Body Sway Velocity Research Articles

Characteristics of static balance performance in 4-stage balance test in the healthy older adults

Background The 4-Stage Balance test is one of the most commonly used tests to assess balance for older adults. Although it is generally accepted that the four positions (including side-by-side (SBSS), semi-tandem (STS), tandem (TS), and single-leg stance (SLS)) in this test are progressively more difficult, there are no studies comparing the balance parameters of the four positions in older adults to prove this result. The purpose of this study is to determine the difficulty of 4 positions in the 4-Stage Balance test and the effect of the dominant and non-dominant lower extremities on static balance among healthy older adults. Methods A total of 115 community-dwelling healthy older adults were included. The postural parameters (including sway range standard deviation (SR), velocity of body sway (V), total sway area (TSA) and sway perimeter (TSP) of the center of pressure) were measured during 8 static postures (including SBSS, left STS, right STS, left TS, right TS, left SLS, right SLS and comfortable stance (CS)). Repeated measures ANOVA was used to analyze the postural parameters in 8 static postures. Results The static balance stability of the five stances in older adults can be ranked in the following sequence: CS > SBSS/STS > TS > SLS. Moreover, changing foot placement in STS, TS and SLS tasks has no influence on stability. This study has been registered in China Clinical Trial Registry (ChiCTR2200065803). Conclusions Our findings suggest that it is feasible to simplify the 4-Stage Balance test to a 3-Stage Balance test in the older adults.

Axial Postural Abnormalities in Parkinsonism: Gaps in Predictors, Pathophysiology, and Management.

Axial Postural Abnormalities in Parkinsonism: Gaps in Predictors, Pathophysiology, and Management.

Influence of Auditory Information on Postural Control During Different Gait Tasks in the Elderly.

Hearing loss is frequently associated with reduced postural control. This is possibly not only related to simultaneous pathophysiological changes within the hearing and vestibular system. The auditory input itself could provide helpful information for maintaining postural control. Previous studies of our group already showed that continuous or interrupted white noise can significantly improve postural control during gait conditions in young healthy individuals. The present study aimed at investigating if those effects are also active in the elderly. Elderly volunteers (mean age 67 years) without any history of disorders to influence gait performance successfully completed 5 walking tasks under 4 different acoustic conditions. Angular sway velocity was measured close to the center of gravity with the Vertiguard® system. Significant changes in body sway velocity were found in 4 of 5 investigated tasks. Only "walking with turning head in rhythm" was not associated with any change in the acoustic input. The sway increased by 8.9% during "walking with open eyes" in the pitch direction and by 11.5% during "tandem walking" in the roll direction if ear protection was applied. The sway was reduced by 9.1% during "walking over barriers" in the pitch direction and by 16.7% in the roll direction during "walking with closed eyes" if a stationary source of continuous white noise was presented. The data of the present study indicate that auditory information could significantly alter postural control during walking in the elderly. Continuous white noise seems to be helpful for maintaining balance in different walking tasks.

Less Vibrotactile Feedback Is Effective to Improve Human Balance Control during Sensory Cues Alteration.

For individuals with altered sensory cues, vibrotactile feedback improves their balance control. However, should vibrotactile feedback be provided every time balance control is compromised, or only one-third of the time their balance is compromised? We hypothesized that vibrotactile feedback would improve balance control more when provided every time their balance is compromised. Healthy young adults were randomly assigned to two groups: group 33% feedback (6 males and 6 females) and group 100% feedback (6 males and 6 females). Vibrotactile feedbacks related to the body’s sway angle amplitude and direction were provided, while participants stood upright on a foam surface with their eyes closed. Then, we assessed if balance control improvement lasted when the vibrotactile feedback was removed (i.e., post-vibration condition). Finally, we verified whether or not vibrotactile feedback unrelated to the body’s sway angle and direction (sham condition) altered balance control. The results revealed no significant group difference in balance control improvement during vibrotactile feedback. Immediately following vibrotactile feedback, both groups reduced their balance control commands; body sway velocity and the ground reaction forces variability decreased. For both groups, unrelated vibrotactile feedback worsened balance control. These results confirmed that participants processed and implemented vibrotactile feedback to control their body sways. Less vibrotactile feedback was effective in improving balance control.

