It doesn't usually happen to chickens, since flying isn't much of their strong point. The chicken in the picture was one being feather clipped, as we do to our parrots.
Though I guess I should've really worded some of the paragraphs a little better.
Well, I've revised some of it. Just one section. I've also added a section, right under the one I reworded it, so they shouldn't be that hard to find (especially since I added another picture under the new section).
I will revise it more when I have more information. Thank you for your comments, guys!