When 'good' is not good enough: a retrospective Rasch analysis study of the Berg Balance Scale for persons with Multiple Sclerosis.

Background: The Berg Balance Scale (BBS) is one of the most used tools to quantify balance in Persons with Multiple Sclerosis, a population at high risk of falling. Aim: To evaluate the measurement characteristics of the BBS in Multiple Sclerosis through Rasch analysis. Design: Retrospective study. Setting: Outpatients in three Italian Rehabilitation centers. Population: Eight hundred and fourteen persons with Multiple Sclerosis able to stand independently for more than 3 s. Methods: The sample (N = 1,220) was split into one validating (B1) and three confirmatory subsamples. Following the Rasch analysis performed on B1, the item estimates were exported and anchored to the three confirmatory subsamples. After obtaining the same final solution across all samples, we studied the convergent and discriminant validity of the final BBS-MS using the EDSS, the ABC scale, and the number of falls. Results: The base analysis on the B1 subsample failed the monotonicity, local independence, and unidimensionality requirements and did not fit the Rasch model. After grouping locally dependent items, the BBS-MS fitted the model (χ28 = 23.8; p = 0.003) and satisfied all requirements for adequate internal construct validity (ICV). However, it was mistargeted to the sample, given the striking prevalence of higher scores (targeting index 1.922) with a distribution-independent Person Separation Index sufficient for individual measurements (0.962). The B1 item estimates were anchored to the confirmatory samples with confirmation of adequate fit (χ2 = [19.0, 22.8], value of ps = [0.015, 0.004]) and satisfaction of all ICV requirements for all subsamples. The final BBS-MS directly correlated with the ABC scale (rho = 0.523) and inversely with EDSS (rho = -0.573). The BBS-MS estimates significantly differed across groups according to the pre-specified hypotheses (between the three EDSS groups, between the ABC cut-offs, distinguishing 'fallers' vs. 'non-fallers', and between the 'low' vs. 'moderate' vs. 'high' levels of physical functioning; and, finally, between 'no falls' vs. 'one or more falls'). Conclusion: This study supports the internal construct validity and reliability of the BBS-MS in an Italian multicentre sample of persons with Multiple Sclerosis. However, as the scale is slightly mistargeted to the sample, it represents a candidate tool to assess balance, mainly in more disabled people with an advanced walking disability.

Effects of stochastic resonance whole-body vibration on sensorimotor function in elderly individuals-A systematic review.

Introduction: Due to demographic changes, falls are increasingly becoming a focus of health care. It is known that within six months after a fall, two thirds of fallers will fall again. Therefore, therapeutic procedures to improve balance that are simple and can be performed in a short time are needed. Stochastic resonance whole-body vibration (SR-WBV) may be such a procedure. Method: An electronic search to assess the effectiveness of SR-WBV on balance in the elderly was conducted using databases that included CINAHL Cochrane, PEDro, and PubMed. Included studies were assessed using the Collaboration Risk of Bias Tool by two independent reviewers. Results: Nine studies showing moderate methodological quality were included. Treatment parameters were heterogeneous. Vibration frequency ranged from 1 to 12 Hz. Six studies found statistically significant improvements of balance from baseline to post measurement after SR-WBV interventions. One article found clinical relevance of the improvement in total time of the "Expanded Time to Get Up and Go Test". Discussion: Physiological adaptations after balance training are specific and may explain some of the observed heterogeneity. Two out of nine studies assessed reactive balance and both indicated statistically significant improvements after SR-WBV. Therefore, SR-WBV represents a reactive balance training.

Postural control of Parkinson's disease: A visualized analysis based on Citespace knowledge graph.

Postural control impairment is one of the primary motor symptoms in patients with Parkinson's disease, leading to an increased risk of falling. Several studies have been conducted on postural control disorders in Parkinson's disease patients, but no relevant bibliometric analysis has been found. In this paper, the Web of Science Core Collection database was searched for 1,295 relevant papers on postural control in Parkinson's disease patients from December 2011 to December 2021. Based on the Citespace knowledge graph, these relevant papers over the last decade were analyzed from the perspectives of annual publication volume, countries and institutes cooperation, authors cooperation, dual-map overlay of journals, co-citation literature, and keywords. The purpose of this study was to explore the current research status, research hotspots, and frontiers in this field, and to provide a reference for further promoting the research on postural control in Parkinson's disease patients.

