MEASURING POSTURE AND MOTION USING THE THIGH- AND POCKET-WORN FIBION AND ACTIVPAL MONITORS IN A LABORATORY AND FREE-LIVING SETTING.
Start Date
April 2025
Location
3rd floor - Library
Abstract
BACKGROUND: It is important to have accurate measurements to better understand the health impacts of time spent in different postures. Inclinometer-based accelerometers are tools to classify these postures. PURPOSE: To determine the validity and reliability of a new monitor (Fibion) for classifying posture, in a laboratory and free-living setting, compared to an established monitor (activPAL). METHODS: 25 adult participants (12 male; age 40±15 yr) wore one activPAL (right thigh), and four Fibion (both thighs and front pants/shorts pockets) while performing 12 activities of daily living for 2 minutes each in a laboratory setting. Laboratory activity postural output (sit, stand, step, or cycle) from all devices was compared to direct observation (percent agreement and weighted kappa), and percentage of time each activity was correctly classified was calculated. For sweeping, walking or standing was counted as a correct posture; for rowing, cycling or walking was counted as a correct posture. Monitors were then worn for three days during normal activities and during waking hours. RESULTS: Average accuracy for the Fibion thigh monitors was 86% (kappa=0.8; p<0.001) with high accuracy (90%–100%) for detecting lying, sitting, walking, stair climbing, jogging, and sweeping. Average accuracy for the Fibion pocket monitors was 75% (kappa 0.65; p<0.001). The thigh-worn activPAL had overall accuracy of 73.0% (kappa 0.61; p<0.001). Across 63,775 total minutes, Fibion L and R thigh had 85.6% agreement (kappa=0.73), and L and R pocket had 76.1% agreement (kappa=0.57; both p<0.001). CONCLUSION: The Fibion monitor shows promise as a tool for measuring activities and postures.
MEASURING POSTURE AND MOTION USING THE THIGH- AND POCKET-WORN FIBION AND ACTIVPAL MONITORS IN A LABORATORY AND FREE-LIVING SETTING.
3rd floor - Library
BACKGROUND: It is important to have accurate measurements to better understand the health impacts of time spent in different postures. Inclinometer-based accelerometers are tools to classify these postures. PURPOSE: To determine the validity and reliability of a new monitor (Fibion) for classifying posture, in a laboratory and free-living setting, compared to an established monitor (activPAL). METHODS: 25 adult participants (12 male; age 40±15 yr) wore one activPAL (right thigh), and four Fibion (both thighs and front pants/shorts pockets) while performing 12 activities of daily living for 2 minutes each in a laboratory setting. Laboratory activity postural output (sit, stand, step, or cycle) from all devices was compared to direct observation (percent agreement and weighted kappa), and percentage of time each activity was correctly classified was calculated. For sweeping, walking or standing was counted as a correct posture; for rowing, cycling or walking was counted as a correct posture. Monitors were then worn for three days during normal activities and during waking hours. RESULTS: Average accuracy for the Fibion thigh monitors was 86% (kappa=0.8; p<0.001) with high accuracy (90%–100%) for detecting lying, sitting, walking, stair climbing, jogging, and sweeping. Average accuracy for the Fibion pocket monitors was 75% (kappa 0.65; p<0.001). The thigh-worn activPAL had overall accuracy of 73.0% (kappa 0.61; p<0.001). Across 63,775 total minutes, Fibion L and R thigh had 85.6% agreement (kappa=0.73), and L and R pocket had 76.1% agreement (kappa=0.57; both p<0.001). CONCLUSION: The Fibion monitor shows promise as a tool for measuring activities and postures.
