Plantar pressure distribution measurements. Technical background and clinical applications

Summary Measurement of ground contact forces can be used to assess the loads to which the human body is subjected in normal activities, like walking, or in more demanding situations such as in sports. With regard to clinical problems it is useful to compare the loads in the limb either between injured and non-injured or pre- and post-traumatic or -operative states. Otherwise, comparisons between patients and control groups are necessary. Measurement of the plantar pressure, i.e. the distribution of force over the sole of the foot, is useful as it provides detailed information specific to each region of contact. A wide variety of measurement systems are available on the market. These systems should be considered with respect to their technical specifications and the intended application. In general, one should distinguish between different sensor principles (resistive, capacitive, piezoelectric) and different devices (platform, insole, single transducer system). Platform systems are restricted to use in a laboratory setting (embedded in a walkway) and are used for barefoot measurements. Insole or single transducer systems can be used to record the plantar pressures within the shoe and therefore are appropriate to evaluate the effects of different shoe constructions or modifications like orthotics. Some of the precautions to be taken into account for reproducible measurements and the factors influencing pressure patterns have to be considered. Furthermore, the application of plantar pressure measurements to various clinical problems will be discussed.