Variation in Movement Efficiency of the Olympic Lifts Relative to Barbell Starting Position: 3511 Board #272 May 30, 9

For a competitive Olympic weightlifter, the efficiency required to complete the lift may be the difference between winning and losing, as well as impact the lifter’s ability to withstand the demands of the sport and attenuate injury. Minimizing horizontal displacement (HD) of the bar path may enhance efficiency. PURPOSE: To determine the most efficient bar path based on a traditional (T) vs experimental (E) starting position and its outcome on peak power (PP), average power (AP), velocity (V), and mass lifted (M), subjects performed the snatch (S) and Clean (C) lifts. The traditional start position places the barbell over the metatarsophalangeal joints (MTP) and below the acromioclavicular joint (AC). The experimental position places the barbell over the navicular (N) bone of the foot and below the most inferior and medial aspect of the scapular spine. In this study, efficiency is defined as a barbell path approaching linear movement. METHODS: 7 male and 3 female subjects (age 24.5 ± 4.1 yr, ht 1.55 ± 0.4 m, body mass 75.1.3 ± 22 kg, S max 74.9 ± 30 kg, C max 98.8 ± 37.3 kg) with at least two years of Olympic lifting experience were randomly assigned to a cross-over design of TS, ES, TC, and EC trials. Four warm-up sets were performed as a percentage of 90% of the subject’s self-reported one-repetition maximum (1RM) for S and C at 30, 50, 65 and 80% of 1 RM. Foot placement conditions were guaranteed identical by marking the subject’s shoe at the N bone and MTP joints. Subjects were positioned in the T or E anatomical alignments by the researcher immediately prior to the trials at 90% of 1 RM. A 3 minute break between each attempt was required. Subjects were videotaped during all trials and analyzed for bar displacement using Dartfish software. A Tendo Power and Speed Analyzer was used to measure force outcomes. Statistical analysis by t test at P