Anteroposterior Sway Research Articles

Effect of cognitive task on postural control of the patients with chronic ankle instability during single and double leg standing

The aim of this study was to investigate the effect of a cognitive task on standing postural control of the injured and non-injured leg of athletes with chronic ankle instability. Postural stability was measured by center of pressure parameters while chronic ankle instability patients (n=8) randomly performed single and double leg standing in isolation or concurrently with a digit-backward cognitive task. After performing a concurrent cognitive task, anteroposterior sway significantly decreased in injured leg (P<0.05) and area significantly decreased in both injured and non-injured legs (P<0.05). There was no significant difference in all center of pressure parameters between injured and non-injured legs. The findings confirm the effect of a concurrent digit-backwards memory task on single leg standing balance in chronic ankle instability patients but the response to cognitive loading was not significantly different between the injured and non-injured legs.

Altered Kinematics and Time to Stabilization During Drop-Jump Landings in Individuals With or Without Functional Ankle Instability.

It has been proposed that altered dynamic-control strategies during functional activity such as jump landings may partially explain recurrent instability in individuals with functional ankle instability (FAI). To capture jump-landing time to stabilization (TTS) and ankle motion using a multisegment foot model among FAI, coper, and healthy control individuals. Cross-sectional study. Laboratory. Participants were 23 individuals with a history of at least 1 ankle sprain and at least 2 episodes of giving way in the past year (FAI), 23 individuals with a history of a single ankle sprain and no subsequent episodes of instability (copers), and 23 individuals with no history of ankle sprain or instability in their lifetime (controls). Participants were matched for age, height, and weight (age = 23.3 ± 3.8 years, height = 1.71 ± 0.09 m, weight = 69.0 ± 13.7 kg). Ten single-legged drop jumps were recorded using a 12-camera Vicon MX motion-capture system and a strain-gauge force plate. Mediolateral (ML) and anteroposterior (AP) TTS in seconds, as well as forefoot and hindfoot sagittal- and frontal-plane angles at jump-landing initial contact and at the point of maximum vertical ground reaction force were calculated. For the forefoot and hindfoot in the sagittal plane, group differences were present at initial contact (forefoot: P = .043, hindfoot: P = .004). At the hindfoot, individuals with FAI displayed more dorsiflexion than the control and coper groups. Time to stabilization differed among groups (AP TTS: P < .001; ML TTS: P = .040). Anteroposterior TTS was longer in the coper group than in the FAI or control groups, and ML TTS was longer in the FAI group than in the control group. During jump landings, copers showed differences in sagittal-plane control, including less plantar flexion at initial contact and increased AP sway during stabilization, which may contribute to increased dynamic stability.

Relationship between Spectral Characteristics of Spontaneous Postural Sway and Motion Sickness Susceptibility.

Motion sickness (MS) usually occurs for a narrow band of frequencies of the imposed oscillation. It happens that this frequency band is close to that which are spontaneously produced by postural sway during natural stance. This study examined the relationship between reported susceptibility to motion sickness and postural control. The hypothesis is that the level of MS can be inferred from the shape of the Power Spectral Density (PSD) profile of spontaneous sway, as measured by the displacement of the center of mass during stationary, upright stance. In Experiment 1, postural fluctuations while standing quietly were related to MS history for inertial motion. In Experiment 2, postural stability measures registered before the onset of a visual roll movement were related to MS symptoms following the visual stimulation. Study of spectral characteristics in postural control showed differences in the distribution of energy along the power spectrum of the antero-posterior sway signal. Participants with MS history provoked by exposure to inertial motion showed a stronger contribution of the high frequency components of the sway signal. When MS was visually triggered, sick participants showed more postural sway in the low frequency range. The results suggest that subject-specific PSD details may be a predictor of the MS level. Furthermore, the analysis of the sway frequency spectrum provided insight into the intersubject differences in the use of postural control subsystems. The relationship observed between MS susceptibility and spontaneous posture is discussed in terms of postural sensory weighting and in relation to the nature of the provocative stimulus.

EEG-biofeedback Intervention Improves balance in Stroke Survivor

Postural instability while performing daily activity is main problem to individuals with stroke. Increased postural sway is related to postural instability resulting in falls. Internal and external foci of attention were used to decline postural sway of individuals with neurological deficits. Electroencephalogram (EEG) biofeedback may be efficiency device for clinical training which external focus of attention. The purpose of this study is to explore whether external (EEG biofeedback) and internal foci of attention with unstable surface would affect postural sway in chronic stroke. Twenty-one hospitalized people with stroke were participated. Postural sway was measured at three conditions randomly while participants stood on the force platform with unstable surface. The conditions were control (quiet stand), internal focus of attention (focus on the own body), and external focus of attention (focus on the outside of body by EEG biofeedback). The external focus of attention resulted in less postural sway relative to both the internal focusof attention and control conditions. There was no significant difference between the external and internal foci of attention on anteroposterior sway velocity. In conclusions, the results are suggested that external focus of attention better to postural control than internal focus of attention or control condition during standing for individuals with stroke. The outcomes have possibly important for intervention by clinicians and the reduction of postural instability in stroke patients.

