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Yang WC, Wang SY, Chiu CH, Ye X, Weng MC, Jhang JC, Chen CH. Effect of different resistance increments during warm-up on the snatch performance of male weightlifters. Heliyon 2024; 10:e34827. [PMID: 39149053 PMCID: PMC11324978 DOI: 10.1016/j.heliyon.2024.e34827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 08/17/2024] Open
Abstract
This study investigated the effect of different resistance increments during warm-up on snatch performance of male weightlifters. Nine male college weightlifters were recruited. The 3 warm-up protocols were performed every 7 days with a randomized order: 1. Power snatch exercise with 10 % resistance increment (50 %, 60 %, 70 %, and 80 % of one-repetition maximum); 2. Power snatch exercise with 15 % resistance increment (50 %, 65 %, and 80 % of one-repetition maximum); 3. Self-selected resistance increment. Participants were tested based on 85 % maximum weight snatch after warm-up. Snatch performance was measured using peak vertical ground reaction force. Postural stability was measured using center-of-pressure displacement. Activation of seven shoulder, back, and leg muscles was measured using electromyography on the dominant side. In snatch performance, the 10 % increment protocol had a significantly higher peak vertical ground reaction force during the second-pull phase than the 15 % increment (d = 0.92, p < 0.05) and self-selected (d = 1.32, p < 0.05) protocols. In postural stability, no significant differences in center-of-pressure displacement among the three protocols were observed. For muscle activation, the 10 % increment protocol resulted in significantly higher activation of shoulder (d = 1.2-2.2, p < 0.05) during the second-pull phase than the other two protocols and higher activation of hip muscles (d = 1.73, p < 0.05) than self-selected protocol. To conclude, a warm-up protocol combining slow progression is preferable in improving power output during snatch in male weightlifters, probably through facilitating the activation of proximal limb muscles. It can enhance training quality while potentially reducing the risk of sports injuries.
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Affiliation(s)
- Wen-Chieh Yang
- Department of Physical Therapy, Hung Kuang University, Taiwan
| | - Shin-Yuan Wang
- Graduate Program in Department of Exercise Health Science, National Taiwan University of Sport, Taichung, 404, Taiwan
| | - Chih-Hui Chiu
- Graduate Program in Department of Exercise Health Science, National Taiwan University of Sport, Taichung, 404, Taiwan
| | - Xin Ye
- Department of Rehabilitation Sciences, University of Hartford, West Hartford, USA
| | - Ming-Chia Weng
- Department of Physical Education, Chinese Culture University, Taiwan
| | - Jhih-Ciang Jhang
- Graduate Program in Department of Exercise Health Science, National Taiwan University of Sport, Taichung, 404, Taiwan
| | - Che-Hsiu Chen
- Department of Sport Performance, National Taiwan University of Sport, Taichung, 404, Taiwan
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Sandau I, Langen G, Nitzsche N. Variability of time series barbell kinematics in elite male weightlifters. Front Sports Act Living 2023; 5:1264280. [PMID: 37780124 PMCID: PMC10534034 DOI: 10.3389/fspor.2023.1264280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 08/18/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction Barbell kinematics are an essential aspect of assessing weightlifting performance. This study aimed at analyzing the total variability of time series barbell kinematics during repeated lifts in the snatch and the clean and jerk at submaximal and maximal barbell loads. Methods In a test-retest design, seven male weightlifters lifted submaximal [85% planned one-repetition maximum (1RMp)] and maximal (97% 1RMp) loads in the snatch and the clean and jerk during training. Barbell trajectory, vertical velocity, and vertical acceleration were determined using video analysis. Standard error of measurement (SEM), intraclass correlation coefficient (ICC), and smallest real difference (SRD) were used to determine the total variability during the lifts. Hedge's g effect size was used to assess differences in SEM between submaximal and maximal loads. Results The main findings indicated that variability-in particular for the barbell velocity-was lower at maximal compared to submaximal barbell loads (g = 0.52-2.93). SEM of time series data showed that variability increased in the snatch and the clean and jerk from the 1st pull/dip to the catch position irrespectively of the barbell load. Discussion This study presents values of total variability of time series barbell kinematics during the snatch, the clean, and the jerk. Further, the SRD can be used to evaluate changes in barbell kinematics in response to training. In addition, when interpreting barbell kinematics, coaches should take into account that the variability of barbell kinematics can vary depending on the exercise and the barbell load.
