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At least 1,135 records · Page 63Linked to original sources

PubMed2006

Dizziness among patients with whiplash-associated disorder: a randomized controlled trial.

OBJECTIVE: To investigate whether vestibular rehabilitation for patients with whiplash-associated disorder and dizziness had any effect on balance measures and self-perceived handicap. DESIGN: Randomized, controlled trial. SUBJECTS: Twenty-nine patients, 20 women and 9 men, age range 22-76 years. METHODS: The patients were randomized to an intervention group or a control group. The intervention comprised vestibular rehabilitation. All patients were assessed at baseline, after 6 weeks and after 3 months with 4 different balance measures and the Dizziness Handicap Inventory. RESULTS: After 6 weeks, the intervention group showed statistically significant improvements compared with the control group in the following measures: standing on one leg eyes open (p=0.02), blindfolded tandem stance (p=0.045), Dizziness Handicap Inventory total score (p=0.047), Dizziness Handicap Inventory functional score (p=0.005) and in Dizziness Handicap Inventory physical score (p=0.033). After 3 months, the intervention group showed statistically significant improvements compared with the control group in the following measures: standing on one leg eyes open (p=0.000), tandem stance (p=0.033) and Dizziness Handicap Inventory physical score (p=0.04). CONCLUSION: Vestibular rehabilitation for patients with whiplash-associated disorder can decrease self-perceived handicap and increase postural control.

Adult↗

PubMed2004

Motor strategies in standing up in children with hemiplegia.

In spastic hemiplegia, the organization of whole body movements is impaired by deficient postural control. We studied segmental motor patterns involved in standing up from supine position in 15 children with spastic hemiplegic cerebral palsy and 14 unimpaired children using a visual analysis scale previously validated for developmental research. This approach examines specific movement patterns in upper limbs, axis, and lower limbs. We found that children with hemiplegia use movement patterns described in normal children but with reduced interindividual variability and a significant preponderance of asymmetric patterns. One previously undescribed stereotyped lower limb pattern was observed in two children with spastic hemiplegia. Emergence of these patterns is consistent with the referent body image theory. This approach can systematically characterize the limited repertoire of movement in patients with disorders of movement and posture and therefore contribute to a better understanding of motor control. The approach may guide management proposals with particular reference to variability and symmetry and might be used as a follow-up tool.

Cerebral Palsy↗

PubMed1980

A distributed computer system for hierarchical control of a clinical vestibular laboratory.

A vestibular testing laboratory with five test stations was implemented as a clinical research and testing facility, automating and adapting tests for patients with inner-ear balance disorders. These were designed to quantitate postural control, and eye movement response to rotational, caloric, and visual (optokinetic) stimuli. Microprocessors were used as satellite processors in a star network under hierarchical control of a host minicomputer. All disk storage was controlled by the host, with data transfer from satellites via parallel interfaces. Network software was designed and implemented to be under control of the host in a foreground-background structure. The practical operation of this laboratory required that technicians at each satellite test station initiate, perform, and complete an individual test in dependently of other tests. Examples from two test stations are presented. A 2-year data base of test results provides important multitest correlations for use in diagnostic evaluations.

Computers↗

PubMed2004

The development of the Stroke Physiotherapy Intervention Recording Tool (SPIRIT).

PURPOSE: To develop a recording system that describes physiotherapy interventions for the rehabilitation of postural control post-stroke. METHODS DESIGN: A draft recording tool was developed using the method described by Edwards et al, involving literature searches and collaboration with senior clinicians. It was piloted with stroke physiotherapists using a cross-sectional survey design to assess validity, utility and completeness. Participants used the recording tool to record five treatment sessions. Feedback regarding the utility and completeness of the system was obtained via short semi-structured interviews. SETTING: 11 NHS Trusts. PARTICIPANTS: 35 stroke physiotherapists working in acute and rehabilitation settings recorded the treatment of 120 patients in 590 treatment sessions. RESULTS: A double-sided A4 form with a checklist of 79 physiotherapy interventions in 9 categories was produced: the Stroke Physiotherapy Intervention Recording Tool (SPIRIT). The participants found it quick and easy to use and reflective of clinical practice. There were a few missing interventions and some confusion regarding definition of terms. Revisions were to include the omitted interventions and to produce a user's booklet defining the categories and interventions. CONCLUSIONS: SPIRIT provides a system for recording physiotherapy treatment for stroke patients which reflects current clinical practice in acute and rehabilitation settings.

