Non-linear dynamical feature of center of pressure extracted by approximate entropy in people with various stages of Parkinson’s Disease

2020 ◽  
Author(s):  
mohammad Karimi ◽  
Mina Mirahmadi
Keyword(s):  
Parkinson’S Disease ◽  
Control System ◽  
Postural Control ◽  
Group Interaction ◽  
Approximate Entropy ◽  
Rigid Surface ◽  
Dynamical Feature ◽  
Postural Control System ◽  
Environmental Perturbation ◽  
Non Linear

Abstract Introduction : Postural instability, one of the most important features of Parkinson’s Disease (PD), is associated with increased falls and loss of independence in these population. It is postulated the abilities of individuals to adjust to environmental perturbation for postural control is different in various stages of PD. The aim of current study is to investigate the non-linear dynamical feature of COP in various stages of PD and in different environmental challenges. Method : 38 persons with PD (mild PD =19, moderate PD =6 and sever PD =13) and 33 healthy aged, gender, weight and height matched subjects were asked to stand on force plate in four test conditions included: 1) Rigid Surface with Opened Eyes, 2) Rigid Surface with Closed Eyes, 3) Foam Surface with Opened Eyes, and 4) Foam Surface with Closed Eyes. COP velocity and Approximate Entropy (ApEn) in both Anteroposterior (AP)/Mediolateral (ML) directions were calculated. A Mixed ANOVA 4*2*2 (Group*Vision*Surface) test was applied for statistical analysis . Results : Both COP velocity and COP ML ApEn were significantly higher in participants with PD in comparison to healthy individuals. Moreover, COP ML ApEn increased by eye closure in all studied groups but the amount of this increase was lesser in PD groups. For COP velocity, vision, surface and group interaction was significant in all directions (P ≤ 0.016). For COP ApEn, vision, surface and group interaction (P = 0.002) were statistically meaningful in only ML direction. Conclusion : Balance system irregularity is more in people with PD compared to healthy matched individuals. In addition, their adaptive capacity of the postural control system in response to environmental perturbation is reduced. PD induced complexity of the postural control system is associated with the loss of adaptive behavior that is organized over the confluence of constraints of the individual, environment and task.

Prolonged Standing Task Affects Adaptability of Postural Control in People With Parkinson’s Disease

2020 ◽  
Vol 35 (1) ◽  
pp. 58-67
Author(s):  
Gabriel Felipe Moretto ◽  
Felipe Balistieri Santinelli ◽  
Tiago Penedo ◽  
Luis Mochizuki ◽  
Natalia Madalena Rinaldi ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Control System ◽  
Postural Control ◽  
The Body ◽  
Quiet Standing ◽  
Body Sway ◽  
Control Group ◽  
Postural Control System ◽  
Prolonged Standing

Background Studies on short-term upright quiet standing tasks have presented contradictory findings about postural control in people with Parkinson’s disease (pwPD). Prolonged trial durations might better depict body sway and discriminate pwPD and controls. Objective The aim of this study was to investigate postural control in pwPD during a prolonged standing task. Methods A total of 26 pwPD and 25 neurologically healthy individuals performed 3 quiet standing trials (60 s) before completing a constrained prolonged standing task for 15 minutes. Motion capture was used to record body sway (Vicon, 100 Hz). To investigate the body sway behavior during the 15 minutes of standing, the analysis was divided into three 5-minute-long phases: early, middle, and late. The following body sway parameters were calculated for the anterior-posterior (AP) and medial-lateral (ML) directions: velocity, root-mean-square, and detrended fluctuations analysis (DFA). The body sway area was also calculated. Two-way ANOVAs (group and phases) and 1-way ANOVA (group) were used to compare these parameters for the prolonged standing and quiet standing, respectively. Results pwPD presented smaller sway area ( P < .001), less complexity (DFA; AP: P < .009; ML: P < .01), and faster velocity (AP: P < .002; ML: P < .001) of body sway compared with the control group during the prolonged standing task. Although the groups swayed similarly (no difference for sway area) during quiet standing, they presented differences in sway area during the prolonged standing task ( P < .001). Conclusions Prolonged standing task reduced adaptability of the postural control system in pwPD. In addition, the prolonged standing task may better analyze the adaptability of the postural control system in pwPD.

