 8-WEEK DANCE PROGRAM IN FEMALE ELDERLY

This study investigated the effect of an 8wk dance program on orthostatic postural control in elderly. Thirty-four elderly participants were randomly assigned to dance group (DG: n=19; 69.1 ± 6.57 years, 72.5 ± 11.7kg) and control group (CG: n=15; 71.5 ± 7.45 years; 70.9 ± 9.3kg). A force plate was used to measure three dimensional ground reaction force data in three conditions: narrow stance position eyes open and closed and tandem position eyes open, randomly registered over a period of 60 seconds pre and post the intervention. The mean velocity sway and the COP path area were calculated. The results showed that the ballroom dancing program with low/moderate intensity significantly improved balance. Dance would be an optimal activity for an elderly population since it can improve postural control and thus prevent fall incidence

Methodology to determinate trunk volumes during breathing using projected light and surface reconstruction

Orientador: Ricardo Machado Leite de BarrosDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação FísicaResumo: Este trabalho tem como objetivo desenvolver uma metodologia baseada em videogrametria para determinação dos volumes do tronco durante a respiração usando projeção de luz e reconstrução de superfície. A metodologia proposta consiste em: a) Projetar uma malha de marcas circulares sobre a superfície anterior e posterior do tronco; b) Registrar cada superfície através de um par de câmeras de vídeo digitais. c) Segmentar e rastrear as marcas através de ferramentas de processamento de imagens; d) Estabelecer uma correspondência entre as marcas nas seqüências de imagens registradas pelas câmeras; e) Reconstruir as coordenadas 3D das marcas; f) Reconstruir a superfície do tronco; g) Calcular o volume do tronco. A metodologia proposta foi avaliada através de dois experimentos: 1) Comparação entre a medida de volume de um manequim de tronco masculino obtida por imersão (M!) e através da metodologia proposta (MO); 2) Avaliação da aplicabilidade da metodologia para o cálculo do volume do tronco durante a manobra respiratória de capacidade vital. Os resultados mostram que .a metodologia foi capaz de medir e estabelecer uma correspondência automática de mais de duas mil marcas o que possibilitou a reconstrução de uma superfície com alta resolução. No primeiro experimento, a MI foi de 38,39 litros contra 37,34 litros da MO (acurácia relativa de 3%). Os resultados do segundo experimento mostraram que a metodologia foi capaz de identificar um sinal coerente com o ciclo respiratório em manobra de capacidade vital realizado pelo sujeito. Sendo assim, podemos concluir que a metodologia baseada em projeção de luz e reconstrução de superfície proposta é adequada e acurada para medir os volumes do tronco durante a respiraçãoAbstract: This work proposes a video-based method for measuring the trunk volumes during breathing using projected light and surface reconstruction. The method consists of: a) Projecting a grid of circular markers on the anterior and posterior trunk surface; b) Registering each surface using a pair of digital video cameras; c) Segmenting and tracking of the markers using image processing tools; d) Establishing the correspondence between marks in the video sequences registered by different cameras; e) Reconstructing the 3D coordinates; f) Reconstructing the surface; g) Calculating the trunk volume. The evaluation of the method was based on twoexperiments. 1) Comparison of the volume of a trunk model (mannequin) by immersion and using the proposed method (1M). 2) Analysis of the applicability of the method to measure a subject trunk volumes during vital capacity respiratory manoeuvre (OM). The results related to the methodological aspects showed that the method was able to measure and establish the correspondence automatically of more than two thousand points that this provides a very detailed anterior and posterior trunk surfaces. In the first experiments, the 1M were 38.39 liters against 37.34 liters obtained by OM (relative accuracy of 3%). The ana1ysis of the experiment 2 revealed the capability of the method identifies signals coherent with the respiratory cyc1es in vital capacity manoeuvres. In conc1usion, the method based on light projection and surface reconstruction provides an accurate, non-invasive and useful method to calculate human trunk volumes during breathMestradoMestre em Educação Físic

Proposition and evaluation of a method based on light projection for trunk surface reconstruction and analysis during respiration

