Dynamic Regulation of Sensorimotor Integration in Human Postural Control

2004 ◽  
Vol 91 (1) ◽  
pp. 410-423 ◽  
Author(s):  
Robert J. Peterka ◽  
Patrick J. Loughlin
Keyword(s):  
Postural Control ◽  
Postural Stability ◽  
Sensory Systems ◽  
Body Sway ◽  
Accurate Information ◽  
Support Surface ◽  
Proprioceptive Information ◽  
Postural Control System ◽  
Eyes Closed ◽  
Orientation Information

Upright stance in humans is inherently unstable, requiring corrective action based on spatial-orientation information from sensory systems. One might logically predict that environments providing access to accurate orientation information from multiple sensory systems would facilitate postural stability. However, we show that, after a period in which access to accurate sensory information was reduced, the restoration of accurate information disrupted postural stability. In eyes-closed trials, proprioceptive information was altered by rotating the support surface in proportion to body sway (support surface “sway-referencing”). When the support surface returned to a level orientation, most subjects developed a transient 1-Hz body sway oscillation that differed significantly from the low-amplitude body sway typically observed during quiet stance. Additional experiments showed further enhancement of the 1-Hz oscillation when the surface transitioned from a sway-referenced to a reverse sway-referenced motion. Oscillatory behavior declined with repetition of trials, suggesting a learning effect. A simple negative feedback-control model of the postural control system predicted the occurrence of this 1-Hz oscillation in conditions where too much corrective torque is generated in proportion to body sway. Model simulations were used to distinguish between two alternative explanations for the excessive corrective torque generation. Simulation results favor an explanation based on the dynamic reweighting of sensory contributions to postural control rather than a load-compensation mechanism that scales torque in proportion to a fixed combination of sensory-orientation information.

Postural sway with earth-fixed and body-referenced finger contact in young and older adults

1999 ◽  
Vol 9 (2) ◽  
pp. 103-109
Author(s):  
Reginald L. Reginella ◽  
Mark S. Redfern ◽  
Joseph M. Furman
Keyword(s):  
Older Adults ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Sensory Information ◽  
Body Sway ◽  
Support Surface ◽  
Proprioceptive Information ◽  
Postural Control System ◽  
Fixed Reference ◽  
Older Subjects

Sensory information from lightly touching a reference with the hand is known to influence postural sway in young adults. The primary aim of this study was to compare the influence of finger contact (FC) with an earth-fixed reference to the influence of FC with a body-fixed reference. A second goal of this study was to determine if FC is used differently by older adults compared to younger adults. Using a force plate, center of pressure at the feet was recorded from blindfolded young and older subjects during several conditions. Subjects either did or did not lightly touch a force-sensitive plate that was either earth-fixed or moved forward and backward in synchrony with body sway (that is, sway-referenced). In addition, support surface conditions were also varied, including a fixed floor and a sway-referenced floor using an EquitestTM. Results showed that the type of FC, floor condition, and age each had an effect on postural sway. Touching an earth-fixed plate decreased postural sway as compared to no touching, while touching a sway-referenced plate incresased sway. This influence of FC was enhanced when the floor was sway-referenced. Although older subjects swayed more than young subjects overall, no age-FC interactions occurred, indicating that FC was not utilized differently between the age groups. This study suggests that FC cannot be disregarded as erroneous, especially when proprioceptive information from the legs is distorted. Further, FC is integrated with other sensory information by the postural control system similarly in young and older persons.

scholarly journals Dissociating proprioceptive deficits in Autism Spectrum Disorders: Intact acuity but impaired sensory integration in postural control

2019 ◽  
Author(s):  
Michail Doumas ◽  
Rebekah Knox ◽  
Cara O’Brien ◽  
Chesney E. Craig
Keyword(s):  
Postural Control ◽  
Sensory Integration ◽  
Autism Spectrum ◽  
Sensory Profile ◽  
Group Differences ◽  
Body Sway ◽  
Support Surface ◽  
Proprioceptive Information ◽  
Baseline Phase ◽  
Adults With Asd

