Information For Postural Control Research Articles

Influence of Visual Information and Sex on Postural Control in Children Aged 6-12 Years Assessed with Accelerometric Technology.

The performance of postural control is believed to be linked to how children use available sensory stimuli to produce adequate muscular activation. Therefore, the aim of the present study was to thoroughly explore postural stability under normal conditions and without visual information in postural control in children aged 6–12 years during static single-leg support. A descriptive cross-sectional study was conducted with 316 children (girls = 158). The analyzed variables were the mean and maximum values obtained in each of the three body axes and their root mean square during two static single-leg support tests: one with eyes open and one with eyes closed. Girls showed lower magnitudes in the recorded accelerations at all ages and in all the variables of both tests. Accelerations during the tests showed progressively lower values from 6 to 12 years of age. The sex had a significant influence on the magnitude obtained in the accelerations recorded during the tests. Improvements in balance with increasing age were greater with visual information than without visual information. The tests of single-leg support showed preferential sensorimotor strategies in boys and girls: boys tend to rely more on visual inputs, and girls process somesthetic information in a preferential way.

Assessment of anxiety and postural balance in strategy for health care for elderly women

Introduction. The relevance of the study is determined by the tasks set in the National Project “Demography” (Federal Project “Senior Generation”), and consists in the need for registration of functional characteristics of the organism of older age groups in the accounting system of measures to preserve their health.Aim of the study is to establish the characteristics of anxiety and components of the postural balance (CPB) in elderly women with the risk of recurrent falls.Material and methods. We examined 232 women aged 55-69 years who reported that they experienced two or more falls over the past 12 months. The first age group included women whose calendar age was in the range of 55-64 years (n = 72), the second - women aged 65-69 years (n = 160). Using the self-assessment diagnostic technique by Spielberger, Ch. D., and Khanin, Yu. L. we determined the level of situational (SA) and personal (PA) anxiety. To assess the features of the CPB, a US-manufactured computerized dynamic posturography complex Smart Equitest Balance Manager was used. Sensory Organization Test (SOT) and Motor Control Test (MCT) tests were conducted. Results. When analyzing anxiety scale values, a high level of PA was revealed in both groups of women, however, the SA indices in women 55-64 years old were lower than for women 65-69 years old (p = 0.005). All this indicates that the development of recurrent falls among women older 64 years will be accompanied by mental tension and pronounced emotional responses to postural changes. According to computerized dynamic posturography testing, age-related differences in CPB have been revealed. There was a decrease in the quality of the equilibrium function by test 5 SOT and vestibular information in postural control found in women of age group 55-64, whereas for women in the age group 65-69 there was a decrease in the quality of equilibrium function by test 4 and visual information in balance control. In the latter, there was also found an increase in the time of coordinated motor response by the test of unexpected external impact on the shift of the center of gravity capable of enhancing the risks of stuttering and falls when walking fast.Conclusion. The suggested criteria for assessing the risk of falls in elderly women can be used to develop individual health programs to prevent serious consequences in such events.

Putting proprioception for balance to the test: Contrasting and combining sway referencing and tendon vibration

BackgroundPostural control relies on sensory information from visual, vestibular and proprioceptive channels, with proprioception being the key sensory modality in this task. Two well-established ways of manipulating proprioceptive information in postural control are tendon vibration and sway referencing. The aim of the present study was to assess postural adaptation when inaccurate proprioceptive information is introduced using tendon vibration and sway referencing in isolation and combination. MethodsSeventeen young adults were asked to stand, without vision, for 2 min on a fixed surface (baseline) immediately followed by 3 min of bilateral Achilles tendon vibration, sway reference, or combined presentation of the two manipulations (adaptation) and finally 3 min of standing on a fixed surface (aftereffect). ResultsDuring adaptation, vibration showed the lowest sway variability, followed by sway reference and the combined condition. Spectral analyses focusing on the dominant frequencies in this task (0–0.4 Hz) showed that in the first half of adaptation sway amplitude was greater when the two manipulations were combined compared with each manipulation alone. However, in the second half differences between sway reference and the combined condition disappeared but differences between vibration and the other two conditions increased. ConclusionWe interpret these findings primarily as due to a prolonged attenuation in effects of vibration over the course of the adaptation phase and we offer two explanations for this phenomenon. One is a decline in neurotransmitter release from the group Ia terminals and the other is sensory reweighting which down-weights proprioception and up-weights the accurate, vestibular information.

Neck muscle vibration produces diverse responses in balance and gait speed between individuals with and without neck pain

BackgroundNeck muscle vibration can influence cervical proprioception and sensorimotor function. It is hypothesized to affect motor performance differently in persons with and without neck pain. Study designCross-sectional study. ObjectiveTo clarify the extent to which vibration-induced motor responses of neck muscles affect static standing balance and gait speed in persons with and without neck pain. MethodsThirty participants with chronic neck pain and 30 healthy controls were recruited. Balance and gait were measured before and after 30 s of suboccipital neck muscle vibration. Balance was measured in a confortable stance with eyes closed using a swaymeter and gait using the timed 10 m walk test. ResultsAt baseline, neck pain participants had greater postural sway, particularly in the anterior-posterior direction and slower gait speed than healthy controls (p < 0.001). Immediately after vibration, neck pain participants displayed decreased postural sway, and increased gait speed (p < 0.001). Healthy controls had increased postural sway and decreased gait speed (p < 0.001). ConclusionNeck muscle vibration improved standing balance and gait speed in participants with neck pain but reduced performance in healthy controls. The study supports the importance of cervical proprioceptive information in postural control. Use of vibration could be considered neck pain patients' rehabilitation.