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Affiliation(s)
- Ingo Sandau
- Department Strength, Power, and Technical Sports, Institute for Applied Training Science, Leipzig, Germany
| | - Georg Langen
- Department Strength, Power, and Technical Sports, Institute for Applied Training Science, Leipzig, Germany
| | - Nico Nitzsche
- Department Sports Medicine/Sports Biology, Institute of Human Movement Science, University of Technology Chemnitz, Chemnitz,Germany
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Nagao H, Huang Z, Kubo Y. Biomechanical comparison of successful snatch and unsuccessful frontward barbell drop in world-class male weightlifters. Sports Biomech 2023; 22:1120-1135. [PMID: 32772836 DOI: 10.1080/14763141.2020.1787498] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 06/18/2020] [Indexed: 10/23/2022]
Abstract
This study aimed to clarify the success factor of snatch based on barbell trajectory and lifter's motion among elite male weightlifters. Motion analysis of snatch was conducted using digital videos recorded at the 2015 World Weightlifting Championships. Data on successful and unsuccessful snatch lifts of 22 lifters, each using the same weights, were analysed; the unsuccessful lift was due to a frontward barbell drop. Results revealed that the difference in backward barbell displacement between the turnover to catch phase (DxL) and peak backward barbell velocity (pVx-) was significantly greater in successful snatch than in frontward barbell drops (DxL: p < 0.001, d > 5.0, pVx-: p < 0.01, d > 2.0). Backward displacement of the lifters' centre of mass (COM) between the transition to turnover phase in a successful snatch lift was significantly smaller than that in an unsuccessful lift (p < 0.05, d > 2.0). It is considered that there was excessive backward leaning during unsuccessful lifts. However, no significant difference in maximum barbell height (Dy1) was found. Based on these findings, DxL and pVx- are success factors for snatch, whereas Dy1 is not. It is suggested that avoiding excessive backward-leaning of the body in the turnover phase may vary the chances of successful snatch among elite male weightlifters.
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Affiliation(s)
- Hideyuki Nagao
- Department of Sport Research, Japan Institute of Sports Sciences, Tokyo, Japan
| | | | - Yasuyuki Kubo
- Department of Sport Sciences, Japan Institute of Sports Sciences, Tokyo, Japan
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Ang CL, Kong PW. Field-Based Biomechanical Assessment of the Snatch in Olympic Weightlifting Using Wearable In-Shoe Sensors and Videos-A Preliminary Report. SENSORS (BASEL, SWITZERLAND) 2023; 23:1171. [PMID: 36772210 PMCID: PMC9919757 DOI: 10.3390/s23031171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/06/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Traditionally, the biomechanical analysis of Olympic weightlifting movements required laboratory equipment such as force platforms and transducers, but such methods are difficult to implement in practice. This study developed a field-based method using wearable technology and videos for the biomechanical assessment of weightlifters. To demonstrate the practicality of our method, we collected kinetic and kinematic data on six Singapore National Olympic Weightlifters. The participants performed snatches at 80% to 90% of their competition one-repetition maximum, and the three best attempts were used for the analysis. They wore a pair of in-shoe force sensors loadsol® (novel, Munich, Germany) to measure the vertical ground reaction forces under each foot. Concurrently, a video camera recorded the barbell movement from the side. The kinematics (e.g., trajectories and velocities) of the barbell were extracted using a free video analysis software (Kinovea). The power-time history was calculated from the force and velocity data. The results showed differences in power, force, and barbell velocity with moderate to almost perfect reliability. Technical inconsistency in the barbell trajectories were also identified. In conclusion, this study presented a simple and practical approach to evaluating weightlifters using in-shoe wearable sensors and videos. Such information can be useful for monitoring progress, identifying errors, and guiding training plans for weightlifters.