Effects of 24 weeks of Tai Chi Exercise on Postural Control among Elderly Women

This study examined the effects of 24 weeks of Tai Chi Quan on the postural control of elderly women. A total of 43 women aged 55–68 years participated in the study. A Tai Chi group (n = 22) underwent an organized Tai Chi exercise, whereas the control group (n = 21) maintained a habitual, no-regular-exercise lifestyle. A Good Balance tester (Metitur, Finland) was used to measure the time, paths and velocity of the center of pressure (COP) of subjects during stance while shifting COP to targeted positions shown on a monitor. After 24 weeks, the Tai Chi group showed significantly shorter total (18.6%, p = 0.005), mediolateral (21.9%, p = 0.002) and anteroposterior (18.3%, p = 0.002) COP sway paths than the control group. The results indicate that 24 weeks of the Tai Chi exercise improved the efficiency of postural control for elderly women.

Factors influencing referrals to physiotherapy and subsequent follow-up for management of low back pain: preliminary results from a cohort study

standardized mean differences for analysis of continuous variables. Risk ratios were derived and 95% confidence intervals calculated. Results: Six studieswere included. Three trials (64 participants) compared Wii and conventional rehabilitation versus conventional rehabilitation alone. Three trials (102 participants) compared Wii with other exercise interventions. The addition of Wii to conventional rehabilitation resulted in significantmean differences in favor of additionalWii compared to standard care for Timed Up and Go test (TUG) (0.81 points, CI 0.29 to 1.33, P= 0.002), but not for other mobility and functional outcomes: Functional Independence Measure (FIM) score (0.45, CI−0.21 to 1.11, P= 0.18), Berg Balance Score (−0.64, CI −3.66 to 2.39, P= 0.68), antero-posterior postural sway (0.23, CI −0.38 to 0.84, P= 0.46). No serious adverse events were reported and whenWii was compared to exercise alone we demonstrated a decreased risk of participants dropping out of follow up (RR 0.40, CI 0.20 to 0.78, P= 0.007). Conclusion(s): The addition of Wii gaming to conventional rehabilitation in chronic stroke patients significantly improved performance in TUG and not in the other physical measures. The pooled effect was small and not beyond the minimal detectable change. However, Wii can be used safely in stroke patients and participants were less likely to drop out in the Wii group. This review highlights the need for further high quality studies to demonstrate the efficacy of Wii in stroke rehabilitation. Implications: Nintendo Wii can be use as an adjunct in stroke rehabilitation to allowmore training time outside therapy hours. It also makes therapy more interactive, engaging and enjoyable for the stroke survivors.

Prediction of future falls in a community dwelling older adult population using instrumented balance and gait analysis.

The role of instrumented balance and gait assessment when screening for prospective fallers is currently a topic of controversial discussion. This study analyzed the association between variables derived from static posturography, instrumented gait analysis and clinical assessments with the occurrence of prospective falls in a sample of community dwelling older people. In this study 84 older people were analyzed. Based on a prospective occurrence of falls, participants were categorized into fallers and non-fallers. Variables derived from clinical assessments, static posturography and instrumented gait analysis were evaluated with respect to the association with the occurrence of prospective falls using a forward stepwise, binary, logistic regression procedure. Fallers displayed a significantly shorter single support time during walking while counting backwards, increased mediolateral to anteroposterior sway amplitude ratio, increased fast mediolateral oscillations and a larger coefficient (Coeff) of sway direction during various static posturography tests. Previous falls were insignificantly associated with the occurrence of prospective falls. Variables derived from posturography and instrumented gait analysis showed significant associations with the occurrence of prospective falls in a sample of community dwelling older adults.

Effects of dual-task training on balance and executive functions in Parkinson's disease: A pilot study

The aim of this study was to analyze the efficacy of cognitive–motor dual-task training compared with single-task training on balance and executive functions in individuals with Parkinson's disease. Fifteen subjects, aged between 39 and 75 years old, were randomly assigned to the dual-task training group (n = 8) and single-task training group (n = 7). The training was run twice a week for 6 weeks. The single-task group received balance training and the dual-task group performed cognitive tasks simultaneously with the balance training. There were no significant differences between the two groups at baseline. After the intervention, the results for mediolateral sway with eyes closed were significantly better for the dual-task group and anteroposterior sway with eyes closed was significantly better for the single-task group. The results suggest superior outcomes for the dual-task training compared to the single-task training for static postural control, except in anteroposterior sway with eyes closed.

