Complexity, composition, and control of bipedal balancing movements as the postural control system adapts to instable support surfaces or altered feet positions

Publication date: Available online 3 February 2020Source: NeuroscienceAuthor(s): Arunee Promsri, Thomas Haid, Peter FederolfAbstractThe 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, modified- and conventional balance boards). We hypothesized that movement complexity and muscle activation would increase with increased balance-task difficulty, and that differences in 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 firm surface, different movement structures were observed between narrowed- and wide-based standing (p ≤ 0.016); whereas differe...

Source: Neuroscience - February 4, 2020 Category: Neuroscience Source Type: research