Abstract: A self-opening cuff comprising a fixed member, to which a cylindrically curved cuff is pivoted for swinging movement in a vertical plane. The fixed member is rigidly attached to the crutch tubing, and has two laterally projecting, angularly spaced side arms with an included angle of approximately 90.degree. between them. The two side arms have a cylindrically curved inner surface with the same radius of curvature as the cuff, and this curved surface is interrupted at its midpoint by a vertical slot. Disposed within the slot and swingably connected to the fixed member by a pivot bolt is a lug which is provided on the outside of the cuff. The top portion of the cylindrically curved surface is smoothly rounded with a curvature having its center at the pivot bolt axis, forming a ramp that the outer surface of the cuff rides on as it swings upwardly.