Date of Award
Master of Science
Dawn P. Coe
David R. Bassett, Jr, Dixie L. Thompson
Purpose: To determine the step count accuracy of three pedometers and one accelerometer in pregnant women during treadmill walking. Methods: Subjects were 30 women in the second or third trimester (20-36 weeks) who were screened for pregnancy-related risk factors. Each subject was fitted with a belt containing three physical activity monitors: Yamax Digiwalker SW-200 (DW), New Lifestyles NL 2000 (NL), and GT3X Actigraph accelerometer (ACT). The Omron HJ-720 (HJ) was placed in the pants pocket. Subjects walked at 54, 67, 80, and 94 m•min-1 for two minutes each. Actual steps were determined by an investigator using a hand-tally counter. Percentage of actual steps was calculated for each device at each speed and compared. Results: There was a significant interaction between speed and device (F9,20=7.574,P<0.001). At all speeds, the NL and HJ were most accurate. At 54 m•min-1, the DW was significantly less accurate (P<0.001) than all other devices and the ACT was significantly less accurate (P<0.001) than the NL and HJ. At 67 m•min-1, the ACT and DW were significantly less accurate (P<0.001) than the NL and HJ. At 80 m•min-1, the DW was significantly less accurate (P=0.024) than the NL and HJ. At 94 m•min-1, the ACT was significantly less accurate (P=0.001) than the NL and HJ. No significant differences were found at any speed for the NL (P=0.996) and HJ (P=0.298). Trimester did not significantly affect device accuracy. Conclusion: In pregnant women, the ACT and DW are less accurate than the NL and HJ. The HJ appeared to be the most accurate. These results can be useful in developing further research studies and physical activity programs that focus on walking during pregnancy.
Connolly, Christopher P., "Accuracy of Physical Activity Monitors in Pregnant Women. " Master's Thesis, University of Tennessee, 2010.