Adult↗

PubMed2004

Activity of pyramidal tract neurons in the cat during postural corrections.

The dorsal side-up body orientation in quadrupeds is maintained by a postural control system. We investigated participation of the motor cortex in this system by recording activity of pyramidal tract neurons (PTNs) from limb representations of the motor cortex during postural corrections. The cat was standing on the platform periodically tilting in the frontal plane, and maintained equilibrium at different body configurations: with the head directed forward (symmetrically alternating loading of the left and right fore limbs), or with the head voluntary turned to the right or to the left (asymmetrical loading). We found that postural corrective responses to tilts included an increase of the contact forces and activity of limb extensors on the side moving down, and their decrease on the opposite side. The activity of PTNs was strongly modulated in relation to the tilt cycle. Phases of activity of individual PTNs were distributed over the cycle. Thus the cortical output mediated by PTNs appeared closely related to a highly automatic motor activity, the maintenance of the body posture. An asymmetrical loading of limbs, caused by head turns, resulted in the corresponding changes of motor responses to tilts. These voluntary postural modifications were also well reflected in the PTNs' activity. The activity of a part of PTNs correlated well with contact forces, in some others with the limb muscle activity; in still others no correlation with these variables was observed. This heterogeneity of the PTNs population suggests a different functional role of individual PTNs.

Animals↗

PubMed1991

Repeatability and effect of instruction of body sway.

The effect of instruction and repeatability of posturography measurement was studied in 24 healthy volunteers. In an instruction, "stable" (inverted pendular model) and "relaxed" (segmental oscillating model) positions were studied. In addition, the effect of habituation adaptation, and day-to-day variation were investigated. Sway velocity and average and maximum displacement during vibration perturbated stance were analysed. In individual responses, no statistically significant day-to-day variation could be observed and the individual variation was small. In the "relaxed" condition, the instability was greater when maximum displacement was analysed. No significant changes in sway velocity and average displacement were observed. The results demonstrated remarkable stability of normal postural control mechanism.

Adult↗

PubMed2005

Differences in preferred reference frames for postural orientation shown by after-effects of stance on an inclined surface.

This study reports a postural after-effect of leaning that follows a period of stance on an inclined surface with eyes closed. This leaning after-effect maintained the body-to-surface relationship as if subjects still stood on the incline. We examined the incidence and robustness of the leaning after-effect in 51 healthy subjects. The location of the center of pressure (CoP) under the feet and the alignment of the trunk and legs were measured before, during and after blindfolded subjects stood on a 5 degrees toes-up inclined surface for 2.5 min. When the surface was inclined, all subjects stood with their trunk and legs aligned near to gravity-vertical, similar to the alignment adopted in the pre-incline period. When the surface returned to horizontal in the post-incline period, there was a continuum of postural alignment strategies across subjects. At one extreme, subjects leaned forward, with an average trunk lean near 5 degrees . The leaned posture decayed exponentially toward baseline postural alignment across a period of up to 5 min. At the other extreme, subjects did not lean in the post-incline period, but instead, stayed aligned near upright with respect to gravity. Subjects were highly consistent in their post-incline postural behaviors upon repeated testing over days to months and across different directions of surface inclination. Our results suggest that individuals have well-established, preferred, sensory strategies for controlling postural orientation when vision is not available. Subjects who leaned in the post-incline period appear to depend more on the geometry of the support surface as a reference frame and to rely more on proprioceptive information to extract kinematic relationships, whereas subjects who did not lean appear to depend more on gravity as a reference frame and to rely more on sensory information related to forces and load.

Adaptation, Physiological↗

PubMed1993

Ventilatory responses during arm and leg exercise at varying speeds and forces in untrained female humans.

