Physical activity and mobility are critical for healthy aging and predict diverse health outcomes. While wrist-worn accelerometers are widely used to monitor physical activity, estimating gait metrics from wrist data remains challenging. We extend ElderNet, a self-supervised deep-learning model previously validated for walking-bout detection, to estimate gait metrics from wrist accelerometry. Validation involved 819 older adults (Rush-Memory- and-Aging-Project) and 85 individuals with gait impairments (Mobilise-D), from six medical centers. In Mobilise-D, ElderNet achieved an absolute error of 8.82 cm/s and an intra-class correlation of 0.87 for gait speed, outperforming state-of-the-art methods (p < 0.001) and models using a lower-back sensor. ElderNet outperformed (percentage error; p < 0.01) competing approaches in estimating cadence and stride length, and better (p < 0.01) classified mobility disability (AUC = 0.80) than conventional gait or physical activity metrics. These results render ElderNet a scalable tool for gait assessment using wrist-worn devices in aging and clinical populations.

ABSTRACT Background Older adults with (pre)frailty are vulnerable to deteriorations in physical functioning, mobility and independence. Evidence for frailty interventions utilizing existing services within primary healthcare structure is limited. The PromeTheus trial aimed to evaluate the effectiveness of a home‐based, multifactorial, interdisciplinary intervention to prevent functional and mobility decline in (pre)frail older adults. Methods In this multicentre, assessor‐blinded, randomized controlled trial, 385 community‐dwelling (pre)frail older adults (clinical frailty scale 4–6, ≥ 70 years) were randomly allocated (1:1) into the intervention group (IG: n = 196) or control group (CG: n = 189). The IG underwent the PromeTheus programme for 12 months, which included an obligatory unsupervised home‐based physical exercise programme and facultative counselling services (person‐environment fit, nutrition and coping with everyday life), implemented through existing healthcare services and referral to community group activities. The CG received usual care. The first primary outcome was the function component of the Late‐Life Function and Disability Instrument (LLFDI‐FC) after 12 months; Life‐Space Assessment (LSA) served as the second primary outcome. Secondary outcomes included participation (short‐form LLFDI disability component, LLFDI‐DC), frailty status, physical capacity (Short Physical Performance Battery, SPPB) and fall rate. Data analyses followed the intention‐to‐treat principle. An exploratory stratified analysis according to baseline physical capacity (SPPB ≤ 6 points [n = 210] vs. SPPB > 6 points [n = 175]) was also conducted. Results Participants had a mean age of 81.2 ± 5.9 years, with 73.5% (n = 283) being female. At the 12‐month follow‐up, a significant between‐group difference in favour of the IG was observed for the change in the LLFDI‐FC (1.38 points, 95% confidence interval [CI] 0.08, 2.68) but not for the change in the LSA (0.49 points, 95% CI –3.65, 4.64). Change in frailty status (odds ratio for being in a ‘better’ change status 1.72, 95% CI 1.11, 2.64) and SPPB (0.58 points, 95% CI 0.10, 1.05) also showed significant between‐group differences in favour of the IG. The intervention did not affect the short form LLFDI‐DC or fall rate (p = 0.055–0.689). The stratified analysis showed significant improvements in the LLFDI‐FC, short‐form LLFDI‐DC (limitation), frailty status and SPPB (p = 0.002–0.020) in the IG compared to the CG for participants with SPPB ≤ 6 points but not for those with SPPB > 6 points. There were no study‐related serious adverse events. Conclusions The PromeTheus programme had positive effects on physical functioning, frailty status and physical capacity but not on life‐space mobility and fall rate in community‐dwelling (pre)frail older adults. Participants with lower baseline physical capacity may benefit more from the programme.

