Off balance, walking on "knees"

[takia]

I did a search and I think I have an idea, but hoping someone can check my theory. Have a 12-14 week old Easter egger as part of my 10 member flock. This morning all was fine, now she is struggling to balance herself and her left leg is at a weird angle when she walks, but she is also spending time walking on her knees. She is eating and drinking fine, and has a full, but no fuller than the others, crop. They are on fermented feed get fruits and veg daily in moderation and free range 4-6 hours a day. No other sickness in the coop.

I'm thinking vitamin b treatment, but could very well be mareks so I need to start preparing for flock loss.

 

[takia]

 

[Eggcessive]

Walking on hocks and curled under toes can be a sign of riboflavin (B2) deficiency, but could be a sign of Mareks. Injury might also be a possibility. I would definitely give 1/2 tablet of human super B complex vitamins orally or crushed into some moistened feed or egg daily for a couple of weeks. Here is a good B complex:
https://www.walmart.com/ip/Spring-V...MIubayodn0jQMVJk5HAR3WDgdrEAQYBCABEgIG6vD_BwE