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Nagao H, Yamashita D. Validation of video analysis of marker-less barbell auto-tracking in weightlifting. PLoS One 2022; 17:e0263224. [PMID: 35089977 PMCID: PMC8797250 DOI: 10.1371/journal.pone.0263224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 01/14/2022] [Indexed: 11/18/2022] Open
Abstract
We determined the marker-less barbell auto-tracking accuracy using the Kanade–Lucas–Tomasi (KLT) algorithm in a digital video for two-dimensional analysis (2D-AT). The position coordinates of the barbell’s right end during multiple loads (60%–90% of one-repetition maximum) of snatch motion in eight participants were recorded using a three-dimensional motion capture system. Simultaneously, the snatch motion was recorded by a digital camera from the right side. Based on the digital video, the center of the barbell’s right end was auto-tracked using the KLT algorithm. Six barbell kinematic variables (forward, backward, and vertical displacement, peak forward, backward, and vertical velocity) were calculated. Intraclass correlation coefficient (ICC) analysis was performed to establish the agreement level between the methods. The Bland–Altman plots and regression were used to examine the agreement between the methods. ICCs of 0.999–0.971 revealed a strong agreement level between the methods. The Bland–Altman plot showed small bias (-0.001–0.001 m, -0.034 –-0.005 m/s). We considered that 2D-AT could obtain barbell position coordinates with sufficient accuracy to discriminate the difference in the lifter’s level and a successful or unsuccessful lift.
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Affiliation(s)
- Hideyuki Nagao
- Department of Sports Research, Japan Institute of Sport Sciences, Kita-ku, Tokyo, Japan
- * E-mail:
| | - Daichi Yamashita
- Department of Sport Science, Japan Institute of Sport Sciences, Kita-ku, Tokyo, Japan
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Souissi MA, Souissi H, Elghoul Y, Masmoudi L, Trabelsi O, Ammar A, Chtourou H, Souissi N. Information Processing and Technical Knowledge Contribute to Self-Controlled Video Feedback for Children Learning the Snatch Movement in Weightlifting. Percept Mot Skills 2021; 128:1785-1805. [PMID: 33910395 DOI: 10.1177/00315125211011728] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Our aim in this study was to examine, via technical performance analysis and speed of execution, whether information processing and technical knowledge help explain learning benefits of self-controlled video feedback in children's weightlifting performance. We randomized 24 children (aged 10 to 12 years) into self-controlled (SC) and yoked (YK) feedback groups. Learners underwent test sessions one week before (pre-test) and one day after (post-test) six weightlifting training sessions. During each test session, we recorded kinematic parameters of snatch performance using Kinovea version 0.8.15 software. After the learning sessions, the SC group improved on most kinematic parameters (e.g., the horizontal displacement of the bar between the first and the second pulls [MDXV = 25.42%, SD = 18.96, p = 0.003) and the maximum height reached by the bar (MHMV = 5.51%, SD = 7.71, p < 0.05)], while the YK group improved only on the DxV (MDXV = 19.08%, SD = 24.68, p < 0.05). In addition, the SC group showed a more advanced phase of cognitive processing compared to the YK group, and the SC group showed a superior improvement in their technical knowledge level (p < 0.001) compared to the YK group (p < 0.05). Thus, key elements to correcting motor errors in children's weightlifting through self-controlled feedback were improvements in information processing and technical knowledge.
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Affiliation(s)
- Mohamed Abdelkader Souissi
- Physical Activity, Sport and Health, Research Unit, UR18JS01, National Observatory of Sport, Tunis, Tunisia.,Higher Institute of Education and Continuous Training, Virtual University, Tunis, Tunisia
| | - Hichem Souissi
- Physical Activity, Sport and Health, Research Unit, UR18JS01, National Observatory of Sport, Tunis, Tunisia.,High Institute of Sports and Physical Education, Sfax University, Tunisia
| | - Yousri Elghoul
- Physical Activity, Sport and Health, Research Unit, UR18JS01, National Observatory of Sport, Tunis, Tunisia.,High Institute of Sports and Physical Education, Sfax University, Tunisia
| | - Liwa Masmoudi
- Physical Activity, Sport and Health, Research Unit, UR18JS01, National Observatory of Sport, Tunis, Tunisia.,High Institute of Sports and Physical Education, Sfax University, Tunisia
| | - Omar Trabelsi
- High Institute of Sports and Physical Education, Sfax University, Tunisia
| | - Achraf Ammar
- Institute of Sport Science, Otto-von-Guericke-University Magdeburg, Germany.,Interdisciplinary Laboratory in Neurosciences, Physiology and Psychology: Physical Activity, Health and Learning (LINP2), UFR STAPS, UPL, Paris Nanterre University, France
| | - Hamdi Chtourou
- Physical Activity, Sport and Health, Research Unit, UR18JS01, National Observatory of Sport, Tunis, Tunisia.,High Institute of Sports and Physical Education, Sfax University, Tunisia
| | - Nizar Souissi
- Physical Activity, Sport and Health, Research Unit, UR18JS01, National Observatory of Sport, Tunis, Tunisia.,High Institute of Sport and Physical Education of Ksar-Said, Manouba University, Tunisia
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Abstract
The aim of this study was to identify biomechanical factors affecting successful and unsuccessful snatch attempts in elite female weightlifters during the 2013 World Weightlifting Championships. Fourteen female competitors took part in this study. Their successful and unsuccessful snatch lifts with the same load were recorded with 2 camcorders (50 Hz), and selected points were digitized manually on to the body and the barbell using the Ariel Performance Analysis System. The kinetic and kinematic barbell movement as well as the athlete’s body movement variables during the liftoff phase were examined. The results of this study show statistical differences (p ≤ 0.05) between successful and unsuccessful attempts in relation to the angle values in the knee and hip joints in preparation for the aerial phase position. Similarly, the center of gravity velocity was significantly higher in successful attempts during the catch phase. Thus, coaches should pay particular attention to the accuracy of the execution in preparation for the aerial phase position and to the velocity of the center of gravity of the competitors during the catch phase.
