Work

Use of Objective Measures to Estimate Sedentary Time in Youth

Year: 2018

Type: article

Abstract: ). Direct observation was used during the structured activities. SB time was estimated using the inclinometer function of the AP and AG, and count thresholds with AG (<75 vector magnitude (VM) counts/10-s, < 25 vertical axis (VA) counts/10-s, and <50, 100, 150, and 200 VA counts/min). For the structured activities, the AG inclinometer and AP correctly classified supine rest about 45% of the time, seated activities 54.6% and 65.1% of the time, respectively, and walking and running >96% of the time. For the free-living measurement, the VA <25 counts/10-s has the lowest RMSE (20.6 min), while the VM <75 counts/10-s had the lowest MAPE (69.2%). The AG inclinometer was within 0.2 minutes of measured time, but had the highest MAPE (107.1%). The AP was within 1.6 minutes of measured time, but had the highest RMSE (28.5 minutes). Compared to measured SB time, the VA <25 counts/10-s and VM <75 counts/10-s provided the most precise estimates of SB during free-living activity. Further refinement is needed to improve the AP and AG posture estimates.

Source: Journal for the Measurement of Physical Behaviour

DOI: 10.1123/jmpb.2018-0007

Authors: Scott E. Crouter, Paul R. Hibbing, Samuel R. LaMunion

Institution: University of Tennessee at Knoxville

Language: English

Topic: Physical Activity and Health

Subfield: Physiology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: green

Funders: National Institutes of Health, National Heart, Lung, and Blood Institute