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Re‐examination of accelerometer data processing and calibration for the assessment of physical activity intensity
Author(s) -
Arvidsson Daniel,
Fridolfsson Jonatan,
Börjesson Mats,
Andersen Lars Bo,
Ekblom Örjan,
Dencker Magnus,
Brønd Jan Christian
Publication year - 2019
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.13470
Subject(s) - accelerometer , acceleration , calibration , work (physics) , intensity (physics) , energy expenditure , metabolic equivalent , computer science , simulation , mathematics , statistics , medicine , physical activity , physical medicine and rehabilitation , physics , optics , classical mechanics , thermodynamics , endocrinology , operating system
This review re‐examines the use of accelerometer and oxygen uptake data for the assessment of activity intensity. Accelerometers capture mechanical work, while oxygen uptake captures the energy cost of this work. Frequency filtering needs to be considered when processing acceleration data. A too restrictive filter attenuates the acceleration signal for walking and, to a higher degree, for running. This measurement error affects shorter (children) more than taller (adults) individuals due to their higher movement frequency. Less restrictive filtering includes more movement‐related signals and provides measures that better capture mechanical work, but may include more noise. An optimal filter cut‐point is determined where most relevant acceleration signals are included. Further, accelerometer placement affects what part of mechanical work being captured. While the waist placement captures total mechanical work and therefore contributes to measures of activity intensity equivalent by age and stature, the thigh and wrist placements capture more internal work and do not provide equivalent measures. Value calibration of accelerometer measures is usually performed using measured oxygen uptake with the metabolic equivalent of task (MET) as reference measure of activity intensity. However, the use of MET is not stringent and is not a measure of activity intensity equivalent by age and stature. A candidate measure is the mass‐specific net oxygen uptake, VO 2 net (VO 2 tot − VO 2 stand). To improve measurement of physical activity intensity using accelerometers, research developments are suggested concerning the processing of accelerometer data, use of energy expenditure as reference for activity intensity, and calibration procedure with absolute versus relative intensity.