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Validity, practical utility, and reliability of the activPAL in preschool children

By G. Davies, J. Reilly, A. McGowan, P. Dall, M. Granat and J. Paton


<p>Purpose: With the increasing global prevalence of childhood obesity, it is important to have appropriate measurement tools for investigating factors (e.g. sedentary time) contributing to positive energy balance in early childhood. For pre-school children, single unit monitors such as the activPALTM are promising. However, validation is required as activity patterns differ from adults.</p>\ud <p>Methods: Thirty pre-school children participated in a validation study. Children were videoed for one hour undertaking usual nursery activity while wearing an activPALTM. Video (criterion method) was analyzed on a second-by-second basis to categorise posture and activity. This was compared with the corresponding activPALTM output. In a subsequent sub-study investigating practical utility and reliability, 20 children wore an activPALTM for seven consecutive 24-hour periods.</p>\ud <p>Results: A total of 97,750 seconds of direct observation from 30 children were categorized as sit/lie (46%), stand (35%), walk (16%); with 3% of time in nonsit/lie/upright postures (e.g. crawl/crouch/kneel-up). Sensitivity for the overall total time matched seconds detected as activPALTM ‘sit/lie’ was 86.7%, specificity 97.1%, and positive predictive value (PPV) 96.3%. For individual children, the median (interquartile range) sensitivity for activPALTM sit/lie was 92.8% (76.1-97.4), specificity 97.3% (94.9-99.2), PPV 97.0% (91.5-99.1). The activPALTM underestimated total time spent sitting (mean difference -4.4%, p<0.01), and overestimated time standing (mean difference 7.1%, p<0.01). There was no difference in overall % time categorised as ‘walk’ (p=0.2). The monitors were well tolerated by children during a seven day period of free-living activity. In the reliability study, at least five days of monitoring were required to obtain an intraclass correlation coefficient of ≥0.8 for time spent sit/lie according to activPALTM output.</p> \ud <p>Conclusion: The activPAL had acceptable validity, practical utility, and reliability for the measurement of posture and activity during freeliving activities in pre-school children.</p&gt

Publisher: Lippincott, Williams & Wilkins on behalf of American College of Sports Medicine
Year: 2012
OAI identifier:
Provided by: Enlighten

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  2. (1997). Ambulatory monitoring of children's activity. Med Eng Phys. doi
  3. (2004). Ambulatory system for the quantitative and qualitative analysis of gait and posture in chronic pain patients treated with spinal cord stimulation. Gait Posture. doi
  4. (2003). An objective method for measurement of sedentary behavior in 3- to 4-year olds. Obes Res. doi
  5. (1990). Body mass index reference curves for the UK, doi
  6. Childhood obesity, other cardiovascular risk factors, and premature death. doi
  7. (2004). Classification of basic daily movements using a triaxial accelerometer. Med Biol Eng Comput. doi
  8. Comparison of the performance of the activPAL Professional physical activity logger to a discrete accelerometer-based activity monitor. Med Eng Phys. doi
  9. (2005). Conducting accelerometer-based activity assessments in field-based research. Med Sci Sports Exerc. doi
  10. (1990). Cross sectional stature and weight reference curves for the UK, doi
  11. Design of posture and activity detector (PAD). doi
  12. Increased television viewing is associated with elevated body fatness but not with lower total energy expenditure in children. doi
  13. Interindividual variation in posture allocation: possible role in human obesity. doi
  14. Is body mass index before middle age related to coronary heart disease risk in later life? Evidence from observational studies. doi
  15. Laboratory measurement of posture allocation and physical activity in children. Med Sci Sports Exerc. doi
  16. (2003). Measurement of human daily physical activity. Obes Res. doi
  17. (2001). Measuring daily behavior using ambulatory accelerometry: the Activity Monitor. Behav Res Methods Instrum Comput. doi
  18. Monitoring activity in individuals with Parkinson disease: a validity study. doi
  19. (2006). Monitoring of physical activity in young children: How much is enough? Pediatr Exerc Sci.
  20. Motion pattern and posture: correctly assessed by calibrated accelerometers. doi
  21. Objective measurement of habitual sedentary behavior in pre-school children: comparison of activPAL with Actigraph monitor. Pediatr Exerc Sci. doi
  22. (1999). Physical activity monitoring based on accelerometry: validation and comparison with video observation. Med Biol Eng Comput. doi
  23. Predicting overweight and obesity in adulthood from body mass index values in childhood and adolescence.
  24. (1998). Quantification of physical activities by means of ambulatory accelerometry: a validation study. doi
  25. Sedentary behavior, physical activity, and the metabolic syndrome among U.S. adults. Obes Res. doi
  26. (2011). Sedentary time and cardio-metabolic biomarkers in US adults: NHANES 2003-06. Eur Heart J. doi
  27. Sinaiko AR. Adiposity in childhood predicts obesity and insulin resistance in young adulthood. doi
  28. Statistical methods for assessing agreement between two methods of clinical measurement. doi
  29. (1995). The level and tempo of children's physical activities: an observational study. Med Sci Sports Exerc. doi
  30. (2009). The sensitivity and specificity of an activity monitor in detecting functional activities in young people with cerebral palsy. Arch Phys Med Rehabil. doi
  31. (2006). The validation of a novel activity monitor in the measurement of posture and motion during everyday activities. doi
  32. The validity and reliability of a novel activity monitor as a measure of walking.
  33. Total energy expenditure and physical activity in young Scottish children: mixed longitudinal study. doi
  34. Validation of two activity monitors in patients with COPD. doi
  35. Validity of ambulatory accelerometry to quantify physical activity in heart failure. doi
  36. Validity of the ActiReg system in assessing energy requirement in chronic obstructive pulmonary disease patients. Clin Nutr. doi

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