Orientador: Ricardo Machado Leite de BarrosTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação FísicaResumo: Este trabalho teve como objetivo propor e avaliar um método baseado em projeção de luz para reconstrução e análise da superfície do tronco durante a respiração. O método consistiu em: projetar uma malha de marcas circulares sobre a superfície anterior e posterior do tronco; registrar as superfícies do tronco através de quatro câmeras de vídeo durante a respiração; segmentar as imagens e rastrear as marcas projetadas através de técnicas de pré-processamento de imagens, operações morfológicas e algoritmos de detecção; estabelecer uma correspondência entre as marcas nas seqüências de imagens registradas pelas câmeras; reconstruir as coordenadas 3D das marcas; reconstruir a superfície do tronco a partir da nuvem de pontos desordenada usando o método QHULL. Medidas de variação de volume e perímetro do tronco ao longo do ciclo respiratório e mapas de contorno foram usados para analisar a superfície reconstruída. A acurácia da medida de volume foi avaliada através da comparação entre a medida de volume de um manequim de tronco masculino obtida por imersão e através da metodologia proposta. Um exemplo de aplicação da análise foi realizado com dois sujeitos com formas e tamanhos de tronco distintos, um do sexo feminino com escoliose idiopática severa e um do sexo masculino sem deformações na coluna vertebral. A variação do volume do tronco foi comparada com a variação do volume de ar trocado durante o ciclo respiratório medido através da espirometria. O método foi capaz de reconstruir com alto nível de detalhamento a superfície do tronco possibilitando a identificação de estruturas anatômica e a diferenciação da forma do tronco dura ate as fases do ciclo respiratório. A acurácia relativa na determinação do volume foi de 2,9%. A variação do volume do tronco durante a respiração apresentou um sinal coerente com o ciclo respiratório e apresentou altos valores de correlação (r=0.988) quando comparado com o volume de ar trocado. A análise da superfície através de mapas de contorno mostrou ser uma ferramenta promissora na identificação de deformações da superfície. Podemos concluir que a proposta do uso de um método baseado em de projeção de luz foi adequada para reconstrução e análise da superfície do tronco durante a respiraçãoAbstract: This study aimed to propose and evaluate a method based on light projection for trunk surface reconstruction and analysis during respiration. The method consisted of: to project a grid of circular markers on the anterior and posterior surface of the trunk; to register the trunk surfaces by four video cameras during respiration; to segment the video stream and track the projected markers using pre-processing techniques, morphological operators and detection algorithms; to establish a correspondence between the markers in the sequences of images recorded by the cameras; to reconstruct the 3D coordinates of the markers; to reconstruct the trunk surface from cloud of unorganized points using the QHULL method. Measures of volume and perimeter along the respiratory cycle and contour maps were used to analyze the reconstructed surface. The accuracy of volume measurement was assessed by comparing the volume of a male torso mannequin obtained by water displacement and through the proposed method. An application example of the analysis was conducted with two subjects with different shapes and sizes of different body, a female with severe idiopathic scoliosis and a male without spine deformation. The change in trunk volume was compared with the air exchanged volume variation during the respiratory cycle measured by spirometry. The method was able to reconstruct with high level of detail the trunk surface allowing the identification of anatomical structures and differentiation of the trunk shape during the phases of the respiratory cycle. The relative accuracy in determining the volume was 2.9%. The variation of the trunk volume during respiration showed a coherent signal with the respiratory cycle and showed high correlation (r2 = 0,983) when compared with the volume of air exchanged. The analysis of the surface through contour maps proved to be a promising tool in the identification of the surface deformations. We can conclude that the proposed use of a method based on projection of light was adequate for reconstruction and analysis of the trunk surface during respirationDoutoradoBiodinamica do Movimento HumanoDoutor em Educação Físic

VARIABILITY AND RELIABILITY OF GAIT KINEMATIC PARAMETERS AFTER CONTROLLED TRIPPING IN OLDER ADULTS: A PRELIMINARY STUDY

<div><p>ABSTRACT Approximately 21% of the falls in older adults occur due to tripping, while walking. There is a paucity of information regarding the gait variability and reliability when a tripping is induced in different days mainly with elderly. It was aimed to analyze the variability and the reliability (intra- and inter-day) of spatiotemporal gait parameters and joint angles after controlled tripping in older adults. Eight healthy older women participated. The trip was induced during the early-mid swing phase on the transposing segment and the kinematic data was obtained from trials. The variability and reliability of spatiotemporal gait parameters and joint angles during the gait cycle were checked through the coefficient of variation (CV), the intraclass coefficient correlation (ICC) and the standard error of measurement (SEM). The variability of spatiotemporal and intra- and inter-day angular parameters was low for most variables, except for plantar flexion. The SEM was low for all parameters. Intra-day reliability was moderate to high for the spatiotemporal and angular parameters. Inter-day reliability was considered low to moderate for all parameters. The variables did not differ between instants and days. Experimental procedures demonstrate that the walking pattern did not change, but should be considered with caution in studies that include intervention, particularly for angular parameters during gait.</p></div