Comparing biomechanical time series data across countermovement shrug loads. Issue 15 (3rd August 2022)

• Record Type: Journal Article
• Authors: Meechan, David; McErlain-Naylor, Stuart A; McMahon, John J; Suchomel, Timothy J; Comfort, Paul
• Is Part Of: Journal of sports sciences. Volume 40:Issue 15(2022)
• Page Start: 1658
• Page End: 1667
• Publication Date: 2022-08-03
• Subjects: Weightlifting -- performance -- resistance training -- statistical parametric mapping; Sports -- Periodicals; Sports -- Physiological aspects -- Periodicals; Sports -- Psychological aspects -- Periodicals; 612.044
• DOI: 10.1080/02640414.2022.2091351
• Languages: English
• ISSNs: 0264-0414

Abstract

ABSTRACT: The effect of load on time-series data has yet to be investigated during weightlifting derivatives. This study compared the effect of load on the force–time and velocity–time curves during the countermovement shrug (CMS). Twenty-nine males performed the CMS at relative loads of 40%, 60%, 80%, 100%, 120%, and 140% one repetition maximum (1RM) power clean (PC). A force plate measured the vertical ground reaction force (VGRF), which was used to calculate the barbell-lifter system velocity. Time-series data were normalized to 100% of the movement duration and assessed via statistical parametric mapping (SPM). SPM analysis showed greater negative velocity at heavier loads early in the unweighting phase (12–38% of the movement), and greater positive velocity at lower loads during the last 16% of the movement. Relative loads of 40% 1RM PC maximised propulsion velocity, whilst 140% 1RM maximized force. At higher loads, the braking and propulsive phases commence at an earlier percentage of the time-normalized movement, and the total absolute durations increase with load. It may be more appropriate to prescribe the CMS during a maximal strength mesocycle given the ability to use supramaximal loads. Future research should assess training at different loads on the effects of performance.