Orientação do corpo humano como um todo a partir do seu elipsoide central de inercia

Orientador: René BrenzikoferTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação FisicaResumo: Esta pesquisa propõe uma metodologia para definir a orientação do corpo humano como um todo a partir do seu elipsóide central de inércia, determinado pelo seu tensor central de inércia, calculado a partir da sua distribuição de massa. Definimos um sistema de referência local somático, fixo ao corpo, de forma a apresentar origem no centro de massa deste corpo e eixos com direções coincidentes com as direções dos eixos principais do tensor central de inércia do corpo. Dessa forma, a movimentação do corpo humano é descrita pela translação realizada pelo centro de massa e pelas rotações do sistema local somático, em relação a um sistema inercial. Para isso, o corpo humano é tratado como sendo um modelo fisico formado por um conjunto de segmentos rígidos articulados entre si por juntas ideais fixas em relação aos segmentos adjacentes. Tais segmentos são considerados sólidos geométricos de densidade homogênea. O tensor central de inércia do corpo humano é determinado utilizando um conjunto de dados tridimensionais que permitem obter a localização e orientação dos segmentos do corpo; e dos parâmetros inerciais massa, localização do centro de massa e os três momentos principais de inércia dos segmentos, obtidos a partir do modelo antropométrico proposto por Zatsiorsky et al. (1983, 1985 e 1990). Os dados cinemáticos são obtidos por registro em vídeo do corpo durante o movimento, utilizando o sistema de aquisição e reconstrução tridimensional Dvideow, proposto por Barros et aI. (1999). Mostramos uma aplicação onde um sujeito realiza uma técnica da Capoeira chamada "parafuso". O corpo humano é orientado e localizado em 45 imagens do movimento, nas quais determinamos a localização tridimensional do centro de massa; o sistema local somático fixo ao corpo; os ângulos de Euler entre o sistema local somático e um sistema inercial; o elipsóide central de inércia do corpo, que caracteriza a variação da distribuição de massa do corpo pela variação da forma do elipsóide de Legendre construído a partir deleAbstract: This research propose a methodology to define the orientation of the human body as a unit trom its central ellipsoid of inertia, which is determined by its central tensor of inertia, calculated trom the body mass distribution. A body local reference system was defined, fixed to the body, in a way that its origin is coincident to the body' s center of mass and the axes are towards the same directions of that form the principal axes of the body' s central tensor of inertia. The body movement is then described by the center of mass' translation and by the body local system's rotation, according to a inertial system. To do soo, the human body is considered a physical model formed by rigid segments articulated by ideal joints fixed according to the adjacent segments. These segments are considered geometric solids with homogeneous density. The central tensor of inertia is determined by a group of three-dimensional data, which allow one to obtain the localization and orientation of the body' s segments; and by the inertial parameters, which are mass, center of mass localization and the segments three principal momentum of inertia, obtained trom the model proposed by Zatsiorsky et ai. (1983, 1985 e 1990). The cinematic data are obtained by recording body movements in video, using the acquisition system and three-dimensional reconstruction Dvideow, proposed by Barros et al. (1999). One application where a person performs a Capoeira technique called "screw" is shown. The human body is oriented and localized in 45 trames, in which the threedimensional localization of the center of mass, the fixed body local system, the Euler angles between the body local system and the inertial system, the central ellipsoid of inertia of the body, which characterizes the variation of the body's mass distribution by the variation of the Legendre' s ellipsoid shape constructed with it, are determinedDoutoradoDoutor em Educação Físic

Angle of attack of center of mass during the running of an entire 100m dash

The angle of attack is related to the body posture and changes during sprinting because of changes in the horizontal velocity. The aim of this study was to analyze the angle of attack of the center of mass and the horizontal velocity during a 100 m dash. Twelve video cameras were positioned along a running track to obtain the position of the center of mass. The horizontal velocity was derived from the position data. When the different sides were compared, the angles were lower on the right side than on the left side (P < 0.05), which tended to decrease with increasing horizontal velocity. The results show the variability of the angle of attack as associated to the horizontal velocity, and the differences considering laterality

Physical Activity Demands in Elite Basketball Games

We describe a new classification of the physical demands of basketball by comparing different positions and functions of players on the team. We classified movements into three categories: horizontal displacements (divided into six subcategories), vertical displacements (divided into six subcategories), and contact forces (divided into two subcategories). The increased number of contact forces recorded in a basketball game reveals the importance of including this category in the analysis. This work reveals the importance of considering physical activities in different ways using more detailed categories

DISTANCE COVERED IN DIFFERENT GAME SITUATIONS BY HIGHLEVEL BASKETBALL PLAYERS FROM BRAZIL

The aim of this study was to propose a way to classify four different game situations in a basketball game and quantify the covered distances by player positions in each category, using a video-based system. One game of the season 2011/2012 New Basketball Brazil was analyzed. The data on distance covered by the players on both teams was obtained with a video-based manual tracking method (Dvideo System). The game situations were classified as: attack, defense, transition to attack or transition to defense. The distances covered are shown by each player’s position. Significant differences were observed between attack and defense vs. transition to attack and transition to defense, and also for transition to attack vs. transition to defense

