Validating the Sedentary Sphere method in children: Does wrist or accelerometer brand matter? |
| |
| Authors: | Liezel Hurter Alex V Rowlands Stuart J Fairclough Karl C Gibbon Zoe R Knowles Lorna A Porcellato |
| |
| Institution: | 1. Physical Activity Exchange, Research Institute of Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK;2. Diabetes Research Centre, University of Leicester, Leicester General Hospital, Leicester, UK;3. NIHR Leicester Biomedical Research Centre, Leicester General Hospital, Leicester, UK;4. Division of Health Sciences, Alliance for Research in Exercise, Nutrition and Activity (ARENA), Sansom Institute for Health Research, University of South Australia, Adelaide, Australia;5. Department of Sport and Physical Activity, Edge Hill University, Ormskirk, UK;6. Public Health Institute, Faculty of Education, Health and Community, Liverpool John Moores University, Liverpool, UK |
| |
| Abstract: | This study aimed to validate the Sedentary Sphere posture classification method from wrist-worn accelerometers in children. Twenty-seven 9–10-year-old children wore ActiGraph GT9X (AG) and GENEActiv (GA) accelerometers on both wrists, and activPAL on the thigh while completing prescribed activities: five sedentary activities, standing with a phone, walking (criterion for all 7: observation) and 10-min free-living play (criterion: activPAL). In an independent sample, 21 children wore AG and GA accelerometers on the non-dominant wrist and activPAL for two days of free-living. Per cent accuracy, pairwise 95% equivalence tests (±10% equivalence zone) and intra-class correlation coefficients (ICC) analyses were completed. Accuracy was similar, for prescribed activities irrespective of brand (non-dominant wrist: 77–78%; dominant wrist: 79%). Posture estimates were equivalent between wrists within brand (±6%, ICC > 0.81, lower 95% CI ≥ 0.75), between brands worn on the same wrist (±5%, ICC ≥ 0.84, lower 95% CI ≥ 0.80) and between brands worn on opposing wrists (±6%, ICC ≥ 0.78, lower 95% CI ≥ 0.72). Agreement with activPAL during free-living was 77%, but sedentary time was underestimated by 7% (GA) and 10% (AG). The Sedentary Sphere can be used to classify posture from wrist-worn AG and GA accelerometers for group-level estimates in children, but future work is needed to improve the algorithm for better individual-level results. |
| |
| Keywords: | Wearable technology activity classification sedentary behaviour |
|
|
