Postural control in gymnasts: anisotropic fractal scaling reveals proprioceptive reintegration in vestibular perturbation

Dexterous postural control subtly complements movement variability with sensory correlations at many scales. The expressive poise of gymnasts exemplifies this lyrical punctuation of release with constraint, from coarse grain to fine scales. Dexterous postural control upon a 2D support surface might...

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Main Authors: Madhur Mangalam, Ivan Seleznov, Elena Kolosova, Anton Popov, Damian G. Kelty-Stephen, Ken Kiyono
Format: Article
Language:English
Published: Frontiers Media S.A. 2024-04-01
Series:Frontiers in Network Physiology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fnetp.2024.1393171/full
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author Madhur Mangalam
Ivan Seleznov
Elena Kolosova
Elena Kolosova
Anton Popov
Anton Popov
Damian G. Kelty-Stephen
Ken Kiyono
author_facet Madhur Mangalam
Ivan Seleznov
Elena Kolosova
Elena Kolosova
Anton Popov
Anton Popov
Damian G. Kelty-Stephen
Ken Kiyono
author_sort Madhur Mangalam
collection DOAJ
description Dexterous postural control subtly complements movement variability with sensory correlations at many scales. The expressive poise of gymnasts exemplifies this lyrical punctuation of release with constraint, from coarse grain to fine scales. Dexterous postural control upon a 2D support surface might collapse the variation of center of pressure (CoP) to a relatively 1D orientation—a direction often oriented towards the focal point of a visual task. Sensory corrections in dexterous postural control might manifest in temporal correlations, specifically as fractional Brownian motions whose differences are more and less correlated with fractional Gaussian noises (fGns) with progressively larger and smaller Hurst exponent H. Traditional empirical work examines this arrangement of lower-dimensional compression of CoP along two orthogonal axes, anteroposterior (AP) and mediolateral (ML). Eyes-open and face-forward orientations cultivate greater variability along AP than ML axes, and the orthogonal distribution of spatial variability has so far gone hand in hand with an orthogonal distribution of H, for example, larger in AP and lower in ML. However, perturbing the orientation of task focus might destabilize the postural synergy away from its 1D distribution and homogenize the temporal correlations across the 2D support surface, resulting in narrower angles between the directions of the largest and smallest H. We used oriented fractal scaling component analysis (OFSCA) to investigate whether sensory corrections in postural control might thus become suborthogonal. OFSCA models raw 2D CoP trajectory by decomposing it in all directions along the 2D support surface and fits the directions with the largest and smallest H. We studied a sample of gymnasts in eyes-open and face-forward quiet posture, and results from OFSCA confirm that such posture exhibits the classic orthogonal distribution of temporal correlations. Head-turning resulted in a simultaneous decrease in this angle Δθ, which promptly reversed once gymnasts reoriented their heads forward. However, when vision was absent, there was only a discernible negative trend in Δθ, indicating a shift in the angle’s direction but not a statistically significant one. Thus, the narrowing of Δθ may signify an adaptive strategy in postural control. The swift recovery of Δθ upon returning to a forward-facing posture suggests that the temporary reduction is specific to head-turning and does not impose a lasting burden on postural control. Turning the head reduced the angle between these two orientations, facilitating the release of postural degrees of freedom towards a more uniform spread of the CoP across both dimensions of the support surface. The innovative aspect of this work is that it shows how fractality might serve as a control parameter of adaptive mechanisms of dexterous postural control.