Relationship between balance and cognitive performance in older people.

We investigated the relationship between balance and cognitive level in a group of 70 women with no definite Alzheimer's disease or mild cognitive impairment diagnosis and no impairment of daily activity. Static stabilometry and the Montreal Cognitive Assessment (MoCA) test were performed. The antero-posterior sway component was demonstrated to be the best predictor of the MoCA overall score. As visual and proprioceptive components of balance could safely be excluded in our assessments, the vestibular system is to be considered as a putative link between balance and cognitive impairment.

Novel use of the Wii Balance Board to prospectively predict falls in community-dwelling older adults

BackgroundThe Wii Balance Board has received increasing attention as a balance measurement tool; however its ability to prospectively predict falls is unknown. This exploratory study investigated the use of the Wii Balance Board and other clinical-based measures for prospectively predicting falls among community-dwelling older adults. MethodsSeventy-three community-dwelling men and women, aged 60–85years were followed-up over a year for falls. Standing balance was indexed by sway velocities measured using the Wii Balance Board interfaced with a laptop. Clinical-based measures included Short Physical Performance Battery, gait speed and Timed-Up-and-Go test. Multivariable regression analyses were used to assess the ability of the Wii Balance Board measure to complement the TUG test in fall screening. FindingsIndividually, the study found Wii Balance Board anteroposterior (odds ratio 1.98, 95% CI 1.16 to 3.40, P=0.01) and mediolateral (odds ratio 2.80, 95% CI 1.10 to 7.13, p=0.03) sway velocity measures predictive of prospective falls. However, when each velocity measure was adjusted with body mass index and Timed-Up-and-Go, only anteroposterior sway velocity was predictive of prospective falls (odds ratio 2.21, 95% CI 1.18 to 4.14). A faster anteroposterior velocity was associated with increased odds of falling. Area-under-the-curves for Wii Balance Board sway velocities were 0.67 and 0.71 for anteroposterior and mediolateral respectively. InterpretationThe Wii Balance Board-derived anteroposterior sway velocity measure could complement existing clinical-based measures in predicting future falls among community-dwelling older adults. Trial registrationAustralian New Zealand Clinical Trials Registry number: ACTRN12610001099011.

Measuring Postural Sway in Sitting: A New Segmental Approach

ABSTRACTGlobal measures of trunk sway are traditionally used even though the trunk comprises a multiple number of segments. The authors’ aim was to measure the seated sway of typically developing children using a multisegment approach. Twenty typically developing children divided into 2 groups, older and younger than 10 years old, participated in this study. The children sat unsupported for 30 s while their posture and sway were quantified using stereophotogrammetry. The tendency in both age groups was to sit with a backward tilted pelvis and a kyphotic trunk. The sitting position was most varied in the younger group. Marker sway amplitude and velocity in sitting were age dependent, with reduced sway amplitude and velocity with increased age for all segments. Anteroposterior intersegmental angular sway was not age dependent. The difference in marker sway in the anteroposterior direction for the younger group appeared to result from an equally stable trunk supported on a less stable pelvis. Mediolateral marker sway and intersegmental angular sway showed a clearer age dependency. Trunk postural control does not appear to differ between children older and younger than 10 years old, but sagittal plane pelvic stability can explain the increased sway reported in younger children.

Postural Control of Anteroposterior and Mediolateral Sway in Children With Probable Developmental Coordination Disorder.

To examine postural control of anteroposterior (AP) and mediolateral sway of children with probable developmental coordination disorder (pDCD) and children with typical development (TD). Forty-eight children (24 in each group) aged 11 to 12 years performed an aiming task, maintaining a laser beam within targets placed in 2 locations (front/side). Precision was compromised primarily by the control of mediolateral sway for the front target and by the control of AP sway for the side target. The task was performed with large and small targets. In the side target condition, only (1) the TD group showed reduced AP sway in response to reduced target size, whereas the pDCD group increased AP sway, and (2) aiming performance for reduced target sizes deteriorated to a greater degree in the pDCD group than in the TD group. These findings suggest children with pDCD have specific deficits in controlling AP sway.

Effects of a single session of transcranial direct current stimulation on static balance in a patient with hemiparesis: a case study.

