Real-World Gait Detection Using a Wrist-Worn Inertial Sensor: Validation Study.

BACKGROUND: Wrist-worn inertial sensors are used in digital health for evaluating mobility in real-world environments. Preceding the estimation of spatiotemporal gait parameters within long-term recordings, gait detection is an important step to identify regions of interest where gait occurs, which requires robust algorithms due to the complexity of arm movements. While algorithms exist for other sensor positions, a comparative validation of algorithms applied to the wrist position on real-world data sets across different disease populations is missing. Furthermore, gait detection performance differences between the wrist and lower back position have not yet been explored but could yield valuable information regarding sensor position choice in clinical studies. OBJECTIVE: The aim of this study was to validate gait sequence (GS) detection algorithms developed for the wrist position against reference data acquired in a real-world context. In addition, this study aimed to compare the performance of algorithms applied to the wrist position to those applied to lower back-worn inertial sensors. METHODS: Participants with Parkinson disease, multiple sclerosis, proximal femoral fracture (hip fracture recovery), chronic obstructive pulmonary disease, and congestive heart failure and healthy older adults (N=83) were monitored for 2.5 hours in the real-world using inertial sensors on the wrist, lower back, and feet including pressure insoles and infrared distance sensors as reference. In total, 10 algorithms for wrist-based gait detection were validated against a multisensor reference system and compared to gait detection performance using lower back-worn inertial sensors. RESULTS: The best-performing GS detection algorithm for the wrist showed a mean (per disease group) sensitivity ranging between 0.55 (SD 0.29) and 0.81 (SD 0.09) and a mean (per disease group) specificity ranging between 0.95 (SD 0.06) and 0.98 (SD 0.02). The mean relative absolute error of estimated walking time ranged between 8.9% (SD 7.1%) and 32.7% (SD 19.2%) per disease group for this algorithm as compared to the reference system. Gait detection performance from the best algorithm applied to the wrist inertial sensors was lower than for the best algorithms applied to the lower back, which yielded mean sensitivity between 0.71 (SD 0.12) and 0.91 (SD 0.04), mean specificity between 0.96 (SD 0.03) and 0.99 (SD 0.01), and a mean relative absolute error of estimated walking time between 6.3% (SD 5.4%) and 23.5% (SD 13%). Performance was lower in disease groups with major gait impairments (eg, patients recovering from hip fracture) and for patients using bilateral walking aids. CONCLUSIONS: Algorithms applied to the wrist position can detect GSs with high performance in real-world environments. Those periods of interest in real-world recordings can facilitate gait parameter extraction and allow the quantification of gait duration distribution in everyday life. Our findings allow taking informed decisions on alternative positions for gait recording in clinical studies and public health. TRIAL REGISTRATION: ISRCTN Registry 12246987; https://www.isrctn.com/ISRCTN12246987. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2021-050785.

Association of two geriatric treatment systems with anti-osteoporotic drug treatment and second hip fracture in patients with an index hip fracture: retrospective cohort study.

BACKGROUND: In Germany, geriatricians deliver acute geriatric care during acute hospital stay and post-acute rehabilitation after transfer to a rehabilitation clinic. The rate patients receive acute geriatric care (AGC) or are transferred to post-acute rehabilitation (TPR) differs between hospitals. This study analyses the association between the two geriatric treatment systems (AGC, TPR) and second hip fracture in patients following an index hip fracture. METHODS: Nationwide health insurance data are used to identify the rate of AGC and TPR per hospital following hip fracture surgery in patients aged ≥ 80 years. Outcomes are a second hip fracture after surgery or after discharge within 180 or 360 days and new specific anti-osteoporotic drugs. Cox proportional hazard models and generalised linear models are applied. RESULTS: Data from 29,096 hip fracture patients from 652 hospitals were analysed. AGC and TPR are not associated with second hip fracture when follow-up started after surgery. However, during the first months after discharge patients from hospitals with no AGC or low rates of TPR have higher rates of second hip fracture than patients from hospitals with high rates of AGC or high rates of TPR (Hazard Ratio (95% CI) 1.35 (1.01-1.80) or 1.35 (1.03-1.79), respectively). Lower rates of AGC are associated with lower probabilities of new prescriptions of specific anti-osteoporotic drugs. CONCLUSIONS: Our study suggests beneficial relationships of geriatric treatment after hip fracture with a) the risk of second hip fractures during the first months after discharge and b) an improvement of anti-osteoporotic drug treatment.

