Validation of the Block Walk Method for Assessing Physical Activity occurring on Sidewalks/Streets

Area of Science:

• Public Health
• Epidemiology
• Urban Planning

Background:

• The block walk method (BWM) is a common, but unvalidated, approach for assessing physical activity (PA).
• Limitations include being non-technical, labor-intensive, and lacking validation.
• Assessing PA on sidewalks and streets requires reliable methods.

Purpose of the Study:

• To validate the traditional block walk method (BWM) for PA assessment.
• To explore the utility of wearable video devices (WVDs) for PA assessment on sidewalks/streets.
• To compare the accuracy of BWM with and without WVDs across varying walkability levels.

Main Methods:

• Trained observers conducted the BWM along predefined routes in low, medium, and high walkability areas.
• One observer wore a wearable video device (WVD); a second observer did not.
• Video recordings were reviewed by two independent experts to assess PA.

Main Results:

• The traditional BWM overestimated individuals walking and sitting/standing, while underestimating runners in high-volume areas.
• BWM provided valid PA estimates in low/medium walkability areas and for less common activities like cycling.
• WVD-assisted review showed potential for improved accuracy and reduced resource needs.

Conclusions:

• The traditional BWM's validity is questionable in high-traffic urban areas.
• Wearable video devices (WVDs) offer a promising, more accurate alternative for PA assessment.
• WVDs can enhance accuracy, reduce costs, and enable retrospective PA analysis.