Calibration of the biotrainer pro activity monitor in children

Welk, Gregory J., Eisenmann, Joey D., Schaben, Jodee, Trost, Stewart G., & Dale, Darren (2007) Calibration of the biotrainer pro activity monitor in children. Pediatric Exercise Science, 19(2), pp. 145-158.

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The unique physical and movement characteristics of children necessitate the development of accelerometer equations and cut points that are population specific. The purpose of this study is to develop an ecologically valid cut point for the Biotrainer Pro monitor that reflects a threshold for moderate-intensity physical activity in elementary school children. A sample of 30 children (ages 8-12) wore a Biotrainer monitor while completing a series of 7 movement tasks (calibration phase) and while participating in an organized group activity (cross-validation phase). Videotapes from each session were processed using a computerized direct-observation technique to provide a criterion measure of physical activity. Analyses involved the use of mixed-model regression and receiver operator characteristic (ROC) curves. The results indicated that a cut point of 4 counts/min provides the optimal balance between the related needs for sensitivity (accurately detecting activity) and specificity (limiting misclassification of activity as inactivity). Results with the cross-validation data demonstrated that this value yielded the best overall kappa (.58) and a high classification agreement (84%) for activity determination. The specificity of 93% demonstrates that the proposed cut point can accurately detect activity; however, the lower sensitivity value of 61% suggests that some minutes of activity might be incorrectly classified as inactivity. The cut point of 4 counts/min provides an ecologically valid cut point to capture physical activity in children using the Biotrainer Pro activity monitor.

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ID Code: 72073
Item Type: Journal Article
Refereed: Yes
Additional Information: ISI Document Delivery No.: 173FX
Times Cited: 0
Cited Reference Count: 31
Trost, Stewart G. Dale, Darren
Human kinetics publ inc
Champaign;<Go to ISI>://WOS:000246860000004
Keywords: energy-expenditure, physical-activity, adolescent girls, heart-rate, accelerometry, validity, principles, prediction, validation, pedometry
ISSN: 0899-8493
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Deposited On: 23 May 2014 01:23
Last Modified: 21 Jun 2017 12:01

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