Quality Of Postural Control Research Articles

Postural sway in the moving room scenario: New evidence for functional dissociation between self-motion perception and postural control.

Postural control in quiet standing is often explained by a reflexive response to optical flow, the apparent motion of environmental objects in a visual scene. However, moving room experiments show that even small-amplitude body sway can evoke odd sensations or motion sickness, indicating that a consciousness factor may also be involved. Studies targeting perception of self-motion, vection, typically use rapid visual stimuli moving in a single direction to maintain a constant feeling of vection, and there are few studies of vection using low-speed sinusoidal visual stimuli similar to human pendular movement. In the present study we searched for changes in postural control during periods of vection during quiet standing. Participants (N = 19, age = 20.4 ±1.1 years) were shown dynamic visual stimuli in the form of sinusoidally expanding and contracting random dots, and the stimuli speed and visual field were manipulated. Posture was continually evaluated using Center of Pressure (CoP) measurements. Participants were also asked to report feelings of vection, both by pressing a button during the trial and through an overall rating at the end of each trial. Using repeated-measures ANOVA, we assessed changes in the CoP and vection variables between experimental conditions, as well as possible interactions between the variables. The results show that postural reaction and vection were both affected by the visual stimuli and varied with speed. The peripheral visual field was found to couple to stronger feeling of vection and better quality of postural control. However, no significant relationship between postural control and vection, nor evidence of vection interaction to the relationship between optical flow and postural control, was found. Based on our results we conclude that for postural stability during quiet standing, visual cues dominate over any potential consciousness factor arising due to vection.

A Langevin-Based Model With Moving Posturographic Target to Quantify Postural Control.

Falls are a major concern of public health, particularly for older adults, as the consequences of falls include serious injuries and death. Therefore, the understanding and evaluation of postural control is considered key, as its deterioration is an important risk factor predisposing to falls. In this work we introduce a new Langevin-based model, local recall, that integrates the information from both the center of pressure (CoP) and the center of mass (CoM) trajectories, and compare its accuracy to a previously proposed model that only uses the CoP. Nine healthy young participants were studied under quiet bipedal standing conditions with eyes either open or closed, while standing on either a rigid surface or a foam. We show that the local recall model produces significantly more accurate prediction than its counterpart, regardless of the eyes and surface conditions, and we replicate these results using another publicly available human dataset. Additionally, we show that parameters estimated using the local recall model are correlated with the quality of postural control, providing a promising method to evaluate static balance. These results suggest that this approach might be interesting to further extend our understanding of the underlying mechanisms of postural control in quiet stance.

Factors associated with postural control in nursing home residents

AbstractPurposeDecline of the sensory and motor systems in older people negatively affects postural control. This increases the risk of falls, which is dangerous for older people in long-term care. Being aware of the quality of postural control and the factors affecting it among elderly people, is crucial in implementing an effective fall-prevention program. This study aimed to measure postural control and the demographic, health-related, and functional factors presumed to be correlated with it among nursing home residents. Another aim was to find valid screening tools based on these factors.Materials and methodsSeventy one nursing home residents were included. Postural control was measured using the Berg Balance Scale. Grip strength, the 30-s chair stand test, and the Timed Up and Go test were used to measure global muscle strength, and functional mobility, respectively. The results of these functional tests were dichotomized using age-specific reference values.ResultsPostural control was significantly worse in those who did not reach the age-specific reference values in any of the three functional tests. Effect sizes were large for functional mobility and medium for muscle strength. Multimorbidity and gender had no effect on postural control in our sample.ConclusionsAmong nursing home residents, postural control is related to functional mobility and muscle strength. Thus, routine testing of these skills among elderly people is an important task of the physiotherapist.

ПРЕДСТАВЛЕНИЯ И.Б. КОЗЛОВСКОЙ О ВОЗДЕЙСТВИИМИКРОГРАВИТАЦИИ НА СИСТЕМУ УПРАВЛЕНИЯ ПОЗОЙ

Professor Inesa B. Kozlovskaya led a series of multifaceted systematic studies that explored the impact of space flights and ground-based models of microgravity on motor control in humans. Based on data from these studies, she postulated that the cascade of microgravity-induced impairments in postural control is largely associated with deactivation of the muscle tone system. The decrease in tone of antigravity muscles, in turn, is triggered by the deficit and distortion of gravity-specific sensory input from tactile mechanoreceptors and otoliths. Further studies led by Prof. Kozlovskaya demonstrated that the quality of postural control following space flights depends on the type and amount of in-flight physical activity. These fundamental works have elucidated mechanisms through which microgravity impacts motor control and are instrumental in developing advanced countermeasure means of the negative sensorimotor effects caused by space flights.

