期刊名称：International Journal of Sport, Exercise and Training Sciences
电子版ISSN：2149-8229
出版年度：2017
卷号：3
语种：English
出版社：Balikesir University
摘要：In both the snatch and the clean and jerk events of Olympic weightlifting,the pull refers to the initial portion of the lift in which the barbell is displaced from the floor to approximately waist height (Enoka,1979). The double knee bend technique is presented as one method of performing the pull as consisting of two stages of extension,separated by a period of flexion (Garhammer,1985). PURPOSE: The objective of the study was to compare the kinematics and the energetics of the barbell between the first and the second pull of the clean and jerk in the adolescent elite male weightlifters. METHOD: Thirteen weightlifters (age: 18.8±0.69 years,height: 1.69±0.07 cm,weight: 72.8±14.8 kg) participated in the study. The successful clean and jerk lifts of the weightlifters were selected for the kinematic analysis of the barbell. In order to obtain the kinematic data related with the barbell,a point on the barbell was manually digitized by using the Ariel Performance Analysis System (San Diego,USA). The kinematical differences between the first and the second pull phase of the clean and jerk were compared using the paired t-test. RESULTS: The results showed that the maximum barbell height and the vertical velocity of the barbell were significantly greater in the second pull than did that of the first pull. In addition,it was determined that the absolute and relative mechanical work done on the barbell was significantly greater in the first pull than did that of the second pull. Whereas,the power output was significantly greater in the second pull than did that of the first pull in terms of both absolute and relative values. DISCUSSION: Garhammer (1991) reported that elite heavyweight competitive lifters had power outputs during the 1-RM lifts of 415 W in the bench press,900 W in the squat,and 3413 W in the clean. It was revealed in the present study that the first pull phase of the clean depends on strength because of greater mechanical work during the first pull,and that the second pull depends on the explosive strength because of higher power output.
