The last is characterized in that the rear part and the main part are joined along a circular surface having a horizontal axis located above and at the front of the last. The rear part is provided with a generally U-shaped elastically deformable stirrup, whereby the branches thereof are designed in such a way that they are locked on the support of the last, whereby means are provided to ensure that the stirrup can be moved away from the support and that the rear part can be displaced, in relation to the main part, into a retracted position and vice-versa.