1. Involvement of neural stimuli, central and/or peripheral in origin, in exercise ventilatory control was ascertained by examining the ventilatory responses to varying mechanical conditions of arm and leg cycle ergometries. Twelve untrained women underwent each of two modes of exercise at three levels of loading (0, 5 and 10 N), each at three levels of speed (30, 50 and 72 r.p.m.), during which steady-state values of minute ventilation (VE), tidal volume (VT), respiratory frequency (f) and CO2 excretion (VCO2) were measured. 2. Using the data obtained at the aerobic work intensities, the relationship of ventilatory responses (VE, VT and f) to the metabolic (VCO2) and mechanical (speed and load) variables were studied by multiple linear regression analysis. Coefficient of determination (r2) of the regression model was lowest (0.84) for f in the arm exercise and highest (0.99) for VE in the leg exercise. 3. Standardized partial regression coefficients of the model indicated that VE response is related to VCO2 at the rate of 94 +/- 3% (mean +/- S.E.M.) and to the pedal rate at 8 +/- 3% during the leg exercise, while it is closely related to VCO2 in the arm exercise. For f response, influence of the rate of limb movement was seen in the leg exercise but not in the arm exercise. The different effects of the rate of limb movement between the two exercise modes may be related to familiarity with the exercise modes, suggesting that a familiarity-related mechanism is involved in exercise ventilatory control. 4. A heavier load imposed on the limb muscles elicited a greater VT both in the arm and leg exercise and a lower f in the arm exercise. Postural control in the upper torso during increased limb muscle tension seems to affect VT and f.

Adult↗

PubMed1998

A randomized controlled trial of exercise therapy for dizziness and vertigo in primary care.

BACKGROUND: 'Vestibular rehabilitation' (VR) is an increasingly popular treatment option for patients with persistent dizziness. Previous clinical trials have only evaluated the effects of specialist therapy programmes in small, selective, or uncontrolled patient samples. AIM: To determine the benefits of VR compared with standard medical care, using a brief intervention for dizzy patients in primary care. METHOD: Adults consulting their general practitioner (GP) with dizziness or vertigo were randomly assigned to treatment or control groups. Patients in both groups received the same evaluation at baseline, six-week follow-up, and six-month follow-up, comprising examination of nystagmus, postural control, and movement-provoked dizziness, and a questionnaire assessment of subjective status, symptoms, handicap, anxiety, and depression. At baseline and six weeks later, the treatment group also received an individualized 30-minute therapy session, in which they were taught head, eye, and body exercises designed to promote vestibular compensation and enhance skill and confidence in balance. RESULTS: The treatment group (n = 67) improved on all measures, whereas the control group (n = 76) showed no improvement, resulting in a significant difference between the two groups on physical indices of balance and subjective indices of symptoms and distress. Odds ratios for improvement in treated patients relative to untreated patients were 3.1:1 at six weeks (95% CI = 1.4-6.8) and 3.8:1 at six months (95% CI = 1.6-8.7). CONCLUSION: VR is a simple, inexpensive, and beneficial treatment, and may be an appropriate first stage of management for many dizzy patients in primary care.

Adult↗

PubMed2004

Randomized clinical trial into the impact of rigid foot orthoses on balance parameters in excessively pronated feet.

OBJECTIVE: To evaluate the effect of rigid foot orthoses on balance parameters in participants with clinically diagnosed excessively pronated feet. DESIGN: Randomized clinical trial. SETTING: University biomechanics laboratory. PARTICIPANTS: Thirty female and 20 male healthy participants (mean 23.8+/-2.2 years old) with excessively pronated feet, according to a validated foot classification system were randomly assigned to either a control or intervention group. INTERVENTIONS: Balance testing was performed using the Balance Performance Monitor with an over-the-counter rigid foot orthoses. MAIN OUTCOME MEASURES: Standing balance in the form of mean balance (measures the participants ability to stand with an even load), medial-lateral sway and anterior-posterior sway. All participants were measured while standing bipedally. RESULTS: There was no significant mean difference in balance scores between the control and intervention group at baseline. After four weeks the results demonstrated no significant differences between mean% balance (p >0.05) and anterior-posterior sway (p >0.05). However, there was a reduction with the intervention group in medial-lateral sway (p=0.02). CONCLUSION: The use of foot orthoses in the current study may have improved postural control by stabilizing the rear foot and thus maintaining balance. By the same argument, the benefits of limiting excessive foot pronation may contribute to effective control of internal rotation of the tibia and thereby reduce counter-rotatory motion at the knee and lower leg and maintain balance.

Adult↗

PubMed2004

Assessment of postural response after a self-initiated perturbation.

The aim of this study was to assess postural response efficiency to a self-initiated perturbation using an original method based on the inverted pendulum model. Eight young subjects were asked to perform bilateral arm raising and lowering at 3 different speeds while standing on a force plate. The time necessary to recover a steady state following the movement was computed by analyzing the time evolution of the coefficient of determination between the center of pressure and center of mass difference variable (COP-COM) and the horizontal acceleration of the COM. Results show a spatial reorganization (hip strategy) of the segments following the perturbation and a strong influence of the linear relationship to the arm velocity. However, the conditions of arm velocity did not have any effect on the time response of the postural control, suggesting that this parameter would be an invariant characteristic of the movement. These results support the existence of an internal representation of the inertial constraints related to the movement execution.