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spelling doaj.art-b7210d83c5e047f590a651ac5ef88f092024-04-18T04:24:14ZengFrontiers Media S.A.Frontiers in Network Physiology2674-01092024-04-01410.3389/fnetp.2024.13931711393171Postural control in gymnasts: anisotropic fractal scaling reveals proprioceptive reintegration in vestibular perturbationMadhur Mangalam0Ivan Seleznov1Elena Kolosova2Elena Kolosova3Anton Popov4Anton Popov5Damian G. Kelty-Stephen6Ken Kiyono7Division of Biomechanics and Research Development, Department of Biomechanics, and Center for Research in Human Movement Variability, University of Nebraska at Omaha, Omaha, NE, United StatesGraduate School of Engineering Science, Osaka University, Osaka, JapanNational University of Ukraine on Physical Education and Sport, Scientific Research Institute, Kyiv, UkraineDepartment of Movement Physiology, Bogomoletz Institute of Physiology, Kyiv, UkraineDepartment of Electronic Engineering, Igor Sikorsky Kyiv Polytechnic Institute, Kyiv, UkraineFaculty of Applied Sciences, Ukrainian Catholic University, Lviv, UkraineDepartment of Psychology, State University of New York at New Paltz, New Paltz, NY, United StatesGraduate School of Engineering Science, Osaka University, Osaka, JapanDexterous postural control subtly complements movement variability with sensory correlations at many scales. The expressive poise of gymnasts exemplifies this lyrical punctuation of release with constraint, from coarse grain to fine scales. Dexterous postural control upon a 2D support surface might collapse the variation of center of pressure (CoP) to a relatively 1D orientation—a direction often oriented towards the focal point of a visual task. Sensory corrections in dexterous postural control might manifest in temporal correlations, specifically as fractional Brownian motions whose differences are more and less correlated with fractional Gaussian noises (fGns) with progressively larger and smaller Hurst exponent H. Traditional empirical work examines this arrangement of lower-dimensional compression of CoP along two orthogonal axes, anteroposterior (AP) and mediolateral (ML). Eyes-open and face-forward orientations cultivate greater variability along AP than ML axes, and the orthogonal distribution of spatial variability has so far gone hand in hand with an orthogonal distribution of H, for example, larger in AP and lower in ML. However, perturbing the orientation of task focus might destabilize the postural synergy away from its 1D distribution and homogenize the temporal correlations across the 2D support surface, resulting in narrower angles between the directions of the largest and smallest H. We used oriented fractal scaling component analysis (OFSCA) to investigate whether sensory corrections in postural control might thus become suborthogonal. OFSCA models raw 2D CoP trajectory by decomposing it in all directions along the 2D support surface and fits the directions with the largest and smallest H. We studied a sample of gymnasts in eyes-open and face-forward quiet posture, and results from OFSCA confirm that such posture exhibits the classic orthogonal distribution of temporal correlations. Head-turning resulted in a simultaneous decrease in this angle Δθ, which promptly reversed once gymnasts reoriented their heads forward. However, when vision was absent, there was only a discernible negative trend in Δθ, indicating a shift in the angle’s direction but not a statistically significant one. Thus, the narrowing of Δθ may signify an adaptive strategy in postural control. The swift recovery of Δθ upon returning to a forward-facing posture suggests that the temporary reduction is specific to head-turning and does not impose a lasting burden on postural control. Turning the head reduced the angle between these two orientations, facilitating the release of postural degrees of freedom towards a more uniform spread of the CoP across both dimensions of the support surface. The innovative aspect of this work is that it shows how fractality might serve as a control parameter of adaptive mechanisms of dexterous postural control.https://www.frontiersin.org/articles/10.3389/fnetp.2024.1393171/fullfallfractalhurst exponentmotor disordermultiscaleoriented fractal scaling component analysis
spellingShingle Madhur Mangalam
Ivan Seleznov
Elena Kolosova
Elena Kolosova
Anton Popov
Anton Popov
Damian G. Kelty-Stephen
Ken Kiyono
Postural control in gymnasts: anisotropic fractal scaling reveals proprioceptive reintegration in vestibular perturbation
Frontiers in Network Physiology
fall
fractal
hurst exponent
motor disorder
multiscale
oriented fractal scaling component analysis
title Postural control in gymnasts: anisotropic fractal scaling reveals proprioceptive reintegration in vestibular perturbation
title_full Postural control in gymnasts: anisotropic fractal scaling reveals proprioceptive reintegration in vestibular perturbation
title_fullStr Postural control in gymnasts: anisotropic fractal scaling reveals proprioceptive reintegration in vestibular perturbation
title_full_unstemmed Postural control in gymnasts: anisotropic fractal scaling reveals proprioceptive reintegration in vestibular perturbation
title_short Postural control in gymnasts: anisotropic fractal scaling reveals proprioceptive reintegration in vestibular perturbation
title_sort postural control in gymnasts anisotropic fractal scaling reveals proprioceptive reintegration in vestibular perturbation
topic fall
fractal
hurst exponent
motor disorder
multiscale
oriented fractal scaling component analysis
url https://www.frontiersin.org/articles/10.3389/fnetp.2024.1393171/full
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