Assessing Somatosensory Utilization during Unipedal Postural Control.

Multisensory—visual, vestibular and somatosensory information is integrated for appropriate postural control. The primary goal of this study was to assess somatosensory utilization during a functional motor task of unipedal postural control, in normal healthy adults. Assessing individual bias in the utilization of individual sensory contributions during postural control may help customization of rehabilitation protocols. In this study, a test paradigm of unipedal stance control in supine orientation with and without vision was assessed. Postural control in this test paradigm was hypothesized to utilize predominantly contributions of somatosensory information from the feet and ankle joint, with minimal vestibular input. Fourteen healthy subjects “stood” supine on their dominant leg while strapped to a backpack frame that was freely moving on air-bearings, to remove available otolith tilt cues with respect to gravity that influences postural control when standing upright. The backpack was attached through a cable to a pneumatic cylinder that provided a gravity-like load. Subjects performed three trials each with Eyes-open (EO) and Eyes-closed (EC) while loaded with 60% body weight. There was no difference in unipedal stance time (UST) across the two conditions with EC condition challenging the postural control system greater than the EO condition. Stabilogram-diffusion analysis (SDA) indicated that the critical mean square displacement was significantly different between the two conditions. Vestibular cues, both in terms of magnitude and the duration for which relevant information was available for postural control in this test paradigm, were minimized. These results support our hypothesis that maintaining unipedal stance in supine orientation without vision, minimizes vestibular contribution and thus predominantly utilizes somatosensory information for postural control.

The Role of Cognitive Factors in Old Age Balance Impairments

The ability of human beings to perform more than one task at a time has long been focus of study in the literature on human attention and memory. Older adults are more penalized when they must divide their attention between two input resources i.e input and holding or holding and responding. Falls have potentially devastating physical, social and psychological consequences. Falling is one of the most serious problems associated with ageing. Sensory system deteriorates with age, increased attention is allocated to “HIGHTEN” the signal coming from this system in order to gain necessary information for postural control. Older adults show marked reduction in the ability to perform the postural and cognitive task simultaneously. A study was conducted by physiotherapy and psychology students in a small town of Haryana on institutionalized older adults in which Dual task training under various sets of instruction that is Fixed priority and Variable priority instruction sets effects the balance who are living in residential care facilities. Tinneti Performance Oriented Mobility Assessment (POMA) and Mini mental status examination were used as tools to assess balance and cognitive abilities. Various studies related to the role of cognitive factors in balance impairments were reviewed. Data was analyzed using SPSS 13.0 software packages and paired sample t –test within the group and independent sample t – test between the groups with p – value at a significance level of p &lt; 0.05 was used. The result of the study supported the hypothesis that there is significant improvement in balance of institutionalized elderly people who received dual task training with variable priority instruction set. (p &lt; 0.001). The use of validated measurement tool like Tinnetti performance oriented mobility assessment on balance allowed clearer interpretation of the results. There is improvement in TPOMA Scores after 4 weeks training program in both groups. This shows that cognitive factors do play an important role in maintaining balance and coordination. Any impairment related to sensory system or cognition leads to balance impairments and increased risk for falls.

Utilização da informação visual no controle postural de crianças com paralisia cerebral

INTRODUÇÃO: As limitações impostas pela paralisia cerebral (PC) levam à persistência de distúrbios dos movimentos e da postura. Sendo assim, o controle postural tem um papel importante, pois a capacidade de manter a orientação postural é fundamental para realização das atividades de vida diária. OBJETIVOS: Investigar a utilização da informação visual no controle postural de crianças com PC e de crianças neurologicamente normais (NN). MATERIAIS E MÉTODOS: Foram avaliadas nove crianças com PC diplégica e nove crianças NN de ambos os sexos, entre 6 e 12 anos de idade. Todas as crianças permaneceram em pé e paradas dentro de uma sala móvel nas seguintes condições experimentais: sem movimento da sala com olhos abertos e com olhos fechados e com movimento da sala nas frequências de 0,2 e 0,5 Hz. O registro dos movimentos da sala e das crianças foi realizado por marcadores ativos afixados entre as escápulas das crianças e na parede da sala, respectivamente, e do sistema OPTOTRAK. RESULTADOS: As crianças com PC oscilaram mais em relação às crianças NN, e o movimento da sala influenciou a oscilação corporal de todas as crianças de maneira similar, sendo que todas elas foram influenciadas pela frequência em que a sala foi movimentada. CONCLUSÃO: Crianças com PC e NN são influenciadas pela manipulação da informação visual durante a manutenção da postura ereta e quieta e pela frequência em que o estímulo visual é apresentado.

