The assessment of stationary and locomotion physical behavior using a single versus dual wearable accelerometer in children who use a manual wheelchair

AIMS: Wearable devices such as activity monitors can be used to gain insight into children's physical behavior. However, children who are unable to walk are often excluded from validation studies, and therefore, robust information about their physical behavior is lacking. Therefore, we studied the criterion validity of a wearable prototype activity monitor (AM-p) in children who use a manual wheelchair with and without the ability to walk. METHODS: We analyzed the data for both single-sensor (sensor placement on upper arm or ankle) and dual-sensor use. Therefore, we conducted a study with cross-sectional design, assessing 37 children (12 girls) aged 6-19 years (mean 12 years, SD 4.3). Children wore an AM-p on the ankle and upper arm and were filmed while performing an activity protocol in a natural setting. Videos were labeled per 5-second epoch with individual activity labels. Raw data were synchronized with labels. An algorithm was trained, and labels were subdivided into pre-defined activity categories. Overall accuracy and F1 score (harmonic mean of precision and recall) were calculated per activity. FINDINGS: We demonstrate that the single ankle-worn AM-p can determine "stationary" behavior with excellent accuracy (>90%) and "locomotion" behavior with moderate to good accuracy (77-80%). "Locomotion" behavior includes active wheelchair use of children, which can assist pediatric physical therapists (PPTs) to assess physical behavior correctly in children who use a manual wheelchair. Exploratory analyses indicate that "locomotion" behavior (dual-sensor use), can be divided into "leg activity" and "active wheelchair use" for children who use a manual wheelchair and have the ability to walk. CONCLUSIONS: The single ankle-worn AM-p can determine "stationary" behavior with excellent accuracy and "locomotion" behavior with moderate to good accuracy in children who use a manual wheelchair in daily living. Our findings can assist PPTs to assess physical behavior correctly and tailor individual treatment plans.