Body sway and movement strategies for control of postural stability in people with spinocerebellar ataxia type 3: A cross-sectional study

BackgroundPostural instability with an excessive body sway is a disabling manifestation in spinocerebellar ataxia type 3. Whether the larger body sway reflects distinct movement strategies for postural control remains uncertain. This study compared the control of postural stability of people with spinocerebellar ataxia type 3 with healthy subjects using body sway and movement strategy analyses derived from bi- and three-dimensional posturography. MethodsTwenty-three patients (7 men, 16 women, 47 ± 11 years) and 102 healthy participants (34 men, 68 women; 44 ± 22 years) underwent posturography while standing with eyes open/closed tasks. Postural stability was assessed using elliptical area and average velocity of body sway. Spatial patterns (single-, double-, or multi-centered) were derived from the number of high-density regions in the three-dimensional statokinesigram. FindingsRepeated measures two-way analysis-of-variance showed a vision-by-group interaction effect for area (F1,122 = 28.831, P < 0.001, η2 = 0.037) and velocity (F1,123 = 59.367, P < 0.001, η2 = 0.073); sway area and velocity were higher in spinocerebellar ataxia type 3 and increased under eyes-closed condition, with a higher increase in the spinocerebellar ataxia type 3. A main effect for group (F1,123 = 11.702, P < 0.001, η2 = 0.061) but not vision (F1,123 = 2.257, P = 0.136, η2 = 0.005) was found for the number of high-density regions. Spatial patterns were different between groups under trials with eyes closed (χ22,125 = 7.46, P = 0.023) but not open (χ22,125 = 2.026, P = 0.363), with a shift from single- to double- or multi-centered spatial patterns. InterpretationCompared to healthy subjects, a larger body displacement and velocity in spinocerebellar ataxia type 3, mainly under visual constraints, are not related to the predominance of either ankle or hip movement strategies.

Responses to balance challenges in persons with panic disorder: A pilot study of computerized static and dynamic balance measurements

IntroductionSeveral studies have shown an association between panic disorder (PD) and reduced balance abilities, mainly based on functional balance scales.This pilot study aims to demonstrate the feasibility of studying balance abilities of persons with PD (PwPD) using computerized static and, for the first time, dynamic balance measurements in order to characterize balance control strategies employed by PwPD.MethodsTwelve PwPD and 11 healthy controls were recruited. PD diagnosis was confirmed using the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM‐IV), and the severity of symptoms was evaluated using the Hamilton Anxiety Scale (HAM‐A), PD Severity Scales (PDSS), and Panic and Agoraphobia Scale (PAS). Balance was clinically assessed using the Activities‐Specific Balance Confidence (ABC) scale and physically by the Mini‐Balance Evaluation Systems Test (Mini‐BESTest). Dizziness was evaluated using the Dizziness Handicap Inventory (DHI) scale. Postural control was evaluated statically by measuring body sway and dynamically by measuring body responses to rapid unexpected physical perturbations.ResultsPwPD had higher scores on the HAM‐A (17.6 ± 10.3 vs. 3.0 ± 2.9; p < .001), PDSS (11.3 ± 5.1 vs. 0; p < .001), and PAS (20.3 ± 8.7 vs. 0; p < .001) questionnaires and lower scores on the balance scales compared to the controls (ABC scale: 156.2 ± 5.9 vs. 160 ± 0.0, p = .016; Mini‐BESTest: 29.4 ± 2.1 vs. 31.4 ± 0.9, p = .014; DHI: 5.3 ± 4.4 vs. 0.09 ± 0.3, p < .001). In the static balance tests, PwPD showed a not‐significantly smaller ellipse area of center of pressure trajectory (p = .36) and higher body sway velocity (p = .46), whereas in the dynamic balance tests, PwPD had shorter recovery time from physical perturbations in comparison to controls (2.1 ± 1.2s vs. 1.6 ± 0.9 s, p = .018).ConclusionThe computerized balance tests results point to an adoption of a ‘‘postural rigidity’’ strategy by the PwPD, that is, reduced dynamic adaptations in the face of postural challenges. This may reflect a nonsecure compensatory behavior. Further research is needed to delineate this strategy.

