Snatch Technique Research Articles

Comparison of the Snatch Technique for Female Weightlifters at the 2008 Asian Championships

The purpose of this study was to compare the snatch techniques of Japanese and international female weightlifters. Two high-speed cameras operating at 250 Hz were used to record the snatch lifts of the 5 best weightlifters in the snatch and 5 Japanese weightlifters during the 2008 Asian Weightlifting Championships held in Japan. The results revealed that the forward velocity of the barbell for the Japanese weightlifters during the second pull was significantly greater than that for the best weightlifters and that barbell trajectories of Japanese weightlifters except for the 53-kg class crossed the vertical reference line with great forward displacement of the barbell. In addition, the best weightlifters extended the knee and hip joints during the second pull earlier than the Japanese weightlifters did. These findings indicate that it is important to improve the way of pulling the barbell during the second pull for Japanese female weightlifters.

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.

Kinematic Analysis of the Snatch Technique used by Japanese and International Female Weightlifters at the 2006 Junior World Championship

The purpose of the present study was to compare the snatch techniques of Japanese and international female weightlifters using kinematic analysis. Motion analysis of the snatch techniques conducted using videos recorded at the 2006 Women's Junior World Weightlifting Championship. The results indicated no significant differences between the snatch techniques of Japanese and international weightlifters in terms of the kinematic parameters expressed by the barbell trajectory and joint angles. However, the interval of time between the peak velocity of the hip joint and peak vertical velocity of the barbell was longer for Japanese weightlifters, while the power applied to the barbell was 35% greater for international weightlifters. These findings indicate that differences in strength and power production affected the performances of Japanese and international weightlifters.

DEVELOPMENT OF A SIMULATION MODEL FOR THE SNATCH WEIGHT-LIFT

INTRODUCTION Weightlifting is not a pure strength sport but is influenced by technique factors. The major factor determining success is the ability to produce a very high peak power [1]. The best lifters seem able to limit the knee joint moment by precise control of the knee position [2]. For both the snatch and the clean and jerk, pulling the barbell is the most important movement [3]. Bar-path parameters during weightlifting have been outlined and related to body position and kinetic performances [4], and foot displacement was shown not to significantly affect snatch success or lifting ability in collegiate national level lifters. Moreover, bar kinematics and power outputs of the first, second, and total pulls in women weightlifters were investigated, and it was found that training techniques should focus on generating greater vertical barbell velocity [5]. Since the best technique for the snatch may vary among weightlifters, researchers also adopted a theoretical rather than experimental approach. Jamshidi et al. [6] used a neural network model to minimize the created joint torques, but the model validity was not fully discussed. The purpose of this current study is to develop a suitable model for simulating and optimizing the snatch technique.

APRELIMINARY INVESTIGATION OF THE BIOMECHANICAL AND PERCEPTUAL INFLUENCE OF CHAIN RESISTANCE ON THE PERFORMANCE OF THE SNATCH

The purpose of this study was to determine whether the addition of chains to a barbell during the performance of the snatch would invoke differences in execution compared with lifting a conventional barbell without chains. Additionally, subjects were asked whether they perceived that the addition of chains had effects on their performance, and, if so, what those effects were. Four male and 3 female competitive weightlifters who regularly used chains as part of their training programs participated in the study. They were compared lifting 80% of 1 repetition maximum (1RM) using conventional barbells with 80% of 1RM, 5% of which was accounted for by chains. The same procedure was used with 85% of 1RM. Variables examined included maximum vertical displacement of the bar, maximum bar velocity, rate of force production of the bar, and vertical ground reaction forces for the first pull, unweighting, and second pull phases of the lift. Results indicated that there were no statistically significant differences between the chain vs. no-chain conditions at either 80% or 85% of 1RM. In contrast, 100% of the subjects stated that they perceived that the addition of chains made them work harder during the snatch. They suggested that the chains forced them to pull harder throughout the lift and that oscillation of the chains required their shoulders, abdominals, and back to work harder to stabilize the bar in the catch phase. Although statistical results indicate that chains have no influence on the snatch technique, chains may have a psychological impact and possibly invoke a physiological training response by increasing strength of muscles required to stabilize the bar during the catch phase if used over time.

A Preliminary Investigation of the Biomechanical and Perceptual Influence of Chain Resistance on the Performance of the Snatch

The purpose of this study was to determine whether the addition of chains to a barbell during the performance of the snatch would invoke differences in execution compared with lifting a conventional barbell without chains. Additionally, subjects were asked whether they perceived that the addition of chains had effects on their performance, and, if so, what those effects were. Four male and 3 female competitive weightlifters who regularly used chains as part of their training programs participated in the study. They were compared lifting 80% of 1 repetition maximum (1RM) using conventional barbells with 80% of 1RM, 5% of which was accounted for by chains. The same procedure was used with 85% of 1RM. Variables examined included maximum vertical displacement of the bar, maximum bar velocity, rate of force production of the bar, and vertical ground reaction forces for the first pull, unweighting, and second pull phases of the lift. Results indicated that there were no statistically significant differences between the chain vs. no-chain conditions at either 80% or 85% of 1RM. In contrast, 100% of the subjects stated that they perceived that the addition of chains made them work harder during the snatch. They suggested that the chains forced them to pull harder throughout the lift and that oscillation of the chains required their shoulders, abdominals, and back to work harder to stabilize the bar in the catch phase. Although statistical results indicate that chains have no influence on the snatch technique, chains may have a psychological impact and possibly invoke a physiological training response by increasing strength of muscles required to stabilize the bar during the catch phase if used over time.

