Spatio-temporal gait parameters derived from low-cost IMUs for frailty assessment in older adults: a cross-sectional study in Honduras

Resumen

Population aging represents an increasing challenge for healthcare systems and society as a whole. This phenomenon is particularly relevant in low- and middle-income countries, where access to objective and scalable tools for functional assessment remains limited or nonexistent. Frailty in older adults is commonly assessed through clinical physical performance tests such as the Short Physical Performance Battery (SPPB). However, these evaluations rely on observer-based scoring, which may limit the detection of subtle changes in functional performance. This study proposes the instrumentation of the SPPB using low-cost inertial measurement units (IMUs) to obtain objective gait and balance metrics. A cross-sectional observational study was conducted with 30 participants (mean age: 72.4 ± 6.8 years). Three portable IMUs were placed at the waist and both ankles during the execution of the SPPB subtests. Data processing included filtering, event-based segmentation, and parameter extraction. The analyzed metrics included gait speed, cadence, and balance variability, estimated through root mean square (RMS) acceleration along the anteroposterior and mediolateral axes. Additionally, a temporal slope index was incorporated, calculated from the difference between the duration of the last and first repetitions of the chair-stand test and normalized by the number of intervals. The median gait speed was 0.384 m/s (IQR: 0.164–0.495). Participants with poorer performance exhibited lower gait speed and higher cadence, suggesting compensatory strategies. These results demonstrate the feasibility of the proposed approach for extracting spatiotemporal gait parameters from low-cost IMUs as an objective support tool for frailty assessment in older adults.