Dual-task clinical and functional MRI correlates in Parkinson's disease with postural instability and gait disorders.

BACKGROUND: Dual-task is a challenge for Parkinson's disease patients with postural instability and gait disorders (PD-PIGD). OBJECTIVE: This study investigated clinical, cognitive and functional brain correlates of dual-task deficits in PD-PIGD patients using quantitative gait analysis, neuropsychological evaluations and functional MRI (fMRI). METHODS: Twenty-three PD-PIGD patients performed a clinical assessment of gait/balance abilities. Single and dual-task Timed-Up-and-Go tests were monitored using an optoelectronic system to study turning velocity. Patients underwent executive-attentive function evaluation and two fMRI tasks: motor-task (foot anti-phase movements), and dual-task (foot anti-phase movements while counting backwards by threes starting from 100). Twenty-three healthy subjects underwent neuropsychological and fMRI assessments. RESULTS: Dual-task in PD-PIGD patients resulted in worse gait performance, particularly during turning. Performing the dual-task relative to the motor-fMRI task, healthy subjects showed widespread increased recruitment of sensorimotor, cognitive and cerebellar areas and reduced activity of inferior frontal and supramarginal gyri, while PD-PIGD patients showed increased recruitment of inferior frontal gyrus and supplementary motor area and reduced activity of primary motor, supramarginal and caudate areas. Dual-task gait alterations in patients correlated with balance and executive deficits and with altered dual-task fMRI brain activity of frontal areas. CONCLUSIONS: This study suggested the correlation between dual-task gait difficulties, postural instability and executive dysfunction in PD-PIGD patients. FMRI results suggest that an optimized recruitment of motor and cognitive networks is associated with a better dual-task performance in PD-PIGD. Future studies should evaluate the effect of specific gait/balance and dual-task trainings to improve gait parameters and optimize brain functional activity during dual-tasks.

Reemplazo de silla por balón de estabilidad mejora fuerza muscular y calidad de vida en trabajadores de oficina: Estudio piloto / Chair Replacement by Stability Ball Improves Muscle Strength and Quality of Life in Office Workers: Pilot Study

RESUMEN Objetivo: Determinar si el reemplazo parcial de silla de oficina por un balón de estabilidad aumenta la fuerza-resistencia de musculatura extensora de tronco y equilibrio estático, así como mejora la calidad de vida relacionada con la salud en adultos que realizan trabajo de oficina. Materiales y métodos: Estudio de diseño preexperimental pre-post sin grupo control. La muestra fue intencionada, de 18 trabajadores de oficina entre 25 y 55 años. Durante 8 semanas se realizó un reemplazo parcial y progresivo de una silla de oficina por un balón de estabilidad durante las horas de trabajo. Pre y post al reemplazo se evaluó la fuerza-resistencia de la musculatura extensora de tronco mediante el test clínico Biering Sorensen, el equilibrio estático mediante oscilografía postural y la calidad de vida con el cuestionario de percepción de calidad de vida relacionado con la salud SF-36. Resultados: Se observó una mayor fuerza-resistencia muscular (p=0,003), y un mejor puntaje en las dimensiones rol físico (p=0,041), dolor corporal (p=0,017), salud general (p=0,027), función social (p=0,017), rol emocional (p=0,043) y salud mental (p=0,036). Conclusiones: El reemplazo parcial y progresivo de la silla de oficina por un balón de estabilidad durante 8 semanas aumentó la fuerza-resistencia de la musculatura extensora de tronco y mejoró la percepción de calidad de vida en trabajadores de oficina.

ABSTRACT Aim: To determine if the partial replacement of the office chair with a stability ball increases the strength-resistance of the trunk extensor muscles and static balance, as well as improves the health-related quality of life in office workers. Materials and methods: Pre-post experimental design study without control group. Intentional sample of 18 office workers between 25 and 55 years old. For 8 weeks, a partial and progressive replacement of an oice chair with a stability ball was performed during working hours. Before and after replacement, the strength-resistance of the trunk extensor muscles was evaluated using the Biering Sorensen clinical test, static balance was measured using postural oscillography and quality of life was evaluated with the quality of life perception questionnaire related to health SF-36. Results: Greater muscular strength-endurance (p = 0.003), and a better score in the dimensions of physical role (p = 0.041), body pain (p = 0.017), general health (p = 0.027), social function ( p = 0.017), emotional role (p = 0.043) and mental health (p = 0.036) were observed. Conclusions: The partial and progressive replacement of the office chair by a stability ball for 8 weeks increased the strength-resistance of the trunk extensor muscles and improved the perception of quality of life in office workers.

