From Wikipedia: "The knee splitter was a form of torture used mainly during the inquisition. It was created from two spiked wood blocks, placed on top of, and behind the knee. The blocks were connected with two large screws. When turned, the blocks would close towards each other, destroying the knee underneath them. This method was used to render the knees useless. The number of spikes on the blocks would range from three to twenty, depending on the captive."

This is a low-poly prop intended for FLARE, but hopefully useful in other horror-themed games.  It is not rigged, but the top bar can easily be moved up and down in object mode.  The textures are from Blender's built-in system, except the blood which I made myself.