Adult↗

PubMed2003

Balance and gait in total hip replacement: a pilot study.

OBJECTIVE: Evaluation of balance, gait changes, sexual functions, and activities of daily living in patients with total hip replacement in comparison with healthy subjects. DESIGN: A total of 30 patients were included in the study after total hip replacement. Balance was examined using dynamic posturography, and gait evaluation was done clinically. Sexual functions and activities of daily living were also assessed. A total of 30 healthy subjects of comparable age and sex served as a control group. RESULTS: Dynamic balance and gait differed significantly in both the groups. Despite capsulectomy, no significant difference was observed on testing proprioception. In the sensory organization tests with difficult tasks, patients needed more sensory input from vision and vestibular sense, despite normal proprioceptive sense. Significant difference was observed for limits of stability, rhythmic weight shifts, and for gait variables other than walking base. Some of the patients had major difficulties with sexual functions and activities of daily living. CONCLUSIONS: Compared with the healthy age- and sex-matched controls, patients with total hip replacement did not have any proprioceptive deficit. Patients required extrasensory input, and there was a delayed motor response. Gait and dynamic balance results also indicated the motor deficit and required a compensatory strategy. Restoration of the postural control in these patients is thus essential. Necessary training is required for balance, gait, and activities of daily living, and proper sexual counseling is necessary in postoperative care.

Activities of Daily Living↗

PubMed1998

Dynamic and randomized perturbed posturography in the follow-up of patients with polyneuropathy.

BACKGROUND: The purpose of the study was to investigate and follow the equilibrium performance of patients with chronic polyneuropathy using Dynamic Posturography (DP) and Randomized Perturbed Posturography (RPP). METHODS: Fourteen patients with chronic polyneuropathy, aged 53-83 years, were evaluated by clinical investigation, vibrametry, DP and RPP in a six-year follow-up. The patient group was compared to 14 healthy volunteers, aged 63-80 years. The DP comprises a sensory organization (SO) part in which the platform and visual surround are stable or referenced to the patient sway, with eyes open or closed. In a movement coordination (MC) part, the platform makes active movements. In RPP, the platform moves randomly in the anteroposterior direction. RESULTS: Comparison between the first and second study of the patient group showed decreased equilibrium scores under stable conditions and when vision was excluded. Compared with controls, the patients showed significantly lower scores in most of the SO test conditions except when the platform was sway referenced with stable surround; in the MC part, the patients showed prolonged muscular response latencies, and in the RPP, the patients showed increased sway areas. CONCLUSIONS: The results are further evidence that proprioception is probably the single most important sensory input for postural control in humans. Posturography proved to be an objective method to study and follow the equilibrium performance in patients with PN.

Aged↗

PubMed2005

Postural stability in patients with different durations of benign paroxysmal positional vertigo.

Postural stability maintenance was investigated in patients with "idiopathic" benign paroxysmal positional vertigo of the posterior semicircular canal (BPPV-PSC) and compared to healthy subjects. To measure the postural stability during a quiet upright stance, we used static posturography in two conditions: with open and with closed eyes. The effect of the repositioning Epley's maneuver on the recovery of postural stability in patients with different durations of BPPV-PSC less than 60 days after the first attack of positioning vertigo (group I) and more than 60 days (group II) was examined. The investigation was made 1 h after the positive Dix-Hallpike test and 7 days after treatment with the Epley maneuver. "Sway velocity" (SV) and "relative power spectrum" (RPS) of the stabilograms were calculated to evaluate the postural stability for each subject and each experimental condition. We found a pronounced spectral density peak in the frequency range of 1.0-2.0 Hz and smaller spectral density in the range of 0.15-0.5 Hz compared to that in healthy subjects. Our results showed that the postural maintenance in BPPV-PSC patients depended on the disease duration. Patients with a duration of BPPV symptoms less than 60 days after the first attack demonstrated a high dependence on the visual input for postural stability. One week after the Epley maneuver, differences in the recovery of postural control in both groups of patients were also found. We assume that the disturbed otolith function together with the impaired dynamics of the semicircular canal generate a particular pattern of postural maintenance. The different degree of restoration of postural stability 1 week after the EM treatment in BPPV-PSC patients with different durations of the disease gives us reason to believe that after removing the otoconia from the semicircular canal, some stimulation of other sensory subsystems and adaptation mechanisms occur that lead to a new pattern of postural maintenance.

