Temperature and measurement changes over time for F-Scan sensors

Plantar pressure measurement is an important tool for understanding foot and gait biomechanics. F-Scan is a popular device for measuring in-shoe plantar pressures; however, the validity of the F-Scan force measurements has been questioned. Therefore, a study was performed to analyze changes in plantar pressure and temperature over time. One participant was fitted with two F-Scan sensors before step calibration. Single leg standing trials were captured for each limb while the subject stood on a force plate, then the subject performed multiple trials of level ground walking. Sensor temperatures were measured immediately after each set of walking trials. This procedure was repeated every 10 minutes for 140 minutes. Total force values decreased over time, with the largest decrease in total force occurring in the first 60 minutes. Sensor temperature increased during the first hour and then leveled off. Centre of pressure trajectories were similar over 140 minutes, indicating that cell pressures change similarly over time. This study showed that F-Scan is appropriate for evaluating pressure profiles and centre of pressure shape but additional considerations are required when using total force as an outcome measure.