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Hypothetical control of postural sway
- Source :
- J R Soc Interface
- Publication Year :
- 2021
- Publisher :
- The Royal Society, 2021.
-
Abstract
- Quiet standing exhibits strongly intermittent variability that has inspired at least two interpretations. First, variability can be intermittent through the alternating engagement and disengagement of complementary control processes at distinct scales. A second and perhaps deeper way to interpret this intermittency is through the possibility that postural control depends on cascade-like interactions across many timescales at once, suggesting specific non-Gaussian distributional properties at different timescales. Multiscale probability density function (PDF) analysis shows that quiet standing on a stable surface exhibits a crossover from low, increasing non-Gaussianity (consistent with exponential distributions) at shorter timescales, reflecting inertial control, towards higher non-Gaussianity. Feedback-based control at medium to longer timescales yields a linear decrease characteristic of cascade dynamics. Destabilizing quiet standing with unstable surface or closed eyes serves to attenuate inertial control and to elicit more of the feedback-based control over progressively shorter timescales. The result was to strengthen the appearance of the linear decay indicating cascade dynamics. Finally, both linear and nonlinear indices of postural sway also govern the relative strength of crossover or of linear decay, suggesting that tempering of non-Gaussianity across log-timescale is a function of both extrinsic constraints and endogenous postural control. These results provide new evidence that cascading interactions across longer-timescales supporting postural corrections can even recruit shorter-timescale processes with novel task constraints that can destabilize posture.
- Subjects :
- Adult
Male
Adolescent
Posture
Crossover
Biomedical Engineering
Biophysics
Bioengineering
Probability density function
Relative strength
Biochemistry
Postural control
Feedback
law.invention
Biomaterials
Young Adult
03 medical and health sciences
0302 clinical medicine
law
Intermittency
Humans
Statistical physics
Control (linguistics)
Postural Balance
030304 developmental biology
Physics
0303 health sciences
Middle Aged
Scale invariance
Exponential function
Nonlinear system
Cascade
Female
Life Sciences–Mathematics interface
030217 neurology & neurosurgery
Quiet standing
Biotechnology
Subjects
Details
- ISSN :
- 17425662
- Volume :
- 18
- Database :
- OpenAIRE
- Journal :
- Journal of The Royal Society Interface
- Accession number :
- edsair.doi.dedup.....03f12acd09845c4ec33cafeb03c037b7