Background:: Short narrative reports (SNR) are often recorded immediately after fall events. SNRs have not been used to study falls, most likely because they have unknown structure and consistency. We aimed to investigate SNRs provided alongside verified real world falls, to determine whether they can provide useful insight into the mechanism of falls in two settings: community-dwelling (CD) and geriatric rehabilitation (GR) settings. Methods:: We analysed 270 SNRs of real-world falls, captured immediately after each event. The SNRs included a narrative description from the individual or a bystander, and prompts for specific information (e.g. fall direction, pre-fall activity). We developed a framework to analyse the SNRs and identify core sub-themes that were consistently reported, and then compared key themes (transitions and object interactions) across the CD and GR groups. Results:: We extracted four core sub-themes for the framework: initial status, intended status, interacting object, and fall direction. Of the 270 falls, 211 (78%) were sufficiently detailed to chart complete fall scenarios. Objects were involved in 82% (173/211) of these falls. Falls were frequently reported to occur during transitions between sitting, standing, and walking, and often reported to involve interaction with objects such as static seats, mobility aids, and static furniture. CD participants reported more diverse fall circumstances (47 unique scenarios), often involving standing up from or sitting down on static seats, walking without object involvement, or navigating near static furniture. GR participants reported more walking-related falls involving mobility aids, but fewer varied scenarios (22 scenarios). Conclusions:: The SNRs can provide consistent, and potentially important insights into real-world fall circumstances. Our analysis highlights how specific activities and object interactions may contribute to loss of balance, particularly during common daily transitions; this supports group-specific prevention strategies for CD and GR populations.

Background: Falls are a leading cause of injury among older adults, often resulting from dynamic balance disturbances. It is influenced by a complex interplay of intrinsic and extrinsic fall-risk factors. To identify individual fall risks, it is important to understand the underlying associations. Objective: This study aimed to build an experimental setup modeling selected factors leading to a loss of balance, measured by the margin of stability (MoS) in an ecologically valid real-world example (tripping). Additionally, these analyses aimed to assess the feasibility and safety of the protocol and to explore the use of the MoS as part of a prototypical dynamic fall-risk model to differentiate between fall-risk groups. Methods: Nineteen community-dwelling older adults (mean age of 71, SD 3.67 y; n=7, 37% women) completed the tripping protocol involving perturbations under various conditions. Clinical assessments were used to identify relevant fall-related intrinsic fall-risk factors. MoS was measured using an 8-camera motion capture system. Receiver operating characteristic analyses determined the ability of MoS to distinguish between low and high fall-risk groups. Results: Approximately one-quarter of participants discontinued before or at the start of the tripping scenario because of discomfort or fear of perturbations, indicating that perceived safety is an important feasibility factor. Perturbations significantly disrupted MoS, with a median MoS of-106.05 (IQR-181.40 to-41.50) mm during the perturbed step compared to 114 (IQR 81.20-155.20) mm in the preperturbation step. Recovery steps showed progressive stabilization, with the second recovery step achieving a median MoS of 88.45 (IQR 47.50-137.80) mm. The second recovery step exhibited the highest predictive accuracy for fall-risk differentiation, with area under the curve values reaching 82.3% during slow walking with a series of right-sided perturbations. In contrast, fast walking with random perturbations yielded lower area under the curve values (64.9%). Slow walking conditions generally demonstrated the clearest separation between fall-risk groups. Conclusions: This pilot and feasibility study demonstrates the applicability of a tripping paradigm to perturb MoS in older adults and provides preliminary insights into its association with fall-risk indices. While the protocol proved safe and feasible for fit older adults, perceived safety limited full participation. The findings are exploratory and intended to guide the design of larger prospective studies rather than to establish predictive conclusions. These data suggest that MoS during controlled tripping may help differentiate fall-risk strata, but confirmation will require adequately powered studies in more diverse and frailer older populations-and across multiple real-world scenarios-before any clinical implementation can be considered.

Digital mobility outcomes (DMOs) measured under real-world conditions allow for differentiated insights into mobility patterns of older adults. This study provides an advanced description of real-world walking in community-dwelling older adults and identifies correlates of walking amount, pattern and speed. This cross-sectional study used baseline data from the SMART-AGE intervention trial with community-dwelling older adults (age ≥ 67 years). Assessment procedures included one-week monitoring of real-world walking using a wearable device (Axivity AX6), clinical outcomes, and tablet-based questionnaires. DMOs describing the amount (steps, walking duration), pattern (e.g., number of walking bouts [WBs]) and pace (mean and 90th percentile [P90] walking speed) of real-world walking were extracted using a validated computational pipeline. Data were included with ≥ 12 h/day wear time on ≥ 3 days. Stepwise hierarchical linear mixed modelling examined associations between DMOs and sociodemographic correlates, environmental conditions, health status (Body Mass Index), locomotor capacity (Timed Up Go [TUG]), fall-related concerns (Short FES-I) and cognitive processing speed (Symbol Search Score). The final sample of 569 participants with a mean age of 75.0 ± 5.6 years (52

