Snatch Weightlifting Research Articles

Concentration time values in two-arm snatch weightlifting, 109-kg junior class (under 20)

Elite sport is a social phenomenon strongly anchored in the reality of today’s world. In an increasingly advanced technological society, no one is surprised by the use of the fastest means of multimedia communication. Implementing this technology in the field of top-level sport offers multiple possibilities for an objective behavioural analysis of athletes during competition. This study, the first to address juniors aged 17-20 years, is part of a broader research aimed at investigating athletes (of both genders and different classes) with regard to certain moments that involve the analysis of concentration times characterising weightlifting styles. The current study focuses on the recording and analysis of concentration times from the moment the feet are just under the bar until the bar is lifted off. Objectives: 1. To examine the possibilities of using the computerised imaging technique in snatch weightlifting; 2. To identify concentration times in snatch weightlifting by recordings and measurements performed with AviSynth equipment. The main research method used is computerised technology connected to video technology. The research presents the recording and analysis of concentration times for snatch weightlifters in value group A, 109-kg Junior Class. It includes 11 male athletes aged 17-20 from various countries. Thus, Bulgaria participated with two athletes, and Albania, Armenia, Azerbaijan, Belarus, Georgia, Poland, Russia, Spain and Turkey, with one athlete each. The result analysis highlights aspects regarding concentration times in the snatch event: average concentration times for the three attempts and for each attempt, the relationship between lifted weight and concentration time.

Distance Motor Learning during the COVID-19 Induced Confinement: Video Feedback with a Pedagogical Activity Improves the Snatch Technique in Young Athletes.

The purpose of the present study was to investigate which of two strategies, Video Feedback with Pedagogical Activity (VF-PA) or Video Feedback (VF), would be more beneficial for the remote error correction of the snatch weightlifting technique during the confinement period. Thirty-five school aged children with at least three months of weightlifting experience were randomized to one of three training conditions: VF-PA, VF or the Control group (CONT). Subjects underwent test sessions one week before (T0) and one day after (T1) a six-session training period and a retention test session a week later (T2). During each test session, the Kinovea version 0.8.15 software measured the kinematic parameters of the snatch performance. Following distance learning sessions (T1), the VF-PA improved various kinematic parameters (i.e., barbell horizontal displacements, maximum height, looping and symmetry) compared with T0 (p < 0.5; Cohen’s d = 0.58–1.1). Most of these improvements were maintained during the retention test (T2) (p<0.01, Cohen’s d = 1.2–1.3) when compared withT0. However, the VF group improved only twoparameters (i.e., barbell symmetry and horizontal displacement) at T1 (p < 0.05; Cohen’s d = 0.9), which were not maintained at T2. Better horizontal displacement and looping values were registered during the retention test in the VF-PA group compared with theCONT group (p < 0.05, Cohen’s d = 1.49–1.52). The present findings suggest combining video feedback with pedagogical activity during the pandemic induced online coaching or physical education to improve movement learning in school aged children.

