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

Repeated exposure to virtual reality decreases reliance on visual inputs for balance control in healthy adults

Postural control may encounter acute challenges when individuals are immersed in a virtual reality (VR) environment, making VR a potential pertinent tool for enhancing balance capacity. Nonetheless, the effects of repeated exposure to VR on balance control remain to be fully elucidated. Fifty-five healthy participants stood upright for six bouts of 90 s each in an immersive virtual reality (VR) environment using a head-mounted display (repeated VR exposure). During these bouts, participants experienced simulated forward and backward displacements. Before and after the repeated VR exposure, the center of pressure mean velocity (VELCOP) was measured in response to simulated forward and backward displacement in VR, as well as during quiet upright standing with eyes open (EO) and closed (EC) in the real environment. The results revealed a significant decrease in VELCOP for forward and backward simulated displacements in both antero-posterior and medio-lateral directions (p < 0.01) after compared to before repeated VR exposure. Furthermore, VELCOP significantly decreased when participants stood upright in EC (-5%; p = 0.004), but not EO (+3%; p > 0.05) in the real environment after repeated VR exposure. The Romberg ratio (EC/EO) was reduced in both antero-posterior and medio-lateral directions (p < 0.05) after VR exposure. This study indicates that repeated exposure to VR induces changes in balance control in both virtual and real environments. These changes may be attributed, in part, to a reduction in the weighting of visual inputs in the multisensory integration process occurring during upright standing. Accordingly, these findings highlight VR as a potentially effective tool for balance rehabilitation. SIGNIFICANCE STATEMENT: This study indicates that repeated exposure to VR induces changes in balance control in both virtual and real environments that can rely, in part, on a reduction in the weighting of visual inputs in the multisensory integration process occurring during upright standing.

Wearable gait analysis systems: ready to be used by medical practitioners in geriatric wards?

Aim

To investigate the feasibility of wearable gait analysis in geriatric wards by testing the effectiveness and acceptance of the system.

Findings

Wearable gait analysis can be implemented into geriatric wards, showing its readiness for a transformation from a pure research tool to a practically usable gait analysis system.

Message

Despite good transferability into clinical practice, future research should aim to increase functionality and applicability of wearable gait analysis systems in clinical contexts.

Purpose

We assess feasibility of wearable gait analysis in geriatric wards by testing the effectiveness and acceptance of the system.

Methods

Gait parameters of 83 patients (83.34 ± 5.88 years, 58/25 female/male) were recorded at admission and/or discharge to/from two geriatric inpatient wards. Gait parameters were tested for statistically significant differences between admission and discharge. Walking distance measured by a wearable gait analysis system was correlated with distance assessed by physiotherapists. Examiners rated usability using the system usability scale. Patients reported acceptability on a five-point Likert-scale.

Results

The total distance measures highly correlate (r = 0.89). System Usability Scale is above the median threshold of 68, indicating good usability. Majority of patients does not have objections regarding the use of the system. Among other gait parameters, mean heel strike angle changes significantly between admission and discharge.

Conclusion

Wearable gait analysis system is objectively and subjectively usable in a clinical setting and accepted by patients. It offers a reasonably valid assessment of gait parameters and is a feasible way for instrumented gait analysis.

Validation of F3ALLS Assessment in Older Adults

OBJECTIVES

The study aimed to evaluate the brief F3ALLS assessment's validity in screening fall risk.

DESIGN

This is a cross sectional and longitudinal study.

SETTING

Participants were recruited from outpatient primary care clinics.

PARTICIPANTS

Older ambulatory adults ages 65-90 volunteered for this study.

MEASUREMENTS

Falls risk was measured with TGBA and F3ALLS questionnaires. A 6-month follow-up period assessed for falls using falls diaries and chart review.

RESULTS

Participants (n=97) were older adults ages 73.91±6.4, 68% (n=66) female. 31% of participants reported at least one fall at 6-months. F3ALLS scores were higher in participants who reported 1 or more falls at 6-months follow-up (3.23±1.5). Higher F3ALLS scores were associated with 6-month fall risk (OR=1.463, 95% CI=1.098-1.949). A score > 3 stratified patients as at risk of falling (AUC=0.77, P<.001; Sensitivity=0.65, Specificity=0.71).

CONCLUSION

The F3ALLS questionnaire adequately classifies person at risk versus not at risk for falls, and higher (worse) F3ALLS scores are associated with falls over 6 months.