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James LP, Suchomel TJ, McMahon JJ, Chavda S, Comfort P. Effect of Onset Threshold on Kinetic and Kinematic Variables of a Weightlifting Derivative Containing a First and Second Pull. J Strength Cond Res 2019; 34:298-307. [PMID: 31373974 DOI: 10.1519/jsc.0000000000003316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
James, LP, Suchomel, TJ, McMahon, JJ, Chavda, S, and Comfort, P. Effect of onset threshold on kinetic and kinematic variables of a weightlifting derivative containing a first and second pull. J Strength Cond Res 34(2): 298-307, 2020-This study sought to determine the effect of different movement onset thresholds on both the reliability and absolute values of performance variables during a weightlifting derivative containing both a first and second pull. Fourteen men (age: 25.21 ± 4.14 years; body mass: 81.1 ± 11.4 kg; and 1 repetition maximum [1RM] power clean: 1.0 ± 0.2 kg·kg) participated in this study. Subjects performed the snatch-grip pull with 70% of their power clean 1RM, commencing from the mid-shank, while isolated on a force platform. Two trials were performed enabling within-session reliability of dependent variables to be determined. Three onset methods were used to identify the initiation of the lift (5% above system weight [SW], the first sample above SW, or 10 N above SW), from which a series of variables were extracted. The first peak phase peak force and all second peak phase kinetic variables were unaffected by the method of determining movement onset; however, several remaining second peak phase variables were significantly different between methods. First peak phase peak force and average force achieved excellent reliability regardless of the onset method used (coefficient of variation [CV] < 5%; intraclass correlation coefficient [ICC] > 0.90). Similarly, during the second peak phase, peak force, average force, and peak velocity achieved either excellent or acceptable reliability (CV < 10%; ICC > 0.80) in all 3 onset conditions. The reliability was generally reduced to unacceptable levels at the first sample and 10 N method across all first peak measures except peak force. When analyzing a weightlifting derivative containing both a first and second pull, the 5% method is recommended as the preferred option of those investigated.
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Affiliation(s)
- Lachlan P James
- Department of Rehabilitation, Nutrition and Sport, School of Allied Health, La Trobe University, Victoria, Australia
| | - Timothy J Suchomel
- Department of Human Movement Sciences, Carroll University, Waukesha, Wisconsin
| | - John J McMahon
- Directorate of Sport, Exercise and Physiotherapy, University of Salford, Salford, Greater Manchester, United Kingdom; and
| | - Shyam Chavda
- London Sport Institute, School of Science and Technology, Middlesex University, Hendon, United Kingdom
| | - Paul Comfort
- Directorate of Sport, Exercise and Physiotherapy, University of Salford, Salford, Greater Manchester, United Kingdom; and
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A Biomechanical Comparison of Successful and Unsuccessful Snatch Attempts among Elite Male Weightlifters. Sports (Basel) 2019; 7:sports7060151. [PMID: 31234453 PMCID: PMC6628121 DOI: 10.3390/sports7060151] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/11/2019] [Accepted: 06/20/2019] [Indexed: 11/25/2022] Open
Abstract
The success factor of the snatch has not been identified. Determining the success factors of the snatch among elite weightlifters might help to attain a successful snatch. This study aimed at clarifying the factors that lead to a successful snatch based on barbell trajectory among elite male weightlifters. Data were collected at the 2017 World and Junior World Weightlifting Championships. We digitized the barbell trajectory of the successful and unsuccessful snatch attempts of 61 lifters—an unsuccessful lift would be as a result of a frontward barbell drop—and calculated the kinematic and kinetic parameters of the barbell. No significant difference was found in the barbell maximum height (Dy1) between the successful and unsuccessful lifts. The amount of backward displacement of the barbell in the second pull phase to the catch position (DxL) of the successful lift was significantly larger than that of the unsuccessful lift (successful: 0.11 ± 0.05 m; unsuccessful: 0.10 ± 0.06 m; p < 0.01; d = 0.278). The barbell drop distance in the catch phase (Dy3) of the successful lift was significantly smaller than that in the unsuccessful lift (successful: 0.17 ± 0.04 m; unsuccessful: 0.18 ± 0.04 m; p < 0.001, d = 0.361). These results suggest that DxL and Dy3 are factors leading to a successful snatch lift, but not Dy1. The relative position in the sagittal axis of the barbell and the lifter in the catch position, and catching the barbell when its momentum was low, are important in order to achieve a successful snatch.