Perturbation-based balance training (PBT) specifically targets fall mechanisms and holds promise for fall prevention in older adults, but its reliance on near-fall exposure may pose a barrier to engagement. Successful implementation depends on acceptability among participants and trainers, yet a mixed-methods, multi-perspective evaluation of PBT acceptability is lacking. To evaluate the acceptability of treadmill PBT in older adults at risk of falling and in trainers, and to examine associations with participant characteristics. Twenty-nine participants (79.9 ± 5.5 years) completed a 6-week treadmill PBT intervention, delivered by three trainers. Retrospective acceptability was assessed using a questionnaire (maximum score: 35 pt. for participants, 30 pt. for trainers) and semi-structured focus groups (12 participants, all trainers), guided by Theoretical Framework of Acceptability (TFA) domains and additional context-specific topics. Associations between participant characteristics and questionnaire scores were analyzed using multivariate regression. Focus-group data were analyzed deductively using the TFA. Median questionnaire scores were high for participants (28 [interquartile range, IQR 23–32] pt.) and trainers (26 [IQR 25–26] pt.). Fall history emerged as the only independent predictor of lower acceptability among participants. Focus groups revealed that both participants and trainers generally perceived PBT as acceptable. High perceived safety and effectiveness for improving reactive balance, adequate tailoring and supervision, and strong coherence were reported as facilitators. Potential barriers included anxiety, fall-related memories, the demanding nature of PBT, and setting-related factors (e.g., monotony, limited social interaction, missing handrails, narrow belt). Treadmill PBT were generally well accepted by trainers and older adults at risk of falling but showed lower acceptability among participants with fall history. Implementing PBT in individuals with no fall history may help mitigate anxiety related to prior fall experiences and support higher acceptability. DRKS00030805 (December 14, 2022).

Abstract Digital mobility outcomes (DMOs) offer unique insights into recovery of real-world mobility after proximal femoral fracture (PFF), but their clinical validity remains to be established. This study assessed construct validity (convergent, divergent, and known-groups) of 24 DMOs measuring walking activity (amount, pattern) and gait (pace, rhythm, bout-to-bout variability) in patients within one year after PFF. Patients were recruited from inpatient and outpatient lists at five European sites, resulting in 505 included participants (66% female), with mean age of 77.6 ± 9.4 years and supervised gait speed of 0.7 ± 0.4 m/s. Mobility was monitored over seven days using a single wearable device on the lower back. Convergent and divergent validity analyses were stratified by two groups: acute (≤ 14 days since surgery) and non-acute (≥ 15 days since surgery). Correlations between DMOs and related (clinical- and patient-reported mobility outcomes) and unrelated constructs (hearing impairment and systolic blood pressure) were compared to a priori expected correlations. Known-groups validity was assessed across four recovery phases. The results were evaluated individually by experts and in a subsequent consensus meeting, with 17 of 24 DMOs showing evidence of construct validity in non-acute PFF patients. These findings represent an initial step in a larger process towards regulatory endorsement.

Background: Although the ability to walk longer distances is critical to regaining independence after hip fracture surgery, capacity for walking distance is typically measured in clinical settings and it remains unclear what distances people cover in their daily lives. Wearable devices can measure daily-life walking behaviour, but methods to quantify real-world walking distance remain limited and clinical validation is required. This study assessed the construct and longitudinal validity of real-world walking distance metrics derived from both single walking bouts (WBs) and a novel method for clustering WBs, using a single wearable device during recovery after hip fracture surgery. Methods: This multicentre prospective cohort study recruited patients from inpatient and outpatient lists, with real-world mobility and clinical- and patient-reported outcomes collected at first visit, 6- and 12 months follow-up. A total of 8 digital mobility outcomes (DMOs) descriptive of the walking distance were computed for both Single WBs > 30s and Clustered WBs (Distance DMOs: Mean, SD, Median and 95th percentile/P95) and were examined for construct (convergent, divergent, known-groups) validity. In addition, the two P95 DMOs were examined for longitudinal validity (ability to detect change and predicted trajectories). Analyses were performed comparing Spearman correlations and effect sizes with a priori expectations, and using linear mixed-effects models. Results: The total sample (N = 505) had a median age of 79 years (P25-P75: 72–84), with 66% women, and a 6-minute walk test (6MinWT) distance of 284 ± 126 m. Seven out of eight Distance DMOs demonstrated evidence for construct validity, showing expected weak-to-strong correlations with related constructs, and distinguishing between four hip fracture recovery phase groups. The two P95 Distance DMOs showed longitudinal validity, including ability to detect change, comparable to the 6MinWT distance. Conclusion: Real-world Walking Period Distance DMOs, derived from single WBs > 30s and a novel WB clustering approach, demonstrated evidence of construct and longitudinal validity in patients after hip fracture. The upper-range Distance DMOs showed correlations, effect sizes, and longitudinal trajectories comparable to 6MinWT distance, with the Cluster Distance consistent with patient-reported unchanged or improved walking ability. These findings support the clinical relevance of upper-range Distance DMOs for characterising real-world walking performance in hip fracture rehabilitation.