AbstractWe investigated the presence of proprioceptive deficits in adults with Autism Spectrum Disorder (ASD), by assessing peripheral proprioceptive information (or proprioceptive acuity) as well as integration of proprioceptive information in the context of postural control. We hypothesized that proprioceptive acuity would be intact but that integration during a postural control task would be impaired. Sixteen adults with ASD and sixteen Neurotypical (NT) adults were screened using an IQ test and the adolescent-adult sensory profile. Proprioceptive acuity was assessed using an ankle Joint Position Sense (JPS) task and integration of proprioceptive information was assessed using a postural adaptation task. This task comprised standing upright, without vision in three phases: standing on a fixed surface for 2 minutes (baseline), followed by standing on a surface tilting in proportion to participants’ body sway, or support-surface sway reference for 3 minutes (adaptation) and finally standing on the restored fixed surface for 3 minutes (reintegration). Results showed no group differences in proprioceptive acuity and in the baseline phase, but greater postural sway during adaptation in individuals with ASD compared with NT controls. Specifically, group differences were not present in the first 30s of adaptation, but emerged after the second window suggesting a deficit in sensory integration of proprioception in adults with ASD. Our results suggest that peripheral proprioceptive information is intact in ASD but neural sensory integration of proprioception is impaired in this group.

Effect of Head Orientation on Human Postural Stability Following Unilateral Vestibular Ablation

1991 ◽  
Vol 1 (2) ◽  
pp. 153-160
Author(s):  
Charles R. Fox ◽  
Gary D. Paige
Keyword(s):  
Postural Control ◽  
Postural Stability ◽  
Postural Sway ◽  
Normal Subjects ◽  
Head Orientation ◽  
Support Surface ◽  
Eyes Closed ◽  
Vestibular Information ◽  
Postural Equilibrium ◽  
Vestibular Pathology

Effective interpretation of vestibular inputs to postural control requires that orientation of head on body is known. Postural stability might deteriorate when vestibular information and neck information are not properly coupled, as might occur with vestibular pathology. Postural sway was assessed in unilateral vestibulopathic patients before and acutely, 1,4, and 18+ months after unilateral vestibular ablation (UVA) as well as in normal subjects. Postural equilibrium with eyes closed was quantified as scaled pk-pk sway during 20 s trials in which the support surface was modulated proportionally with sway. Subjects were tested with the head upright and facing forward, turned 45∘ right, and 45∘ left. Equilibrium was uninfluenced by head orientation in normal subjects. In contrast, patients after UV A showed both a general reduction in stability and a right/left head orientation-dependent asymmetry. These abnormalities adaptively recovered with time. It is concluded that vestibular inputs to postural control are interpreted within a sensory-motor context of head-on-body orientation.

scholarly journals Stimulus-Dependent Changes in the Vestibular Contribution to Human Postural Control

2006 ◽  
Vol 95 (5) ◽  
pp. 2733-2750 ◽  
Author(s):  
Massimo Cenciarini ◽  
Robert J. Peterka
Keyword(s):  
Postural Control ◽  
Sensory System ◽  
Weighting Factor ◽  
Body Sway ◽  
Support Surface ◽  
Sensory Reweighting ◽  
Eyes Closed ◽  
Relative Contribution ◽  
Lateral Body ◽  
Highly Correlated

Humans maintain stable stance in a wide variety of environments. This robust behavior is thought to involve sensory reweighting whereby the nervous system adjusts the relative contribution of sensory sources used to control stance depending on environmental conditions. Based on prior experimental and modeling results, we developed a specific quantitative representation of a sensory reweighting hypothesis that predicts that a given reduction in the contribution from one sensory system will be accompanied by a corresponding increase in the contribution from different sensory systems. The goal of this study was to test this sensory-reweighting hypothesis using measures that quantitatively assess the relative contributions of the proprioceptive and graviceptive (vestibular) systems to postural control during eyes-closed stance in different test conditions. Medial/lateral body sway was evoked by side-to-side rotation of the support surface (SS) while simultaneously delivering a pulsed galvanic vestibular stimulus (GVS) through electrodes behind the ears. A model-based interpretation of sway evoked by SS rotations provided estimates of the proprioceptive weighting factor, Wp, and showed that Wp declined with increasing SS amplitude. If the sensory-reweighting hypothesis is true, then the decline in Wp should be accompanied by a corresponding increase in Wg, the graviceptive weighting factor, and responses to the GVS should increase in proportion to the value of Wg derived from responses to SS rotations. Results were consistent with the predictions of the proposed sensory-reweighting hypothesis. GVS-evoked sway increased with increasing SS amplitude, and Wg measures derived from responses to GVS and from responses to SS rotations were highly correlated.