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10
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Ammar A, Riemann BL, Abdelkarim O, Driss T, Hökelmann A. Effect of 2- vs. 3-Minute Interrepetition Rest Period on Maximal Clean Technique and Performance. J Strength Cond Res 2018; 34:2548-2556. [PMID: 30138239 DOI: 10.1519/jsc.0000000000002785] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ammar, A, Riemann, BL, Abdelkarim, O, Driss, T, and Hökelmann, A. Effect of 2- vs. 3-minute interrepetition rest period on maximal clean technique and performance. J Strength Cond Res 34(9): 2548-2556, 2020-Currently, it is widely accepted that adopting a long rest period (3-5 minutes) during maximal strength and power exercise is of importance in reducing acute fatigue and maintaining power and technique proficiency. However, despite the fact that weightlifting is an example of maximal strength exercise, only 2 minutes are officially allowed when athletes attempt 2 successive lifts. The purpose of this study was to compare 3- vs. 2-minute intermaximal repetition rest periods (IMRRPs) on performance, rate of perceived exertion (RPE), technical efficiency, and power production during 2 successive maximal repetitions of clean & jerk (C&J). Nine elite weightlifters (age: 24.4 ± 3.6 years, body mass: 77.2 ± 7.1 kg, height 176.0 ± 6.4 cm, and 1 repetition maximum C&J: 170.0 ± 5.0 kg) performed 2 separate testing sessions using 2-minute IMRRP (IMRRP-2) and 3-minute IMRRP (IMRRP-3), in a randomized order, while barbell kinematics and kinetics were recorded. Results showed that the longer IMRRP-3 minutes led to the maintenance of clean technique (from the first to the second repetition) evidenced by a 1.86% lower decline in peak vertical displacement (p = 0.03) and attenuation of increased peak horizontal displacements with a 1.74% (p = 0.03) less backward movement during the first pull, a 3.89% (p = 0.008) less forward movement during the second pull, and a 4.7% (p = 0.005) less backward movement during the catch phase. In addition, attenuation of peak velocity (2.22%; p = 0.02), peak vertical ground reaction force (1.70%; p = 0.03), and peak power (2.14%; p = 0.02) declines were shown using IMRRP-3 compared with IMRRP-2. Increasing IMRRP from 2 to 3 minutes was also shown to decrease RPE values (8.02%; p = 0.008) and to enhance supramaximal C&J performance (1.55%; p = 0.003). The results of this study suggest 3 minutes to be the most advantageous IMRRP in terms of maintaining technical efficiency, power output, reducing fatigue perception, and enhancing performance in elite weightlifters.