How sacculo-collic function assessed by cervical vestibular evoked myogenic Potentials correlates with the quality of postural control in hearing impaired children?

ObjectiveFunctional integrity of vestibular end organs is essential for gaze stabilization, dynamic visual acuity, postural control and spatial orientation. Some authors hypothesized on the importance of saccules for postural control and motor development in children, including achievements such as standing up and walking. The purpose of this article was to observe how saccular dysfunction assessed by cervical Vestibular Evoked Myogenic Potentials (cVEMPs) correlates with the quality of postural control in non-syndromic deaf children. MethodSeventy-six non-syndromic hearing-impaired children were retrospectively included. Sacculo-collic pathway was assessed with cVEMPs elicited in bone conduction. The response was quoted “normal” if a reproducible wave P13–N23 of at least 50μV in amplitude was present, if not, it was quoted “absent”. The sample was divided in 3 groups depending on the presence of the sacculo-collic responses: normal bilateral group (Group 1), normal unilateral (Group 2) and absent bilaterally group (Group 3). Motor assessment was achieved with Movement Assessment Battery for Children, second edition (MABC-2). Postural control (PC) was assessed using the dynamic Balance Quest platform. The scores obtained with MABC-2, and the postural parameters recorded on the Balance Quest platform (sway of Centre of Pressure and spectral power index) were analyzed and compared throughout the groups. ResultsGroup 1 (normal bilateral) showed the best scores regarding motor abilities and postural stability within available normative data. Group 3 (absent bilateral) had the lowest motor and postural control skills. A good correlation between the scores obtained by MABC-2 motor test and dynamic posturography (Balance Quest) was observed. ConclusionsThe presence of at least one sacculo-collic response would predict satisfactory static and dynamic motor and postural control skills in non-syndromic hearing-impaired children. MABC-2 and Dynamic Posturography Balance Quest appears reliable and comparable tools for PC assessment in hearing impaired children. In the light of these results, it appears that in young children candidates for uni- or bilateral CI whose walking is not yet acquired, should receive a vestibular assessment before surgery to avoid the risk of bilateral sacculo-collic function impairment.

Postural Patterns of the Subjects with Vergence Disorders: Impact of Orthoptic Re-education, a Pilot Study.

Aim:Vergence insufficiency is a common oculomotor disorder which causes visual but also general, and even postural symptoms. This study aimed to characterise postural control of subjects with isolated vergence disorder and assess whether orthoptic therapy affects it.Method:Vergence disorders were evaluated and treated by orthoptists. Postural control quality was measured before and after orthoptic therapy in different conditions to study the role of vision, fixating distance, binocular vision and ocular dominance.Results:Before orthoptic therapy, we recorded less body sway when subjects had their eyes closed than when they had their eyes open, and also less sway for the binocular condition when compared with monocular viewing conditions. This is opposite to well-known normal behaviour. Moreover, no distance or ocular dominance effect was found. After orthoptic therapy, our subject’s body sway was less when they had their eyes open than with their eyes closed and less when they looked at near fixation. No difference was found between monocular and binocular viewing conditions, but a small advantage of ocular dominance was found for one parameter.Conclusion:We conclude that subjects with vergence disorders show postural behaviour that is not characterized by the normal regularities observed in healthy subjects. Orthoptic re-education may have contributed to promoting such regularities. Further studies are needed to confirm these preliminary results.

Comparison of an Innovative Rehabilitation, Combining Reduced Conventional Rehabilitation with Balneotherapy, and a Conventional Rehabilitation after Anterior Cruciate Ligament Reconstruction in Athletes.

