Design and validation of a simple automated optical step counting method for treadmill walking

Area of Science:

• Biomechanics
• Locomotion Analysis
• Wearable Technology

Background:

• Accurate step counting is crucial for locomotion research.
• Existing methods are often inaccurate, time-consuming, costly, or cumbersome.
• A novel camera-based optical method for automatic step counting is presented.

Purpose of the Study:

• To develop and validate a cost-effective, camera-based optical system for automatic step counting.
• To assess the accuracy and reliability of the proposed method across various locomotion speeds.
• To provide an alternative to existing step counting technologies in research settings.

Main Methods:

• Fifteen healthy adults performed walking, jogging, and running on a treadmill at controlled and varying speeds.
• A visual marker was placed on the subject's left foot.
• Synchronous video recording at low and high resolutions was performed, followed by manual and automated video analysis for step counting.

Main Results:

• The optical method demonstrated high reliability, with an Intra-class correlation coefficient (ICC) of ≥0.98.
• Quantitative assessments using Bland-Altman plots and relative error confirmed the device's accuracy.
• The system provided accurate step counts across the tested range of speeds.

Conclusions:

• The camera-based optical method provides accurate step counts for diverse locomotion speeds.
• The system utilizes customizable open-source software and readily available hardware, ensuring low implementation costs.
• Researchers gain access to raw sensor data, facilitating in-depth analysis and method customization.