Emmah Baque1, Leanne Sakzewski, Stewart G Trost, Roslyn N Boyd, Lee Barber. 1. Queensland Cerebral Palsy and Rehabilitation Research Centre (Drs Baque, Sakzewski, Boyd, and Barber), Child Health Research Centre, Faculty of Medicine, The University of Queensland, Brisbane, Australia; Institute of Health and Biomedical Innovation at the Queensland Centre for Children's Health Research (Dr Trost), School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane, Australia.
Abstract
PURPOSE: To evaluate the validity of the ActiGraph accelerometer (AG) to differentiate between standardized, physical activity tasks using oxygen consumption ((Equation is included in full-text article.)O2) as the criterion measure in children and adolescents with an acquired brain injury; to determine vector magnitude activity intensity cut-points; to compare performance of cut-points to previously published cut-points. METHODS: Twenty-seven children performed standardized walking and stepping activities wearing a portable indirect calorimeter, AG, and heart rate monitor. Differences in (Equation is included in full-text article.)O2 and AG vector magnitude activity counts were measured during activities. Receiver operating characteristic curves were determined for intensity cut-points. RESULTS: (Equation is included in full-text article.)O2 and AG activity counts significantly increased as walking speed increased. Discrimination of the newly derived cut-points was excellent and demonstrated greater agreement compared with the previously published cut-points. CONCLUSION: Output from accelerometers can differentiate physical activity intensity in children with an acquired brain injury. Future studies can apply these cut-points to evaluate physical activity performance.
PURPOSE: To evaluate the validity of the ActiGraph accelerometer (AG) to differentiate between standardized, physical activity tasks using oxygen consumption ((Equation is included in full-text article.)O2) as the criterion measure in children and adolescents with an acquired brain injury; to determine vector magnitude activity intensity cut-points; to compare performance of cut-points to previously published cut-points. METHODS: Twenty-seven children performed standardized walking and stepping activities wearing a portable indirect calorimeter, AG, and heart rate monitor. Differences in (Equation is included in full-text article.)O2 and AG vector magnitude activity counts were measured during activities. Receiver operating characteristic curves were determined for intensity cut-points. RESULTS: (Equation is included in full-text article.)O2 and AG activity counts significantly increased as walking speed increased. Discrimination of the newly derived cut-points was excellent and demonstrated greater agreement compared with the previously published cut-points. CONCLUSION: Output from accelerometers can differentiate physical activity intensity in children with an acquired brain injury. Future studies can apply these cut-points to evaluate physical activity performance.