Associations between device-measured physical activity and performance-based physical function outcomes in adults: a systematic review and meta-analysis

This systematic review and meta-analysis aimed to examine the association between device-measured physical activity (PA) and performance-based measures of physical function (PF). Databases searched included CINAHL, Embase, MEDLINE/PubMed, SPORTDiscus, and Web of Science (last search conducted on November 11, 2022). Observational studies (cross-sectional or prospective) reporting associations between wearable device-measured PA and PF outcomes in non-clinical adults were eligible. Forty-two studies with a pooled sample of 27 276 participants were eligible, with 34 studies reporting a standardised regression coefficient (β) between at least one of four PA measures and one of six PF outcomes. All measures of PA were positively associated with all measures of PF, except for step count with grip strength. Largest associations were seen with lower-body PF tests; gait speed (βs=0.11–0.26), walk tests (βs=0.18–0.41), chair-rise test (βs=0.10–0.26), balance (βs=0.07–0.24) and Timed Up-and-Go (βs=0.10–0.24) all p<0.01. Small or no association was seen with grip strength (βs=0.02–0.07). In observational studies of general adult populations, there were associations between multiple dimensions of PA and a broad range of PF measures. The findings provide provisional support for the use of device measures of movement to remotely monitor people for risk of low PF. Prospective designs are needed to determine the direction of the relationship. Future studies should also explore a broader range of PA metrics beyond simple aggregate measures of time spent at different acceleration values as there is evidence that the temporal distribution of activity is related to health and functional outcomes.