[Purpose] Cerebrovascular accident (stroke) is characterized by an abrupt onset of focal or global neurological signs and symptoms. Asymmetry of the limbs is common following a stroke due to hemiplegia or hemiparesis. [Subject and Methods] A male patient having suffered an ischemic stroke was initially evaluated using the Timed Up-and-Go Test and the Six-Minute Walk Test. Static balance was evaluated using a force plate (Kistler model 9286BA) for the stabilometry analysis of center of pressure (COP) sway. The data were interpreted using the SWAY software program (BTS Engineering) synchronized with the SMART-D 140® system. Anodal transcranial direct current stimulation (tDCS; 2 mA) was applied over the primary motor cortex for 20 minutes during gait training on a treadmill. [Results] Under the condition of eyes open, reductions were found in anteroposterior sway (6.18%), trace length (3.3%) and sway velocity (3.3%) immediately following tDCS. [Conclusion] A single session of anodal tDCS combined with treadmill training had a positive effect on the static balance of a subject with chronic hemiparesis stemming from a stroke.

Commentary on "Postural Control of Anteroposterior and Mediolateral Sway in Children With Probable Developmental Coordination Disorder".

Commentary on "Postural Control of Anteroposterior and Mediolateral Sway in Children With Probable Developmental Coordination Disorder".

Effect of constrained weight shift on the static balance and muscle activation of stroke patients.

[Purpose] The purpose of this study was to evaluate the effects of constrained weight shift induced by shoe lift beneath the unaffected lower extremity, on balance functions and electromyography of the affected lower extremity of stroke patients. [Subjects and Methods] Twelve patients with unilateral stroke were recruited as volunteers for this study. The subjects were repeatedly measured in a randomized order under three conditions: no-shoe lift, and shoe lifts of 5 mm and 10 mm heights beneath the unaffected lower extremity. [Results] Standing with a 10 mm shoe lift for the unaffected lower extremity decreased the mean velocity of mediolateral sway compared to no-shoe lift. Regarding the velocity of anteroposterior sway, standing with 5 mm and 10 mm shoe lifts decreased the mean velocity of anteroposterior sway. The muscle activation of the affected lower extremity was not significantly different among the no-shoe lift, 5 mm shoe lift and 10 mm shoe lift conditions; however, the muscle activities of the rectus femoris, biceps femoris, tibialis anterior, and medial gastrocnemius of the affected lower extremity progressively improved with increasing height of the shoe lift. [Conclusion] A constrained weight shift to the affected side elicited by a shoe insole of 10 mm height on the unaffected side can improve the static standing balance of stroke patients, and it resulted in 14–24% increases in the muscle activities of the affected leg.

Effect of the cognitive-motor dual-task using auditory cue on balance of surviviors with chronic stroke: a pilot study

Objective: To investigate the effect of a cognitive-motor dual-task using auditory cues on the balance of patients with chronic stroke. Design: Randomized controlled trial. Setting: Inpatient rehabilitation center. Subjects: Thirty-seven individuals with chronic stroke. Interventions: The participants were randomly allocated to the dual-task group (n=19) and the single-task group (n=18). The dual-task group performed a cognitive-motor dual-task in which they carried a circular ring from side to side according to a random auditory cue during treadmill walking. The single-task group walked on a treadmill only. All subjects completed 15 min per session, three times per week, for four weeks with conventional rehabilitation five times per week over the four weeks. Main measures: Before and after intervention, both static and dynamic balance were measured with a force platform and using the Timed Up and Go (TUG) test. Results: The dual-task group showed significant improvement in all variables compared to the single-task group, except for anteroposterior (AP) sway velocity with eyes open and TUG at follow-up: mediolateral (ML) sway velocity with eye open (dual-task group vs. single-task group: 2.11 mm/s vs. 0.38 mm/s), ML sway velocity with eye close (2.91 mm/s vs. 1.35 mm/s), AP sway velocity with eye close (4.84 mm/s vs. 3.12 mm/s). After intervention, all variables showed significant improvement in the dual-task group compared to baseline. Conclusion: The study results suggest that the performance of a cognitive-motor dual-task using auditory cues may influence balance improvements in chronic stroke patients.

Effects of stimulating surface during static upright posture in the elderly

This study aimed to investigate the influence of three stimulating surfaces based on center of pressure (CoP), anteroposterior sway velocity (VA/P), and medio-lateral sway velocity (VM/L) of 40 elderly subjects. CoP and VM/L showed a significant decrease in all visual conditions only in the stimulating surface whereas VA/P showed a significant decrease only on the same surface with eyes open. Results confirm the importance of multisensory stimulation in postural control in the elderly.