Adaptation and Reintegration of Proprioceptive Information in Young and Older Adults' Postural Control

2010 ◽  
Vol 104 (4) ◽  
pp. 1969-1977 ◽  
Author(s):  
Michail Doumas ◽  
Ralf Th. Krampe
Keyword(s):  
Older Adults ◽  
Postural Control ◽  
Path Length ◽  
Reference Conditions ◽  
Age Groups ◽  
Linear Feedback ◽  
Body Sway ◽  
Support Surface ◽  
Proprioceptive Information ◽  
Age Related

We investigated age-related changes in adaptation and sensory reintegration in postural control without vision. In two sessions, participants adapted their posture to sway reference and to reverse sway reference conditions, the former reducing (near eliminating) and the latter enhancing (near doubling) proprioceptive information for posture by means of support-surface rotations in proportion to body sway. Participants stood on a stable platform for 3 min (baseline) followed by 18 min of sway reference or reverse sway reference (adaptation) and finally again on a stable platform for 3 min (reintegration). Results showed that when inaccurate proprioception was introduced, anterior-posterior (AP) sway path length increased in comparable levels in the two age groups. During adaptation, young and older adults reduced postural sway at the same rate. On restoration of the stable platform in the reintegration phase, a sizeable aftereffect of increased AP path length was observed in both groups, which was greater in magnitude and duration for older adults. In line with linear feedback models of postural control, spectral analyses showed that this aftereffect differed between the two platform conditions. In the sway-referenced condition, a switch from low- to high-frequency COP sway marked the transition from reduced to normal proprioceptive information. The opposite switch was observed in the reverse sway referenced condition. Our findings illustrate age-related slowing in participants' postural control adjustments to sudden changes in environmental conditions. Over and above differences in postural control, our results implicate sensory reweighting as a specific mechanism highly sensitive to age-related decline.

Effects of hypothermic anesthesia of the feet on vibration-induced body sway and adaptation

2003 ◽  
Vol 13 (1) ◽  
pp. 39-52 ◽  
Author(s):  
F. Stål ◽  
P.A. Fransson ◽  
M. Magnusson ◽  
M. Karlberg
Keyword(s):  
Postural Control ◽  
Sensory Loss ◽  
Body Sway ◽  
Cutaneous Mechanoreceptors ◽  
Supporting Surface ◽  
Eyes Closed ◽  
Somatosensory Input ◽  
Eyes Open ◽  
Sensor Information ◽  
Ice Water

The aim of this study was to investigate the significance of information from the plantar cutaneous mechanoreceptors in postural control and whether postural control could compensate for reduced cutaneous information by adaptation. Sixteen healthy subjects were tested with eyes open or eyes closed with hypothermic and normal feet temperature during posturography where body sway was induced by vibratory proprioceptive stimulation towards both calf muscles. The hypothermic anesthesia was obtained by cooling the subject's feet in ice water for 20 minutes. Body movements were evaluated by analyzing the anteroposterior and lateral torques induced towards the supporting surface by a force platform during the posturography tests. The reduction of cutaneous sensor information from the mechanoreceptors of the feet significantly increased the vibration-induced torque variance mainly in the anteroposterior direction. However, the effects of disturbed mechanoreceptors information was rapidly compensated for through postural adaptation and torque variance was in level with that without anesthesia within 50 to 100 seconds of stimulation, both when standing with eyes open and eyes closed. Our findings suggest that somatosensory input from mechanoreceptors in the foot soles contribute significantly in maintaining postural control, but the sensory loss could be compensated for.

Effects of Hand Vibration on Postural Stability

1992 ◽  
Vol 36 (10) ◽  
pp. 765-769
Author(s):  
Lisa Fletcher ◽  
Hee-Seok Park ◽  
Bernard J Martin
Keyword(s):  
Risk Factor ◽  
Postural Stability ◽  
Center Of Pressure ◽  
Environmental Context ◽  
Proprioceptive Information ◽  
Vibration Exposure ◽  
Dominant Hand ◽  
Erect Posture ◽  
Spatial Reference ◽  
Eyes Closed

