GENERALIZABILITY OF IN-SHOE PEAK PRESSURE MEASURES USING THE F-SCAN SYSTEM

In-shoe pressure analysis can be useful in the management of a variety of foot and ankle problems, but guidelines are needed to determine th e practical limitations of the measures. The primary purpose of this s tudy was to determine the reliability of peak plantar pressures taken with the F-Scan system over multiple steps, sensors, and days, and usi ng a force platform for additional calibration. Data were collected on 10 healthy subjects as they walked across a force platform for a mini mum of three trials on four separate sessions that were 1 week apart. Using a mean of three steps with a single sensor on 1 day, generalizab ility coefficients were 0.75 for manufacturer calibration and 0.82 wit h force platform calibration; reliability coefficients for absolute de cisions (index of dependability) were 0.60 for manufacturer calibratio n and 0.76 with force platform calibration. Force measures from the F- Scan and force platform were highly correlated (r = 0.93), but the abs olute difference between the measures varied between sensors and over time. Relevance-Peak pressure measures taken from a mean of three step s with procedures outlined by the F-Scan manufacturer provide pressure values that demonstrate adequate reliability for clinical and researc h purposes when rank ordering of measures is indicated, If measures ar e to be used for making absolute decisions (e.g., identifying a thresh old for injury), calibration from a stable source such as a force plat form is recommended.