"TiC-TUG": technology in clinical practice using the instrumented timed up and go test-a scoping review.

Digitized assessments have a considerable potential to guide clinicial decision making and monitor progress and disease trajectories. The Timed Up and Go test (TUG) has been long established for assessment in geriatric medicine and instrumented versions (iTUG) have been developed and validated. This scoping review includes studies that applied the iTUG and aims to identify use cases to show where and how iTUG assessment could guide interventions and clinical management. The literature search was limited to peer-reviewed studies that performed pre- and post-intervention measurements with a 3-meter TUG instrumented with body-worn technology in samples of at least 20 subjects aged 60+ years. Of 3018 identified articles 20 were included. Four clinical use cases were identified: stratification for subsequent therapy, monitoring of disease or treatment-associated changes and evaluation of interventions in patients with idiopathic normal pressure hydrocephalus (1), and patients with Parkinson's disease (2); monitoring after joint replacement surgery (3), and evaluation after different exercise and rehabilitation interventions (4). The included studies show diversity in terms of iTUG technology and procedures. The identified use cases highlight clinical relevance and high potential for the clinical application of the iTUG. A consensual approach as well as comprehensive reporting would help to further exploit the potential of the iTUG to support clinical management. Future studies should investigate the benefits of segmental iTUG analysis, responsiveness and participants' perspectives on clinically meaningful changes in iTUG.

Automated Gait Detection in Older Adults during Daily-Living using Self-Supervised Learning of Wrist-Worn Accelerometer Data: Development and Validation of ElderNet.

Progressive gait impairment is common in aging adults. Remote phenotyping of gait during daily living has the potential to quantify gait alterations and evaluate the effects of interventions that may prevent disability in the aging population. Here, we developed ElderNet, a self-supervised learning model for gait detection from wrist-worn accelerometer data. Validation involved two diverse cohorts, including over 1,000 participants without gait labels, as well as 83 participants with labeled data: older adults with Parkinson's disease, proximal femoral fracture, chronic obstructive pulmonary disease, congestive heart failure, and healthy adults. ElderNet presented high accuracy (96.43 ± 2.27), specificity (98.87 ± 2.15), recall (82.32 ± 11.37), precision (86.69 ± 17.61), and F1 score (82.92 ± 13.39). The suggested method yielded superior performance compared to two state-of-the-art gait detection algorithms, with improved accuracy and F1 score (p < 0.05). In an initial evaluation of construct validity, ElderNet identified differences in estimated daily walking durations across cohorts with different clinical characteristics, such as mobility disability (p < 0.001) and parkinsonism (p < 0.001). The proposed self-supervised gait detection method has the potential to serve as a valuable tool for remote phenotyping of gait function during daily living in aging adults.

Budget impact analysis of a Lifestyle-integrated Functional Exercise (LiFE) program for older people in Germany: a Markov model based on data from the LiFE-is-LiFE trial.

BACKGROUND: Fall prevention is important for healthy ageing, but the economic impact of fall prevention are scarcely investigated. A recent cost-effectiveness analysis compared a group-delivered Lifestyle-integrated Functional Exercise Program (gLiFE) with an individually-delivered program (LiFE) in community-dwelling people (aged ≥ 70 years) at risk of falling. In addition, the current study aimed to analyze the budget impact of LiFE and gLiFE, compared with standard care in Germany. METHODS: A Markov model was developed to reflect falls and associated care needs for community-dwelling persons over 5 years. The intervention effects of LiFE and gLiFE were shown to be equivalent in a non-inferiority trial, although the costs differed. Outpatient, inpatient, and intervention costs were assessed from a payer's perspective. The effect of parameter uncertainty was assessed in sensitivity analyses. RESULTS: The budget impact due to intervention costs was €510 million for LiFE and €186 million for gLiFE. Over five years, health care expenditures were €35,008 million for those receiving standard care, €35,416 million for those receiving LiFE, and €35,091 million for persons receiving gLiFE. Thereby, LiFE and gLiFE could prevent 2700 deaths and 648,000 falls over 5 years. Parameter uncertainties in the risk of falling, uptake of an intervention offer, and in the intervention effects had a major influence; thus cost savings for LiFE and gLiFE compared with standard care could be achieved for individuals with a high risk of falling. CONCLUSIONS: The results revealed that cost savings for LiFE and gLiFE compared with standard care could only be achieved for individuals at high risk of falling, with gLiFE being superior to LiFE. Future research should consider benefits and aspects of fall prevention beyond falls (e.g., physical activity, social aspects, and personal preferences of participants). TRIAL REGISTRATION: The study was preregistered under underclinicaltrials.gov (identifier: NCT03462654) on 12th March 2018; https://clinicaltrials.gov/ct2/show/NCT03462654 .

