Alpha-hinge lasts have a v-shaped cutout or “vent” between the top of the cone and the socket, as well as a spring and hinge at the bottom of the waist that allows the backpart to be pivoted up or “broken” relative to the forepart, for removal.
Alpha-hinge lasts are particularly popular among production-line tall boot manufacturers.
Alpha-hinge lasts can cause problems for the toplines of lower shoes, since breaking the last causes its overall length to increase slightly as the curve of the heel rises. They may also pose challenges finely finishing the quarters of shoes, since the vent makes a gap where no last material backs the upper for hammering or burnishing.
Lisa Sorrell demonstrating an alpha-hinge last