Falls are a major health concern for older adults, and wearable sensors have been widely explored for detecting falls and enabling timely intervention. However, real-world falls are extremely rare: collecting 100 of them requires an estimated 100,000 days of monitoring, resulting in severely limited labelled data for training machine learning models. Consequently, many approaches rely on simulated datasets, often reporting high laboratory performance but limited real-world generalisation. We present a systematic evaluation of motion representations for wearable fall detection under real-world data scarcity. Using accelerometer signals, we compare interval-based, kernel-based, symbolic, and foundation model representations. As an interpretable baseline, we additionally investigate a lightweight symbolic representation that converts short motion segments into symbolic sentences augmented with physically-grounded impact descriptors. Experiments use FallAllD, a simulated falls dataset, and FARSEEING, a clinically verified real-world falls dataset. Through cross-validation, controlled data scarcity, and cross-dataset transfer, we examine how representation choices affect robustness under realistic deployment. Our results reveal that highly parameterised kernel and foundation models excel on simulated data but degrade severely under both data scarcity and domain shift. Although the interval-based representation achieves the strongest absolute real-world performance, augmenting a symbolic representation with physically-grounded impact descriptors yields the smallest degradation under domain shift and retains detection sensitivity under extreme scarcity, albeit at lower precision. These findings highlight the importance of evaluating beyond simulated benchmarks and show that representation choice is critical for deployable fall detection given the scarcity of real-world data.

Physical activity (PA) is measured objectively through daily wearable monitoring and mobility capacity tests, and subjectively via patient reported outcomes (mobility perception). This study investigated longitudinal changes in, and relationships between, different measures of PA among older adults recovering from proximal femoral fracture (PFF). Participants (N=201) were classified into four groups by time since surgery at baseline (T1) and followed over two assessments (T2, T3). They wore an accelerometer for 7 consecutive days. Daily PA was measured using cut-point free metrics including Average Acceleration, Intensity Gradient, and intensity of the most active accumulated X minutes (MX: M1-M90). Mobility capacity and perception of participants were evaluated using clinical tests (e.g., 6-minute Walking Test (6MinWT)) and questionnaires (Late-Life Function and Disability Instrument (LLFDI)). MX metrics, particularly M1-M15, increased significantly across the first three groups with higher sensitivity in group 1 (p<0.001). Distance covered during the 6MinWT increased significantly (p<0.01). Three of the seven LLFDI s domains showed the largest significant changes. Overall, sustained, moderate-strong positive correlations were observed between the clinical tests, LLFDI, and short-duration MX metrics in group 3 and 4 at T1, and across all participants at T2 and T3. Thus, MX metrics (M1-M15) can reveal change for daily PA intensities, especially among PFF groups in early recovery groups at T1 and reached the late stage at follow-ups. Clinicians may focus on specific LLFDI s domains to maximize assessment efficiency. The direct links between mobility capacity, perceived mobility, and short-duration MX metrics indicate the potential of these metrics to monitor patients remotely.