The present work was aimed at defining the contribution of vibration-induced perturbation of hand proprioceptive/exteroceptive feedback on standing equilibrium. A vibrating handle, free in space or fixed to a stationary support, was held in the dominant hand while maintaining an erect posture on a force platform, eyes closed. Four arm positions were used. The results show that body sways increase significantly during hand vibration exposure when the handle is fixed. Significant shifts of the center of pressure COP are elicited in every situations. Furthermore, the shifts of the COP are clearly oriented in the direction of the handle when this latter is fixed. It is suggested that the proprioceptive information issued from the hand contributes to the elaboration of a spatial reference and to the control of posture as a function of the environmental context. These results indicate that hand vibration exposure can be considered as a risk factor which may contribute to fall accidents.

scholarly journals Time-to-Boundary Function to Study the Development of Upright Stance Control in Children

2017 ◽  
Vol 11 (1) ◽  
pp. 49-58
Author(s):  
Carmen D'Anna ◽  
Maurizio Schmid ◽  
Andrea Scorza ◽  
Salvatore A. Sciuto ◽  
Luisa Lopez ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Postural Control ◽  
Postural Stability ◽  
Age Groups ◽  
Boundary Function ◽  
Mean Value ◽  
Upright Stance ◽  
Eyes Closed ◽  
The Mean ◽  
Spatio Temporal

Background: The development of postural control across the primary school time horizon is a complex process, which entails biomechanics modifications, the maturation of cognitive ability and sensorimotor organization, and the emergence of anticipatory behaviour. Postural stability in upright stance has been thus object of a multiplicity of studies to better characterize postural control in this age span, with a variety of methodological approaches. The analysis of the Time-to-Boundary function (TtB), which specifies the spatiotemporal proximity of the Centre of Pressure (CoP) to the stability boundaries in the regulation of posture in upright stance, is among the techniques used to better characterize postural stability in adults, but, as of now, it has not yet been introduced in developmental studies. The aim of this study was thus to apply this technique to evaluate the development of postural control in a sample population of primary school children. Methods: In this cross-sectional study, upright stance trials under eyes open and eyes closed were administered to 107 healthy children, divided into three age groups (41 for Seven Years' Group, Y7; 38 for Nine Years' Group, Y9; 28 for Eleven Years' Group, Y11). CoP data were recorded to calculate the Time-to-Boundary function (TtB), from which four spatio-temporal parameters were extracted: the mean value and the standard deviation of TtB minima (Mmin, Stdmin), and the mean value and the standard deviation of the temporal distance between two successive minima (Mdist, Stddist). Results: With eyes closed, Mmin and Stdmin significantly decreased and Mdist and Stddist increased for the Y7 group, at Y9 Mmin significantly decreased and Stddist increased, while no effect of vision resulted for Y11. Regarding age groups, Mmin was significantly higher for Y9 than Y7, and Stdmin for Y9 was higher than both Y7 and Y11; Mdist and Stddist resulted higher for Y11 than for Y9. Conclusion: From the combined results from the spatio-temporal TtB parameters, it is suggested that, at 9 years, children look more efficient in terms of exploring their limits of stability than at 7, and at 11 the observed TtB behaviour hints at the possibility that, at that age, they have almost completed the maturation of postural control in upright stance, also in terms of integration of the spatio-temporal information.

Experience on an Elevated Inclined Surface and Postural Control

2005 ◽  
Vol 49 (14) ◽  
pp. 1311-1314
Author(s):  
Chip Wade ◽  
Jerry Davis
Keyword(s):  
College Students ◽  
Postural Control ◽  
Postural Stability ◽  
Support Surface ◽  
Motion Analysis System ◽  
Balance Test ◽  
Significant Decrement ◽  
Peripheral Area ◽  
Analysis System ◽  
Inclined Surface

Historically, roofing work has been ranked among the highest of all industries with incidents of fatal and non-fatal falls. The purpose of this study was to investigate the exposure to an elevated inclined surface on postural stability. Twenty males, 10 experienced roofers, and 10 inexperienced college students participated in this study, which consisted of a preliminary balance test, followed by exposure to an elevated inclined surface for ten-minutes of exposure. While subjects walked, a motion analysis system recorded their position on the elevated roofing surface to determine the amount of time a subject spent in each of two areas, central or peripheral. Results suggest that both experienced and inexperienced individuals demonstrated decreased postural stability following exposure to the elevated inclined surface, with experienced individuals demonstrating a lesser decrement. Furthermore, experienced individuals spent a significantly greater portion of time in the peripheral area (extremities of the elevated roofing surface) surface compared to inexperienced individuals. These findings suggest that there is a significant decrement in postural stability due to exposure to an elevated inclined support surface.

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.

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