Measuring reliability and validity of the ActiGraph GT3X accelerometer for children with cerebral palsy : a feasibility study

O'Neil, Margaret E., Fragala-Pinkham, Maria A., Forman, Jeffrey L., & Trost, Stewart G. (2014) Measuring reliability and validity of the ActiGraph GT3X accelerometer for children with cerebral palsy : a feasibility study. Journal of Pediatric Rehabilitation Medicine, 7(3), pp. 233-240.

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The purposes of this study were to:

1) establish inter-instrument reliability between left and right hip accelerometer placement;

2) examine procedural reliability of a walking protocol used to measure physical activity (PA), and;

3) confirm concurrent validity of accelerometers in measuring PA intensity as compared to the gold standard of oxygen consumption measured by indirect calorimetry.


Eight children (mean age: 11.9; SD: 3.2, 75% male) with CP (GMFCS levels I-III) wore ActiGraph GT3X accelerometers on each hip and the Cosmed K4b<formula>^{2}</formula> portable indirect calorimeter during two measurement sessions in which they performed the six minute walk test (6MWT) at three self-selected speeds (comfortable/slow, brisk, fast). Oxygen consumption (VO2) and accelerometer step and activity count data were recorded.


Inter-instrument reliability of ActiGraph GT3X accelerometers placed on left and right hips was excellent (ICC=0.96-0.99, CI<formula>_{95}</formula>: 0.81-0.99). Reproducibility of the protocol was good/excellent (ICC=0.75-0.95, CI<formula>_{95}</formula>: 0.75-0.98). Concurrent validity of accelerometer count data and VO2 was fair/good (rho=0.67, p< 0.001). The correlation between step count and VO2 was not significant (rho=0.29, p=0.2).


This preliminary research suggests that ActiGraph GT3X accelerometers are reliable and valid devices to monitor PA during walking in children with CP and may be appropriate in rehabilitation research and clinical practice. ActiGraph GTX3 step counts were not valid for this sample and further research is warranted.

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ID Code: 78786
Item Type: Journal Article
Refereed: Yes
DOI: 10.3233/PRM-140292
ISSN: 1875-8894
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > HUMAN MOVEMENT AND SPORTS SCIENCE (110600)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Current > Schools > School of Exercise & Nutrition Sciences
Copyright Owner: Copyright 2014 IOS Press
Deposited On: 19 Nov 2014 23:20
Last Modified: 20 Nov 2014 22:50

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