A static sound source can improve postural stability during walking

BACKGROUND: During walking, postural stability is controlled by visual, vestibular and proprioceptive input. The auditory system uses acoustic input to localize sound sources. For some static balance conditions, the auditory influence on posture was already proven. Little is known about the impact of auditory inputs on balance in dynamic conditions. OBJECTIVE: This study is aimed at investigating postural stability of walking tasks in silence and sound on condition to better understand the impact of auditory input on balance in movement. METHODS: Thirty participants performed: walking (eyes open), tandem steps, walking with turning head and walking over barriers. During each task, acoustic condition changed between silence and presented noise through an earth-fixed loudspeaker located at the end of the walking distance. Body sway velocity was recorded close to the body’s center of gravity. RESULTS: A decreased body sway velocity was significant for walking (eyes open), tandem steps and walking over barriers when noise was presented. Those auditory stimuli did not affect sway velocity while walking with turning head. The posture has probably improved due to the localization ability when walking with the head facing forward, while the localization ability was impaired when turning the head. CONCLUSIONS: The localization ability of a fixed sound source through the auditory system has a significant but limited impact on posture while walking.

Prolonged Standing Task Affects Adaptability of Postural Control in People With Parkinson’s Disease

Background Studies on short-term upright quiet standing tasks have presented contradictory findings about postural control in people with Parkinson’s disease (pwPD). Prolonged trial durations might better depict body sway and discriminate pwPD and controls. Objective The aim of this study was to investigate postural control in pwPD during a prolonged standing task. Methods A total of 26 pwPD and 25 neurologically healthy individuals performed 3 quiet standing trials (60 s) before completing a constrained prolonged standing task for 15 minutes. Motion capture was used to record body sway (Vicon, 100 Hz). To investigate the body sway behavior during the 15 minutes of standing, the analysis was divided into three 5-minute-long phases: early, middle, and late. The following body sway parameters were calculated for the anterior-posterior (AP) and medial-lateral (ML) directions: velocity, root-mean-square, and detrended fluctuations analysis (DFA). The body sway area was also calculated. Two-way ANOVAs (group and phases) and 1-way ANOVA (group) were used to compare these parameters for the prolonged standing and quiet standing, respectively. Results pwPD presented smaller sway area (P < .001), less complexity (DFA; AP: P < .009; ML: P < .01), and faster velocity (AP: P < .002; ML: P < .001) of body sway compared with the control group during the prolonged standing task. Although the groups swayed similarly (no difference for sway area) during quiet standing, they presented differences in sway area during the prolonged standing task (P < .001). Conclusions Prolonged standing task reduced adaptability of the postural control system in pwPD. In addition, the prolonged standing task may better analyze the adaptability of the postural control system in pwPD.

Fall Risk and Balance Confidence in Patients With Diabetic Peripheral Neuropathy: An Observational Study.

ObjectiveIndividuals with diabetic peripheral neuropathy (DPN) have functional deficits that increase their risk of falling. However, psychological aspects such as loss of confidence in undertaking activities could also contribute to this risk. We examined correlations between balance confidence and fall risk among individuals with DPN.MethodsThis was a cross-sectional study of 146 individuals with DPN. Elevated fall risk was determined by timed up-and-go test with standard cut-off time of 13.5 seconds, and balance confidence was measured by 16-item Activities Specific Balance Confidence scale. Functional parameters assessed included functional reach, body sway velocity during quiet standing and muscle strength at ankle and toe.ResultsTwenty percent of the DPN patients were at increased risk of falls. Every unit increase in balance confidence was associated with 9% (95% confidence interval: 0.88, 0.95; p<0.001) reduced odds of falling, after adjusting for socio-demographic, health and functional characteristics. No other functional parameters had significant associations with fall risk in adjusted analyses.ConclusionsPsychological factors like balance confidence appear to be more important for fall risk among DPN patients, compared to objective functional performance. Interventions targeting balance confidence may be beneficial in reducing the risk of falls in this population.