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Affiliation(s)
- Achraf Ammar
- Research Unit (EM2S), High Institute of Sport and Physical Education, Sfax University, Sfax, Tunisia.,Institute of Sport Science, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Bryan L Riemann
- Biodynamics and Human Performance Center, Georgia Southern University, Savannah, Georgia; and
| | - Osama Abdelkarim
- Institute of Sport Science, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Tarak Driss
- Research Center on Sport and Movement (EA 2931), UFR STAPS, University of Paris Nanterre, Nanterre, France
| | - Anita Hökelmann
- Institute of Sport Science, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
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12
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Lee S, DeRosia KD, Lamie LM. Evaluating the contribution of lower extremity kinetics to whole body power output during the power snatch. Sports Biomech 2017; 17:554-556. [PMID: 28933236 DOI: 10.1080/14763141.2017.1371216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This study evaluated the contribution of lower extremity (hip, knee and ankle) net joint torques (NJT) to whole body power (WBP) output during the power snatch (PS). Ten experienced weightlifters (five males and five females) performed five trials of the PS with 60% of one repetition maximum. Lower extremity NJT and WBP were extracted through a three-dimensional motion analyses and used for data analyses. Pearson correlation coefficients were obtained to observe the relationship between lower extremity NJT and WBP. Multiple-regression (stepwise) analyses was also conducted to evaluate the contribution of lower extremity NJT to WBP during the PS with the hip, knee and ankle NJT being the independent variables. Hip NJT was characterised as a significant positive correlation with WBP (r = 0.47, p < 0.01), while knee NJT showed a significant negative correlation with WBP (r = -0.34, p < 0.05). A significant inter-correlation was also observed between hip NJT and knee NJT (r = -0.66, p < 0.01). Hip NJT was identified as a significant contributor to WBP during the PS. Practically, this study suggested that training skills allowing weightlifters to utilise hip extensor muscle action would help to improve WBP during the PS.
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Affiliation(s)
- Sangwoo Lee
- a Department of Human Performance and Health Education, College of Education and Human Development , Western Michigan University , Kalamazoo , MI , USA
| | - Kyle D DeRosia
- a Department of Human Performance and Health Education, College of Education and Human Development , Western Michigan University , Kalamazoo , MI , USA
| | - Landon M Lamie
- a Department of Human Performance and Health Education, College of Education and Human Development , Western Michigan University , Kalamazoo , MI , USA
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13
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Ammar A, Riemann BL, Masmoudi L, Blaumann M, Abdelkarim O, Hökelmann A. Kinetic and kinematic patterns during high intensity clean movement: searching for optimal load. J Sports Sci 2017; 36:1319-1330. [PMID: 28895467 DOI: 10.1080/02640414.2017.1376521] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The aim of the present study was to investigate loading effects on kinematic and kinetic variables among elite-weightlifters in order to identify an optimal training load to maximize power production for clean-movement. Nine elite-weightlifter (age: 24 ± 4years, body-mass: 77 ± 6.5kg, height: 176 ± 6.1cm and 1RM clean: 170 ± 5kg) performed 2 separate repetitions of the clean using 85, 90, 95% and 100%, in a randomized order, while standing on a force platform and being recorded using 3D-capture-system. Differences in kinematics (barbell displacement, velocity and acceleration) and kinetics (power, vertical ground reaction force (vGRF), rate of force development (RFD), and work) across the loads were statistically assessed. Results revealed significant load effects for the majority of the studied parameters (p < 0.01) and showed that typical bar-displacement, greatest bar-velocity and peak-power were achieved at 85 and 90% 1RM (p < 0.001). Additionally greater average power was shown for 90 and 95% (p < 0.01) and greater work and vGRF were shown for 90, 95 and 100% than 85% 1RM (p < 0.05). Load had no significant effect on peak-vGRF and peak-RFD (p > 0.05). The results of this study, suggest 90% 1RM to be the most advantageous load to train explosive-force and to enhance power-outputs while maintaining technical efficiency in elite-weightlifters.