Visual input is critical for postural control in patients with chronic right hemisphere infarcts

Stroke remains a leading cause of long-term disability and is the second most common cause of death worldwide.1 Many persons face restrictions in the performance of day to day tasks after stroke. The return of postural control is an early and central element for both motor and functional recovery and is a prerequisite for recovery of sitting, standing, transferring, turning, and reaching. Poor postural control predicts higher levels of dependence, handicap, and falls.2 A high quality of life is thus strongly dependent on improvement of postural control. Patients with stroke, as compared to healthy age-matched individuals, compensate for motor and sensory impairments with greater dependence on visual information for postural control in both planes, the medial-lateral (ML) and anterior-posterior (AP).3 This increased visual dependence may be a nonspecific strategy to compensate for the loss or distortion of other sensory inputs. Subjects shift their spatial reference frame …

The role of eye movement in upright postural control

Vision contributes to upright postural control by providing afferent feedback to the cerebellum. Vision is generally classified into central and peripheral vision. In measurements of postural sway, in which participants are required to maintain a stable upright posture while fixating on a visual target, non-retinal eye positional information due to the fixation is used as well as the retinal information from both visual fields. However, little is known about the role of non-visual eye positional information in postural control. This study examined the role of non-visual eye position information in upright postural control by comparing participants’ centre of pressure (COP) sway between two experimental conditions: (1) a space-fixed visual target condition (control), in which eye movement was not controlled, and (2) a head-fixed visual target condition (treatment), in which eye movement was inhibited. Using 12 university students, COP sway and electrooculograms (EOG) were measured under both conditions. In the space-fixed condition, participants maintain an upright posture while fixating on a visual target fixed on a screen 1 m in front of them. In the head-fixed condition, participants maintained an upright posture while gazing at a target moving in sync with their head sway on the screen. The COP was evaluated by path length, area, root mean square, velocity and position. Eye movements were evaluated by the mean eye movement angle. The mean eye movement angle was significantly larger in the vertical direction then in the horizontal direction in both experimental conditions and was also found to be larger in the space-fixed condition than in the head-fixed condition. No significant different was found in any COP parameter between both conditions. It was suggested that non-visual eye position information from the external eye muscles to the sensory perception system contributes little to postural stabilisation under the measurement conditions used in this study.

Diabetic neuropathy and surface sway-referencing disrupt somatosensory information for postural stability in stance

In order to determine the type of somatosensory information for postural control that is most affected by neuropathy, we compared the relative effects of three methods of sway-referencing the surface in a group of subjects with profound loss of somatosensory function associated with sensory polyneuropathy from diabetes with age-matched control subjects. Sway-referencing disrupted somatosensory feedback for postural control by servo-controlling the dorsi- and plantar-flexion rotation of the support surface in proportion to anterior-posterior excursion of (1) ankle angle, (2) center of body mass (CoM) angle or (3) filtered center of pressure (CoP). Postural sway in subjects with somatosensory loss was significantly larger than normal on a firm surface but not on the sway-referenced surfaces, suggesting that sway-referencing disrupts somatosensory information for postural control already disrupted by neuropathy. Control subjects standing on any sway-referenced surface swayed significantly more than neuropathy subjects who stood on a firm surface, suggesting that sway-referencing disrupts more somatosensory information than disrupted by severe neuropathy. CoP sway-referencing was less sensitive than ankle or CoM sway-referencing for distinguishing postural sway in subjects with somatosensory loss from age-matched control subjects. Given that filtered CoP sway-referencing disrupts the ability to utilize somatosensory information related to surface reactive force to a greater extent than the other two methods of sway-referencing, then these results support the hypothesis that subjects with diabetic peripheral neuropathy have lost more CoP information, than ankle or CoM angle information, for controlling postural sway in stance.

Postural stability and fractal dynamics

Methods of non-linear dynamics and deterministic chaos may provide us with effective quantitative descriptors of the dynamics of postural control. The goal of this study was to introduce a new measure, which would allow to determine the fractal structure of posturographic signals and to measure the effect of the loss of visual feedback information in postural control. The results of the study show that fractal dimension (Df) is a very useful, reliable and sensitive measure of the complexity of posturographic signals. Therefore Df can be used for the evaluation of postural stability and its changes due to pathology or an age-related decline.

Effects of Different Treatments on Postural Performance in Patients with Cervical Root Compression1

Patients with cervical root compression were used as a "model" to investigate the possible importance of neck disorders and cervical sensory information in postural control. We assessed postural performance with posturography before and after treatment in 71 consecutive patients with MRI-verified cervical root compression without medullary compression. The patients were randomized to surgery (n = 22), physiotherapy (n = 24) or treatment with cervical collars (n = 25). There were no differences in postural performance or pain intensity between the groups before treatment. After treatment, the surgery group manifested significant improved postural performance and reduced neck pain scores, as compared to the two conservative treatment groups, and their postural performance had improved to the same level manifested by healthy controls. The conservative treatment groups manifested no consistent significant changes in postural performance or pain scores. Decreased muscular tension due to reduction of cervical pain after surgery and normalization of cervical proprioception are suggested as possible explanations of the improved postural control.