shackles (made out of metal or leather) 2 of them connected with short chain. when locked on the ankles they prevent wearer from making big steps. together with high heals it is quite debilitating for movement. There is also a “hobble skirt” (A long skirt, popular between 1910 and 1914, that was so narrow below the knees that it restricted normal stride) that achieves the same thing. Quite sexy!