Biomechanical assessment while using production tables on mast climbing work platforms

The objective of this study was to assess the impact of using alternative mast climbing work platform (MCWP) designs on trunk motion and postural stability with masonry workers while performing bricklaying and stepping down tasks using a conventional MCWP setting (i.e. with a step deck) as well as two types of production tables (straight- and L-shaped). The trunk angles and postural sway parameters of twenty-five masonry workers were recorded for the following tasks: (1) standing on a simulated MCWP and laying bricks on an adjacent wall, and (2) stepping down onto the step deck to get into position for doing the bricklaying task. Results indicated that the use of the L-shaped production table resulted in the lowest trunk ranges of motion and significantly reduced the workers' trunk angles in all three planes when compared to both the straight-shaped production table and the conventional approach of not using a production table. Data showed that both body sway velocity and area were significantly reduced when using either one of the production tables. The use of production tables significantly reduced impact sway forces when workers stepped from the main platform to the step deck. The use of production tables on MCWPs improved workers’ postures and overall stability, which could reduce the risk of injury.

Saccadic Eye Movements Attenuate Postural Sway but Less in Sleep-Deprived Young Adults.

Sleep deprivation affects the performance of postural control and several other aspects related to attentional mechanisms that may alter sensory cue acquisition strategies. This study aimed to examine the possible effects of horizontal saccades and ocular fixation on a target in the performance of postural control in young adults with sleep deprivation. Twenty-six adults formed two groups, tested in two evaluations. In the first evaluation, participants slept normally on the night before. In the second evaluation, 13 participants were sleep deprived (SD) and 13 slept normally (control group [CG]) on the night before. In both evaluations, each participant stood upright as still as possible, in two experimental conditions: fixating the eye on a target and performing saccadic movement toward a target presented in two different locations (0.5 Hz). Each participant performed 3 trials in each condition, lasting 62 s each. Body oscillation was obtained in both anterior–posterior and medial–lateral directions. Results showed that SD participants swayed with a larger magnitude and higher velocity after sleep deprivation in the fixation condition. In the saccadic condition, body sway magnitude and velocity were reduced but were still larger/higher in the SD participants. Sleep deprivation deteriorates the performance of postural control. Saccadic eye movements improve postural control performance even in sleep-deprived participants but are still not sufficient to avoid postural control deterioration due to sleep deprivation.

Auditory influence on postural control during stance tasks in different acoustic conditions.

Postural stability might be influenced by auditory input as humans utilize spatiotemporal information to localise sound sources. Earlier studies investigated the acoustic influence on posture but unfortunately experimental setup, room acoustics and conditions of participants varied widely. This study aimed at recording body sway velocity under clearly defined acoustic conditions in a homogenous group of young healthy participants. Thirty participants performed five stance tasks (standing eyes open/closed, standing on a foam support eyes open/closed, Tandem Romberg test eyes closed) under four acoustic conditions (in quiet, with a loudspeaker presenting continuous/interrupted noise, with ear protectors) in two different rooms (long/short reverberation time). Body sway velocity was determined close to body's centre of gravity. Postural stability decreased significantly when continuous noise was applied and increased significantly when interrupted noise was presented in the reverberant room. The usage of ear protectors increased body sway velocity compared to quietness in both rooms. An impaired auditory input by plugging/acoustic masking reduced postural control. Interrupted noise seems to provide a continuously repeated feedback about the postural position in a reverberant room. Hence, the effect of hearing on posture highly depends on the structure of the auditory signal, the sensorimotor condition and the acoustic environment.

