Functional data analysis of vertical barbell acceleration during the pull of the power clean

The purpose of this study was to examine the relationship between vertical barbell acceleration patterns and power clean performance. Thirty strength-power athletes performed a one repetition maximum (1RM) power clean test, recording vertical barbell acceleration data from their heaviest successful lifts. This data was then analysed using functional principal component (fPC) analysis methods. Three vertical barbell acceleration patterns were extracted, with each primarily reflecting variations in the magnitude of vertical barbell acceleration during the second pull (fPC1), the transition (fPC2), and the first pull (fPC3). Additionally, two fPCs were extracted from displacement fields, which explain timing variations in barbell acceleration data, with the first fPC capturing timing variations during the first pull and the second fPC capturing timing variations during the transition. There were no significant or meaningful correlations between any of these patterns and power clean performance, suggesting that the amplitude and timing variations of vertical barbell acceleration patterns may not be the key biomechanical factor impacting power clean performance. Therefore, vertical barbell acceleration profiles should not be interpreted as a direct indicator of power clean technique, as these patterns may simply reflect acceptable individual variation, rather than representing technical proficiency or inefficiency. These findings may highlight that isolated measures of barbell kinematics should be considered informative, yet insufficient for assessing weightlifting technique, without additional variables reflecting the kinetics and kinematics of the lifter considered.