A video-based framework for automatic 3d localization of multiple basketball players : a combinatorial optimization approach

Sports complexity must be investigated at competitions; therefore, non-invasive methods are essential. In this context, computer vision, image processing, and machine learning techniques can be useful in designing a non-invasive system for data acquisition that identifies players’ positions in official basketball matches. Here, we propose and evaluate a novel video-based framework to perform automatic 3D localization of multiple basketball players. The introduced framework comprises two parts. The first stage is player detection, which aims to identify players’ heads at the camera image level. This stage is based on background segmentation and on classification performed by an artificial neural network. The second stage is related to 3D reconstruction of the player positions from the images provided by the different cameras used in the acquisition. This task is tackled by formulating a constrained combinatorial optimization problem that minimizes the re-projection error while maximizing the number of detections in the formulated 3D localization problem8286CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNão temNão temNão temWe would like to thank the CAPES, FAEPEX, FAPESP, and CNPq for funding their research. This paper has content from master degree’s dissertation previously published (Monezi, 2016) and available onlin

3D KINEMATICAL ANALYSIS OF THE HAMMER THROW IN COMPETITIONS

This study analyzes 14 throws accomplished in Brazilian competitions and it compares with available international results in the literature. It calculates the angle, the velocity and the height of release of the hammer and the velocity curves in function of the time, starting from the 3D trajectory of the head of the hammer. The analyses relate the difference between Brazilian (averages of 55.38m male and 52.05m female) and international results (averages of 79.44m male and 70.60m female) and the release velocity (Brazilian averages of 24.59m/s male and 23.59m/s female, and international of 29.60m/s male and 28.89m/s female). The velocity curves in function of the time of the international releases show that the accelerations are higher and the deceleration lower during the turns, when compared with a Brazilian throw

Technical Indicators registered as a function of the playing time in Brazilian basketball

Basketball performance analysis using technical indicators dissociated from the moment they occurred in the game seems to no longer respond to emerging issues of the game as it does not identify the periods when a team’s offensive efficiency has increased or decreased. The aim was to characterize and compare the technical indicators in the positive and negative periods and in the whole game of winning and losing teams in men’s professional basketball. Fourteen games of professional men’s teams of the “Novo Basquete Brasil” Championship in the regular 2011/2012 season were filmed and analyzed. The Kolmogorov-Smirnov test was used to verify data normality. The independent T test was used for variables with normal distribution and the Mann-Whitney test for variables that did not present normal distribution, in order to compare teams’ performance. Analysis in the whole game showed that winning teams had significantly higher averages in successful 3-point field goals but in the positive periods, they showed higher averages for successful free throws, successful layups, defensive rebounds and defensive fouls, and in negative periods, losing teams made more defensive and offensive fouls. The teams’ performance in the whole game may not elucidate the determinant indicators for building the difference in the scoreboard. It is suggested that coaches should identify the periods of best and worst teams’ performance in the game and the indicators involved, preparing teams to overcome the negative periods and obtain more positive periods in the game

The distances covered by basketball referees in a match increase throughout the competition phases, with no change in physiological demand

It is crucial to know the demands on basketball referees, in different match periods (MPs) and phases of competition, for planning referee training and subsequent successful refereeing. To measure and evaluate the distance covered by referees in a match by measuring the number of interruptions, percentage of heart rate (%HR), and blood lactate concentration ([lac]) in different phases of competition and in different MPs. We studied the qualifying (QP), semifinal (SP), and final (FP) phases of a total of 12 matches (four matches in each phase) of the 2009-2010 Brazilian Basketball League. Distance covered, number of match interruptions, and referees' %HR and [lac] were analyzed. We compared the results between competition phases and between MPs (1st MP, 2nd MP, 3rd MP, and 4th MP). Regarding the distances covered, we observed significant differences (P < 0.05) in the 1st, 2nd, and 3rd MPs between the FP and the other two phases (SP and QP) throughout the match, between each phase; in the 4th MP, a significant difference was found when comparing the QP and the other two phases. Comparing the periods within each phase, we found that a greater distance was covered in the 4th MP in relation to the 3rd MP during the FP. No significant differences were found among the remaining variables. The distances covered by referees in a basketball match increase throughout competition phases. This information is essential for planning of training and for the subsequent success of a referee.It is crucial to know the demands on basketball referees, in different match periods (MPs) and phases of competition, for planning referee training and subsequent successful refereeing. To measure and evaluate the distance covered by referees in a match by measuring the number of interruptions, percentage of heart rate (%HR), and blood lactate concentration ([lac]) in different phases of competition and in different MPs. We studied the qualifying (QP), semifinal (SP), and final (FP) phases of a total of 12 matches (four matches in each phase) of the 2009-2010 Brazilian Basketball League. Distance covered, number of match interruptions, and referees' %HR and [lac] were analyzed. We compared the results between competition phases and between MPs (1st MP, 2nd MP, 3rd MP, and 4th MP). Regarding the distances covered, we observed significant differences (P < 0.05) in the 1st, 2nd, and 3rd MPs between the FP and the other two phases (SP and QP) throughout the match, between each phase; in the 4th MP, a significant difference was found when comparing the QP and the other two phases. Comparing the periods within each phase, we found that a greater distance was covered in the 4th MP in relation to the 3rd MP during the FP. No significant differences were found among the remaining variables. The distances covered by referees in a basketball match increase throughout competition phases. This information is essential for planning of training and for the subsequent success of a referee419319