A review of center of pressure (COP) variables to quantify standing balance in elderly people: Algorithms and open-access code

Postural control is often quantified by recording the trajectory of the center of pressure (COP)-also called stabilogram-during human quiet standing. This quantification has many important applications, such as the early detection of balance degradation to prevent falls, a crucial task whose relevance increases with the aging of the population. Due to the complexity of the quantification process, the analyses of sway patterns have been performed empirically using a number of variables, such as ellipse confidence area or mean velocity. This study reviews and compares a wide range of state-of-the-art variables that are used to assess the risk of fall in elderly from a stabilogram. When appropriate, we discuss the hypothesis and mathematical assumptions that underlie these variables, and we propose a reproducible method to compute each of them. Additionally, we provide a statistical description of their behavior on two datasets recorded in two elderly populations and with different protocols, to hint at typical values of these variables. First, the balance of 133 elderly individuals, including 32 fallers, was measured on a relatively inexpensive, portable force platform (Wii Balance Board, Nintendo) with a 25-s open-eyes protocol. Second, the recordings of 76 elderly individuals, from an open access database commonly used to test static balance analyses, were used to compute the values of the variables on 60-s eyes-open recordings with a research laboratory standard force platform.

Postadychute-AG, Detection, and Prevention of the Risk of Falling Among Elderly People in Nursing Homes: Protocol of a Multicentre and Prospective Intervention Study

Introduction: While falls among the elderly is a public health issue, because of the social, medical, and economic burden they represent, the tools to predict falls are limited. Posturography has been developed to distinguish fallers from non-fallers, however, there is too little data to show how predictions change as older adults' physical abilities improve. The Postadychute-AG clinical trial aims to evaluate the evolution of posturographic parameters in relation to the improvement of balance through adapted physical activity (APA) programs. Methods: In this prospective, multicentre clinical trial, institutionalized seniors over 65 years of age will be followed for a period of 6 months through computer-assisted posturography and automatic gait analysis. During the entire duration of the follow-up, they will benefit from a monthly measurement of their postural and locomotion capacities through a recording of their static balance and gait thanks to a software developed for this purpose. The data gathered will be correlated with the daily record of falls in the institution. Static and dynamic balance measurements aim to extract biomechanical markers and compare them with functional assessments of motor skills (Berg Balance Scale and Mini Motor Test), expecting their superiority in predicting the number of falls. Participants will be followed for 3 months without APA and 3 months with APA in homogeneous group exercises. An analysis of variance will evaluate the variability of monthly measures of balance in order to record the minimum clinically detectable change (MDC) as participants improve their physical condition through APA. Discussion: Previous studies have stated the MDC through repeated measurements of balance but, to our knowledge, none appear to have implemented monthly measurements of balance and gait. Combined with a reliable measure of the number of falls per person, motor capacities and other precipitating factors, this study aims to provide biomechanical markers predictive of fall risk with their sensitivity to improvement in clinical status over the medium term. This trial could provide the basis for posturographic and gait variable values for these elderly people and provide a solution to distinguish those most at risk to be implemented in current practice in nursing homes. Trial Registration: ID-RCB 2017-A02545-48. Protocol Version: Version 4.2 dated January 8, 2020.

Validity and Reliability of the Satel 40 Hz Stabilometric Force Platform for Measuring Quiet Stance and Dynamic Standing Balance in Healthy Subjects

BACKGROUND

A force platform must have validity and reliability for optimal use. The objective of this study was to analyze the validity and the reliability of the Satel 40 Hz stabilometric force platform.

METHODS

A study of instrumental validity and reliability, involving a cross-sectional correlational and comparative analysis was performed. To determine the validity, four certified weights located on three axes were used and the ability of the stabilometric force platform to detect changes in the position of the different axes was observed. A test-retest was performed to analyze the reliability. Forty-two symptom-free volunteers participated in the study. Assessments were taken in a standing static position and in a dynamic position, with the eyes open and closed. Three measurements were taken and the intra-class correlation coefficient (ICC) was calculated.

RESULTS

The validity increased as the weight increased for all the variables measured in the stabilometric parameters (p < 0.05). The reliability was shown to be good to excellent for the two visual conditions. The positional variables obtained a higher ICC. The variable with the best ICC was the Y mean in OE (ICC 0.874 and a p < 0.001). All the values showed an increase in a dynamic situation.

CONCLUSION

The findings support the reliability and validity of the Satel 40 Hz stabilometric force platform. The platform could be recommended to evaluate static and dynamic standing balance in healthy adult individuals. Guidelines for treatment and the level of quality of stabilometry could be obtained from its use.

