Marco Giurgiu, Carina Nigg, Janis Fiedler, Irina Timm, Ellen Rulf, Johannes B.J. Bussmann, Claudio R. Nigg, Alexander Woll, and Ulrich W. Ebner-Priemer
Purpose: To raise attention to the quality of published validation protocols while comparing (in)consistencies and providing an overview on wearables, and whether they show promise or not. Methods: Searches from five electronic databases were included concerning the following eligibility criteria: (a) laboratory conditions with humans (<18 years), (b) device outcome must belong to one dimension of the 24-hr physical behavior construct (i.e., intensity, posture/activity type outcomes, biological state), (c) must include a criterion measure, and (d) published in a peer-reviewed English language journal between 1980 and 2021. Results: Out of 13,285 unique search results, 123 articles were included. In 86 studies, children <13 years were recruited, whereas in 26 studies adolescents (13–18 years) were recruited. Most studies (73.2%) validated an intensity outcome such as energy expenditure; only 20.3% and 13.8% of studies validated biological state or posture/activity type outcomes, respectively. We identified 14 wearables that had been used to validate outcomes from two or three different dimensions. Most (n = 72) of the identified 88 wearables were only validated once. Risk of bias assessment resulted in 7.3% of studies being classified as “low risk,” 28.5% as “some concerns,” and 71.5% as “high risk.” Conclusion: Overall, laboratory validation studies of wearables are characterized by low methodological quality, large variability in design, and a focus on intensity. No identified wearable provides valid results across all three dimensions of the 24-hr physical behavior construct. Future research should more strongly aim at biological state and posture/activity type outcomes, and strive for standardized protocols embedded in a validation framework.
Jeong Ah Kim, Sungwoo Park, Linda Fetters, Sandrah P. Eckel, Masayoshi Kubo, and Barbara Sargent
This study quantified the spatial exploration of 13 infants born very and extremely preterm (PT) at 4 months corrected age as they learned that moving their feet vertically to cross a virtual threshold activated an infant kick-activated mobile and compared results to 15 infants born full-term (FT) from a previously published study. Spatial exploration was quantified using two general spatial exploration variables (exploration volume and exploration path), two task-specific spatial variables (duration of time in the task-specific region of interest and vertical variance of kicks), and one non-task-specific spatial variable (horizontal variance of kicks). The infants born PT, similar to FT, increased their general spatial exploration and duration in the region of interest and did not change the vertical and horizontal variances of kicks. However, the infants born PT, compared to FT, spent less time in the task-specific region of interest and had a greater non-task-specific horizontal variance throughout the task. This may indicate that infants born PT and FT exhibit similar general spatial exploration, but infants born PT exhibit less task-specific spatial exploration. Future research is necessary to determine the contribution of learning and motor abilities to the differences in task-specific exploration between infants born PT and FT.