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Affiliation(s)
- Achraf Ammar
- a Research Unit: Education, Motricity, Sport and Health, UR15JS01, High Institute of Sport and Physical Education of Sfax , Sfax University , Sfax , Tunisia.,b Institute of Sport Science , Otto-von-Guericke-University Magdeburg , Magdeburg , Germany
| | - Bryan L Riemann
- c Biodynamics and Human Performance Center , Armstrong State University , Savannah , GA , USA
| | - Liwa Masmoudi
- a Research Unit: Education, Motricity, Sport and Health, UR15JS01, High Institute of Sport and Physical Education of Sfax , Sfax University , Sfax , Tunisia
| | - Marcel Blaumann
- b Institute of Sport Science , Otto-von-Guericke-University Magdeburg , Magdeburg , Germany
| | - Osama Abdelkarim
- b Institute of Sport Science , Otto-von-Guericke-University Magdeburg , Magdeburg , Germany
| | - Anita Hökelmann
- b Institute of Sport Science , Otto-von-Guericke-University Magdeburg , Magdeburg , Germany
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Ross JA, Keogh JW, Wilson CJ, Lorenzen C. External kinetics of the kettlebell snatch in amateur lifters. PeerJ 2017; 5:e3111. [PMID: 28367368 PMCID: PMC5374970 DOI: 10.7717/peerj.3111] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 02/20/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Kettlebell lifting has gained increased popularity as both a form of resistance training and as a sport, despite the paucity of literature validating its use as a training tool. Kettlebell sport requires participants to complete the kettlebell snatch continuously over prolonged periods of time. Kettlebell sport and weightlifting involve similar exercises, however, their traditional uses suggest they are better suited to training different fitness qualities. This study examined the three-dimensional ground reaction force (GRF) and force applied to the kettlebell over a 6 min kettlebell snatch set in 12 kettlebell-trained males. METHODS During this set, VICON was used to record the kettlebell trajectory with nine infrared cameras while the GRF of each leg was recorded with a separate AMTI force plate. Over the course of the set, an average of 13.9 ± 3.3 repetitions per minute were performed with a 24 kg kettlebell. Significance was evaluated with a two-way ANOVA and paired t-tests, whilst Cohen's F (ESF) and Cohen's D (ESD) were used to determine the magnitude. RESULTS The applied force at the point of maximum acceleration was 814 ± 75 N and 885 ± 86 N for the downwards and upwards phases, respectively. The absolute peak resultant bilateral GRF was 1,746 ± 217 N and 1,768 ± 242 N for the downwards and upwards phases, respectively. Bilateral GRF of the first and last 14 repetitions was found to be similar, however there was a significant difference in the peak applied force (F (1.11) = 7.42, p = 0.02, ESF = 0.45). Unilateral GRF was found have a significant difference for the absolute anterior-posterior (F (1.11) = 885.15, p < 0.0001, ESF = 7) and medio-lateral force vectors (F (1.11) = 5.31, p = 0.042, ESF = 0.67). DISCUSSION Over the course of a single repetition there were significant differences in the GRF and applied force at multiple points of the kettlebells trajectory. The kettlebell snatch loads each leg differently throughout a repetition and performing the kettlebell snatch for 6 min will result in a reduction in peak applied force.
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Affiliation(s)
- James A. Ross
- School of Exercise Science, Australian Catholic University, Melbourne, VIC, Australia
| | - Justin W.L. Keogh
- Faculty of Health Sciences and Medicine, Bond University, Gold Coast, QLD, Australia
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
- Cluster for Health Improvement, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sunshine Coast, QLD, Australia
| | - Cameron J. Wilson
- School of Exercise Science, Australian Catholic University, Melbourne, VIC, Australia
| | - Christian Lorenzen
- School of Exercise Science, Australian Catholic University, Melbourne, VIC, Australia
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15
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Schutts KS, Wu WFW, Vidal AD, Hiegel J, Becker J. Does Focus of Attention Improve Snatch Lift Kinematics? J Strength Cond Res 2016; 31:2758-2764. [PMID: 28030531 DOI: 10.1519/jsc.0000000000001753] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent motor control literature has demonstrated that using verbal instructions to direct a performer's attention externally (i.e., toward the movement outcome) enhances motor skill performance. The purpose of this study was to investigate how an athlete's focus of attention impacts kinematic performance of the snatch. Using a counterbalanced within-participant design, 12 competitively trained athletes (8 male and 4 female athletes) performed 2 instructional blocks of 3 snatch repetitions at 80% of their most recent training 1 repetition maximum. Blocks of internal and external instructions were given to the athlete in a random fashion. Results showed that, when focusing internally, athletes significantly (p ≤ 0.05) increased elbow velocity relative to focusing externally, whereas the external instructions significantly increased horizontal barbell velocity, relative to internal instructions. Additionally, an internal focus resulted in significantly larger barbell-cervical-hip angles at maximum height of the barbell compared with an external focus, indicating that the athletes squatted under the barbell too soon. This information adds to the literature suggesting small changes in coaching instructions can impact performance significantly. It is recommended that coaches use instructions that direct an athlete's attention externally, toward the movement outcome, rather than the action itself.
