Lame guinea fowl

[Plucky Clucks]

This spring I hatched my first guinea fowl along with a bunch of chickens and quail and until recently everything had been going great. However I noticed one of my guineas favoring one of its feet a week or so ago so I caught it to take a look (a harrowing experience for us both) but couldn't find anything wrong with the foot so I let it go and just kept an eye out. A few days later I noticed my banty rooster being aggressive towards it so I put it in a small pen with some of my younger chickens to keep it away from the adult free-range chickens. By this time it was spending the majority of its time laying down close to the water and food dispensers and moving very little but still alert and with good appetite. Since separating it from the main flock it moves around mainly by pushing itself with its wings. I have picked it up and checked both its feet and legs and have found that they work fine for kicking and scratching but when set back on the ground it will lay down and use its wings to push itself around. It is still fully alert and chatters back and forth with the other guinea fowl that hang out around it on the other side of the fence. Any ideas of what's going on with my poor little guinea fowl?