How Well iPhones Measure Steps in Free-Living Conditions: Cross-Sectional Validation Study.
Shiho AmagasaMasamitsu KamadaHiroyuki SasaiNoritoshi FukushimaHiroyuki KikuchiI-Min LeeShigeru InouePublished in: JMIR mHealth and uHealth (2019)
Smartphones may be of practical use to individuals, clinicians, and researchers for monitoring physical activity. However, their data on step counts should be interpreted cautiously because of the possibility of underestimation due to noncarrying time.