Background Older adults' walking has so far been evaluated using standardised assessments of walking capacity within a clinical setting. By taking the evaluation out of the laboratory into the real world, this study provides first evidence of the ability of Digital Mobility Outcomes (DMOs) to detect changes over time and the Minimal Important Difference (MID) in patients after proximal femoral fracture (PFF). This will guide the implementation of DMOs in research and clinical care. Methods For this multicenter prospective cohort study, 381 community-dwelling older adults were included within one year after sustaining a PFF and assessed at two time points, separated by six months. Walking activity and gait DMOs were measured using a single wearable device worn on the lower back for up to seven days. A global impression of change question and three mobility-related outcome measures (Late-Life Function and Disability Instrument; Short Physical Performance Battery; 4m gait speed) were used as anchor variables. To assess each DMOs ability to detect changes, we calculated the standardized mean change as effect size. For estimating MIDs, both distribution-based and anchor-based methods were applied, followed by triangulation by experts if at least three anchor-based estimates were available per DMO, resulting in single-point estimates. Results All three anchor variables demonstrated substantial changes. Overall, 10 out of 24 available DMOs showed large and 7 DMOs moderate positive effects in the expected direction of the respective anchors. Seven DMOs showed no or only small effects. For 12 DMOs, at least three anchor-based estimates were available, enabling MID triangulation. MIDs for walking activity DMOs per day were: a walking duration of 10 minutes, a step count of 1,000 steps, 50 walking bouts (WB), and 15 WBs in WBs over 10 seconds. For gait DMOs, depending on the walking bout length, MIDs for walking speed were between 0.04 m/s and 0.08 m/s, and MIDs for cadence between 4 and 6 steps/minute. Almost all DMOs showed a strong ability to detect improvement in mobility, but rarely in detecting decline. Conclusions For the first time, MIDs are presented for real-world DMOs in PFF patients. These MIDs inform sample size requirements and interpretation of intervention effects for clinical trials, thereby providing guidance and reassurance for clinicians and regulatory bodies. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by the Mobilise-D project that has received funding from the Innovative Medicines Initiative (IMI) 2 Joint Undertaking (JU) under grant agreement number 820820. This JU receives support from the European Union's Horizon 2020 research and innovation programme and the European Federation of Pharmaceutical Industries and Associations (EFPIA). The content of the current publication reflects the authors' view, and neither IMI nor the European Union, EFPIA or any Associated Partners are responsible for any use that may be made of the information contained herein. SDD and LR were supported by the National Institute for Health and Care Research (NIHR) Newcastle Biomedical Research Centre based at The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle University and the Cumbria, Northumberland and Tyne and Wear (CNTW) NHS Foundation Trust. The research was also supported by NIHR Newcastle Clinical Research Facility (CRF) Infrastructure funding. SDD and LR were also supported by the Innovative Medicines Initiative 2 Joint Undertaking (IMI2 JU) project IDEA-FAST - Grant Agreement 853981. SDD and LR were supported by the UK Research and Innovation (UKRI) Engineering and Physical Sciences Research Council (EPSRC) (Grant Ref: EP/X031012/1 and Grant Ref: EP/X036146/1). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study obtained ethical approval from all relevant Ethical Committees (EC of the Medical Faculty of Eberhard-Karls-University Tuebingen [Stuttgart; vote 976/2020BO2], Regional Committee for Medical and Health Professional Research Ethics [Trondheim; vote 216069], Committee of the Protection of Persons, South-Mediterranean II [Montpellier; vote 221 B08]) and was registered at the ISRCTN registry on 12/10/2020 (ISRCTN Number: 12051706). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data presented in this paper will be made available under a CC4.0 license in June 2026. Upon release, it can be accessed at: https://zenodo.org/communities/mobilise-d/

BACKGROUND:Mobility, defined as movement in all its forms, is a hallmark of healthy ageing. As wearable technologies become increasingly integrated into population health surveillance and ageing research, the absence of standardised terminology, measurement protocols and reporting practices presents a major barrier to progress. This consensus exercise aimed to establish minimum standards for measuring mobility with wearable technology in ageing populations and set priorities for future research in the field. METHODS:A two-day, in-person consensus meeting was convened with 24 international experts in ageing, mobility and digital health. Using a modified nominal group technique facilitated by a trained moderator, participants engaged in structured small-group brainstorming, followed by iterative large-group discussions. Consensus was achieved through anonymised digital voting on proposed measures, principles and priorities. FINDINGS:Consensus (≥80% agreement) was reached on 20 core device-derived mobility measures and 30 guiding principles for the optimal use of wearable technology in older populations. Experts also identified and ranked 16 priority areas for future research, with the top five including: (i) longitudinal studies and data collection, (ii) digital biomarkers and health outcomes, (iii) contextual data capture, (iv) algorithm development and validation and (v) integration with healthcare systems. INTERPRETATIONS:These consensus-based standards provide a foundational framework for the consistent and transparent use of wearable devices in ageing research and practice. They can inform the development of regulations and guidelines, support harmonisation across studies and chart a path for future research to enhance the utility and impact of wearable technologies in ageing populations.

