scholarly journals Inter-Individual Variability in Postural Control During External Center of Mass Stabilization

2022 ◽  
Vol 12 ◽  
Author(s):  
Daša Gorjan ◽  
Nejc Šarabon ◽  
Jan Babič
Keyword(s):  
Postural Control ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Individual Variability ◽  
Quiet Standing ◽  
Pendulum System ◽  
Velocity Amplitude ◽  
Postural Responses ◽  
External Stabilization ◽  
Underlying Mechanisms

Understanding the relation between the motion of the center of mass (COM) and the center of pressure (COP) is important to understand the underlying mechanisms of maintaining body equilibrium. One way to investigate this is to stabilize COM by fixing the joints of the human and looking at the corresponding COP reactions. However, this approach constrains the natural motion of the human. To avoid this shortcoming, we stabilized COM without constraining the joint movements by using an external stabilization method based on inverted cart-pendulum system. Interestingly, this method only stabilized COM of a subgroup of participants and had a destabilizing effect for others which implies significant variability in inter-individual postural control. The aim of this work was to investigate the underlying causes of inter-individual variability by studying the postural parameters of quiet standing before the external stabilization. Eighteen volunteers took part in the experiment where they were standing on an actuated cart for 335 s. In the middle of this period we stabilized their COM in anteroposterior direction for 105 s. To stabilize the COM, we controlled the position of the cart using a double proportional–integral–derivative controller. We recorded COM position throughout the experiment, calculated its velocity, amplitude, and frequency during the quiet standing before the stabilization, and used these parameters as features in hierarchical clustering method. Clustering solution revealed that postural parameters of quiet standing before the stabilization cannot explain the inter-individual variability of postural responses during the external COM stabilization. COM was successfully stabilized for a group of participants but had a destabilizing effect on the others, showing a variability in individual postural control which cannot be explained by postural parameters of quiet-stance.

scholarly journals Gait Initiation in Community-Dwelling Adults With Parkinson Disease: Comparison With Older and Younger Adults Without the Disease

2002 ◽  
Vol 82 (6) ◽  
pp. 566-577 ◽  
Author(s):  
Matthew Martin ◽  
Mindi Shinberg ◽  
Maggie Kuchibhatla ◽  
Laurie Ray ◽  
James J Carollo ◽  
...  
Keyword(s):  
Postural Control ◽  
Parkinson Disease ◽  
Analysis Of Variance ◽  
Center Of Pressure ◽  
Center Of Mass ◽  
Community Dwelling ◽  
Quiet Standing ◽  
Gait Initiation ◽  
Younger Adults ◽  
Analysis System

Abstract Background and Purpose. Initiation of gait requires transitions from relatively stationary positions to stability with movement and from double- to single-limb stances. These are deliberately destabilizing activities that may be difficult for people with early Parkinson disease (PD), even when they have no problems with level walking. We studied differences in postural stability during gait initiation between participants with early and middle stages of PD (characterized by Hoehn and Yahr as stages 1–3) and 2 other groups of participants without PD—older and younger adults. Subjects. The mean ages of the 3 groups of participants were as follows: subjects with PD, 69.3 years (SD=5.7, range=59–78); older subjects without PD, 69.0 years (SD=3.9, range=65–79); and younger subjects without PD, 27.5 (SD=3.9, range=22–35). Methods. A 3-dimensional motion analysis system was used with 2 force platforms to obtain data for center of mass (COM) and center of pressure (COP). The distance between the vertical projections of the COM and the COP (COM–COP distance) was used to reflect postural control during 5 events in gait initiation. Results. By use of multivariate analysis of variance, differences in COM–COP distance were found among the 3 groups. An analysis of variance indicated differences for 4 of the 5 events in gait initiation. A Scheffe post hoc analysis demonstrated differences in gait initiation between the subjects with PD and both groups of subjects without PD (2 events) and between the subjects with PD and the younger subjects without PD (2 events). Discussion and Conclusion. The COM–COP distance relationship was used to measure postural control during the transition from quiet standing to steady-state gait. Differences between groups indicated that individuals with impaired postural control allow less COM–COP distance than do individuals with no known neurologic problems. The method used could prove useful in the development and assessment of interventions to improve ambulation safety and enhance the independence of people with impaired postural control.

Surface height effects on postural control: A hypothesis for a stiffness strategy for stance*

1999 ◽  
Vol 9 (4) ◽  
pp. 277-286 ◽  
Author(s):  
Mark G. Carpenter ◽  
James S. Frank ◽  
Cathy P. Silcher
Keyword(s):  
Postural Control ◽  
Center Of Pressure ◽  
High Surface ◽  
Quiet Standing ◽  
Vestibular Input ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Balance Confidence ◽  
Eyes Closed ◽  
Ankle Stiffness

