Luciano Allegretti Mercadante

Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques

Abstract In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players’ movement patterns during goalball matches that can be used to plan more effective training.

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.

Concordância e correlação entre três métodos distintos para quantificação da altura do salto vertical

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.