A comparison of two studies of the pressure distribution under the feet of normal subjects using different equipment.

There is growing interest in the use of foot pressure measurement both clinically and in the study of normal subjects. A number of systems are now commercially available, but comparison of the results is complicated by the different techniques employed. This paper compares the results of two studies. The first examined a large group of normal subjects using the dynamic pedobarograph. The second was identical to the first except that the EMED F system was used. The second study was carried out in order to verify existing results and to assess the clinical significance of the expected differences. Comparison of the results from the two studies showed that the median peak pressures demonstrated similar patterns with the highest pressure in the forefoot under the second/third metatarsal heads and the toes taking gradually reduced pressure from the first to the fifth toe. The EMED F showed higher peak pressures than the dynamic pedobarograph under the heel, the medial four metatarsal heads, and the great toe and showed lower peak pressures and shorter contact times under the lateral four toes. The pattern of loading across the metatarsal heads was further analyzed using an objective method of splitting the subjects into groups. Four groups were isolated from both sets of results, and this has confirmed that only a proportion of normal subjects demonstrate highest loading under the first metatarsal head whereas the remainder show highest loading centrally within the forefoot.