Multiple sclerosis (MS) is a common cause of disability in working age adults. Current clinical assessments are inadequate at disability assessment or predicting clinically relevant outcomes. Loss of mobility is an important functional disability to people with MS. Mobilise-D aims to develop, validate, and implement a digital mobility solution which measures unsupervised mobility performance across several chronic conditions, including MS, using a single wearable device. Six hundred two adults with MS, an Expanded Disability Status Scale (EDSS) score of 3.0–6.5, documented disability worsening over the previous 2 years and a 30-day freedom from relapses, were recruited across four European centres. Of 1416 invited, 602 participants (42

To describe digital mobility outcomes in a sample of home-dwelling participants with a hip fracture at different phases of recovery (within 1 year from surgery) Overall, 90

This study examined the association between the availability of an orthogeriatric co-management and secondary fractures in 97,976 hip fracture patients. We found that the presence of orthogeriatric co-management was associated with a small but sustainable reduction in secondary fragility fractures in patients with an initial hip fracture. The risk of experiencing a subsequent fracture is particularly high immediately following an initial fragility fracture. Geriatricians are increasingly involved in the management of fragility fractures. However, there is currently no evidence indicating whether this orthogeriatric co-management (OGCM) can reduce the incidence of secondary fracture. This study aimed to analyse the association between OGCM and the occurrence of secondary fragility fractures in patients with an initial hip fracture. Nationwide health insurance data from Germany were used to identify hip fracture patients aged ≥ 80 years. According to the presence of an OGCM, hospitals were categorised into those with OGCM and those without OGCM. Outcomes were secondary fragility fractures (i.e. humerus, forearm, hip, pelvis, spine) within different time periods after an initial hip fracture. Crude incidences and hazard rate ratios for a secondary fragility fracture were calculated. The dataset included 97,976 hip fracture patients aged 80 and older from 716 hospitals (71

Abstract Background Digital interventions for older adults may significantly extend preventive action to postpone disability and preserve health-related quality of life. However, more evidence is needed from multi-domain interventions using broad-scale objective and self-report assessments and intra-individual change data-analytical techniques. Method SMART-AGE examines the effect of an app-based multilevel treatment designed to enhance social participation, physical fitness, and health awareness. The target population comprises healthy and community-dwelling adults 67 years and older with basic digital skills in two socially diverse communities. Treatment relies on an Android-based tablet computer, on which three apps offering interventions in the core areas of social participation, physical fitness, and health awareness are pre-installed. A feedback app designed to provide participants with a feedback option at any time is also offered. Participants are randomly assigned to three intervention arms and assessed at baseline and after 3 and 6 months. Arm 1 receives the full intervention, consisting of the social participation app, the physical fitness app, the health awareness app, and the feedback app. The health awareness app is available in months 4 to 6, meaning that participants receive the full three-app intervention only in the second half of the intervention period. Arm 2 receives the social participation app and the feedback app throughout the intervention. Arm 3 serves as an active control condition in that a stand-alone tablet with a low-dose introduction to publicly available standard apps is provided. The data protocol includes assessment of three primary outcome domains: social support and loneliness, motor capacity and physical performance, and health awareness and health locus of control. Potential moderators (e.g., cognitive function, depression) as well as various technology-oriented constructs (e.g., skills, acceptance) are also assessed. App use data are automatically collected across the full intervention interval in arms 1 and 2. Data management is conducted within a cloud-based REDCap architecture. Feedback recordings via the feedback app are collected in arms 1 and 2 and undergo qualitative analysis. Discussion The SMART-AGE intervention aims to enhance core domains of health-related quality of life in community-dwelling older adults through an app-based multi-domain intervention and a user-centered approach. Trial registration German-Clinical-Trials-Register, DRKS00034316. Registered 29-May-2024, https://drks.de/search/en/trial/DRKS00034316 . The study’s design and hypotheses were also pre-registered in the Open Science Framework (OSF) prior to study enrollment ( https://doi.org/10.17605/OSF.IO/YQEBW , 2023–04-28).