One possible factor influencing the control of upright stance is the perceived threat to one's personal safety, i.e. balance confidence. We explored this factor by examining the control of stationary stance when standing on an elevated platform under various conditions of reduced visual and vestibular inputs. Twenty-eight adults (14 male and 14 female, mean age = 23.5 years) participated in the experiment. Postural control was examined by recording the amplitude variability (RMS) and mean power frequency (MPF) of center of pressure excursions (COP) over a 2-minute interval while participants stood in a normal stance on a low (0.19 m) and a high (0.81 m) platform with toes positioned either at or away from the edge of the platform. Vision was manipulated through eyes open and eyes closed trials. Vestibular input was reduced by tilting the head into extension [1]. Anterior-posterior RMS and MPF of COP were significantly influenced by an interaction between surface height and vision. When vision was available, a significant decrease in RMS was observed during quiet standing on a high surface compared to a low surface independent of step restriction. When vision was available MPF increased when subjects were raised from a low to a high surface. The mean position of the COP was significantly influenced by an interaction between height and step restriction. Differences in RMS and MPF responses to height manipulation were observed between genders in eyes closed conditions. Vestibular input influenced postural control at both low and high levels with significant increases in RMS when vestibular input was reduced. The reciprocal changes observed in RMS and MPF suggest modifications to postural control through changes in ankle stiffness. Vision appears to play a role in increasing ankle stiffness when balance confidence is compromised.

scholarly journals Characteristics of Functional Stability in Young Adolescent Female Artistic Gymnasts

2021 ◽  
Vol 77 (1) ◽  
pp. 51-59
Author(s):  
Agnieszka Opala-Berdzik ◽  
Magdalena Głowacka ◽  
Kajetan J. Słomka
Keyword(s):  
Postural Control ◽  
Center Of Pressure ◽  
National Level ◽  
Stability Limit ◽  
Young Adolescent ◽  
Quiet Standing ◽  
Adolescent Female ◽  
Functional Stability ◽  
Postural Control System ◽  
Stability Limits

Abstract The aim of this study was to determine whether young adolescent female artistic gymnasts demonstrate better functional stability than age- and sex-matched non-athletes. Different characteristics of the gymnasts’ postural control were expected to be observed. Twenty-two 10- to 13-year-old healthy females (ten national-level artistic gymnasts and twelve non-athletes) participated in the study. To assess their forward functional stability, the 30-s limit of stability test was performed on a force plate. The test consisted of three phases: quiet standing, transition to maximal forward leaning, and standing in the maximal forward leaning position. Between-group comparisons of the directional subcomponents of the root mean squares and mean velocities of the center of pressure and rambling-trembling displacements in two phases (quiet standing and standing in maximal leaning) were conducted. Moreover, anterior stability limits were compared. During standing in maximal forward leaning, there were no differences in the center of pressure and rambling measures between gymnasts and non-athletes (p > 0.05). The values of trembling measures in both anterior-posterior and medial-lateral directions were significantly lower in gymnasts (p < 0.05). Both groups presented similar values for anterior stability limits (p > 0.05). The comparisons of rambling components may suggest a similar supraspinal control of standing in the maximal leaning position between gymnasts and healthy non-athletes. However, decreased trembling in gymnasts may indicate reduced noise in their postural control system possibly due to superior control processes at the spinal level. The anterior stability limit was not influenced by gymnastics training in female adolescents.

scholarly journals The Effects of Active Self-Correction on Postural Control in Girls with Adolescent Idiopathic Scoliosis: The Role of an Additional Mental Task

2020 ◽  
Vol 17 (5) ◽  
pp. 1640 ◽  
Author(s):  
Elżbieta Piątek ◽  
Michał Kuczyński ◽  
Bożena Ostrowska
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Postural Control ◽  
Repeated Measures ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Force Plate ◽  
Stroop Test ◽  
Quiet Standing ◽  
Mental Task

Due to balance deficits that accompany adolescent idiopathic scoliosis (AIS), the potential interaction between activities of daily living and active self-correction movements (ASC) on postural control deserves particular attention. Our purpose was to assess the effects of ASC movements with or without a secondary mental task on postural control in twenty-five girls with AIS. It is a quasi-experimental within-subject design with repeated measures ANOVA. They were measured in four 20-s quiet standing trials on a force plate: no task, ASC, Stroop test, and both. Based on the center-of-pressure (COP) recordings, the COP parameters were computed. The ASC alone had no effect on any of the postural sway measures. Stroop test alone decreased COP speed and increased COP entropy. Performing the ASC movements and Stroop test together increased the COP speed and decreased COP entropy as compared to the baseline data. In conclusion, our results indicate that AIS did not interfere with postural control. The effects of the Stroop test accounted for good capacity of subjects with AIS to take advantage of distracting attentional resources from the posture. However, performing both tasks together exhibited some deficits in postural control, which may suggest the need for therapeutic consultation while engaging in more demanding activities.

