Comparing biomechanical time series data across countermovement shrug load

Meechan, D; McErlain-Naylor, S; McMahon, J; Suchomel, T; Comfort, P

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.

• Journal Article Type: Article
• Acceptance Date: Jun 14, 2022
• Online Publication Date: Aug 11, 2022
• Publication Date: Aug 11, 2022
• Deposit Date: Aug 16, 2022
• Publicly Available Date: Aug 16, 2022
• Journal: Journal of Sports Sciences
• Print ISSN: 0264-0414
• Electronic ISSN: 1466-447X
• Publisher: Taylor and Francis
• Volume: 40
• Issue: 15
• Pages: 1658-1667
• DOI: https://doi.org/10.1080/02640414.2022.2091351
• Publisher URL: https://doi.org/10.1080/02640414.2022.2091351
• Related Public URLs: https://www.tandfonline.com/toc/rjsp20/current