Comparability and feasibility of wrist-and hip-worn accelerometers in free-living adolescents

Objective: to determine the comparability and feasibility of wrist-and hip-worn accelerometers among free-living adolescents. Design: 89 adolescents (age = 13-14 years old) from eight secondary schools in New South Wales (NSW), Australia wore wrist-worn GENEActiv and hip-worn ActiGraph (GT3X+) accelerometers simultaneously for seven days and completed an accelerometry behavior questionnaire. Methods: Bivariate correlations between the wrist-and hip-worn out-put were used to determine concurrent validity. Paired samples t-test were used to compare minutes per day in moderate-to-vigorous physical activity (MVPA). Group means and paired sample t-tests were used to analyze participants' perceptions of the wrist-and hip-worn monitoring protocols to assist with determining the feasibility. Results: Wrist-worn accelerometry compared favorably with the hip-worn in average activity (r = 0.88, p<0.001) and MVPA (r = 0.84 p<0.001, mean difference = 3.54min/day, SD = 12.37). The wrist-worn accelerometer had 50% fewer non-valid days (75 days, 12%) than the hip-worn accelerometer (n = 152, 24.4%). Participants reported they liked to wear the device on the wrist (p<0.01), and that it was less uncomfortable (p = 0.02) and less embarrassing to wear on the wrist (p<0.01). Furthermore, that they would be more willing to wear the device again on the wrist over the hip (p < 0.01). Conclusions: Our findings reveal there is a strong linear relationship between wrist-and hip-worn accelerometer out-put among adolescents in free-living conditions. Adolescent compliance was significantly higher with wrist placement, with participants reporting that it was more comfortable and less embarrassing to wear on the wrist.(c) 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.