“SmartPhone” Pedometer Validation

Mechanical devices, such as pedometers, can be used to measure physical activity behavior. Some of the advantages of using pedometers include the ability to quantify physical activity, freedom from researcher bias, and low researcher and participant burden (Oliver, Schofield, & Kolt, 2007). With the growing popularity of smartphone applications, the purpose of this study was to validate the accuracy of an iPhone pedometer application with adults. Four graduate student assistants (ages 20-30) participated. An iPhone accelerometer pedometer application, All-In Pedometer by Arawella Corporation, was validated against a criterion measure of manually counted steps. In addition to a manual step count, the previously validated NewLifestyles NL-2000 pedometer (Schneider, Crouter, Lukajic, & Bassett, 2003) served as an additional criterion measure. Participants wore the NL-2000 pedometer on the hip of their waistline and the iPhone was placed in the adjacent hip pocket. Participants were asked to run and walk on a 100m path. The run and walk conditions were counterbalanced and replicated. Participants were video recorded for the purpose of manually counting steps with a hand tally counter. Bland-Altman (Bland & Altman, 1986) plots revealed that the All-In Pedometer application closely estimated steps (p \u3c 0.05) when compared to the criterion measures during the walk and run conditions. It is important to have objective, accurate measures to assess changes in physical activity as the previous research has often depended on unreliable self-report measures (McIver, Brown, Pfeiffer, Dowda, & Pate, 2007)