3-Dimensional Performance Optimization Model of Snatch Weightlifting

Object : The goals of this research were to make Performance Enhanced Model(PE) taken the largest performance index (PI) through artificial variation of principle components calculated by principle component analysis for trial data, and to verify the effect through comparing kinematic factors between trial data (Raw) and PE. Method : Ten subjects (5 men, 5 women) were recruited and 80% of their maximal record was considered. The PI is a regression equation. In order to develop PE, we extracted Principle components from trial position data (by Principle Components Analysis (PCA)). Before PCA, we made 17 position data to 3 row matrix according to components. We calculated 3 eigen value (principle components) through PCA. And except Y (medial-lateral direction) component (because motion of Y component is small), principle components of X (anterior-posterior direction) and Z (vertical direction) components were changed as following. Changed principle components = principle components + principle components <TEX>${\times}$</TEX> k. After changing the each principle component, we reconstructed position data using the changed principle components and calculated performance index (PI). A Paired t-test was used to compare Raw data and Performance Enhanced Model data. The level of statistical significance was set at <TEX>$p{\leq}0.05$</TEX>. Result : The PI was significantly increased about 12.9kg at PE (<TEX>$101.92{\pm}6.25$</TEX>) when compared to the Raw data (<TEX>$91.29{\pm}7.10$</TEX>). It means that performance can be increased by optimizing 3D positions. The difference of kinematic factors as follows : the movement distance of the bar from start to lock out was significantly larger (about 1cm) for PE, the width of anterior-posterior bar position in full phase was significantly wider (about 1.3cm) for PE and the horizontal displacement toward the weightlifter after beginning of descent from maximal height was significantly greater (about 0.4cm) for PE. Additionally, the minimum knee angle in the 2-pull phase was significantly smaller (approximately 2.7cm) for the PE compared to that of the Raw. PE was decided at proximal position from the Raw (origin point (0,0)) of PC variation). Conclusion : PI was decided at proximal position from the Raw (origin point (0,0)) of PC variation). This means that Performance Enhanced Model was decided by similar motion to the Raw without a great change. Therefore, weightlifters could be accept Performance Enhanced Model easily, comfortably and without large stress. The Performance Enhance Model can provide training direction for athletes to improve their weightlifting records.

Prediction of weightlifter’s motor behavior to evaluate snatch weightlifting techniques based on a new method of investigation of consumed energy

Using proper technique in different sports is an inevitable factor. In this study, available techniques for snatch weightlifting are mathematically evaluated. The optimal motion trajectory is a technique used by weightlifters, which could be determined based on minimizing specific object functions. Object functions based on total kinetic energy, total torque and total power and some new multiobjective functions are minimized using genetic algorithm and the minimax principle. Some important motion characteristics of 13 professional weightlifters were extracted and used to validate the mathematical results. The double knee bending (DKB) technique was studied as a benchmark test. Some important movement features of the technique were shown by the mathematical analysis when applying an object function, that minimized joint torques and powers of different muscles independently. An object function based on joint forces did not show these features.

Cost evaluation of different snatch trajectories by using dynamic programming method

The barbell trajectory of snatch weightlifting has been investigated by several researchers. They suggested three optimal trajectory patterns (type A, B and C). But, there is no agreement for introducing the best overall trajectory. One probable reason would be this idea that the selected criterion used by the previous researchers might not be appropriate. Therefore we used a mathematical approach to judge between the conflicts. We made a multi-segments biomechanical model to evaluate the snatch motions while considering the selected mechanical cost. This method is an appropriate tool for coaches to examine several trajectories for making a good decision.

Power Enhancement of Weightlifters during Snatch through Reducing Torque on Joints by Particle Swarm Optimization

In this research, an athlete's body on sagittal plane in tension phase of snatch weightlifting has been modeled in two dimensions for calculating the generated torques in joints. The error back propagation multi-layer perceptrons has been used for modeling the torque through changing the angular velocity, angular acceleration and absolute angle of each segment. Finally, the torque in joints has been minimized by particle swarm optimization technique and the power of athlete has been maximized. The method of weightlifting has been captured by high speed camera and the films have been analyzed through motion analysis software. Consequently, the required kinematic data for mathematical model of weightlifter has been produced. Unlike previous research reports, the technique of weightlifting has been modified with the aid of artificial neural network modeling to enhance athlete's power, instead of optimizing the effect of body parameters and sport facilities. In addition, this study focuses on computational intelligent techniques for optimization instead of classical methods.

