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Muscle Power during Standing and Seated Trunk Rotations with Different Weights
Authors: Erika Zemková, Michal Jeleň, Ludmila Zapletalová and Dusan Hamar
Number of views: 720
This study compares peak and mean power during standing and seated trunk rotations with different weights. Twenty seven fit
men completed four trials of trunk rotations in both standing and seated positions with a bar weight of 5.5, 10.5, 15.5, and 20 kg
placed on the shoulders. The FiTRO Torso Premium was used to monitor basic biomechanical parameters throughout the
movement. Results showed significantly higher peak power during standing than seated trunk rotations at weights of 20 kg
(274.4±63.5 vs. 206.4±54.6 W, p=0.004), 15.5 kg (371.2±93.9 vs. 313.5±72.3 W, p=0.007), and 10.5 kg (336.9±77.8 vs. 286.3±66.0
W, p=0.009) but not at 5.5 kg (191.6±46.2 vs. 166.0±37.0 W, p=0.061). Similarly, mean power in the acceleration phase of trunk
rotations was significantly higher when performed in standing than seated position at weights of 20 kg (143.2±32.1 vs. 101.9±23.7
W, p=0.008), 15.5 kg (185.1±42.3 vs. 150.4±36.5 W, p=0.019), and 10.5 kg (169.8±40.7 vs. 139.7±31.6 W, p=0.024) but not at 5.5
kg (107.4±29.4 vs. 86.5±21.1 W, p=0.111). Furthermore, peak and mean power during standing trunk rotations significantly
correlated with values achieved in the seated position at the weight of 5.5 kg (r=0.684, p=0.027; r=0.676, p=0.033) but not at 10.5
kg (r=0.589, p=0.089; r=0.552, p=0.143), 15.5 kg (r=0.493, p=0.243; r=0.436, p=0.298), and 20 kg (r=0.357, p=0.361; r=0.333,
p=0.417). In conclusion, power production is greater during standing as compared to seated trunk rotations, with more
pronounced differences at higher weights. This fact has to be taken into account when training and testing the trunk rotational
power.