Chicken can barely walk
What is your setup about feeders and waterer? Could she be bullied or kept from getting enough water or food? I would make sure that she is getting vitamins and electrolytes, and check to see if she is weak in her legs, or walking on her hocks, and if her toes are curled under. Was she vaccinated for Mareks disease? Could your feed be old or rancid, where she is suffering from a vitamin deficiency?
There is a leg bone deformity that causes a knock-kneed appearance called valgus deformity. They are more common in meat chickens, but also common in egg layers. Although there is no treatment, I would offer her vitamins that contain trace minerals--something such as Poultry Nutri-drench or Poultry Cell to put in the water or give orally, or Poultry Booster for the feed. Those are easy to find at feed or farm stores, or online. Here is some info about leg bone disorders:
Edited by Eggcessive - 10/18/15 at 7:50am