Try to guess what this is. My first guess was that this is some kind of a prosthesis.
Patented by Warden, J.C Gardner in 1866, the Oregon Boot or Gardner Shackle was manufactured at the Oregon state penitentiary by prisoners.
A heavy iron band locked around the ankle and was attached to the heel of the boot by an iron ring. Weighing between 5 and 28 pounds each, the boot was designed as a way of dealing with escape attempts and was fitted to every inmate. When Gardner left the prison, he demanded payment for the use of the design. Wearing the shackle for long periods of time caused great physical damage and prisoners referred to the device as a “man-killer”.