Development of simple and portable device for plantar pressure measurement for improvement of foot assessment

Abstract

Background : The most common cause of foot problems is an abnormal plantar pressure distribution. Evaluation of plantar pressure is therefore necessary in management of foot problems. The tool for plantar pressure measurement is; however, expensive, complicated and needs special technicians to operate, so it is not widely used clinically. For this reason, the researchers develop a simple portable device for plantar pressure measurement that is of lower cost and easier to use.

Objective : To develop a simple, low cost and easy to use in-shoe pressure measurement and define the correlation with the standard plantar pressure measurement tool (F-scan).

Design : Descriptive and analytical study.

Setting : Biomedical Engineering, Faculty of Engineering, Chulalongkorn University and Center of Excellence in Gait and Motion, King Chulalongkorn Memorial Hospital.

Material and Method : The researchers developed a simple in-shoe system by using Piezoresistive-insole-sensor to measure plantar pressure at the heel, the 1^st and 5^th metatarsal head (MTH) during dynamic movement in real-time. We recruited 30 healthy volunteers (10 males and 20 females) to measure their plantar pressure during standing and walking by our developed device and the standard plantar pressure measurement tool which is F-scan. The peak plantar pressures of the heel, 1^st and 5^th MTH were evaluated. The static pressures were recorded during standing for 30 seconds, and the dynamic pressures were recorded during walking for 5 meters. The average of 3 trials for each session was collected; the data were assessed by the intra-class correlation between the data from our developed device and that of the standard reference tool.

Result : The ICCs ( = 0.05) of the static plantar pressure measurement of both feet were 0.641 (0.370 – 0.811), 0.466 (0.133 – 0.705), and 0.721 (0.491 – 0.857) for the right heel, 5^th and 1^st MTH, and 0.727 (0.501 – 0.860), 0.502 (0.179 – 0.727), and 0.545 (0.235 – 0.754) for the left heel, 5^th and 1^st MTH, respectively. According to the dynamic plantar pressure, the ICCs were 0.884 (0.771 – 0.943), 0.799 (0.620 – 0.899) and 0.878 (0.760 – 0.940) for the right heel, 5^th and 1^st MTH, and 0.826 (0.666 – 0.913), 0.796 (0.614 – 0.897), and 0.711 (0.476 – 0.851) for the left heel, 5^th and 1^st MTH, respectively.

Conclusion : Our developed device and the standard reference tool were correlated by the ICCs, Therefore, our developed device could be used to evaluate abnormal plantar pressure distribution in clinical foot care.