Follow-Up Studies↗

PubMed2006

Changes in postural sway and its fractions in conditions of postural instability.

We investigated changes in postural sway and its fractions associated with manipulations of the dimensions of the support area. Nine healthy adults stood as quietly as possible, with their eyes open, on a force plate as well as on 5 boards with reduced support area. The center of pressure (COP) trajectory was computed and decomposed into rambling (Rm) and trembling (Tr) trajectories. Sway components were quantified using RMS (root mean square) value, average velocity, and sway area. During standing on the force plate, the RMS was larger for the anterior-posterior (AP) sway components than for the mediolateral (ML) components. During standing on boards with reduced support area, sway increased in both directions. The increase was more pronounced when standing on boards with a smaller support area. Changes in the larger dimension of the support area also affected sway, but not as much as changes in the smaller dimension. ML instability had larger effects on indices of sway compared to AP instability. The average velocity of Rm was larger while the average velocity of Tr was smaller in the AP direction vs. the ML direction. The findings can be interpreted within the hypothesis of an active search function of postural sway. During standing on boards with reduced support area, increased sway may by itself lead to loss of balance. The findings also corroborate the hypothesis of Duarte and Zatsiorsky that Rm and Tr reveal different postural control mechanisms.

Adult↗

PubMed1988

Computerized posturography, a development of the measuring system.

A computerized posturography system is composed of a custom made strain gauge force platform and it utilizes commercially available amplifiers. The body sway response signals are digitized for the calculation of the following parameters by a computer: average velocity of body sway, mean value for fore-aft and lateral body sway, and maximal amplitude of body sway. Calf muscles were exposed to vibration to disturb the postural control. The program contains appropriate filters to remove transient and quantification noise.

Humans↗

PubMed2005

Postural visual dependence after recent stroke: assessment by optokinetic stimulation.

INTRODUCTION: This study was conducted to assess visual dependence of postural control early after stroke. DESIGN: Case control study. SETTING: A Physical Medicine and Rehabilitation Department. METHOD: Twenty-five patients impaired by severe hemiplegia due to a recent first stroke, were examined. Fourteen had a right and 11 a left hemispheric lesion. There were aged 52+/-13 years, time since stroke was 30+/-12 days. Patients' data were compared to data for 25 healthy subjects. Sitting posture was assessed on a dynamic balance, using two parameters: frontal plane displacement of the centre of pressure under optokinetic stimulation (OKS), and the total length of centre of pressure displacement for the stability reaction. On the basis of 90th percentile control data, patients' behaviour was classified as totally visuo independent (VI), totally visuo dependent (VD) or mixed. RESULTS: Body tilt under OKS was greater in patients than controls. No control subject was totally VD, 19 subjects were totally VI. Four patients were totally VD and only six were VI. The only clinical parameter linked to the effect of OKS was the sensitivity impairment. Overall patients with visuospatial neglect were the most perturbed, but two were totally visuo independent. DISCUSSION AND CONCLUSION: Assessment of postural variations in sitting under OKS is proposed for estimating visual dependence early after stroke. Individual reactions are more important than mean group reactions. Visual dependence is not solely due to neurological impairment, implying that previous physiological behaviour may be involved. Knowledge of these characteristics may affect rehabilitation programmes.

Case-Control Studies↗

PubMed1995

Exercise, posture, and back pain during pregnancy.

One of the expected benefits of exercise programmes for pregnant women is to reduce or prevent back pain by improving posture. The aim of this project was to evaluate the effect of fitness classes for pregnant women on posture and back pain. In this article, postural aspects are reported. Sixty five pregnant volunteers were included in the study, of whom 27 were enrolled in exercise classes designed according to Canadian guidelines and 38 acted as sedentary controls. Posture was assessed every 4 weeks during pregnancy and 4 months postpartum by measuring curvatures of the lumbar and thoracic spines in a standard relaxed standing position from lateral photographs. Laxity of knee ligaments was also monitored using a clinical arthrometer. Weight gain could explain part of lordosis increase during pregnancy but the effect was not very strong. No effect of exercise on posture was detected. RELEVANCE: This study showed that fitness classes for pregnant women designed according to Canadian guidelines had no detectable effect on posture during pregnancy.

Journal Article↗