Measurement properties of instruments to measure lower limb functional ability and balance after technology-assisted physical activity interventions in community-dwelling older adults: an umbrella review of systematic reviews and meta-analyses

With the growing evidence of technology-assisted interventions, psychometrically robust instruments are essential for evaluating their outcomes and providing evidence-based clinical decisions. This umbrella review aimed to determine lower-limb functional ability and balance instruments used in technology-assisted physical activity interventions for community-dwelling older adults and evaluate their measurement properties to guide clinical practice. In this two-step umbrella review, PubMed and Web of Knowledge were systematically screened for systematic reviews (SRs) and meta-analyses of studies using technology-assisted physical activity interventions in community-dwelling older adults to (i) identify instruments assessing lower-limb functional ability and balance and (ii) conduct a systematic search of SRs and meta-analyses on measurement properties for instruments identified in step 1. Methodological quality was assessed using a Measurement Tool to Assess systematic Reviews (AMSTAR-2), and measurement properties were synthesized using Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) guidelines. Review protocol was registered on PROSPERO (CRD42023414672). A total of 33 studies were included in step 1, reporting a total of 30 instruments. In step 2, 37 studies met the eligibility criteria on measurement properties of 38 different measurement instruments, including short versions and adaptations of similar instruments with the Timed Up and Go (TUG) and Berg Balance Scale (BBS) being the most frequently utilized. While most instruments were rated as having adequate reliability, adequate validity was limited to specific tools: criterion (Fullerton Advanced Balance Scale-FAB and Romberg), discriminative (POMA, Functional Reach Test, and Mini-BESTest), or predictive (TUG fast, Gait Velocity fast, and Four-Square Test). No single measurement instrument was assessed or rated adequate for all measurement properties. Furthermore, measurement error and responsiveness were rarely reported, when these are critical aspects for evaluating intervention impact over time. While traditional tests such as TUG and BBS remain common choices, clinicians and researchers should prioritize the Mini-BESTest and gait speed due to their superior psychometrics, particularly in validity. Future research should prioritize establishing validity and responsiveness for optimal assessment.