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Accelerometer wear-site detection: When one site does not suit all, all of the time

Journal Article


Abstract


  • Objectives: Choice of accelerometer wear-site may facilitate greater compliance in research studies. We aimed to test whether a simple method could automatically discriminate whether an accelerometer was worn on the hip or wrist from free-living data. Design: Cross-sectional. Methods: Twenty-two 10-12. y old children wore a GENEActiv at the wrist and at the hip for 7-days. The angle between the forearm and the total acceleration vector for the wrist-worn monitor and between the pelvis and the total acceleration vector for the hip-worn monitor (i.e. the angle between the Y-axis component of the acceleration and the total acceleration vector) was calculated for each 5. s epoch. The standard deviation of this angle (SDangle) was calculated over time for the wrist-worn and hip-worn monitor for windows of varying lengths. We hypothesised that the wrist angle would be more variable than the hip angle. Results: Wear site could be discriminated based on SDangle; the shorter the time window the lower the optimal threshold and Area under the Receiver-Operating-Characteristic curve (AUROC) for discrimination of wear-site (AUROC = 0.833 (1. min) - 0.952 (12. h)). Classification accuracy was good for windows of 8. min (sensitivity = 90%, specificity = 87%, AUROC = 0.92) and plateaued for windows of ¿60. min (sensitivity and specificity >90%, AUROC = 0.95-0.96). Conclusions: We have presented a robust, computationally simple method that detects whether an accelerometer is being worn on the hip or wrist from 8 to 60. min of data. This facilitates the use of wear-site specific algorithms to analyse accelerometer data.

Authors


  •   Rowlands, Alex V. (external author)
  •   Olds, Timothy S. (external author)
  •   Bakrania, Kishan (external author)
  •   Stanley, Rebecca M.
  •   Parfitt, Gaynor C. (external author)
  •   Eston, Roger G. (external author)
  •   Yates, Thomas (external author)
  •   Fraysse, Francois (external author)

Publication Date


  • 2017

Citation


  • Rowlands, A. V., Olds, T. S., Bakrania, K., Stanley, R. M., Parfitt, G., Eston, R. G., Yates, T. & Fraysse, F. (2017). Accelerometer wear-site detection: When one site does not suit all, all of the time. Journal of Science and Medicine in Sport, 20 (4), 368-372.

Scopus Eid


  • 2-s2.0-85009860285

Ro Metadata Url


  • http://ro.uow.edu.au/sspapers/2915

Number Of Pages


  • 4

Start Page


  • 368

End Page


  • 372

Volume


  • 20

Issue


  • 4

Abstract


  • Objectives: Choice of accelerometer wear-site may facilitate greater compliance in research studies. We aimed to test whether a simple method could automatically discriminate whether an accelerometer was worn on the hip or wrist from free-living data. Design: Cross-sectional. Methods: Twenty-two 10-12. y old children wore a GENEActiv at the wrist and at the hip for 7-days. The angle between the forearm and the total acceleration vector for the wrist-worn monitor and between the pelvis and the total acceleration vector for the hip-worn monitor (i.e. the angle between the Y-axis component of the acceleration and the total acceleration vector) was calculated for each 5. s epoch. The standard deviation of this angle (SDangle) was calculated over time for the wrist-worn and hip-worn monitor for windows of varying lengths. We hypothesised that the wrist angle would be more variable than the hip angle. Results: Wear site could be discriminated based on SDangle; the shorter the time window the lower the optimal threshold and Area under the Receiver-Operating-Characteristic curve (AUROC) for discrimination of wear-site (AUROC = 0.833 (1. min) - 0.952 (12. h)). Classification accuracy was good for windows of 8. min (sensitivity = 90%, specificity = 87%, AUROC = 0.92) and plateaued for windows of ¿60. min (sensitivity and specificity >90%, AUROC = 0.95-0.96). Conclusions: We have presented a robust, computationally simple method that detects whether an accelerometer is being worn on the hip or wrist from 8 to 60. min of data. This facilitates the use of wear-site specific algorithms to analyse accelerometer data.

Authors


  •   Rowlands, Alex V. (external author)
  •   Olds, Timothy S. (external author)
  •   Bakrania, Kishan (external author)
  •   Stanley, Rebecca M.
  •   Parfitt, Gaynor C. (external author)
  •   Eston, Roger G. (external author)
  •   Yates, Thomas (external author)
  •   Fraysse, Francois (external author)

Publication Date


  • 2017

Citation


  • Rowlands, A. V., Olds, T. S., Bakrania, K., Stanley, R. M., Parfitt, G., Eston, R. G., Yates, T. & Fraysse, F. (2017). Accelerometer wear-site detection: When one site does not suit all, all of the time. Journal of Science and Medicine in Sport, 20 (4), 368-372.

Scopus Eid


  • 2-s2.0-85009860285

Ro Metadata Url


  • http://ro.uow.edu.au/sspapers/2915

Number Of Pages


  • 4

Start Page


  • 368

End Page


  • 372

Volume


  • 20

Issue


  • 4