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Affiliation(s)
- Kyle S Schutts
- Department of Kinesiology, Center for Sport Training and Research, California State University-Long Beach, Long Beach, California
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16
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Kipp K, Harris C. Muscle-Specific Effective Mechanical Advantage and Joint Impulse in Weightlifting. J Strength Cond Res 2016; 31:1905-1910. [PMID: 27669187 DOI: 10.1519/jsc.0000000000001658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Kipp, K, and Harris, C. Muscle-specific effective mechanical advantage and joint impulse in weightlifting. J Strength Cond Res 31(7): 1905-1910, 2017-Lifting greater loads during weightlifting exercises may theoretically be achieved through increasing the magnitudes of net joint impulses or manipulating the joints' effective mechanical advantage (EMA). The purpose of this study was to investigate muscle-specific EMA and joint impulse as well as impulse-momentum characteristics of the lifter-barbell system across a range of external loads during the execution of the clean. Collegiate-level weightlifters performed submaximal cleans at 65, 75, and 85% of their 1-repetition maximum (1-RM), whereas data from a motion analysis system and a force plate were used to calculate lifter-barbell system impulse and velocity, as well as net extensor impulse generated at the hip, knee, and ankle joints and the EMA of the gluteus maximus, hamstrings, quadriceps, and triceps surae muscles. The results indicated that the lifter-barbell system impulse did not change as load increased, whereas the velocity of the lifter-barbell system decreased with greater load. In addition, the net extensor impulse at all joints increased as load increased. The EMA of all muscles did not, however, change as load increased. The load-dependent effects on the impulse-velocity characteristics of the lifter-barbell system may reflect musculoskeletal force-velocity behaviors, and may further indicate that the weightlifting performance is limited by the magnitude of ground reaction force impulse. In turn, the load-dependent effects observed at the joint level indicated that lifting greater loads were due to greater net extensor impulses generated at the joints of the lower extremity and not greater EMAs of the respective extensor muscles. In combination, these results suggest that lifting greater external loads during the clean is due to the ability to generate large extensor joint impulses, rather than manipulate EMA.
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Affiliation(s)
- Kristof Kipp
- 1Department of Physical Therapy-Program in Exercise Science, Marquette University, Milwaukee, Wisconsin; and 2Department of Health Science, Central Oregon Community College, Bend, Oregon
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17
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Eltoukhy M, Travascio F, Asfour S, Elmasry S, Heredia-Vargas H, Signorile J. Examination of a lumbar spine biomechanical model for assessing axial compression, shear, and bending moment using selected Olympic lifts. J Orthop 2015; 13:210-9. [PMID: 27408480 DOI: 10.1016/j.jor.2015.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 04/22/2015] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND/AIMS Loading during concurrent bending and compression associated with deadlift, hang clean and hang snatch lifts carries the potential for injury to the intervertebral discs, muscles and ligaments. This study examined the capacity of a newly developed spinal model to compute shear and compressive forces, and bending moments in lumbar spine for each lift. METHODS Five male subjects participated in the study. The spine was modeled as a chain of rigid bodies (vertebrae) connected via the intervertebral discs. Each vertebral reference frame was centered in the center of mass of the vertebral body, and its principal directions were axial, anterior-posterior, and medial-lateral. RESULTS The results demonstrated the capacity of this spinal model to assess forces and bending moments at and about the lumbar vertebrae by showing the variations among these variables with different lifting techniques. CONCLUSION These results show the model's potential as a diagnostic tool.
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Affiliation(s)
- Moataz Eltoukhy
- Sports Medicine and Motion Analysis Laboratory, Department of Kinesiology and Sport Sciences, University of Miami, Coral Gables, FL, USA
| | - Francesco Travascio
- Biomechanics Research Laboratory, Department of Industrial Engineering, University of Miami, Coral Gables, FL, USA
| | - Shihab Asfour
- Biomechanics Research Laboratory, Department of Industrial Engineering, University of Miami, Coral Gables, FL, USA
| | - Shady Elmasry
- Biomechanics Research Laboratory, Department of Industrial Engineering, University of Miami, Coral Gables, FL, USA
| | - Hector Heredia-Vargas
- Sports Medicine and Motion Analysis Laboratory, Department of Kinesiology and Sport Sciences, University of Miami, Coral Gables, FL, USA
| | - Joseph Signorile
- Sports Medicine and Motion Analysis Laboratory, Department of Kinesiology and Sport Sciences, University of Miami, Coral Gables, FL, USA; Center on Aging, Miller School of Medicine, University of Miami, Miami, FL, USA
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