TRAJETÓRIA NO BASQUETEBOL E PERFIL SOCIODEMOGRÁFICO DE ATLETAS BRASILEIRAS AO LONGO DA CARREIRA: UM ESTUDO COM A LIGA DE BASQUETE FEMININO (LBF)

Starting in the 2000s, we observed a challenging scenario for the development of female basketball athletes in Brazil. In 2010, the Women’s Basketball League (LBF) was created to restructure that sport in the country. The aim of the study was to describe LBF 2018 athletes’ trajectories and sociodemographic profiles throughout their careers. Data were collected through an online questionnaire voluntarily answered by 57 athletes (average age 25.9 ± 6.6 years). The school was the main place for their first contact with basketball. Most athletes (79%) played for junior National Teams and 30% reached the adult National Team. Brazil’s Southeast stood out as the main region for practicing female basketball. A career in basketball creates a perception of improvement in terms of social class. Finally, the group of athletes had higher levels of education than the average Brazilian population.  Después del año 2000, observamos un escenario desafiador para el desarrollo de mujeres atletas de baloncesto en Brasil. En 2010, se crea la Liga de Baloncesto Femenino (LBF) para contribuir con la reestructuración de esa modalidad deportiva en el país. El objetivo del estudio fue investigar índices deportivos y sociodemográficos a lo largo de la carrera de atletas de la LBF en 2018. Los datos se recolectaron mediante un cuestionario online que respondieron voluntariamente 57 atletas (edad media 25,9 ± 6,6 años). La escuela fue el principal lugar de primer contacto con ese deporte. La mayoría de las atletas (79%) fue convocadas para selecciones y el 30% llegó a la selección adulta. La región Sudeste se destacó como la principal región donde se practica esta modalidad. La carrera en el baloncesto proporcionó una percepción de mejoría de clase social. Finalmente, el grupo de atletas presentó niveles de escolaridad más altos que la media de la población brasileña. Após os anos 2000, observamos um cenário desafiador ao desenvolvimento de mulheres atletas de basquetebol no Brasil. Em 2010, a Liga de Basquete Feminino (LBF) foi criada para contribuir com a reestruturação da modalidade no país. O objetivo do estudo foi investigar indicativos esportivos e sociodemográficos ao longo da carreira de atletas da LBF 2018. Os dados foram coletados por um questionário online respondido voluntariamente por 57 atletas (média de idade 25,9 ± 6,6 anos). A escola foi o principal local de primeiro contato com a modalidade. A maioria das atletas (79%) foi convocada para seleções e 30% chegaram à seleção adulta. O Sudeste se destacou como a principal região de prática da modalidade. A carreira no basquetebol proporcionou percepção de melhoria de classe social. Por fim, o grupo de atletas apresentou níveis de escolaridade mais altos do que a média da população brasileira.

Agreement and correlation among three different methods for the quantification of the vertical jump height

O presente estudo teve como objetivo analisar a correlação e concordância entre três diferentes métodos para quantificação da altura do salto vertical: cinta de Abalakov (AB), tapete de contato (TC) e videogrametria (VG). Treze atletas de vôlei do sexo feminino. Realizaram três saltos verticais máximos com contramovimento sem o auxílio dos membros superiores. Os três métodos mediram a altura do salto simultaneamente. Foram realizados os testes de correlação de Pearson (r) entre cada par de métodos (AB x TC, AB x VG e TC x VG). Por fim, a concordância entre cada par de métodos foi avaliada através da análise gráfica de Bland e Altman. A menor correlação encontrada (r = 0,77; p < 0,01) ocorreu entre os métodos de VG e AB, enquanto que a maior correlação encontrada (r = 0,92; p < 0,01) ocorreu entre os métodos de VG e TC. Não houve concordância satisfatória entre os valores encontrados para os diferentes métodos, sugerindo que profissionais da área tenham cautela na comparação entre resultados de altura do salto vertical obtidos por diferentes métodos.The purpose of the present study was to analyze the association and the agreement among three different methods to quantify of the vertical jump height: abalakov belt (AB), contact mat (TC) and videogrammetry (VG). Thirteen female volleyball players performed three maximal countermovement jumps, without the help of upper limbs. The three methods were used simultaneously to quantify the jump height. The lowest correlation (r = 0.77; p < 0.01) was found between VG and AB, while the strongest correlation (r = 0.92; p < 0.01) was found between VG and TC methods. In addition, Bland and Altman plots revealed no satisfactory agreement between the methods. These findings suggest precaution to compare the results of vertical jump height from different methods