Center of pressure displacement characteristics differentiate fall risk in older people: A systematic review with meta-analysis

Falling is the second most prevalent cause of accidental death in the world. Currently available clinical tests to assess balance in older people are insufficiently sensitive to screen for fall risk in this population. Laboratory tests that record the center of pressure (COP) trajectory could overcome this problem but despite their widespread use, the choice of COP trajectory features for use as a biomarker of fall risk lacks consensus. This systematic review and meta-analysis aimed at identifying the best COP characteristics to predict risk of falling in older adults. More than 4000 articles were screened; 44 (7176 older adults) were included in this study. Several COP parameters emerged as good indices to discriminate fallers from non-fallers. From sensitivity analysis, Sway area per unit time, anteroposterior mean velocity, and radial mean velocity were the best traditional features. In this study, identification of older people with a high fall risk was demonstrated using quiet-standing recordings. Such screening would also be useful for routine follow-up of balance changes in older fallers in clinical practice.

Health, Functional and Nutritional Determinants of Falls Experienced in the Previous Year-A Cross-Sectional Study in a Geriatric Ward

Falls are a serious health problem in older adults. A limited number of studies assessed their multifactorial nature in geriatric ward patients. The aim of this study is to explore health, functional and nutritional correlates of experiencing fall(s) in the previous year by older inpatients. A cross-sectional study of patients admitted to the department of geriatrics was conducted. A "faller status" was defined based on positive history of falls in the previous 12 months. Health, functional and nutritional factors associated with falls were evaluated, and multivariable logistic regression analysis models were built. A total of 358 patients (median age 82 (IQR 76-86) years, 77.9% women) were recruited, 43.9% of whom reported falls. The "fallers" presented with a significantly higher number of chronic diseases, higher prevalence of Parkinson's disease, peripheral arterial disease, chronic osteoarthritis, more frequently reported urinary incontinence and were dependent on others for daily living activities. They had significantly worse results for the assessment of gait, balance and frailty status. The Mini Nutritional Assessment-Short Form scores and the mean value of serum albumin were significantly lower in the fallers' group. Parkinson's disease (OR = 2.82, CI-1.07-7.45; p = 0.04) and osteoarthritis (OR = 2.08, CI-1.02-4.23; p = 0.04) were the main variables for the outcome prediction, according to the direct multivariable logistic regression analysis. Our findings suggest that Parkinson's disease and osteoarthritis are the main predictors independently associated with a history of falls in patients admitted to the geriatric ward, although the influence of some factors may be underestimated due to the tendency of not taking the history of falls in very frail, functionally dependent and bedridden individuals.

Raising and stabilization phase of the sit-to-stand movement better discriminate healthy elderly adults from young subjects: a pilot cross-sectional study

Background

The sit-to-stand (STS) test is usually included in the clinical assessment of balance and its instrumented analysis may support clinicians in objectively assessing the risk of falling. The aim of the present study was to assess if kinetic parameters of STS collected using a force platform, with particular focus on the raising and stabilization phase, could discriminate between young and older adults.

Methods

Twenty-four adults (age ranging from 18 to 65 years old) and 28 elderly adults (older than 65 years old) performed STS on a force platform. Data on ground reaction forces, sway, displacement and velocity of the center of pressure were gathered during the raising and the stabilization phases.

Results

elderly subjects showed significant greater global sway (146.97 vs 119.85; p < 0.05) and a higher velocity (vs 40.03 vs 34.35 mm/s; p < 0.05) of execution of STS. Between-group comparisons highlighted a greater postural sway in the raising phase (21.63 vs 13.58; p < 0.001) and a doubled sway during the stabilization phase (12.38 vs 4.98; p < 0.001).

Conclusions

The analysis of STS performed on a force platform provides further information about the age-specific pattern of STS execution. The stabilization phase of STS seems to be the more challenging for functional independent older adults and should be considered during balance assessment.Further studies are needed to confirm findings and improve generalizability of this study.

The Aachen Falls Prevention Scale: Multi-Study Evaluation and Comparison

Background

Fall risk assessment is a time-consuming and resource-intensive activity. Patient-driven self-assessment as a preventive measure might be a solution to reduce the number of patients undergoing a full clinical fall risk assessment.

Objective

The aim of this study was (1) to analyze test accuracy of the Aachen Falls Prevention Scale (AFPS) and (2) to compare these results with established fall risk assessment measures identified by a review of systematic reviews.

Methods

Sensitivity, specificity, and receiver operating curves (ROC) of the AFPS were calculated based on data retrieved from 2 independent studies using the AFPS. Comparison with established fall risk assessment measures was made by conducting a review of systematic reviews and corresponding meta-analysis. Electronic databases PubMed, Web of Science, and EMBASE were searched for systematic reviews and meta-analyses that reviewed fall risk assessment measures between the years 2000 and 2018. The review of systematic reviews was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. The Revised Assessment of Multiple SysTemAtic Reviews (R-AMSTAR) was used to assess the methodological quality of reviews. Sensitivity, specificity, and ROC were extracted from each review and compared with the calculated values of the AFPS.

