Accuracy in Step Counting Is Not Accuracy in Quantifying Walking Activity: A Criterion Validity Study of Wearable Devices Under Free-Living Conditions.
PURPOSE To determine the criterion validity of research- and consumer-grade wearables (18 step-based methods) for quantifying step counts and step-derived walking metrics in free-living conditions. METHODS Sixty healthy adults (20-80 years, balanced by sex and decade) wore six monitors for seven days: StepWatch (ankl...