• Arunee Promsri, Thomas Haid, and Peter Federolf.
• Department of Sport Science, University of Innsbruck, Fürstenweg 185 A-6020 Innsbruck, Austria; Department of Physical Therapy, University of Phayao, 19 Moo 2 Maeka, Muang, Phayao 56000, Thailand. Electronic address: arunee.pr@up.ac.th.
• Neuroscience. 2020 Mar 15; 430: 113-124.

AbstractThe current project investigated the dynamics of postural movements and muscle activity during balancing with feet-together and feet-apart positions on different support surfaces (firm surface (FS), modified- and conventional balance boards). We hypothesized that movement complexity and muscle activation would increase with increased balance-task difficulty, and that differences in the composition and control of postural movements between bipedal wide- and narrow-based balancing would be observed in all surface conditions. We applied a principal component analysis (PCA) to decompose postural movement trajectories of 26 active-young adults into sets of movement components (principal movements; PMs). Three PCA-based variables were calculated for each PM: the cumulative relative variance as a measure of movement complexity; the relative explained variance as a measure of the composition of postural movements; and the PM-acceleration as a measure for the control of the movement components. The main results revealed that both movement complexity and muscle activity increased with increased balance-task difficulty, of which altering support surfaces yielded more and greater effects than changing feet positions. Only on the FS, different movement structures were observed between narrowed- and wide-based standing (p ≤ 0.016); whereas different control of PMs was observed on all surfaces (p < 0.05). Standing on the stable surface illustrated opposite control behaviors compared to balancing on both multiaxial-unstable surfaces. In summary, on stable surface, changing the feet position affected inter-segment coordination. On unstable surfaces, the postural control system appeared to maintain inter-segment coordination characteristics, while the adaptation was confined to the sensorimotor integration processes.Copyright © 2020 IBRO. Published by Elsevier Ltd. All rights reserved.

14 keywords...

hide…