Classification accuracy of the wrist-worn gravity estimator of normal everyday activity accelerometer. Med Sci Sports Exerc 2013 Oct;45(10):2012-9
Date
04/16/2013Pubmed ID
23584403Pubmed Central ID
PMC3778030DOI
10.1249/MSS.0b013e3182965249Scopus ID
2-s2.0-84885019180 (requires institutional sign-in at Scopus site) 49 CitationsAbstract
PURPOSE: The purpose of this study was to determine whether the published left-wrist cut points for the triaxial Gravity Estimator of Normal Everyday Activity (GENEA) accelerometer are accurate for predicting intensity categories during structured activity bouts.
METHODS: A convenience sample of 130 adults wore a GENEA accelerometer on their left wrist while performing 14 different lifestyle activities. During each activity, oxygen consumption was continuously measured using the Oxycon mobile. Statistical analysis used Spearman's rank correlations to determine the relationship between measured and estimated intensity classifications. Cross tabulations were constructed to show the under- or overestimation of misclassified intensities. One-way χ2 tests were used to determine whether the intensity classification accuracy for each activity differed from 80%.
RESULTS: For all activities, the GENEA accelerometer-based physical activity monitor explained 41.1% of the variance in energy expenditure. The intensity classification accuracy was 69.8% for sedentary activities, 44.9% for light activities, 46.2% for moderate activities, and 77.7% for vigorous activities. The GENEA correctly classified intensity for 52.9% of observations when all activities were examined; this increased to 61.5% with stationary cycling removed.
CONCLUSIONS: A wrist-worn triaxial accelerometer has modest-intensity classification accuracy across a broad range of activities when using the cut points of Esliger et al. Although the sensitivity and the specificity are less than those reported by Esliger et al., they are generally in the same range as those reported for waist-worn, uniaxial accelerometer cut points.
Author List
Welch WA, Bassett DR, Thompson DL, Freedson PS, Staudenmayer JW, John D, Steeves JA, Conger SA, Ceaser T, Howe CA, Sasaki JE, Fitzhugh ECAuthor
Whitney A. Morelli PhD Assistant Professor in the Physical Medicine and Rehabilitation department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AccelerometryAdult
Energy Metabolism
Female
Gravitation
Humans
Male
Middle Aged
Monitoring, Ambulatory
Motor Activity
Oxygen Consumption
Physical Exertion
Wrist
Young Adult