Presentation Title

The complexity of postural control variability while walking on an unstable support surface

Advisor Information

Mukul Mukherjee

Location

Dr. C.C. and Mabel L. Criss Library

Presentation Type

Poster

Start Date

6-3-2015 9:00 AM

End Date

6-3-2015 10:30 AM

Abstract

The maintenance of balance during locomotion requires control of anteroposterior and mediolateral postural sway. Walking on the unstable support surface requires learning the dynamics of the support surface and counteracting this to maintain stability. The complexity of displacement along each axis can provide information on control processes involved in this type of behavior. In this study, 8 healthy individuals performed a locomotor task while exposed to different types of mediolateral support surface perturbations. The perturbation conditions were presented in order: stable 1, adaptation 1 (surface roll: ± 5°), stable 2, adaptation 2. All participants were exposed to the conditions in this order. Postural sway was quantified as the anteroposterior and mediolateral displacement of the pelvis. The complexity of displacement along the two movement axes was analyzed using sample entropy; a measure of variability. Statistical analyses consisted of a one-way RM ANOVA per movement axis. The analyses revealed overall higher complexity along the anteroposterior axis, indicated by larger sample entropy values. In response to the random and sinusoidal platform motion conditions, control of the pelvis became more complex. This is significantly different from locomotion on the stable support surface in the baseline and catch trials. Along the anteroposterior axis on the other hand, no significant effect of condition was observed. The results indicate learning to maintain balance while walking on an unstable support surface requires a change in complexity. Complexity of postural control increases only along the perturbation axis, suggesting the system can learn to control for perturbations along selected axes.

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Mar 6th, 9:00 AM Mar 6th, 10:30 AM

The complexity of postural control variability while walking on an unstable support surface

Dr. C.C. and Mabel L. Criss Library

The maintenance of balance during locomotion requires control of anteroposterior and mediolateral postural sway. Walking on the unstable support surface requires learning the dynamics of the support surface and counteracting this to maintain stability. The complexity of displacement along each axis can provide information on control processes involved in this type of behavior. In this study, 8 healthy individuals performed a locomotor task while exposed to different types of mediolateral support surface perturbations. The perturbation conditions were presented in order: stable 1, adaptation 1 (surface roll: ± 5°), stable 2, adaptation 2. All participants were exposed to the conditions in this order. Postural sway was quantified as the anteroposterior and mediolateral displacement of the pelvis. The complexity of displacement along the two movement axes was analyzed using sample entropy; a measure of variability. Statistical analyses consisted of a one-way RM ANOVA per movement axis. The analyses revealed overall higher complexity along the anteroposterior axis, indicated by larger sample entropy values. In response to the random and sinusoidal platform motion conditions, control of the pelvis became more complex. This is significantly different from locomotion on the stable support surface in the baseline and catch trials. Along the anteroposterior axis on the other hand, no significant effect of condition was observed. The results indicate learning to maintain balance while walking on an unstable support surface requires a change in complexity. Complexity of postural control increases only along the perturbation axis, suggesting the system can learn to control for perturbations along selected axes.