Format

Send to

Choose Destination
Med Sci Sports Exerc. 2014 Oct;46(10):2025-9. doi: 10.1249/MSS.0000000000000326.

Detection of lying down, sitting, standing, and stepping using two activPAL monitors.

Author information

1
1Department of Kinesiology, Recreation, and Sport Studies, University of Tennessee, Knoxville, TN; and 2Department of Health Sciences, Northeastern University, Boston, MA.

Abstract

The activPAL is an accelerometer-based monitor worn on the thigh that classifies daily activities into three categories (sitting/lying down, standing, and stepping). The monitor discriminates between sitting/lying and the upright position by detecting the inclination of the thigh. It detects stepping from the acceleration versus time wave form. However, a current limitation of the activPAL is that it does not discriminate between sitting and lying down.

PURPOSE:

This study aimed to determine whether placing a second activPAL monitor on the torso would allow the detection of seated versus lying postures.

METHODS:

Fifteen healthy adults (18-55 yr of age) wore an activPAL on the right thigh and another activPAL over the right rib cage. Both monitors were synchronized and initialized to record data in 15-s epochs. Participants performed a semistructured routine of activities for 3 min each. Activities included lying down (while supine, prone, and on the side), sitting, standing, sweeping, treadmill walking at 3 mph, and treadmill running at 6 mph. The spatial orientation of the thigh and chest monitors was used to determine body posture, and the activPAL on the thigh was used to detect ambulation.

RESULTS:

The use of two activPAL devices enabled four behaviors to be accurately classified. The percentages of observations that were classified accurately were as follows: lying down (100%), sitting (100%), standing/light activity in the upright position (90.8%), and stepping (100%).

CONCLUSIONS:

The current method allows researchers to obtain more detailed information on postural allocation compared with that in the use of a single activPAL on the thigh.

PMID:
24598698
DOI:
10.1249/MSS.0000000000000326
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wolters Kluwer
Loading ...
Support Center