Postural Behavior in Medicated Parkinson Disease Patients: A Preliminary Study Searching for Indicators to Track Progress.

Purpose:The establishment of early diagnostic methods for Parkinson disease (PD) is one of the key features to clinically control the rate of PD progression. This study aimed to give a first step toward recognizing the efficacy of multiple postural indices of balance control in differentiating medicated PD patients from health participants.Methods:Nine individuals with PD (Hoehn and Yahr Stage up to 2), 9 staged 2.5 and up, and 9 healthy age-matched Controls performed bipedal stances for 120 seconds with eyes either open or closed on a stable force platform. All participants with PD were under anti-Parkinsonian medication. Non-parametric tests investigated the effects of PD and visual input on postural indices extracted from the center of pressure coordinates.Results:Independent of the stage of the disease, individuals with PD presented faster and shakier body sway compared with Controls. Advanced stages of PD also revealed increased body sway length and variability. In addition, medio-lateral postural instability was more pronounced in all stages of PD when visual inputs were not allowed.Conclusion and Significance:Body sway velocity, jerkiness, length, and its variability revealed to be potential markers for subclinical signs of adjustments in the neuromechanisms of balance control and postural instability even at early stages of disease and under anti-Parkinsonian medication. Results produced here will direct future studies aiming to investigate the efficacy of these same indices on recognizing subclinical development of PD as well as those individuals susceptible to faster rates of progression.

Disambiguating the cognitive and adaptive effects of contextual cues of an impending balance perturbation

Contextual cueing advancing the characteristics of an impending balance perturbation has been thought to induce optimized automatic postural responses. In this investigation, we aimed to disambiguate the cognitive and adaptive components of cueing a balance perturbation through the direction sequence of a series of base of support translations. We compared three experimental conditions: (a) block, with one perturbation cueing that the following one would be in the same direction; (b) serial, with one perturbation cueing that the following one would be in the opposite direction; and (c) random, representing a control uncued condition. Participants were instructed about the perturbation sequences. With this arrangement, at the cognitive level there was no directional uncertainty both in the block and serial sequences, while at the non-cognitive level only the block sequence was expected to lead to optimized responses in comparison to the random sequence. Results showed that the block sequence led to the generation of more stable automatic postural responses in comparison to the serial and random sequences, as indicated by lower amplitudes of body sway and lower velocity of center of pressure displacement. Increased balance stability in the block sequence was associated with longer delays of activation onset of leg distal muscles. Comparisons between the serial and random perturbation sequences failed to show any significant differences. These results indicate that optimized postural responses in the block sequence are due to adaptive processes underlying repetitive perturbations over trials rather than to processing of contextual cues at the cognitive level reducing uncertainty about characteristics of an impending perturbation.

Long-term evaluation of the effect of middle ear effusion on the vestibular system in children

BackgroundOtitis media with effusion (OME) is one of the most common clinical conditions in childhood. Fluid accumulation in the middle ear may impact inner ear. ObjectivesThe purpose of this random sample cohort study was to investigate whether the past history of middle ear effusion has a long-term negative impact on the vestibular system in children. Material and methodsThe study was carried out on 22 children aged 7–15 years who had undergone drainage of the middle ear 5 years before evaluation. The control group consisted of 29 healthy children aged 4–17 years. Vestibular function was examined using sway posturography and electronystagmography (ENG). ResultsThe stabilogram parameters of the study group and the control group were compared. The field of developed area (FDA) and the average body sway velocity (ASV) were analyzed. Elevated stabilogram parameters of FDA and ASV, both with eyes open and eyes closed, were found in the study group. Statistically significant values (p < 0.05) were present for ASV with eyes open and with eyes closed. The ENG recordings were analyzed in both groups. In the study group, spontaneous nystagmus was observed in 40.9% of the children and positional nystagmus occurred in 63.6% of the children. According to tests, eye tracking test was impaired in 27.3% of cases. Rotatory chair testing revealed asymmetry in 18.2% of the children. ConclusionThe presence of effusion in the middle ear in the past has a negative impact on the vestibular part of the inner ear. Clinicians should be aware of the possible negative impact of middle ear effusion on the vestibular function in children with a history of otitis media with effusion. With seeimingly asymptomatic children clinicians should inquire parents about symptoms of dysequlibrium and imbalance.