The construct of balance control in primary school-aged children: Unidimensional and task-specific.

The aim of this study was to determine the dimensionality and task-specificity of balance control by investigating the relationships between different tasks and the degree to which these tasks belong to the same construct in primary school-aged children. Seventy-four South African children were randomly selected from a sample of convenience. They performed 18 different balance tasks that were grouped into four balance scales: the Performance and Fitness (PERF-FIT) static balance score, the PERF-FIT dynamic balance score, the PERF-FIT moving cans balance score and the Balance Sensory score. Spearman rank correlations were calculated between the scores. Principal component analysis (PCA) was used to investigate the number of factors within the construct. Moderate to good correlations were found between: i) PERF-FIT Moving cans balance score and the Balance Sensory score (r = 0.605, p < 0.001); ii) PERF-FIT static balance score and the PERF-FIT Moving cans (r = 0.586, p < 0.001); iii) PERF-FIT static balance score and the Balance Sensory score (r = 0.541, p < 0.001). All other correlations were low to fair. The PCA revealed one component. The three PERF-FIT items (moving cans-, static- and dynamic balance score) and the Balance Sensory score explained 59.4% of the variance of total balance performance.

Development of a Balance Recovery Performance Measure for Gait Perturbation Training Based on the Center of Pressure.

Background: The availability of instrumented treadmills that can apply unexpected perturbations during walking has made gait perturbation training more popular in clinical practice. To quantify and monitor balance recovery while training, easy to use measures are needed and may be based on integrated force plate data. Therefore, we aimed to quantify and evaluate different implementations of the recovery performance measure based on center of pressure data. Methods: Recovery performance was calculated based on differences in center of pressure trajectories between unperturbed walking and balance recovery after a perturbation. Five methodological choices leading to 36 different implementations were evaluated. Test-retest reliability, effect sizes, and concurrent validity were evaluated against trunk velocity measures. Results: Differences in measures of (dis-)similarity, time normalization and reference data affected reliability, sensitivity and validity and none of the performance measure implementations based on center of pressure trajectories was superior on all criteria. Measures assessing perturbation effects on trunk velocities provided more reliable and sensitive recovery outcomes. Discussion: Different implementations of the recovery performance measure can be chosen dependent on constraints imposed in the clinical setting. Conclusion: Quantifying recovery performance based on center of pressure data is possible and may be suitable to monitor improvement in recovery performance after gait perturbations in specific clinical setups. Validity of performance measures in general requires further attention.

Reliability and concurrent validity of a modified timed up and go test for healthy preschoolers.

The purpose of this study was to assess the interrater and test-retest reliability and the concurrent validity of the modified timed up and go test for preschoolers. As such, we aim to determine the most suited outcome of the modified timed up and go test: the best or the average performance. Thirty-two children (age 3-5) performed three timed up and go test trials as fast as possible on two separate occasions. During the first session, two researchers recorded the time to perform the task simultaneously. For reliability analyses, intra-class correlation coefficients (ICCs) and the minimal detectable change were determined. A Pearson correlation coefficient was calculated to determine concurrent validity between the timed up and go test and the balance subscale of the Movement Assessment Battery for Children, 2nd edition. Interrater (ICC > 0.97) and test-retest (ICC > 0.75) reliability were good both for the average and the best timed up and go test performance. A minimal detectable change of 1.86 s was found for the best performance, and 2.30 s for the average performance. Only the best timed up and go test performance correlated significantly with the balance subscale of the Movement Assessment Battery for Children, 2nd edition, though fair (r = -0.347, p = 0.007).Conclusion: The modified timed up and go test for preschoolers using the best performance is reliable and recommended to reduce standard and measurement error. What is Known: • A large variety of timed up and go test protocols is available for children • The protocols differ in the instructions on walking speed (self-selected/fastest), the use of an extra motivation (e.g., touch a star on the wall) and the applied outcome (average/best performance) What is New: • The best timed up and go test performance induces more consistent test results between raters and sessions and also less standard and measurement error in 3- to 5-year-old children • The best timed up and go test performance should be preferred over the average performance to achieve both reliable and valid test results in 3- to 5-year-old children.