[Cooperation of geriatrics and trauma surgery in certified geriatric trauma centers : Insights into different care models and the implementation of requirements resulting from certification]. / Zusammenarbeit von Geriatrie und Unfallchirurgie in zertifizierten alterstraumatologischen Zentren : Einblicke in unterschiedliche Versorgungsmodelle und in die Umsetzung von Anforderungen, die sich aus der Zertifizierung ergeben.

BACKGROUND: In Germany, different models of orthogeriatric co-management have been implemented in certified geriatric trauma centers. So far, it is not clear how the different models are implemented and what influence the certification has on the structures and processes within the centers. The present study examined the extent of cooperation between surgery and geriatrics and if the quality of care had changed since the certification of the centers. METHODS: In this study 4 guided focus group interviews (FGI) were conducted in different teams of certified geriatric trauma centers in 3 federal states with 16 participants. To specify the content of the FGI, two additional interviews were conducted with system auditors. Both types of interview were analyzed by content analysis. RESULTS: The certification supported the implementation of structures and processes in the different orthogeriatric models; however, the quality of care and cooperation between surgery and geriatrics depends on the spatial proximity and the orthogeriatric care model in the geriatric trauma centers. Simultaneously, challenges in the area of geriatric syndromes and the recruitment of skilled staff became relevant. DISCUSSION: The results can help to reflect processes in the certified geriatric trauma centers and to treat geriatric syndromes more effectively. In the future, the challenge will be to establish geriatric care under the existing shortage of skilled staff.

Mobilise-D insights to estimate real-world walking speed in multiple conditions with a wearable device.

This study aimed to validate a wearable device's walking speed estimation pipeline, considering complexity, speed, and walking bout duration. The goal was to provide recommendations on the use of wearable devices for real-world mobility analysis. Participants with Parkinson's Disease, Multiple Sclerosis, Proximal Femoral Fracture, Chronic Obstructive Pulmonary Disease, Congestive Heart Failure, and healthy older adults (n = 97) were monitored in the laboratory and the real-world (2.5 h), using a lower back wearable device. Two walking speed estimation pipelines were validated across 4408/1298 (2.5 h/laboratory) detected walking bouts, compared to 4620/1365 bouts detected by a multi-sensor reference system. In the laboratory, the mean absolute error (MAE) and mean relative error (MRE) for walking speed estimation ranged from 0.06 to 0.12 m/s and - 2.1 to 14.4%, with ICCs (Intraclass correlation coefficients) between good (0.79) and excellent (0.91). Real-world MAE ranged from 0.09 to 0.13, MARE from 1.3 to 22.7%, with ICCs indicating moderate (0.57) to good (0.88) agreement. Lower errors were observed for cohorts without major gait impairments, less complex tasks, and longer walking bouts. The analytical pipelines demonstrated moderate to good accuracy in estimating walking speed. Accuracy depended on confounding factors, emphasizing the need for robust technical validation before clinical application.Trial registration: ISRCTN - 12246987.

Evaluation of costs, osteoporosis treatment, and re-fractures in German collaborative orthogeriatric care after fragility fractures.

Orthogeriatric co-management (OGCM) may provide benefits for geriatric fragility fracture patients in terms of more frequent osteoporosis treatment and fewer re-fractures. Yet, we did not find higher costs in OGCM hospitals for re-fractures or antiosteoporotic medication for most fracture sites within 12 months, although antiosteoporotic medication was more often prescribed. PURPOSE: Evidence suggests benefits of orthogeriatric co-management (OGCM) for hip fracture patients. Yet, evidence for other fractures is rare. The aim of our study was to conduct an evaluation of economic and health outcomes after the German OGCM for geriatric fragility fracture patients. METHODS: This retrospective cohort study was based on German health and long-term care insurance data. Individuals were 80 years and older, sustained a fragility fracture in 2014-2018, and were treated in hospitals certified for OGCM (ATZ group), providing OGCM without certification (OGCM group) or usual care (control group). Healthcare costs from payer perspective, prescribed medications, and re-fractures were investigated within 6 and 12 months. We used weighted gamma and two-part models and applied entropy balancing to account for the lack of randomization. All analyses were stratified per fracture site. RESULTS: We observed 206,273 patients within 12-month follow-up, of whom 14,100 were treated in ATZ, 133,353 in OGCM, and 58,820 in other hospitals. Total average inpatient costs per patient were significantly higher in the OGCM and particularly ATZ group for all fracture sites, compared to control group. We did not find significant differences in costs for re-fractures or antiosteoporotic medication for most fracture sites, although antiosteoporotic medication was significantly more often observed in the OGCM and particularly ATZ group for hip, pelvic, and humerus fractures. CONCLUSION: The observed healthcare costs were higher in ATZ and OGCM hospitals within 12 months. Antiosteoporotic medication was prescribed more often in both groups for most fracture sites, although the corresponding medication costs did not increase.