Examination of Effective Body Sway Parameters for Healthy Elderly

This study aimed to examine body sway characteristics and to propose effective body sway parameters for healthy elderly. The subjects were 311 healthy elderly and 380 healthy young adults. None of the subjects had evidence or known history of gait, posture, or skeletal disorders. The center of foot pressure measurement for 1 min was performed in 1 trial Using Anima’s stabilometer G5500. The data sampling frequency was 20 Hz. Thirty parameters with high reliability were selected from 5 domains of distance, area, velocity, power spectrum, and body sway vector. In comparison with the results for young adults, the elderly had markedly larger values of mean path length and root mean square of x-axis, as well as for 5 velocity parameters and 4 vector velocity parameters. In addition, approximately 10% of the data for parameters related to body sway velocity, especially front/back body sway, even in the healthy elderly fell in an abnormal range of values (mean ± 3 SD). In conclusion, the following parameters may be useful to adequately and simply evaluate the body sway characteristics of the elderly: sway size, sway velocity, and from a directional viewpoint, sway size in the right/left direction and sway velocity in the front/back direction.

Postural control and the relation with cervical sensorimotor control in patients with idiopathic adult-onset cervical dystonia.

Cervical dystonia (CD) is a movement disorder characterized by involuntary muscle contractions leading to an abnormal head posture or movements of the neck. Dysfunctions in somatosensory integration are present and previous data showed enlarged postural sway in stance. Postural control during quiet sitting and the correlation with cervical sensorimotor control were investigated. Postural control during quiet sitting was measured via body sway parameters in 23 patients with CD, regularly receiving botulinum toxin treatment and compared with 36 healthy controls. Amplitude and velocity of displacements of the center of pressure (CoP) were measured by two embedded force plates at 1000Hz. Three samples of 30s were recorded with the eyes open and closed. Disease-specific characteristics were obtained in all patients by the Tsui scale, Cervical Dystonia Impact Profile (CDIP-58) and Toronto Western Spasmodic Rating Scale (TWSTRS). Cervical sensorimotor control was assessed with an infrared Vicon system during a head repositioning task. Body sway amplitude and velocity were increased in patients with CD compared to healthy controls. CoP displacements were doubled in patients without head tremor and tripled in patients with a dystonic head tremor. Impairments in cervical sensorimotor control were correlated with larger CoP displacements (rs ranged from 0.608 to 0.748). Postural control is impaired and correlates with dysfunction in cervical sensorimotor control in patients with CD. Treatment is currently focused on the cervical area. Further research towards the potential value of postural control exercises is recommended.

Functional status mediates the association between peripheral neuropathy and health-related quality of life in individuals with diabetes

AimsTo examine differences in health-related quality of life (HRQoL) between patients with and without diabetic peripheral neuropathy (DPN), and whether these differences can be explained by functional deficits.MethodsThis was a cross-sectional study of 160 patients with type 2 diabetes mellitus, 80 with DPN and 80 without. Assessments included HRQoL (health utility score derived from EQ-5D-5L), functional status measurements [muscle strength, timed up and go (TUG), five times sit-to-stand (FTSTS), functional reach, body sway velocity] and self-reported balance confidence [Activities-specific Balance Confidence (ABC) scale].ResultsMean utility scores were 0.67 ± 0.14 and 0.77 ± 0.16 in patients with and without DPN, respectively (p < 0.001). Patients with DPN had lower great toe extensor strength (6.4 ± 1.8 vs 7.6 ± 2.8 lbs, p = 0.001), greater body sway velocity (2.40 ± 1.31 vs 1.90 ± 0.52 mm/s, p = 0.002), slower TUG (12.1 ± 4.6 vs 10.1 ± 2.3 s, p < 0.001) and FTSTS (15.8 ± 5.8 vs 13.9 ± 5.4 s, p = 0.03) scores, and lower ABC score (73.4 ± 21.3 vs 82.6 ± 16.9, p = 0.003), compared to those without DPN. On stepwise multiple regression, DPN status, FTSTS, body sway velocity, BMI, diabetes duration, pain, and gender explained 38% of HRQoL variance. Addition of ABC score into the model explained 45% of variance. Results from structural equation modelling showed that DPN had direct effects on HRQoL and indirect effects through FTSTS, body sway velocity, and ABC score, with χ2 = 8.075 (p = 0.044), root mean square error of approximation = 0.103 (lower bound 0.015, upper bound 0.191), Comparative Fit Index = 0.966, Tucker–Lewis Index = 0.887, and Standardized Root Mean Square Residual = 0.053.ConclusionsPatients with DPN have worse HRQoL compared to patients without DPN, partly mediated by functional status parameters. Effective interventions targeting functional status may be beneficial in improving HRQoL in these patients.

