Abstract
Purpose: In 1928, Schwartz defined for the first time a quantitative measure of the plantar vault acquired from the footprint. Since that time, a whole series of parameters have been described in the literature. The purpose of the present work was to study the correlations between different footprint parameters and radiographic data obtained in the weight-bearing position.
Material and methods: This retrospective series included a sample of 158 patients (35 men, 123 women) who attended a specialised adult podology clinic. Mean age was 46 years, range 14 – 86 years. Footprints were obtained in two-leg stance on two sheets of standard paper after spreading an iodine (or eosin in case of allergy) alcohol solution on the plant of the foot. Five graphic indexes were retained for analysis. The angle of the arch, the Chippaux-Smirak index, and the contact angles II, II, IV described by Qamra. Indexes described in the literature which require sophisticated equipment (computer, planimeter, pressure captors…) were intentionally not included in the analysis. The Djian-Annonier angle was measured on the radiograms. These measures were chosen because they are used in daily practice in our unit.
Results: The results were evaluated for all 316 feet taken as one population and for the 158 left and 158 right feet as two subpopulations. The coefficient of correlation between the Djian-Annonier angle and the five selected footprint parameters were greater than 0.5 (excepting the arch angle, where −0.24 < r < −0.31). The best correlation was found between the Djian-Annonier angle and the Chippaux index (about 0.60). Intercorrelation between the five footprint parameters showed a coefficient of correlation greater than 0.79, except for the arch angle where r was negative.
Discussion: The Chippaux-Smirak index is a simple way to obtain objective measurement which is statistically related with the Djian-Annonier angle, exhibiting better correlation than more sophisticated indexes such as those described by Qamra in a symptomatic population. But these conclusions are applicable for a population of feet exhibiting normal distribution. The podometric parameters cannot be measured for feet at the extremes of the distribution because the plantar vault is measured in the middle part of the footprint. In case of severe pes cavus there would be no footprint at this area and for a very flat foot the printed/nonprinted ratio would be one.
The abstracts were prepared by Docteur Jean Barthas. Correspondence should be addressed to him at Secrétariat de la Société S.O.F.C.O.T., 56 rue Boissonade, 75014 Paris.