Ecological validity of a deep learning algorithm to detect gait events from real-life walking bouts in mobility-limiting diseases.

Introduction: The clinical assessment of mobility, and walking specifically, is still mainly based on functional tests that lack ecological validity. Thanks to inertial measurement units (IMUs), gait analysis is shifting to unsupervised monitoring in naturalistic and unconstrained settings. However, the extraction of clinically relevant gait parameters from IMU data often depends on heuristics-based algorithms that rely on empirically determined thresholds. These were mainly validated on small cohorts in supervised settings. Methods: Here, a deep learning (DL) algorithm was developed and validated for gait event detection in a heterogeneous population of different mobility-limiting disease cohorts and a cohort of healthy adults. Participants wore pressure insoles and IMUs on both feet for 2.5 h in their habitual environment. The raw accelerometer and gyroscope data from both feet were used as input to a deep convolutional neural network, while reference timings for gait events were based on the combined IMU and pressure insoles data. Results and discussion: The results showed a high-detection performance for initial contacts (ICs) (recall: 98%, precision: 96%) and final contacts (FCs) (recall: 99%, precision: 94%) and a maximum median time error of -0.02 s for ICs and 0.03 s for FCs. Subsequently derived temporal gait parameters were in good agreement with a pressure insoles-based reference with a maximum mean difference of 0.07, -0.07, and <0.01 s for stance, swing, and stride time, respectively. Thus, the DL algorithm is considered successful in detecting gait events in ecologically valid environments across different mobility-limiting diseases.

Co-Creating a Digital Life-Integrated Self-Assessment for Older Adults: User Experience Study.

BACKGROUND: Older adults are at increased risk of developing health disorders and functional decline. However, owing to time constraints and considerable effort, physicians rarely conduct comprehensive assessments to detect early signs of negative trajectories. If designed properly, digital technologies could identify health risks already at a preclinical stage, thereby facilitating preventive efforts and targeted intervention. For this purpose, a Life-integrated Self-Assessment (LiSA) tablet system will be developed through a structured co-creation process. OBJECTIVE: This study aims to investigate older adults' perceptions of different self-assessment domains, components affecting user experience, risks and benefits associated with LiSA, characteristics of potential LiSA users, and the LiSA concept in general. METHODS: A total of 10 community-dwelling older adults aged ≥70 years were recruited. In total, 6 co-creation workshops were held and started with expert input followed by semistructured discussion rounds. Participants performed hands-on activities with a tablet, including testing of preinstalled self-assessment apps. All workshops were audio recorded and additionally documented by the researchers using flipcharts, notes, and photos. Qualitative content analysis was used to analyze the data following a deductive-inductive approach guided by the Optimized Honeycomb Model for user experience. RESULTS: The group (mean age 77.8, SD 5.1 years) was heterogeneous in terms of previous technology experience and health status. The mean workshop duration was 2 hours (122.5, SD 4.43 min), and an average of 8 (SD 1.15) participants attended each workshop. A total of 11 thematic categories were identified, covering results on all research questions. Participants emphasized a strong interest in conducting a digital self-assessment of physical activity and function and sensory and cognitive functions and requested additional features such as recommendations for actions or reminders. LiSA was perceived as empowering and a motivator to engage in active health care planning as well as enabling shared and informed decision-making. Concerns and barriers included the lack of technical competence, feelings of frustration, and fear of being left alone, with negative assessment results. In essence, participants expressed a positive attitude toward using LiSA repeatedly and identified it as an option to increase the chances of maintaining independence when growing older. CONCLUSIONS: The co-creation participants supported the LiSA approach and were interested in performing regular self-assessments on a long-term basis. In their opinion, LiSA should include relevant assessments capturing physical activity and function and sensory and cognitive functions as well as recommendations for actions. It should be customizable to individual needs. These results will form the basis for a prototype. Iterative development and validation will aim to make LiSA accessible in the public domain as a reliable tablet-based system for self-assessment.