Degradation of postural control system as a consequence of Parkinson's disease and ageing

2005 ◽  
Vol 376 (3) ◽  
pp. 215-220 ◽  
Author(s):  
Maciej Bosek ◽  
Bronisław Grzegorzewski ◽  
Andrzej Kowalczyk ◽  
Ignacy Lubiński
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Control System ◽  
Postural Control ◽  
Postural Control System

scholarly journals Free Energy Principle in Human Postural Control System: Skin Stretch Feedback Reduces the Entropy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pilwon Hur ◽  
Yi-Tsen Pan ◽  
Christian DeBuys
Keyword(s):  
Free Energy ◽  
Control System ◽  
Postural Control ◽  
Standing Balance ◽  
Postural Control System ◽  
Energy Principle ◽  
Free Energy Principle ◽  
Sensory Deficits ◽  
Internal States ◽  
Skin Stretch

AbstractHuman upright standing involves an integration of multiple sensory inputs such as vision, vestibular and somatosensory systems. It has been known that sensory deficits worsen the standing balance. However, how the modulation of sensory information contributes to postural stabilization still remains an open question for researchers. The purpose of this work was to formulate the human standing postural control system in the framework of the free-energy principle, and to investigate the efficacy of the skin stretch feedback in enhancing the human standing balance. Previously, we have shown that sensory augmentation by skin stretch feedback at the fingertip could modulate the standing balance of the people with simulated sensory deficits. In this study, subjects underwent ten 30-second trials of quiet standing balance with and without skin stretch feedback. Visual and vestibular sensory deficits were simulated by having each subject close their eyes and tilt their head back. We found that sensory augmentation by velocity-based skin stretch feedback at the fingertip reduced the entropy of the standing postural sway of the people with simulated sensory deficits. This result aligns with the framework of the free energy principle which states that a self-organizing biological system at its equilibrium state tries to minimize its free energy either by updating the internal state or by correcting body movement with appropriate actions. The velocity-based skin stretch feedback at the fingertip may increase the signal-to-noise ratio of the sensory signals, which in turn enhances the accuracy of the internal states in the central nervous system. With more accurate internal states, the human postural control system can further adjust the standing posture to minimize the entropy, and thus the free energy.

Center-of-Pressure Parameters Used in the Assessment of Postural Control

2002 ◽  
Vol 11 (1) ◽  
pp. 51-66 ◽  
Author(s):  
Riann M. Palmieri ◽  
Christopher D. Ingersoll ◽  
Marcus B. Stone ◽  
B. Andrew Krause
Keyword(s):  
Control System ◽  
Postural Control ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Data Sources ◽  
Postural Control System ◽  
Type Data

Objective:To define the numerous center-of-pressure derivatives used in the assessment of postural control and discuss what value each might provide in the assessment of balance.Data Sources:MEDLINE and SPORTDiscus were searched with the termsbalance, postural control, postural sway,andcenter of pressure. The remaining citations were collected from references of similar papers. A total of 67 references were studied.Conclusions:Understanding what is represented by each parameter used to assess postural control is crucial. At the present time the literature has failed to demonstrate how the variables reflect changes made by the postural-control system. Until it can be shown that the center of pressure and its derivatives actually reveal changes in the postural-control system, the value of using these measures to assess deficits in postural control is minimized.

scholarly journals Postural control system influences intrinsic alerting state.

2015 ◽  
Vol 29 (2) ◽  
pp. 226-234 ◽  
Author(s):  
Julien Barra ◽  
Laurent Auclair ◽  
Agnès Charvillat ◽  
Manuel Vidal ◽  
Dominic Pérennou
Keyword(s):  
Control System ◽  
Postural Control ◽  
Postural Control System

scholarly journals Virtual-Reality-Induced Visual Perturbations Impact Postural Control System Behavior

2019 ◽  
Vol 9 (11) ◽  
pp. 113 ◽  
Author(s):  
Harish Chander ◽  
Sachini N. K. Kodithuwakku Arachchige ◽  
Christopher M. Hill ◽  
Alana J. Turner ◽  
Shuchisnigdha Deb ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Control System ◽  
Postural Control ◽  
Repeated Measures ◽  
Postural Stability ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Postural Control System ◽  
Postural Responses ◽  
The Impact

Background: Virtual reality (VR) is becoming a widespread tool in rehabilitation, especially for postural stability. However, the impact of using VR in a “moving wall paradigm” (visual perturbation), specifically without and with anticipation of the perturbation, is unknown. Methods: Nineteen healthy subjects performed three trials of static balance testing on a force plate under three different conditions: baseline (no perturbation), unexpected VR perturbation, and expected VR perturbation. The statistical analysis consisted of a 1 × 3 repeated-measures ANOVA to test for differences in the center of pressure (COP) displacement, 95% ellipsoid area, and COP sway velocity. Results: The expected perturbation rendered significantly lower (p < 0.05) COP displacements and 95% ellipsoid area compared to the unexpected condition. A significantly higher (p < 0.05) sway velocity was also observed in the expected condition compared to the unexpected condition. Conclusions: Postural stability was lowered during unexpected visual perturbations compared to both during baseline and during expected visual perturbations, suggesting that conflicting visual feedback induced postural instability due to compensatory postural responses. However, during expected visual perturbations, significantly lowered postural sway displacement and area were achieved by increasing the sway velocity, suggesting the occurrence of postural behavior due to anticipatory postural responses. Finally, the study also concluded that VR could be used to induce different postural responses by providing visual perturbations to the postural control system, which can subsequently be used as an effective and low-cost tool for postural stability training and rehabilitation.

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