역도 인상동작의 운동학적 분석

This study analyzed snatch technique in weight-lifting performed by female gold, silver, and copper medalists at the 75kg level in the 2002 Pusan Asian Games and obtained the following conclusions. 1. KSH used more extensor in the waist than those in ankles, knees, or hip joints during the second pull, So further training is required to manifest both each of joints and waist extensor effectively and thus for the line from shoulders through barbell to hip joints to form a smooth vertical pattern. 2. Contrary to those in other countries, Korean athlete KSH tended to be swift in starting but slow in the second pull section, showing less effectiveness in movement during the second pull; therefore, they must try to exert a swift movement in lockout. 3. KSH showed slowdown in the speed, which was a factor interfering with performance during second pull, despite the great maximum speed of moving barbell. It is important to use barbell sufficiently not to reduce the speed of vertical movement but rather to keep the speed increasing. 4. KSH, who kept doing inefficient movements such as failure to perform swift lockout after lifting the heel at the maximum angle of lower limbs, needs to reduce this meaningless extension of ankles, knees, or hip joints to exert energy effectively.

Snatch Technique of Collegiate National Level Weightlifters

Bar trajectory during weightlifting movements is related to the position of the body during the lift and the displacement of the feet during the drop-under phase. The purpose of this study was to examine anterior-posterior foot displacement and its relationship with performance in the snatch of collegiate weightlifters. Snatch attempts of men weightlifters from the 1998 U.S.A. Weightlifting Collegiate National Championships were analyzed for horizontal displacement of the feet by video analysis. Lifts were analyzed under 2 conditions: all lifts combined and the heaviest successful attempt for each lifter. Lifts (n = 74) were placed into 4 groups: forward displacement (FD, >2.5 cm); no displacement (ND, ±2.5 cm); rearward displacement (RD, >2.5 cm); and those that showed asymmetric (AS, >7 cm difference in right and left foot) displacement of the feet. Chi-square revealed no significant difference in success rate between groups for all attempts. No statistically significant differences were noted between groups in body mass to bar mass ratio or Sinclair formula for heaviest successful attempts. Results indicate that foot displacement did not significantly affect snatch success or lifting ability in collegiate national level lifters.

Comparative 3-Dimensional Kinematic Analysis of the Snatch Technique in Elite Male and Female Greek Weightlifters

The purpose of the current research was the comparison of the snatch technique between elite male and female weight-lifters. Two S-VHS cameras operating at 60 fields per second were used to record the snatch lifts of 6 male and 6 female Greek weightlifters under competitive conditions. The spatial coordinates of selected points on the body and the barbell were calculated using the direct linear transformation procedure, and the raw data were digitally filtered with a cutoff frequency of 4 Hz. Analyses of variance for dependent and independent samples were used to compare the selected variables in men with the corresponding variables in women. The results revealed that women flexed their knees significantly less and slower than men did during the transition phase (p < 0.05). Women also dropped under the barbell during the turnover and catch phases significantly less and slower than men did (p < 0.05). Moreover, the external mechanical work for the vertical displacement of the barbell in men was significantly greater in the first pull than in the second pull (p < 0.05). In contrast, women showed similar work outputs in the 2 phases. These differences between the 2 sexes might be because of the lower skill level of women in comparison with men, which is partly because of the recent participation of women in weightlifting.

Snatch Technique of Collegiate National Level Weightlifters

Bar trajectory during weightlifting movements is related to the position of the body during the lift and the displacement of the feet during the drop-under phase. The purpose of this study was to examine anterior-posterior foot displacement and its relationship with performance in the snatch of collegiate weightlifters. Snatch attempts of men weightlifters from the 1998 U.S.A. Weightlifting Collegiate National Championships were analyzed for horizontal displacement of the feet by video analysis. Lifts were analyzed under 2 conditions: all lifts combined and the heaviest successful attempt for each lifter. Lifts (n = 74) were placed into 4 groups: forward displacement (FD, >2.5 cm); no displacement (ND, +/-2.5 cm); rearward displacement (RD, >2.5 cm); and those that showed asymmetric (AS, >7 cm difference in right and left foot) displacement of the feet. Chi-square revealed no significant difference in success rate between groups for all attempts. No statistically significant differences were noted between groups in body mass to bar mass ratio or Sinclair formula for heaviest successful attempts. Results indicate that foot displacement did not significantly affect snatch success or lifting ability in collegiate national level lifters.

