Kinematic analysis of the soccer goalkeeper's jump in penalty: effect of instructional video and laterality on performance

Abstract

The penalty in soccer represents a decisive moment in the game, so it is important to understand its aspects for teaching, learning and training. The present study aims to analyze the effect of laterality and instructional video on the goalkeeper's behavior when jumping to defend a penalty kick. Ten volunteer goalkeepers who trains in youth academies of professional soccer clubs in Ribeirão Preto and region will be used. They will be divided into two groups, control and instructional video, the second will be oriented to perform 20 jumps on the field with launched balls, ten before and after receiving video instructions, while the control will only perform the jumps. For kinematic analysis, collections will be recorded by 3 cameras at an acquisition frequency of 240 Hz. The identification of joints and anatomical points in the videos will be done through the trained artificial neural network Open Pose. 2D data will be used for 3D reconstruction of jumps with the 3D-DLT method (direct linear transformation) in Python 3. After calculating the center of body mass, its displacement, velocity and acceleration will be determined. To identify if there will be differences between the first 10 and the last 10 jumps and if there will be differences between the sides of the jump in both groups, the Student's t test for paired samples will be used using the Statistical Parametric Mapping (SPM) method of statistical analysis. In all cases, the level of significance will be p d 0.05. It is expected that there will be no difference in the variables studied between the sides of the jump and that there will be significant differences between the jumps performed before and after the video instruction.