Step Detection and Activity Recognition Accuracy of Seven Physical Activity Monitors

Abstract

The aim of this study was to compare the seven following commercially available activity monitors in terms of step count detection accuracy: Movemonitor (Mc Roberts), Up (Jawbone), One (Fitbit), ActivPAL (PAL Technologies Ltd.), Nike+ Fuelband (Nike Inc.), Tractivity (Kineteks Corp.) and Sensewear Armband Mini (Bodymedia). Sixteen healthy adults consented to take part in the study. The experimental protocol included walking along an indoor straight walkway, descending and ascending 24 steps, free outdoor walking and free indoor walking. These tasks were repeated at three self-selected walking speeds. Angular velocity signals collected at both shanks using two wireless inertial measurement units (OPAL, ADPM Inc) were used as a reference for the step count, computed using previously validated algorithms. Step detection accuracy was assessed using the mean absolute percentage error computed for each sensor. The Movemonitor and the ActivPAL were also tested within a nine-minute activity recognition protocol, during which the participants performed a set of complex tasks. Posture classifications were obtained from the two monitors and expressed as a percentage of the total task duration.The Movemonitor, One, ActivPAL, Nike+ Fuelband and Sensewear Armband Mini underestimated the number of steps in all the observed walking speeds, whereas the Tractivity significantly overestimated step count. The Movemonitor was the best performing sensor, with an error lower than 2% at all speeds and the smallest error obtained in the outdoor walking. The activity recognition protocol showed that the Movemonitor performed best in the walking recognition, but had difficulty in discriminating between standing and sitting. Results of this study can be used to inform choice of a monitor for specific applications.

A Personalized Physical Activity Program With Activity Trackers and a Mobile Phone App for Patients With Metastatic Breast Cancer: Protocol for a Single-Arm Feasibility Trial (Preprint)

“…In exercise programs and research in cancer patients, physical activity trackers are increasingly being used to measure physical activity and promote physical activity behaviors [24][25][26]. These devices might motivate people to remain active and facilitate reaching a personal or recommended goal as a result of the feedback received in real time (e.g., steps) [27][28][29].…”

Validation of smartphone step count algorithm used in STARFISH smartphone application

“…Therefore, the aim of this study was to evaluate the validity of the STARFISH app to measure steps taken by comparing it with the step count data from an activPAL TM device. The activPAL TM is valid in measuring step counts in both free living and laboratory conditions and is regarded as one of the gold standard devices in step count monitoring [10][11][12]. In addition, as device placement may affect the accuracy of the accelerometer within the phone, we sought to compare the validity of the step counts from the accelerometer whilst on different positions on the body.…”

A Validation Study of the Fitbit One in Daily Life Using Different Time Intervals

“…Several studies examined the validity of different types of Fitbit activity trackers (7,20,22,24); however, as far as we are aware, only eight studies examined the validity of the Fitbit One. So far, five studies used a controlled laboratory setting to examine the validity of the Fitbit One with respect to steps taken (n = 4) and energy expenditure (n = 1) (3,16,21,22).…”

“…So far, five studies used a controlled laboratory setting to examine the validity of the Fitbit One with respect to steps taken (n = 4) and energy expenditure (n = 1) (3,16,21,22). Overall, in laboratory settings, studies reported acceptable percentages of relative errors (1.3%-10.5%) for number of steps taken with speeds of 0.7-1.78 mIs j1 on a treadmill (21)(22)(23). Moreover, the Fitbit underestimated the energy expenditure compared with indirect calorimetry.…”