Objectively measured physical activity and sedentary behaviour in young children

Kelly, Louise A. (2005) Objectively measured physical activity and sedentary behaviour in young children. PhD thesis, University of Glasgow.

Abstract

Study 1: Aims: Compare the uniaxial MTI/CSA accelerometer and the biaxial Actiwatch accelerometer against direct observation of total physical activity and minute-by-minute physical activity in 3-4 year olds. Methods: MTI/CSA-7164 and Actiwatch accelerometers simultaneously measured activity during 35-45 minute sessions of structured play in 78, 3-4 year olds. Rank order correlations between accelerometry and direct observation were used to assess the ability of the accelerometers to assess total activity. Within-child minute-by-minute correlations were calculated between accelerometry output and direct observation. Results: For assessment of total activity MTI/CSA output was significantly positively correlated with direct observation (r 0.72, p<0.001), Actiwatch was not (r 0.16, p>0.05). Conclusion: The present study suggests that for epidemiological assessment of total physical activity in young children the MTI/CSA-7164 provides greater accuracy than the Actiwatch.

Study 2: Aim: To cross-validate the 1100 counts/ minute cut-off for the assessment of sedentary behaviour in an independent sample of young children using the MTI/CSA accelerometer. Methods: A previously developed cut-off for MTI-CSA accelerometry output (validation study) in 30 healthy Scottish 3-4 year olds, was cross-validated against direct observation in an independent sample of (n = 52) healthy Scottish 3-4 year olds.

Results: In the cross-validation study sensitivity was 83%: 438/528 inactive minutes were correctly classified. Specificity was 82%: 1251/1526 non-inactive minutes were correctly classified using this cut-off. Conclusion: Sedentary behaviour can be quantified objectively in young children using accelerometry.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: R Medicine > R Medicine (General); R Medicine > RJ Pediatrics > RJ101 Child Health. Child health services
• Colleges/Schools: College of Medical Veterinary and Life Sciences
• Supervisor's Name: Reilly, Dr. John
• Date of Award: 2005
• Depositing User: Mr Toby Hanning
• Unique ID: glathesis:2005-1521
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 15 Feb 2010
• Last Modified: 10 Dec 2012 13:41
• URI: https://theses.gla.ac.uk/id/eprint/1521