A biomechanical analysis of weightlifting pulling derivatives and their application to performance programming
The aims of the studies within this thesis were to determine if kinetics and kinematics differences occur between weightlifting pulling derivatives across loads, and to provide greater context regarding biomechanical time series data across loads. Additionally, another aim was to determine the effect of inter-repetition rest during these exercises and establish how they may be more effectively implemented into training programmes. The results of study 1 showed that the countermovement shrug (CMS) elicited greater kinetics and kinematics than the midthigh pull (MTP) across all loads (40-140% one repetition maximum [1-RM] power clean [PC]), highlighting greater acute outputs. Similarly, the results of study 2 demonstrated greater kinetic and kinematic outputs during the hang pull (HP), across all loads (40-140% 1-RM PC), compared to the pull from the knee (PFK), highlighting the benefits of utilising the stretch shortening cycle. During the CMS (Study 3) and HP (Study 4) statistical parametric mapping was used to establish where differences exist across the entire movement, in addition to peak and mean values. Results indicated greater negative velocity at heavier loads early in the unweighting phase, and greater positive velocity at lower loads during the last 13-16% of the movement. At higher loads, the braking and propulsive phases commence at an earlier percentage of the time-normalised movement, and the total absolute durations increase with load. Study 5 was performed to examine the effect of rest redistribution (RR) on kinetics, kinematics and perceptual effort during the CMS and determined that there were no differences in kinetics and kinematics compared to traditional set (TS) configurations. Lastly, Study 6 was performed to determine the effects of RR on the kinetics, kinematics and perceptual effort during HP and showed that RR protocols did not result in greater kinetics or kinematics during the HP compared to TS, however performing 6x3 (RR72) appears to be a better in maximising velocity compared to RR protocol compared to 9x2 (RR45). The findings across the six studies provide practitioners with: 1) a greater insight into the acute differences between the MTP vs. CMS and PFK vs. HP, which may aid in exercise selection; 2) a greater understanding of how load affects the time-normalised waveform during the CMS and HP, using statistical parametric mapping, and where differences lie outside peak values; 3) RR protocols did not result in greater kinetics or kinematics during the CMS compared to TS, when total rest time was equated, likely due to the limited barbell displacement not resulting in a decline in performance during the TS.Keywords: Weightlifting pulling derivatives, rest redistribution, sports performance; time normalisation
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