Another older post, but appears worthy of an answer.
Fetters are shackles used to restrain the legs. In Buddhism it is also defined by a mental restraint. Fetter is another reference to a restraining of the legs, like hobble.
http://en.wikipedia.org/wiki/Fetter
A switch can also be defined as a small limb used to punish or discipline, as in a spanking. Again a reference to hobble or restrain the actions of.