Background:Recent advances in wearable technologies make it possible to accurately quantify real-world mobility performance through technically validated digital mobility outcomes (DMOs). The aim of the present study was to evaluate the construct validity (convergent, divergent, and known-groups validity) of 24 DMOs quantifying walking activity (amount and pattern) and gait (pace, rhythm and bout-to-bout variability) in people with COPD. Methods:Part of the Mobilise-D observational cohort study, people with COPD, recruited from seven European sites, wore an activity monitor for 7 days during daily life. Functional capacity, health status, dyspnoea, lung function, quadriceps torque and experience of difficulty with physical activity were used as constructs for convergent validity testing (Pearson/Spearman correlation coefficients). Diastolic blood pressure was used as an unrelated construct for divergent validity (criterion: |r|<0.2). Known-groups validity was evaluated across Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages (I-IV), GOLD ABE and modified Medical Research Council dyspnoea grades (linear models with p-for-trend). Results:549 participants (37% females), had mean±sd age of 68±8 years, post-bronchodilator forced expiratory volume in 1 s (FEV1) 54±20% predicted and 6-min walk distance 416±119 m. Convergent validity was supported for the majority of DMOs (17 out of 24) with correlation coefficients meeting or exceeding the a priori hypotheses by clinical experts. All DMOs supported divergent validity. 22 out of 24 DMOs distinguished between disease severity groups successfully. Expert consensus supported construct validity of 17 DMOs. Conclusions:Construct validity was supported for all walking activity (amount and pattern) DMOs, and most of the gait (pace, rhythm, and bout-to-bout variability) DMOs, indicating the clinical utility of these measures.

Total hip arthroplasty (THA) effectively alleviates pain and improves physical function. However, an increase in patients’ physical activity (PA) is often not observed after surgery. This paradox may result from short rehabilitation periods and persistent sedentary habits and be further influenced by methodological limitations of previous PA monitoring approaches. Digital home-based exercise programs and personal caching (PC) using behavioral change techniques for PA promotion, together with recent advances in PA monitoring, may offer new opportunities to address these challenges. The aim of the iPATH study is to evaluate the efficacy of two novel post-rehabilitation interventions, consisting of a digital home-based physical exercise program with or without PC, compared with usual care, for increasing PA in older adults following THA using advanced PA monitoring approaches. In this monocentric, three-arm randomized controlled trial, 213 older THA patients (≥ 65 years) will be assigned in a 1:1:1 ratio post-rehabilitation to a 12-week digital home-based exercise program (“Keep On Keep Up”) with or without additional PC for PA promotion, or usual care. The primary outcome is the mean daily step count at six months post-THA; mean daily walking distance serves as a subordinated primary outcome. Both outcomes will be collected preoperatively, post-rehabilitation, and at six months postoperatively using a body-fixed inertial measurement unit (AX6, Axivity Ltd.) combined with newly validated processing algorithms (Mobilise-D computational pipeline). Secondary outcomes include other digital and self-reported mobility outcomes, physical capacity, hip pain and function, psychological factors, falls, intervention acceptability, and health-related resource use. Primary analyses will follow the intention-to-treat principle. The digital home-based interventions are expected to increase PA compared with usual care. If effective, they have the potential to enhance patient health, reduce morbidity and mortality risk, and be implemented as routine post-rehabilitation care for older adults recovering from THA. ClinicalTrials.gov (NCT07135843); prospectively registered on August 22, 2025.

Abstract Age-related declines in muscle strength and neuromuscular control make sit-to-stand transitions and walking progressively more difficult, compromising mobility and independence. Although wearable assistive technologies have been proposed to alleviate these challenges, few have demonstrated clear benefits in facilitating sit-to-stand movements for older adults who retain a degree of independent mobility. Here, we introduce a soft hip exosuit designed to assist both sit-to-stand transitions and walking activities. In a feasibility study involving ten older adults, the exosuit increased 1-minute sit-to-stand repetitions by an average of 1.8 and reduced the metabolic cost of walking by 13.6% compared with the unassisted condition. These improvements were achieved while preserving natural kinematics, lower-limb stability, and maintaining a strong sense of agency. Our findings demonstrate that soft exosuits can enhance sit-to-stand and walking performance in older adults while preserving biomechanical naturalness and user autonomy, highlighting their potential for practical home-integrated mobility assistance.