Validity and repeatability of three in-shoe pressure measurement systems

Abstract

In-shoe pressure measurement devices are used in research and clinic to quantify plantar foot pressures. Various devices are available, differing in size, sensor number and type; therefore accuracy and repeatability. Three devices (Medilogic, Tekscan and Pedar) were examined in a 2 day x 3 trial design, quantifying insole response to regional and whole insole loading. The whole insole protocol applied an even pressure (50-600 kPa) to the insole surface for 0-30 seconds in the Novel TruBlue TM device. The regional protocol utilised cylinders with contact surfaces of 3.14 and 15.9cm 2 to apply pressures of 50 and 200 kPa. The validity (% difference and Root Mean Square Error: RMSE) and repeatability (Intra-Class Correlation Coefficient: ICC) of the applied pressures (whole insole) and contact area (regional) were outcome variables. Validity of the Pedar system was highest (RMSE 2.6 kPa; difference 3.9%), with the Medilogic (RMSE 27.0 kPa; difference 13.4%) and Tekscan (RMSE 27.0 kPa; difference 5.9%) systems displaying reduced validity. The average and peak pressures demonstrated high between-day repeatability for all three systems and each insole size (ICC≥0.859). The regional protocol contact area % difference ranged from -97 to +249%, but the ICC demonstrated medium to high between-day repeatability (ICC≥0.797). Due to the varying responses of the systems, the choice of an appropriate pressure measurement device must be based on the loading characteristics and the outcome variables sought. Medilogic and Tekscan were most effective between 200-300 kPa; Pedar performed well across all pressures. Contact area was less precise, but relatively repeatable for all systems.3

Plantar Loads of Habitual Forefoot Strikers during Running on Different Overground Surfaces

“…The thickness of each insole is 1.9 mm and the insoles were covered with soft artificial leather. The validity of the Pedar system has been demonstrated previously [28]. Pedar-X was calibrated utilizing a standard device before the beginning of the protocol (Trublu Calibration, Version 25.3.6e, Novel, Munich, Germany, 2009) [14,23].…”

Outcome of the modified Lapidus procedure for hallux valgus deformity during the first year following surgery: A prospective clinical and gait analysis study

“…The ambulatory gait assessment method included pressure insoles (Pedar-X®, Novel, Germany) (Putti et al, 2007) and five 3-D inertial sensors connected with two data-loggers (Physilog®, BioAGM, CH) (Aminian et al, 1999;Rouhani et al, 2012). This ambulatory gait assessment method has been validated against the gold standard method of motion capture, using the high-speed cameras and pressure platforms (Aminian et al, 1999;Price et al, 2016;Rouhani et al, 2012). A description of sensor placement on the tibia, calcaneus, midfoot, and great toe, as well as assessment protocol is detailed in our previous publication (Chopra et al, 2015).…”

Shoe Cushioning Effects on Foot Loading and Comfort Perception during Typical Basketball Maneuvers

“…The insole measurement system (Medilogic Corporation, Germany) was used to capture the plantar pressure of different regions. This system has been validated [21]. Each insole was calibrated using the manufacturer's calibration device (T&T medilogic Medizintechnik GmbH, Schönefeld, Germany) prior to the study.…”