Is there a valid app for that? Validity of a free pedometer iPhone application

Area of Science:

• Biomedical Engineering
• Kinesiology
• Health Informatics

Background:

• Assessing physical activity is crucial for public health.
• Mobile health applications offer a convenient method for activity monitoring.
• The validity of free pedometer applications requires rigorous evaluation.

Purpose of the Study:

• To determine the accuracy of the iPedometer (IP) iPhone application.
• To assess the IP application's validity as a tool for measuring physical activity.

Main Methods:

• Twenty college students participated in the study.
• Participants walked on a treadmill at five different speeds.
• An iPhone with the IP app, a StepWatch (SW), and a tally counter (TC) were used to measure steps.

Main Results:

• The IP application showed significant inaccuracies in step counting across most conditions.
• Statistically significant differences were found between IP, SW, and TC, except in one specific condition.
• Low correlations were observed between the IP and criterion measures.

Conclusions:

• The free iPedometer application is not a valid instrument for monitoring physical activity during treadmill walking.
• The application consistently underestimated step counts compared to validated measures.
• Further research is needed to validate other mobile health applications for physical activity assessment.