"I used to be a reprapper like you, then I took an arrow in the knee".
Now you can fake a knee related arrow injury with this exclusive prosthesis! (Will also work for most other body parts).
It comes with everything you need to make your own arrow as well. The .scad file is somewhat parametric so you can tweak it to fit your needs. The holes are 9-10mm, and you can change out the arrow itself with a twig or a dowel if you prefer.
Before anyone complains about the color of my print, let's just say my printed arrow is supposed to be a glass arrow.
I'd love to see someone print this and put in a proper arrow, though. :)
If you are clueless about this whole thing, take a look here: http://knowyourmeme.com/memes/i-took-an-arrow-in-the-knee
Print. (Slic3r does a good job skeining these).
Heat the feathers a bit with a lighter and bend them against a table. (This is optional as the parts are mirrored and you could glue the entire thing together).
Glue or cable-tie the parts together. (Some sanding may be required, it's a bit tight fit).
Attach the base part to your knee with some string if you have misplaced all your straps, like me.
You could also cut a hole in a pair of pants and stick the arrow through it, to increase the realism.
Complain about all the adventurous days you will never see.