Accuracy and reliability of 10 pedometers for measuring steps over a 400-m walk.

PURPOSE

The purpose of this study was to determine the accuracy and reliability of the following electronic pedometers for measuring steps: Freestyle Pacer Pro (FR), Kenz Lifecorder (KZ), New Lifestyles NL-2000 (NL), Omron HJ-105 (OM), Oregon Scientific PE316CA (OR), Sportline 330 (SL330) and 345 (SL345), Walk4Life LS 2525 (WL), Yamax Skeletone EM-180 (SK), and the Yamax Digi-Walker SW-701 (DW).

METHODS

Ten males (34.7 +/- 12.6 yr) (mean +/- SD) and 10 females (43.1 +/- 19.9 yr) ranging in BMI from 19.8 to 33.6 kg.m-2 walked 400-m around an outdoor track while wearing two pedometers of the same model (one on the right and left sides of the body) for each of 10 models. Four pedometers of each model were assessed in this fashion. The actual steps taken were tallied by a researcher.

RESULTS

The KZ, NL, and DW were the most accurate in counting steps, displaying values that were within +/-3% of the actual steps taken, 95% of the time. The SL330 and OM were the least accurate, displaying values that were within +/-37% of the actual steps, 95% of the time. The reliability within a single model (Cronbach's alpha) was >0.80 for all pedometers with the exception of the SL330. The intramodel reliability was exceptionally high (>0.99) in the KZ, OM, NL, and the DW.

CONCLUSION

Due to the variation that exists among models in regard to the internal mechanism and sensitivity, not all pedometers count steps accurately. Thus, it is important for researchers who use pedometers to assess physical activity to be aware of their accuracy and reliability.