Laboratory and free-living gait performance in adults with COPD and healthy controls.

Background: Gait characteristics are important risk factors for falls, hospitalisations and mortality in older adults, but the impact of COPD on gait performance remains unclear. We aimed to identify differences in gait characteristics between adults with COPD and healthy age-matched controls during 1) laboratory tests that included complex movements and obstacles, 2) simulated daily-life activities (supervised) and 3) free-living daily-life activities (unsupervised). Methods: This case-control study used a multi-sensor wearable system (INDIP) to obtain seven gait characteristics for each walking bout performed by adults with mild-to-severe COPD (n=17; forced expiratory volume in 1 s 57±19% predicted) and controls (n=20) during laboratory tests, and during simulated and free-living daily-life activities. Gait characteristics were compared between adults with COPD and healthy controls for all walking bouts combined, and for shorter (≤30 s) and longer (>30 s) walking bouts separately. Results: Slower walking speed (-11 cm·s-1, 95% CI: -20 to -3) and lower cadence (-6.6 steps·min-1, 95% CI: -12.3 to -0.9) were recorded in adults with COPD compared to healthy controls during longer (>30 s) free-living walking bouts, but not during shorter (≤30 s) walking bouts in either laboratory or free-living settings. Double support duration and gait variability measures were generally comparable between the two groups. Conclusion: Gait impairment of adults with mild-to-severe COPD mainly manifests during relatively long walking bouts (>30 s) in free-living conditions. Future research should determine the underlying mechanism(s) of this impairment to facilitate the development of interventions that can improve free-living gait performance in adults with COPD.

[Update of the recommendations of the Federal Falls Prevention Initiative-Identification and prevention of the risk of falling in older people living at home]. / Update der Empfehlungen der Bundesinitiative Sturzprävention ­ Identifizierung und Prävention des Sturzrisikos bei älteren zu Hause lebenden Menschen.

BACKGROUND: To reduce falls and their consequences, evidence-based and consensus-based recommendations are needed for risk stratification, screening, assessment, and fall prevention as well as treatment. In 2020, the Federal Falls Prevention Initiative (BIS) published recommendations for physical training for falls prevention as a group or individual intervention for older people living at home. In 2022, the world guidelines for falls prevention and management for older adults (WFG) were published. OBJECTIVE: To update the recommendations of the BIS. MATERIAL AND METHODS: The recommendations of the BIS were compared with those of the WFG and, if necessary, extended by methodological and subject-specific aspects. The following areas were considered: 1) screening and risk stratification, 2) interventions, 3) multifactorial assessment and interventions, and 4) specific target groups. RESULTS: The BIS recommendations are largely consistent with those of the WFG. The main reason for differences is the previous focus of the BIS recommendations on physical training. The multifactorial approach, which is described in detail by the WFG, has so far been mentioned in the recommendation paper on physical training in individual settings but not elaborated in detail. The BIS recommendations are supplemented or clarified in this respect. CONCLUSION: By updating the BIS recommendations, the establishment and promotion of fall prevention services for older people in Germany can be further advanced. The implementation can thus be carried out as consistently and scientifically proven as possible.

[Lifestyle-integrated functional exercise for fall prevention : How and why do walking characteristics change?] / Lebensstilintegriertes funktionelles Training zur Sturzprävention : Wie und warum verändert sich das Gehverhalten?