Principal component analysis for ataxic gait using a triaxial accelerometer

BackgroundIt is quite difficult to evaluate ataxic gait quantitatively in clinical practice. The aim of this study was to analyze the characteristics of ataxic gait using a triaxial accelerometer and to develop a novel biomarker of integrated gate parameters for ataxic gait.MethodsSixty-one patients with spinocerebellar ataxia (SCA) or multiple system atrophy with predominant cerebellar ataxia (MSA-C) and 57 healthy control subjects were enrolled. The subjects were instructed to walk 10 m for a total of 12 times on a flat floor at their usual walking speed with a triaxial accelerometer attached to their back. Gait velocity, cadence, step length, step regularity, step symmetry, and degree of body sway were evaluated. Principal component analysis (PCA) was used to analyze the multivariate gait parameters. The Scale for the Assessment and Rating of Ataxia (SARA) was evaluated on the same day of the 10-m walk trial.ResultsPCA divided the gait parameters into four principal components in the controls and into two principal components in the patients. The four principal components in the controls were similar to those found in earlier studies. The second principal component in the patients had relevant factor loading values for gait velocity, step length, regularity, and symmetry in addition to the degree of body sway in the medio-lateral direction. The second principal component score (PCS) in the patients was significantly correlated with disease duration and the SARA score of gait (ρ = −0.363, p = 0.004; ρ = −0.574, p < 0.001, respectively).ConclusionsPCA revealed the main component of ataxic gait. The PCS of the main component was significantly different between the patients and controls, and it was well correlated with disease duration and the SARA score of gait in the patients. We propose that this score provides a novel method to assess the severity of ataxic gait quantitatively using a triaxial accelerometer.

Immediate effect of transcranial direct current stimulation combined with functional electrical stimulation on activity of the tibialis anterior muscle and balance of individuals with hemiparesis stemming from a stroke.

[Purpose] The aim of the present study was to evaluate the immediate effects of transcranial direct current stimulation (tDCS) and functional electrical stimulation (FES) on activity of the tibialis anterior muscle (TA) and static balance of individuals with hemiparesis stemming from stroke. [Subjects and Methods] A randomized, double-blind, crossover, clinical trial conducted with 30 individuals with chronic post-stroke hemiparesis. Median frequency of electrical activity of the TA were determined using electromyography in five contractions concentrics and Static balance (body sway velocity and frequency), both before and immediately after the intervention. The participants were submitted to four 20-minute intervention protocols with 48-hour interval: anodal tDCS + sham FES; sham tDCS + active FES; anodal tDCS + active FES and sham tDCS + sham FES. Anodal tDCS was administered over C3 or C4, the cathode was positioned in the supraorbital region on the contralateral side and FES was administered to the affected TA. [Results] No significant differences among the protocols were found regarding electrical activity of the TA and static balance. [Conclusion] The results demonstrate that tDCS alone or in combination with FES had no immediate effect on electrical activity of the TA and static balance of the 30 individuals analyzed.