Evaluation of the snatch performance quality weightlifters of training groups based on biomechanical analysis

Relevance. Weightlifting refers to sports that require the manifestation of maximum strength. At the same time, demonstration of the maximum weight of the barbell is possible only with the correct technique of performing a competitive exercise. Often, even highly qualified athletes, as a result of mistakes in technique, do not achieve the planned sports result. This may be a consequence of both incorrect implementation of the approach and errors in the process of preliminary training. Most of the research in weightlifting is devoted to building a training process aimed at working with different weights to achieve maximum strength. Exercises on the technique of movement are given relatively less importance. When performing a jerk, the most optimal trajectory of movement is recommended, in which three main directions of horizontal displacement of the bar are distinguished - «to yourself - from yourself - to yourself». That is, the movement of the barbell should be carried out as close as possible to the body of the weightlifter. At the same time, sometimes immediately after lifting the barbell from the platform, a different trajectory of the projectile movement is observed - in the opposite direction from the athlete. It is this starting interval that has a significant impact on the trajectory of lifting the barbell as a whole, leads to possible errors, and therefore requires special study. The aim of the work is to identify biomechanical criteria for assessing the quality of the jerk in athletes of training groups. Research methods. The study involved 10 weightlifters of the training stage aged 13-15 years. The athletes' snatch technique was recorded with the help of highspeed videography. Each athlete recorded 3 attempts in the snatch with a constant increase in the weight of the barbell: 50% of the maximum weight, 70% and 100%. After collecting the primary information, its analysis was carried out using the Kinovea program. The trajectories of the projectile movement and indicators of articular angles between the links of the athlete's body were analyzed. The results of the study were processed by methods of mathematical statistics. The results of the study. The analysis allows us to note that changes in the angles of the body links affect the amount of horizontal displacement of the rod. In order to perform the correct movement in a jerk, it is important to maintain optimal angles in the knee joints: the athlete's legs should be unbent, and the pelvis should move upwards until the barbell reaches the level of the knee joints, and the lower legs will not be in an upright position. From our study, it can be seen that in the acceleration phase, the optimal values of the angle in the knee joint should be 135 - 140 °. In this case, the horizontal displacement of the rod forward will be the smallest. Conclusion. The values of the angles in the knee and hip joints and the horizontal displacement of the barbell can be used to judge the quality of the jerk. The smaller the angle in the knee joints, the stronger the horizontal deflection of the barbell forward, which determines the wrong technique of movements in the pre-acceleration phase.