Quantification of postural control deficits in patients with recent concussion: An inertial-sensor based approach.

BACKGROUND: The aim of this study was to quantify postural control ability in a group with concussion compared with a healthy control group. METHOD: Fifteen concussion patients (4 females, 11 males) and a group of fifteen age- and sex-matched controls were recruited. Participants were tested during the performance of the three stance variants (bilateral, tandem and unilateral) of the balance error scoring system standing on a force place, while wearing an inertial measurement unit placed at the posterior aspect of the sacrum. FINDINGS: The area of postural sway was computed using the force-plate and the '95% ellipsoid volume of sway' was computed from the accelerometer data. Concussed patients exhibited increased sway area (1513mm2 [95% CI: 935 to 2091mm2] vs 646mm2 [95% CI: 519 to 772mm2]; p=0.02) and sway volume (9.46m3s-6 [95% CI: 8.02 to 19.94m3s-6] vs 2.68m3s-6 [95% CI: 1.81 to 3.55m3s-6]; p=0.01) in the bilateral stance position of the balance error scoring system. The sway volume metric also had excellent accuracy in identifying task 'errors' (tandem stance: 91% accuracy [95% CI: 85-96%], p<0.001; unilateral stance: 91% accuracy [95% CI: 86-96%], p<0.001). INTERPRETATION: Individuals with concussion display increased postural sway during bilateral stance. The sway volume that was calculated from the accelerometer data not only differentiated a group with concussion from a healthy control group, but successfully identified when task errors had occurred. This may be of value in the development of a pitch-side assessment system for concussion.

Age-related changes in postural sway in preschoolers.

OBJECTIVES: The present study aimed to investigate age-related differences of postural sway in 3- to 6-year-old typically developing children in different sensory conditions and subsequently to provide reference values for global descriptive sway parameters in preschoolers. METHODS: Ninety-six typically developing children, between 3 and 5 years of age, participated in this cross-sectional study. Postural sway was measured for 40s in four conditions (eyes open/eyes closed on stable ground/foam) by using a force plate. Global descriptive sway parameters were calculated and analysed using a 2 × 2 × 3 (surface × vision × age group) MANOVA (p<0.05) in the children that were able to complete the task (40s). RESULTS: When sensory information was altered, a significantly smaller number of 3- and 4-year-olds was able to complete the task. Significant main effects of vision (p<0.05), surface (p<0.001) and an interaction effect between vision and surface (p<0.05) on all postural sway parameters were found. A significant main effect of age was found for antero-posterior amplitude (p=0.047), medio-lateral root mean square (p=0.012) and area (p=0.009) between 3- and 5-year-olds and 4- and 5-year-olds. No interaction effects (surface × vision × age group) were found. CONCLUSIONS: During natural stance, the amount of postural sway distinguishes 5-year-olds from 3- and 4-year-olds, highlighting the need for age-specific reference values for specific balance-related sway parameters (e.g. RMS_ml). Regarding test conditions with altered sensory input, a larger number of 5-year-old children are able to perform more difficult tasks. Nevertheless, if 3- or 4-year-olds are able to perform the more difficult tasks, their performance can be compared to the older children.

Dynamic balance deficits in individuals with chronic ankle instability compared to ankle sprain copers 1 year after a first-time lateral ankle sprain injury.

