[Sub-astragalar articulation: functional approach using load imprints].

The prints of the subtalar articulation were studied in several positions. An original set allowed the fixation of the articulation under pressure and in the desired position. Contact areas of articular surfaces were coloured by Safranin 0. In inversion and eversion, the rate of incongruency of articular surfaces increased, while the contact was maximal in a mid-position, fixed by a passive blocking of the articulation. According to our results, the support is the main position transmitting the pressures during the gait when the talocrural joint is in motion; the inversion is the essential movement when the foot is not in contact with the ground.