BACKGROUND: The lifestyle-integrated functional exercise (LiFE) program has been shown to increase physical activity. It remains unclear, however, how these changes translate into long vs. short walking episodes. OBJECTIVE: The aim of this work was to investigate changes in short vs. long walking episodes between baseline and 6­month follow-up and to determine which factors are associated with these changes. MATERIAL AND METHODS: This was a two-arm randomized noninferiority study with 309 older adults (mean age 78.7 ± 0.3 years; 73.5% female) at risk of falling who exercised either in a group (gLiFE; n = 153) or individually (LiFE; n = 156). Walking episodes were measured using activPAL 4micro sensors: a distinction was made between walking episodes < 10s, < 20s, and > 60 s. Changes in walking episodes between baseline and 6­month follow-up were analyzed, including calculation of effect sizes (Cohen's d). Determinants of changes in the walking episodes were analyzed using multiple regression. RESULTS: The walking episodes < 10s and < 20 s showed a significant increase in both intervention groups but not for > 60 s. The overall daily walking duration and average steps per day had an influence on changes in the walking episodes between baseline and 6 months. Parameters of objective and subjective function explained a very small but significant amount of the variance. CONCLUSION: The LiFE program seems to work on a behavioral rather than on a functional level. By accumulating short walking episodes, large gains in physical activity can potentially be achieved. This can be of health-promoting benefit especially for persons living in institutional settings or for those who are cautious or even anxious to undertake longer walking episodes (e.g., outdoors).

Feasibility, effectiveness and acceptability of two perturbation-based treadmill training protocols to improve reactive balance in fall-prone older adults (FEATURE): protocol for a pilot randomised controlled trial.

INTRODUCTION: Perturbation-based balance training (PBT) targets the mechanism of falls (eg, slipping, tripping) to specifically train the recovery actions needed to avoid a fall. This task-specific training has shown great promise as an effective and efficient intervention for fall prevention in older adults. However, knowledge about the dose-response relationship of PBT, as well as its feasibility and acceptability in older adults with increased risk of falling is still limited. Thus, the aim of this study is to compare the effectiveness of two different treadmill PBT protocols for improving reactive balance control in fall-prone older adults, and to evaluate the feasibility and acceptability of these protocols. METHODS AND ANALYSIS: The study is designed as a pilot randomised controlled trial with a 6-week intervention and 6-week follow-up period. Thirty-six community-dwelling, fall-prone (Timed Up and Go >12 s, habitual gait speed <1.0 m/s and/or fall history) older adults will be randomised (1:1) to receive six (weeks 1-6) or two treadmill PBT sessions (weeks 1+6) plus four conventional treadmill training sessions (weeks 2-5). Training sessions are conducted 1×/week for 30 min. Each PBT will include 40 perturbations in anterior-posterior and mediolateral directions. Reactive balance after perturbations in standing (Stepping Threshold Test (STT)) and walking (Dynamic Stepping Threshold Test (DSTT)) will be assessed as the primary outcome for effectiveness. Secondary outcomes are spatiotemporal and kinematic parameters collected during STT, DSTT and PBT, maximum perturbation magnitude for each PBT session, static and dynamic balance, physical capacity, physical activity, concerns with falling and executive functions. Feasibility will be assessed via training adherence, drop-out rate, perturbations actually performed and adverse events; and acceptability via self-designed questionnaire and focus groups. ETHICS AND DISSEMINATION: The study has been approved by the Ethics Committee of the Medical Faculty Heidelberg (S-602/2022). Findings will be disseminated through publications in peer-reviewed journals and conference presentations. TRIAL REGISTRATION NUMBER: DRKS00030805.

[Synthesis in French of the 2022 global recommendations for the management and prevention of falls in the elderly]. / Synthèse en langue française des recommandations mondiales 2022 pour la prise en charge et la prévention des chutes chez les personnes âgées.

BACKGROUND: Falls and fall-related injuries are common in older adults, have negative effects on functional independence and quality of life and are associated with increased morbidity, mortality and health related costs. OBJECTIVE: To synthesize evidence-based and expert consensus-based 2022 world guidelines for the management and prevention of falls in older adults. These recommendations consider a person-centred approach that includes the preferences of the patient, caregivers and other stakeholders, gaps in previous guidelines, recent developments in e-health and both local context and resources. RECOMMENDATIONS: All older adults should be advised on falls prevention and physical activity. Opportunistic case finding for falls risk is recommended for communitydwelling older adults. An algorithm is proposed to stratify falls risk and interventions for persons at low, moderate or high risk. Those considered at high risk should be offered a comprehensive multifactorial falls risk assessment with a view to co-design and implement personalised multidomain interventions. Other recommendations cover details of assessment and intervention components and combinations, and recommendations for specific settings and populations. CONCLUSIONS: The core set of recommendations provided will require flexible implementation strategies that consider both local context and resources.

Assessing real-world gait with digital technology? Validation, insights and recommendations from the Mobilise-D consortium.