Optimization of Barbell Trajectory During The Snatch Lift Technique By Using Optimal Control Theory

Mathematical modeling and optimizing of snatch lift technique based on dynamic synthesis, is the aim of this study. The barbell trajectory is proposed as the performance index, evaluated experimentally by several researchers who have introduced some optimum trajectories according to the percentage of their owners' successes. Since none of the mechanical parameters were considered into the optimum trajectories, we develop a mechanical approach to fulfill this lack. Therefore, we use a biomechanical model comprised of five links to obtain the optimum trajectory of snatch weightlifting by means of minimizing a criterion function. To achieve this goal, we should solve the differential equations representing the model motion simultaneously with equations representing the performance criterion; therefore we use the optimal control approach via Pontryagin Maximum Principle (PMP) formulation. The performance criterion is defined as minimizing the sum of actuating torques of all joints during the whole snatch. The barbell trajectory of our optimized model is approximately similar to one which could be observed in experimental results. By comparing the results of this theoretical model with experimental observations of other researchers, it could be concluded that we have introduced a good predictive model. Using the biomechanical characteristics of any specific weightlifter as the input data to this model and comparing the results with the same weightlifter's experimental data can help the coaches to improve the performance of weightlifters.

Performance Enhanced Model in Snatch Weightlifting - Using the kinematic factors -

Y.J Moon Korea Institute of Sports Science; email: moonyj@sports.re.kr INTRODUCTION Weightlifting world record has been broken since weightlifting competition was started. Athletes do their best continually for a new record. In order to increase record, coach or sports researcher support them to enhance skill, physical strength or muscle force exertion and so on. For lower recorded athletes as junior athletes than world champion, we can make a training direction for skill, or physiques easily by compared with more nice recorders. But for world recorders, because they have the best skill and physical strength and muscle force exertion, Anybody don’t know What’s method in order to increase the their record. there is an endeavor to enhance present conditions and to have training more and more. Generally, it is hard to enchance physical strength and muscle exertion force for world recorder and elite athletes but skill is relatively easy to improve. If we can seek the optimal motion or skill, we can offer to make the training direction effectively. Birysiewicz(1981) reported the optimization method of weightlifting skill. Borysiewicz (1981) introduced optimization method in weightlifting and he insist that it can help for atheletes to learn skill. The purpose of this study was to develop the performance enhanced model in snatch weightlifting by using optimization method.

역도 인상동작 수행시 바벨 증가에 따른 EMG 경향성에 대한 연구

This research was to know EMG tendency on increasing record in snatch weightlifting. In order to perform this research, we choiced 3 man national weightlifters, EMG analysis were executed on 8 major muscle(Latissimus Dorsi, Trapezius, Anterior Deltoid, Posterior Deltoid, Gastrocenemius, Vastus Medialis, Erector spinae, Abdominal). First trial record of athletics is 80% of each maximal record and increase the gradually. In this study, EMG signal scale of all muscle except posterior Deltoid muscle don`t increased according to increasing the barbell weight, This showed a difference between general recognition and experiment result. In posterior Deltoid muscle, EMG signal scale increased according to increasing the barbell weight. It was assumed that EMG signal of protagonist shows possibility of linear increasing if motion have a consistency. It was assumed that In present, In order to increase one`s record to , Motion consistency training is more effective training method than increasing the muscle force.

Biomechanical Characteristics of Preactivation and Pulling Phases of Snatch Lift

The biomechanical characteristics of 13 snatch lifts performed by 4 elite athletes were analyzed. Electromyographic data, ground reaction force index (GRFI), knee angular velocities, barbell velocities, and lifting time were obtained 0.2 s before the lift, for the first pulling phase (FP), and for the second pulling phase (SP). The preactivation, normalized electromyographic values correlated negatively with GRFI (p &lt; .01). In the FP and SP, all of the parameters correlated positively with each other except lifting time. GRFI in the FP also correlated positively with GRFI, maximum knee angular velocities, and maximum barbell velocities of the SP (p &lt; .01). In the SP, the ground reaction force reached its maximum first, followed by knee angular velocity and then barbell velocity. Barbell velocity reached its maximum before the knee and the hip joint were fully extended. When the correlation of parameters between the consecutive phases of snatch weight lifting was analyzed, it was demonstrated that the preactivation of trunk and leg muscles is important in the activation of the reflectory system in order to fully utilize the forces for generating lifting speed in the pulling phase.