Instability of the knee, related to anterior cruciate ligament injury, is treated by surgical reconstruction. During recovery, a loss of proprioceptive input can have a significant impact. Few studies have evaluated the benefits of rehabilitation of the knee in aquatic environment on functional outcomes. This study aimed to compare an innovative rehabilitation protocol combining reduced conventional rehabilitation with aquatic rehabilitation, with a conventional rehabilitation, according to the National French Health Authority, in terms of kinetics, development of proprioceptive skills, and functional improvement of the knee. 67 patients, who were amateur or professional athletes, were randomized into two groups: 35 patients followed the conventional rehabilitation protocol (Gr1) and 32 patients followed the innovative rehabilitation protocol (Gr2). Patients were evaluated before surgery, and at 2 weeks, 1, 2, and 6 months after surgery using posturography, and evaluation of muscular strength, walking performance and proprioception. This study is multicenter, prospective, randomized, and controlled with a group of patients following conventional rehabilitation (level of evidence I). For the same quality of postural control, Gr2 relied more on somesthesia than Gr1 at 6 months. The affected side had an impact on postural control and in particular on the preoperative lateralization, at 2 weeks and at 1 month. Lateralization depended on the affected knee, with less important lateralization in Gr2 preoperatively and at 1 month. The quadriceps muscular strength was higher in Gr2 than in Gr1 at 2 and 6 months and muscle strength of the external hamstring was greater in Gr2 than in Gr1 at 6 months. The isokinetic test showed a greater quadriceps muscular strength in Gr2. Gr2 showed a greater walking distance than Gr1 at one month. Gr2 showed an improvement in the proprioceptive capacities of the operated limb in flexion for the first 2 months. The effectiveness of the innovative rehabilitation program permits faster recovery, allowing for an earlier return to social, sporting, and professional activities. Faster retrieval of knee function following aquatic rehabilitation would prevent both short-term risk of lesions of the contralateral limb due to overcompensation and long-term risk of surgery due to osteoarthritis. NCT02225613.

Reeducation of vergence dynamics improves postural control.

The purpose was to investigate the effect of vergence reeducation on postural control, in subjects with isolated vergence disorders. We studied the dynamics of vergence in 19 subjects (20-44 years old) using video-oculography (Eye See Cam). On the basis of orthoptic and symptomatology assessments, ten of the subjects were diagnosed for vergence disorders then vergence eye movements were reeducated with the REMOBI method (US8851669, 5 weekly sessions lasting for 35min). Postural control was measured before and after reeducation, postural recording was done in upright stance (Dynaport), with both eyes closed or open and looking a visual target located at 2m distance. After reeducation with REMOBI, the visual symptomatology faded away and the stereoacuity improved at least for some subjects; the vergence latency decreased significantly and the vergence accuracy increased significantly. In terms of posture, the Mean Power Frequency (MPF) of the body sway decreased significantly in both eyes open and eyes closed conditions. Considering all subjects together (i.e. healthy subjects and subjects with vergence disorders before the reeducation), the antero-posterior body sway (Root Mean Square A/P) was positively correlated with the visual symptomatology: the higher the visual symptomatology, the higher was the body sway. The results bring evidence for synergy between the quality of vergence and the quality of postural control. They open a new research line that bridges the gap between neuroscience, ophthalmology-orthoptics and posturology.

Static-dynamic stability of the body gymnasts qualifications

Purpose: evaluation of individual ways of postural control gymnasts skilled in solving problems on the stability of the body in the motor tests. Material : The study involved engaged in gymnastics (n = 9). The measurements were carried out on the platform stabilographic Kistler. Tests used: handstand, Biryuk sample, sample Romberg. Results: set individual ways microvibrations parts of the body and makrokolebany in the sagittal and frontal planes. Joined symmetry and asymmetry postural control of the body, the various indicators of energy expenditure. The quality of postural control in the performance of motor tests were deterministic complex conditions of body position on the support, limited visual orientation. Also corresponds to the test specificity of the sport. Conclusions : The method microvibrations in solving problems on the stability of the body in the motor tests gymnasts is the most strategically important for the effective development and management of a system of regulation poses athlete. Confirmation rates are economical expenditure of energy during motor tests.

Clinical Assessment of Postural Stability

One of the most important applications of postural sway analysis is the detection of such impairments to the motor system that would allow us to predict risk of falling. Force plate posturography is a commonly used clinical method for the evaluation of postural instability. The diagnostic value of postural sway represented here by oscillations of the center-of-foot pressure (COFP) is being questioned very often. These diagnostic problems result from the lack of an adequate and reliable method of sway analysis — a method that would present a clear connection between stability and quality of postural control. To gain better insight into this problem, the following experiments were done and some effective methods of sway analysis typically applied in conventional mechanics and electrical engineering are presented here. Quality of the postural stability was assessed using, in addition to standard parameters, spatial histograms, body transfer function, contour plots as well as the COFP fractal dimension. Such complex analysis allowed us to extract significant sway parameters that are relevant to postural instability. Analysis of the data revealed that spatial histogram has clear peak which maximum was sensitive to sensory conditions. Changes in the postural sway distributions have been confirmed by the increase of the COFP fractal dimension.