Effect of transcranial direct-current stimulation combined with treadmill training on balance and functional performance in children with cerebral palsy: a double-blind randomized controlled trial.

BackgroundCerebral palsy refers to permanent, mutable motor development disorders stemming from a primary brain lesion, causing secondary musculoskeletal problems and limitations in activities of daily living. The aim of the present study was to determine the effects of gait training combined with transcranial direct-current stimulation over the primary motor cortex on balance and functional performance in children with cerebral palsy.MethodsA double-blind randomized controlled study was carried out with 24 children aged five to 12 years with cerebral palsy randomly allocated to two intervention groups (blocks of six and stratified based on GMFCS level (levels I-II or level III).The experimental group (12 children) was submitted to treadmill training and anodal stimulation of the primary motor cortex. The control group (12 children) was submitted to treadmill training and placebo transcranial direct-current stimulation. Training was performed in five weekly sessions for 2 weeks. Evaluations consisted of stabilometric analysis as well as the administration of the Pediatric Balance Scale and Pediatric Evaluation of Disability Inventory one week before the intervention, one week after the completion of the intervention and one month after the completion of the intervention. All patients and two examiners were blinded to the allocation of the children to the different groups.ResultsThe experimental group exhibited better results in comparison to the control group with regard to anteroposterior sway (eyes open and closed; p<0.05), mediolateral sway (eyes closed; p<0.05) and the Pediatric Balance Scale both one week and one month after the completion of the protocol.ConclusionGait training on a treadmill combined with anodal stimulation of the primary motor cortex led to improvements in static balance and functional performance in children with cerebral palsy.Trial RegistrationEnsaiosclinicos.gov.br/RBR-9B5DH7

The influence of very low illumination on the postural sway of young and elderly adults.

The purpose of the present study was to evaluate the influence of very low ambient illumination and complete darkness on the postural sway of young and elderly adults. Eighteen healthy young participants aged 23.8±1.5 years and 26 community-dwelling elderly aged 69.8±5.6 years were studied. Each participant performed four tests while standing on a force platform in the following conditions: in normal light (215 lx) with open eyes and with closed eyes, in very low illumination (0.25 lx) with open eyes, and in complete darkness with open eyes. The sequences of the tests in the altered visual conditions were determined by random blocs. Postural sway was assessed by means of the force platform measurements. The centre of pressure variables: the medio-lateral and antero-posterior path lengths, mean velocities, sway areas, and fractal dimensions were analysed. Very low illumination resulted in a statistically significant increase in postural sway in both the young and elderly groups compared to normal light, although the increase was significantly smaller than those observed in the eyes closed and complete darkness condition, and no significant effects of illumination on fractal dimensions were detected. The gains of the sways in the very low or no illumination conditions relative to the normal light condition were significantly larger in the group of young participants than in the group of elderly participants (up to 50% and 25%, respectively). However, the response patterns to changes in illumination were similar in the young and elderly participants, with the exception of the short-range fractal dimension of the medio-lateral sway. In conclusion, very low illumination resulted in increased postural sway compared to normal illumination; however, in the closed eye and complete darkness conditions, postural sway was significantly higher than in the very low illumination condition regardless of the age of the participants.

The influence of thoracolumbosacral orthoses on standing balance in patients with adolescent idiopathic scoliosis: a pilot study

Background and aim: The objective of this study was to assess the effect of thoracolumbosacral orthoses (TLSOs) on antero-posterior (AP) sway, medio-lateral (ML) sway and displacement of the center of pressure (COP) during a longitudinal study in patients with adolescent idiopathic scoliosis (AIS). Methods: Eight females aged between 12 and 14.5 years participated in this study. Evaluations were performed prior to the TLSO intervention as a baseline condition, after 1 month, and after 4 months of orthosis use by assessing balance when standing statically on different surfaces. Results: When standing on both lower limbs on a solid surface there were significant differences in ML sway with the eyes both open and closed, and also in A/P sway but only when standing on a solid surface with the eyes open and also when standing on a foam surface with the eyes closed with TLSO use. When standing on the dominant leg, ML sway significantly improved, but AP sway only improved with a foam base surface with the eyes open. Conclusion: This study demonstrated positive effects of wearing a TLSO in improving quiet standing balance and standing on the dominant lower extremity in subjects with AIS after 4 months of brace use.Implications for RehabilitationDue to a change in body shape such as that caused by scoliosis, human posture changes and spinal deformities affect the position of the center of support, and thus balance ability may change.AIS subjects have poor standing stability compared to a healthy matched control group.Brace wearing had positive effect in improving quiet standing balance and standing on the dominant lower extremity in subjects with AIS undergoing brace treatment after 4 months of TLSO use.