Reliability and Repeatability of the Portable EPS-Platform Digital Pressure-Plate System

Abstract

Background: Abnormal plantar pressures are the hallmark characteristic of several conditions and pathologic abnormalities. Pressure platforms allow for quick and accurate screening of patients and help guide clinical treatment. However, it is essential to evaluate the reliability and repeatability of these devices before making clinical decisions. The purpose of this study was to determine the reliability of the EPS-Platform during static and dynamic activities. Methods: Fifty-six healthy individuals stood and walked onto the pressure platform. Five trials were performed during two separate testing sessions to determine intrasession and intersession reliability. Pressure data were obtained and several variables of interest were calculated for intrasession and intersession reliability using intraclass correlation coefficients (ICCs), SEM, percent error, and coefficient of variation. Results: Static and dynamic intrasession and intersession reliability produced moderate-to-excellent ICCs, low SEMs, low percent errors, and low coefficients of variation. Static trials had higher ICCs, lower percent errors, and lower coefficients of variation compared with dynamic trials. Intersession reliability also had higher ICCs, lower percent errors, and lower coefficients of variation compared with intrasession reliability. Conclusions: This study demonstrates that the EPS-Platform is a reliable device for collecting gait plantar pressures. Static trials produce better reliability, most likely owing to the large inherent variability during dynamic gait. Intersession reliability was higher than intrasession reliability owing to the intersession measures being calculated with an average of five trials. By averaging the trials, the variability of gait is decreased, and this improves the accuracy of the results. These results can be used as the basis for future studies and to determine a priori sample sizes for investigations that use the EPS-Platform. (J Am Podiatr Med Assoc 103(3): 197–203, 2013)