Red pullet - injured leg. Help?

[JennyHaines]

I have a red mixed pullet who's about 11 weeks old now. Two days ago she started limping on her one leg. I looked at it and saw a tiny scratch on the top of her foot but no other injuries. Now she won't put any weight on it and holds the leg stretched out in front of her. When I try to move her leg she doesn't want to bend the knee joint. She holds all the toes together and when forced to walk, she curls the foot under and walks on the top of the foot. I can't see any swelling anywhere and otherwise she's eating and drinking. Cleaned the foot and have her on antibiotics for a few days but i'm totally at a loss. Anyone have any ideas?

Thanks!