Results

Sensitivity, specificity, and ROC of the AFPS were evaluated based on 2 studies including a total of 259 older adults. Regarding the primary outcome of the AFPS subjective risk of falling, pooled sensitivity is 57.0% (95% CI 0.467-0.669) and specificity is 76.7% (95% CI 0.694-0.831). If 1 out of the 3 subscales of the AFPS is used to predict a fall risk, pooled sensitivity could be increased up to 90.0% (95% CI 0.824-0.951), whereas mean specificity thereby decreases to 50.0% (95% CI 0.42-0.58). A systematic review for fall risk assessment measures produced 1478 articles during the study period, with 771 coming from PubMed, 530 from Web of Science, and 177 from EMBASE. After eliminating doublets and assessing full text, 8 reviews met the inclusion criteria. All were of sufficient methodological quality (R-AMSTAR score ≥22). A total number of 9 functional or multifactorial fall risk assessment measures were extracted from identified reviews, including Timed Up and Go test, Berg Balance Scale, Performance-Oriented Mobility Assessment, St Thomas’s Risk Assessment Tool in Falling Elderly, and Hendrich II Fall Risk Model. Comparison of these measures with pooled sensitivity and specificity of the AFPS revealed a sufficient quality of the AFPS in terms of a patient-driven self-assessment tool.

Conclusions

It could be shown that the AFPS reaches a test accuracy comparable with that of the established methods in this initial investigation. However, it offers the advantage that the users can perform the self-assessment independently at home without involving trained health care professionals.

Sensor-Based Balance Measures Outperform Modified Balance Error Scoring System in Identifying Acute Concussion

Balance assessment is an integral component of concussion evaluation and management. Although the modified balance error scoring system (mBESS) is the conventional clinical tool, objective metrics derived from wearable inertial sensors during the mBESS may increase sensitivity in detecting subtle balance deficits post-concussion. The aim of this study was to identify which stance condition and postural sway metrics obtained from an inertial sensor placed on the lumbar spine during the mBESS best discriminate athletes with acute concussion. Fifty-two college athletes in the acute phase of concussion and seventy-six controls participated in this study. Inertial sensor-based measures objectively detected group differences in the acutely concussed group of athletes while the clinical mBESS did not (p < 0.001 and p = 0.06, respectively). Mediolateral postural sway during the simplest condition of the mBESS (double stance) best classified those with acute concussion. Inertial sensors provided a sensitive and objective measure of balance in acute concussion. These results may be developed into practical guidelines to improve and simplify postural sway analysis post-concussion.

Elderly fall risk prediction using static posturography

Maintaining and controlling postural balance is important for activities of daily living, with poor postural balance being predictive of future falls. This study investigated eyes open and eyes closed standing posturography with elderly adults to identify differences and determine appropriate outcome measure cut-off scores for prospective faller, single-faller, multi-faller, and non-faller classifications. 100 older adults (75.5 ± 6.7 years) stood quietly with eyes open and then eyes closed while Wii Balance Board data were collected. Range in anterior-posterior (AP) and medial-lateral (ML) center of pressure (CoP) motion; AP and ML CoP root mean square distance from mean (RMS); and AP, ML, and vector sum magnitude (VSM) CoP velocity were calculated. Romberg Quotients (RQ) were calculated for all parameters. Participants reported six-month fall history and six-month post-assessment fall occurrence. Groups were retrospective fallers (24), prospective all fallers (42), prospective fallers (22 single, 6 multiple), and prospective non-fallers (47). Non-faller RQ AP range and RQ AP RMS differed from prospective all fallers, fallers, and single fallers. Non-faller eyes closed AP velocity, eyes closed VSM velocity, RQ AP velocity, and RQ VSM velocity differed from multi-fallers. RQ calculations were particularly relevant for elderly fall risk assessments. Cut-off scores from Clinical Cut-off Score, ROC curves, and discriminant functions were clinically viable for multi-faller classification and provided better accuracy than single-faller classification. RQ AP range with cut-off score 1.64 could be used to screen for older people who may fall once. Prospective multi-faller classification with a discriminant function (-1.481 + 0.146 x Eyes Closed AP Velocity-0.114 x Eyes Closed Vector Sum Magnitude Velocity-2.027 x RQ AP Velocity + 2.877 x RQ Vector Sum Magnitude Velocity) and cut-off score 0.541 achieved an accuracy of 84.9% and is viable as a screening tool for older people at risk of multiple falls.