PURPOSE: To quantify the dynamic balance deficits that characterise a group with chronic ankle instability compared to lateral ankle sprain copers and non-injured controls using kinematic and kinetic outcomes. METHODS: Forty-two participants with chronic ankle instability and twenty-eight lateral ankle sprain copers were initially recruited within 2 weeks of sustaining a first-time, acute lateral ankle sprain and required to attend our laboratory 1 year later to complete the current study protocol. An additional group of non-injured individuals were also recruited to act as a control group. All participants completed the anterior, posterior-lateral and posterior-medial reach directions of the star excursion balance test. Sagittal plane kinematics of the lower extremity and associated fractal dimension of the centre of pressure path were also acquired. RESULTS: Participants with chronic ankle instability displayed poorer performance in the anterior, posterior-medial and posterior-lateral reach directions compared with controls bilaterally, and in the posterior-lateral direction compared with lateral ankle sprain copers on their 'involved' limb only. These performance deficits in the posterior-lateral and posterior-medial directions were associated with reduced flexion and dorsiflexion displacements at the hip, knee and ankle at the point of maximum reach, and coincided with reduced complexity of the centre of pressure path. CONCLUSION: In comparison with lateral ankle sprain copers and controls, participants with chronic ankle instability were characterised by dynamic balance deficits as measured using the SEBT. This was attested to reduced sagittal plane motions at the hip, knee and ankle joints, and reduced capacity of the stance limb to avail of its supporting base. LEVEL OF EVIDENCE: III.

Inter-joint coordination strategies during unilateral stance 6-months following first-time lateral ankle sprain.

BACKGROUND: Longitudinal analyses of participants with a history of lateral ankle sprain are lacking. This investigation combined measures of inter-joint coordination and stabilometry to evaluate eyes-open (condition 1) and eyes-closed (condition 2) static unilateral stance performance in a group of participants, 6-months after they sustained an acute, first-time lateral ankle sprain in comparison to a control group. METHODS: Sixty-nine participants with a 6-month history of first-time lateral ankle sprain and 20 non-injured controls completed three 20-second unilateral stance task trials in conditions 1 and 2. An adjusted coefficient of multiple determination statistic was used to compare stance limb 3-dimensional kinematic data for similarity in the aim of establishing patterns of lower-limb inter-joint coordination. The fractal dimension of the stance limb centre of pressure path was also calculated. FINDINGS: Between-group analyses revealed significant differences in stance limb inter-joint coordination strategies for conditions 1 and 2, and in the fractal dimension of the centre-of-pressure path for condition 2 only. Injured participants displayed increases in ankle-hip linked coordination compared to controls in condition 1 (sagittal/frontal plane: 0.15 [0.14] vs 0.06 [0.04]; η(2)=.19; sagittal/transverse plane: 0.14 [0.11] vs 0.09 [0.05]; η(2)=0.14) and condition 2 (sagittal/frontal plane: 0.15 [0.12] vs 0.08 [0.06]; η(2)=0.23), with an associated decrease in the fractal dimension of the centre-of-pressure path (injured limb: 1.23 [0.13] vs 1.36 [0.13]; η(2)=0.20). INTERPRETATION: Participants with a 6-month history of first-time lateral ankle sprain exhibit a hip-dominant coordination strategy for static unilateral stance compared to non-injured controls.

Postural control strategies during single limb stance following acute lateral ankle sprain.

BACKGROUND: Single-limb stance is maintained via the integration of visual, vestibular and somatosensory afferents. Musculoskeletal injury challenges the somatosensory system to reweight distorted sensory afferents. This investigation supplements kinetic analysis of eyes-open and eyes-closed single-limb stance tasks with a kinematic profile of lower limb postural orientation in an acute lateral ankle sprain group to assess the adaptive capacity of the sensorimotor system to injury. METHODS: Sixty-six participants with first-time acute lateral ankle sprain completed a 20-second eyes-open single-limb stance task on their injured and non-injured limbs (task 1). Twenty-three of these participants successfully completed the same 20-second single-limb stance task with their eyes closed (task 2). A non-injured control group of 19 participants completed task 1, with 16 completing task 2. 3-dimensional kinematics of the hip, knee and ankle joints, as well as associated fractal dimension of the center-of-pressure path were determined for each limb during these tasks. FINDINGS: Between trial analyses revealed significant differences in stance limb kinematics and fractal dimension of the center-of-pressure path for task 2 only. The control group bilaterally assumed a position of greater hip flexion compared to injured participants on their side-matched "involved"(7.41 [6.1°] vs 1.44 [4.8]°; η(2)=.34) and "uninvolved" (9.59 [8.5°] vs 2.16 [5.6°]; η(2)=.31) limbs, with a greater fractal dimension of the center-of-pressure path (involved limb=1.39 [0.16°] vs 1.25 [0.14°]; uninvolved limb=1.37 [0.21°] vs 1.23 [0.14°]). INTERPRETATION: Bilateral impairment in postural control strategies present following a first time acute lateral ankle sprain.