Comparative 3-Dimensional Kinematic Analysis of the Snatch Technique in Elite Male and Female Greek Weightlifters

The purpose of the current research was the comparison of the snatch technique between elite male and female weightlifters. Two S-VHS cameras operating at 60 fields per second were used to record the snatch lifts of 6 male and 6 female Greek weightlifters under competitive conditions. The spatial coordinates of selected points on the body and the barbell were calculated using the direct linear transformation procedure, and the raw data were digitally filtered with a cutoff frequency of 4 Hz. Analyses of variance for dependent and independent samples were used to compare the selected variables in men with the corresponding variables in women. The results revealed that women flexed their knees significantly less and slower than men did during the transition phase (p < 0.05). Women also dropped under the barbell during the turnover and catch phases significantly less and slower than men did (p < 0.05). Moreover, the external mechanical work for the vertical displacement of the barbell in men was significantly greater in the first pull than in the second pull (p < 0.05). In contrast, women showed similar work outputs in the 2 phases. These differences between the 2 sexes might be because of the lower skill level of women in comparison with men, which is partly because of the recent participation of women in weightlifting.

Three-dimensional kinematic analysis of the snatch of elite Greek weightlifters

We investigated the linear kinematics and the change in energy of the barbell and the angular kinematics of the trunk and leg during the snatch technique of 12 elite male Greek weightlifters under competitive conditions after the new weight classification. Two S-VHS cameras operating at 60 Hz were used to record the lifts. The spatial coordinates of selected points were calculated using the direct linear transformation procedure; after digital filtering of the raw data, the angular displacements and angular velocities were calculated for the hip, knee and ankle joints. The following variables were also calculated for the barbell: vertical and horizontal displacement, vertical linear velocity and acceleration, external mechanical work and power output. The results revealed that all weightlifters flexed their knees during the transition phase, independently of their weight category. This indicates that the athletes use the elastic energy produced during the stretch–shortening cycle to enhance their performance. In nine athletes, we found that the barbell trajectory did not cross a vertical reference line that passed through the initial position of the barbell. The vertical linear velocity of the barbell was increased continuously from the beginning of the movement until the second maximum extension of the knee joint, with no notable dip being observed. Regarding the change in energy of the barbell, we found that the mechanical work for the vertical displacement of the barbell in the first pull was significantly greater than the mechanical work in the second pull. In contrast, the estimated average mechanical power output of the athletes during the vertical displacement of the barbell was significantly greater in the second pull than in the first pull. We conclude that the major elements of the snatch technique of elite Greek weightlifters have not been aff ected by the new weight classification.

Kinematic Analysis of the Barbell during the Snatch Movement of Elite Asian Weight Lifters

The purpose of this study was to describe the kinematic characteristics of the snatch technique from the viewpoint of barbell trajectory. Subjects included 6 elite male Asian weight lifters who participated in the first Japan International Friendship Tournament in 1993. Trajectories of the barbell during snatch lifts in the competition were video-taped. Three vertical acceleration peaks of the barbell during the pull movement were observed and corresponded to the first pull transition, and second pull phases. The angle of the resultant acceleration (ARA) of the barbell averaged 85° in the first pull and transition pull phases. In the second pull phase, the ARA was almost 140°, indicating that the barbell was accelerated anteriorly, away from the lifter. The results of this study suggest that during the first pull and transition pull phases, elite lifters pulled the barbell toward themselves to produce the needed vertical acceleration and that the resulting posterior movement of the barbell was controlled by the forward acceleration produced in the second pull phase.

Short term effects of voluminous heavy resistance training and recovery on the snatch technique in weightlifting

Short term effects of voluminous heavy resistance training and recovery on the snatch technique in weightlifting

Three dimensional analysis of the snatch technique for two world record creators at the 6th national athletic meeting of PRC, 1987

Three dimensional analysis of the snatch technique for two world record creators at the 6th national athletic meeting of PRC, 1987

The Snatch Technique of World Class Weightlifters at the 1985 World Championships

The purpose of this study was (a) to describe the snatch technique in terms of kinematic and external and internal kinetic parameters, and (b) to compare the results for athletes of different groups and weight categories. By means of three-dimensional film analysis and measurements of ground reaction forces during the 1985 World Championships in Sweden, it was possible to analyze the spatial movements and to calculate joint moments of force in each leg. Concerning the kinematics, a snatch technique starting with a strong pull toward the lifter could be established. The most interesting kinetic results are that the knee joint moments are relatively small (one third of the hip joint moments of force) and do not correlate very well with the total load. The best lifters seem able to limit the knee joint moment by precise control of the knee position with respect to the ground reaction force. Altogether, the results concerning the internal kinetic parameters question the logic of the classical division of the lifting technique into phases according to external kinetic parameters.

Biomechanics of the Snatch Technique of Highly Skilled and Skilled Weightlifters

Abstract The lifting techniques of 10 world-class weightlifters were compared to those of 26 skilled collegiate weightlifters while performing the first portion of the snatch, from the lift-off of the barbell to the catch of the barbell overhead with the body in a squatting position. Cinematography was used to measure the joint angles, position of the center of gravity of the body, and the position of the barbell. Results indicated that the world-class weightlifters raised the barbell to a relatively lower height, assumed more flexed positions at the hips and knees with a smaller angle between the shank and floor during certain stages of the lift, and lowered their bodies more rapidly during the squatting portion of the lift than the collegiate weightlifters.