Non-traditional wearing positions of pedometers: validity and reliability of the Omron HJ-203-ED pedometer under controlled and free-living conditions

Objectives: To test the validity and intra-instrument reliability of the HJ-203 Omron pedometer when worn in different positions, under controlled and free-living conditions.

Design: Cross-sectional.

Methods: Forty healthy adults (20 men, 29.5±7.7 years) participated in three controlled tests, i.e. 20 step test, stair climbing (up and down), and treadmill walking (five bouts at different speeds). All participants wore a HJ-203 pedometer in the pants pocket, in a carrier bag, and around the neck. Fifty-four adults (23 men, 33.9±11.1 years) participated in a free-living conditions test, wearing a HJ-203 in the pants pocket and around the neck during one day.

Results: During controlled tests, absolute percentage error ranged between 0.1% and 14.0%. Accuracy was influenced by wearing position (p<0.001), walking speed (p<0.001), and wearing position×walking speed (p=0.001). Accuracy was poor for pedometers worn in the pants pocket, especially at slower speeds; and best when worn around the neck. During free-living conditions, APE ranged between 30.7% and 36.9% and did not differ statistically between pants pocket and neck position. Intra-instrument reliability varied for controlled tests (ICC=0.14-0.96) and was acceptable during free-living conditions (ICC=0.94).

Conclusions: The HJ-203 Omron pedometer showed acceptable accuracy for all wearing positions during stairs walking and treadmill walking at higher speeds; but limited accuracy during free-living conditions when worn at non-traditional wearing positions (necklace and pants pocket). Reliability was acceptable during treadmill walking at higher speeds and free-living conditions.