Research Database

192 results for "Validation"

Comparison of Polar Active Watch and Waist- and Wrist-Worn ActiGraph Accelerometers for Measuring Children’s Physical Activity Levels during Unstructured Afterschool Programs

  • Published on Sep 4, 2018

Background: The purpose of this study was to examine the convergent validity of the Polar Active Watch (PAW), a consumer-grade wrist-worn activity monitor, against waist- and wrist-worn research-grade monitors, the ActiGraph GT3X+/GT9X accelerometers, in children. Methods: Fifty-one children (18 boys; mean age = 10.30 ± 0.91 years) wore the three monitors (PAW, ...


Comparison of Two Generations of ActiGraph Accelerometers: The CARDIA Study

  • Published on Jun 2018

Purpose: This study aimed to examine the comparability of the ActiGraph 7164 and wGT3X-BT wear time, count-based estimates, and average time per day in physical activity of different intensities. Methods: We studied 87 Coronary Artery Risk Development in Young Adults (CARDIA) participants 48-60 yr of age who simultaneously wore the 7164 and ...


Reproducibility of objectively measured physical activity and sedentary time over two seasons in children; Comparing a day-by-day and a week-by-week approach

  • Published on Dec 7, 2017

Introduction: Knowledge of reproducibility of accelerometer-determined physical activity (PA) and sedentary time (SED) estimates are a prerequisite to conduct high-quality epidemiological studies. Yet, estimates of reproducibility might differ depending on the approach used to analyze the data. The aim of the present study was to determine the reproducibility of objectively ...


Using Bluetooth proximity sensing to determine where office workers spend time at work

  • Published on Mar 7, 2018

Background: Most wearable devices that measure movement in workplaces cannot determine the context in which people spend time. This study examined the accuracy of Bluetooth sensing (10-second intervals) via the ActiGraph GT9X Link monitor to determine location in an office setting, using two simple, bespoke algorithms. Methods: For one ...


Estimating Energy Expenditure with ActiGraph GT9X Inertial Measurement Unit.

  • Published on May 2018

Purpose: The purpose of this study was to explore whether gyroscope and magnetometer data from the ActiGraph GT9X improved accelerometer-based predictions of energy expenditure (EE). Methods: Thirty participants (mean ± SD: age, 23.0 ± 2.3 yr; body mass index, 25.2 ± 3.9 kg·m) volunteered to complete the study. Participants wore five GT9X monitors (right ...



Physical activity quantified by questionnaire and accelerometry in schoolchildren. A comparison

  • Published on Feb 9, 2018

Introduction: Questionnaires have long been the tool of choice for the measurement of physical activity in large population groups, however, they depend on the accuracy with which they are answered. Accelerometers, on the other hand, can directly measure physical activity, eliminate subjectivity and, allow comparisons with instruments such as questionnaires. ...


Comparison of children’s free-living physical activity derived from wrist and hip raw accelerations during the segmented week

  • Published on Nov 2017

This study assessed children's physical activity (PA) levels derived from wrist-worn GENEActiv and hip-worn ActiGraph GT3X+ accelerometers and examined the comparability of PA levels between the two devices throughout the segmented week. One hundred and twenty-nine 9-10-year-old children (79 girls) wore a GENEActiv (GAwrist) and ActiGraph GT3X+ (AGhip) ...


The Impact of Low Accelerometer Wear Time on the Estimates and Application of Sedentary Behavior and Physical Activity Data in Adults

  • Published on Dec 1, 2017

Background: This investigation sought to determine how accelerometer wear (1) biased estimates of sedentary behavior (SB) and physical activity (PA), (2) affected misclassifications for meeting the Physical Activity Guidelines for Americans, and (3) impacted the results of regression models examining the association between moderate to vigorous physical activity (MVPA) and a clinically relevant ...


Validation of gait characteristics extracted from raw accelerometry during walking against measures of physical function, mobility, fatigability, and fitness

  • Published on Sep 16, 2017

Background: Data collected by wearable accelerometry devices can be used to identify periods of sustained harmonic walking. This report aims to establish whether the features of walking identified in the laboratory and free-living environments are associated with each other as well as measures of physical function, mobility, fatigability, and fitness. ...