Evaluation of Postural Control in Quiet Standing Using Center of Mass Acceleration: Comparison Among the Young, the Elderly, and People With Stroke

2008 ◽  
Vol 89 (6) ◽  
pp. 1133-1139 ◽  
Author(s):  
Erkang Yu ◽  
Masaki Abe ◽  
Kei Masani ◽  
Noritaka Kawashima ◽  
Fumio Eto ◽  
...  
Keyword(s):  
Postural Control ◽  
Center Of Mass ◽  
The Elderly ◽  
Quiet Standing

scholarly journals Attentional demands associated with augmented visual feedback during quiet standing

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5101 ◽  
Author(s):  
Krzysztof Kręcisz ◽  
Michał Kuczyński
Keyword(s):  
Postural Control ◽  
Visual Feedback ◽  
Center Of Pressure ◽  
Quiet Standing ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Postural Control System ◽  
Power Frequency ◽  
Auditory Reaction Time ◽  
Anterior Posterior

To investigate how additional visual feedback (VFB) affects postural stability we compared 20-sec center-of-pressure (COP) recordings in two conditions: without and with the VFB. Seven healthy adult subjects performed 10 trials lasting 20 seconds in each condition. Simultaneously, during all trials the simple auditory reaction time (RT) was measured. Based on the COP data, the following sway parameters were computed: standard deviation (SD), mean speed (MV), sample entropy (SE), and mean power frequency (MPF). The RT was higher in the VFB condition (p < 0.001) indicating that this condition was attention demanding. The VFB resulted in decreased SD and increased SE in both the medial-lateral (ML) and anterior-posterior (AP) planes (p < .001). These results account for the efficacy of the VFB in stabilizing posture and in producing more irregular COP signals which may be interpreted as higher automaticity and/or larger level of noise in postural control. The MPF was higher during VFB in both planes as was the MV in the AP plane only (p < 0.001). The latter data demonstrate higher activity of postural control system that was caused by the availability of the set-point on the screen and the resulting control error which facilitated and sped up postural control.

scholarly journals TEMPORAL AND FRACTAL BEHAVIOR OF THE CENTER OF PRESSURE IN PARKINSONIAN AND HEALTHY ELDERLY COHORTS DURING QUIET STANDING

2020 ◽  
Vol 20 (10) ◽  
pp. 2040036
Author(s):  
SEONHONG HWANG ◽  
JAESUN REE ◽  
JISUN HWANG
Keyword(s):  
Postural Control ◽  
Center Of Pressure ◽  
Open Loop ◽  
Quiet Standing ◽  
Fluctuation Analysis ◽  
Area Formula ◽  
Scaling Exponents ◽  
Loop Control ◽  
Scaling Properties ◽  
Healthy Elderly

This study investigated the quantitative scaling properties of the center of pressure (COP) as well as the spatial-temporal properties of the COP to elucidate the postural control behavior of healthy elderly (HE) adults and adults with Parkinson’s disease (PD) during quiet standing. Eighteen adults with PD and eighteen HE adults participated in this study. The COP movements were recorded while participants stood on either a firm surface or on a foam pad with their eyes either opened or closed. The sway ranges in the anterior–posterior (AP) ([Formula: see text] and medio-lateral (ML) ([Formula: see text] directions, the total length of the trajectory ([Formula: see text], sway area ([Formula: see text], and scaling exponents ([Formula: see text] from detrended fluctuation analysis were computed from the measured COP data. All temporal variables of the COP in all conditions were found to be significantly larger in the PD group than in the HE group. Low scaling exponents obtained for the PD group showed this group possessed diminished postural control ability compared to the HE group. The PD group showed unpredictable open-loop control in both the AP and ML directions. This proprioceptive control became predictable and the time scale relations decreased as the postural challenges increased. The AP and ML closed-loop control of the PD group was more predictable than that of the HE group only when proprioception was distorted using intact visual input, and the visual and proprioceptive inputs were both intact.

Sensory Reweighting During Bipedal Quiet Standing in Adolescents

Motor Control ◽  
2020 ◽  
Vol 24 (3) ◽  
pp. 383-396
Author(s):  
Alberto Pardo-Ibáñez ◽  
Jose L. Bermejo ◽  
Sergio Gandia ◽  
Julien Maitre ◽  
Israel Villarrasa-Sapiña ◽  
...  
Keyword(s):  
Postural Control ◽  
Center Of Pressure ◽  
Age Groups ◽  
Sensory System ◽  
Sensory Information ◽  
Quiet Standing ◽  
Proprioceptive Information ◽  
Sensory Reweighting ◽  
Cross Sectional ◽  
Older Adolescents

A cross-sectional, prospective, between-subjects design was used in this study to establish the differences in sensory reweighting of postural control among different ages during adolescence. A total of 153 adolescents (five age groups; 13–17 years old) performed bipedal standing in three sensory conditions (i.e., with visual restriction, vestibular disturbance, and proprioceptive disturbance). Center of pressure displacement signals were measured in mediolateral and anteroposterior directions to characterize reweighting in the sensory system in static postural control when sensory information is disturbed or restricted during adolescent growth. The results indicate a development of postural control, showing large differences between subjects of 13–14 years old and older adolescents. A critical change was found in sensory reweighting during bipedal stance with disturbance of proprioceptive information at 15 years old. Adolescents of 13–14 years old showed less postural control and performance than older adolescents during the disturbance of proprioceptive information. Moreover, the results demonstrated that the visual system achieves its development around 15–16 years old. In conclusion, this research suggests that a difference of sensory reweighting under this type of sensorial condition and sensory reweight systems would seem to achieve stabilization at the age of 15.

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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