BACKGROUND: Although digital mobility outcomes (DMOs) can be readily calculated from real-world data collected with wearable devices and ad-hoc algorithms, technical validation is still required. The aim of this paper is to comparatively assess and validate DMOs estimated using real-world gait data from six different cohorts, focusing on gait sequence detection, foot initial contact detection (ICD), cadence (CAD) and stride length (SL) estimates. METHODS: Twenty healthy older adults, 20 people with Parkinson's disease, 20 with multiple sclerosis, 19 with proximal femoral fracture, 17 with chronic obstructive pulmonary disease and 12 with congestive heart failure were monitored for 2.5 h in the real-world, using a single wearable device worn on the lower back. A reference system combining inertial modules with distance sensors and pressure insoles was used for comparison of DMOs from the single wearable device. We assessed and validated three algorithms for gait sequence detection, four for ICD, three for CAD and four for SL by concurrently comparing their performances (e.g., accuracy, specificity, sensitivity, absolute and relative errors). Additionally, the effects of walking bout (WB) speed and duration on algorithm performance were investigated. RESULTS: We identified two cohort-specific top performing algorithms for gait sequence detection and CAD, and a single best for ICD and SL. Best gait sequence detection algorithms showed good performances (sensitivity > 0.73, positive predictive values > 0.75, specificity > 0.95, accuracy > 0.94). ICD and CAD algorithms presented excellent results, with sensitivity > 0.79, positive predictive values > 0.89 and relative errors < 11% for ICD and < 8.5% for CAD. The best identified SL algorithm showed lower performances than other DMOs (absolute error < 0.21 m). Lower performances across all DMOs were found for the cohort with most severe gait impairments (proximal femoral fracture). Algorithms' performances were lower for short walking bouts; slower gait speeds (< 0.5 m/s) resulted in reduced performance of the CAD and SL algorithms. CONCLUSIONS: Overall, the identified algorithms enabled a robust estimation of key DMOs. Our findings showed that the choice of algorithm for estimation of gait sequence detection and CAD should be cohort-specific (e.g., slow walkers and with gait impairments). Short walking bout length and slow walking speed worsened algorithms' performances. Trial registration ISRCTN - 12246987.

Evaluating the Effect of Activity and Environment on Fall Risk in a Paradigm-Depending Laboratory Setting: Protocol for an Experimental Pilot Study.

BACKGROUND: Knowledge about the causal factors leading to falls is still limited, and fall prevention interventions urgently need to be more effective to limit the otherwise increasing burden caused by falls in older people. To identify individual fall risk, it is important to understand the complex interplay of fall-related factors. Although fall events are common, they are seldom observed, and fall reports are often biased. Due to the rapid development of wearable inertial sensors, an objective approach to capture fall events and the corresponding circumstances is provided. OBJECTIVE: The aim of this work is to operationalize a prototypical dynamic fall risk model regarding 4 ecologically valid real-world scenarios (opening a door, slipping, tripping, and usage of public transportation). We hypothesize that individual fall risk is associated with an interplay of intrinsic risk factors, activity, and environmental factors that can be estimated by using data measured within a laboratory simulation setting. METHODS: We will recruit 30 community-dwelling people aged 60 years or older. To identify several fall-related intrinsic fall risk factors, appropriate clinical assessments will be selected. The experimental setup is adaptable so that the level of fall risk for each activity and each environmental factor is adjustable. By different levels of difficulty, the effect on the risk of falling will be investigated. An 8-camera motion tracking system will be used to record absolute body motions and limits of stability. All laboratory experiments will also be recorded by inertial sensors (L5, dominant leg) and video camera. Logistic regression analyses will be used to model the association between risk factors and falls. Continuous fall risk will be modeled by generalized linear regression models using margin of stability as outcome parameter. RESULTS: The results of this project will prove the concept and establish methods to further use the dynamic fall risk model. Recruitment and measurement initially began in October 2020 but were halted because of the COVID-19 pandemic. Recruitment and measurements recommenced in October 2022, and by February 2023, a total of 25 of the planned 30 subjects have been measured. CONCLUSIONS: In the field of fall prevention, a more precise fall risk model will have a significant impact on research leading to more effective prevention approaches. Given the described burden related to falls and the high prevalence, considerable improvements in fall prevention will have a significant impact on individual quality of life and also on society in general by reducing institutionalization and health care costs. The setup will enable the analysis of fall events and their circumstances ecologically valid in a laboratory setting and thereby will provide important information to estimate the individual instantaneous fall risk. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/46930.