Immobile chicken?

[want2know]

My 3 year old Buff Orpington, Sunshine, is having mobility issues. I gave been raising chickens for over 7 years and not encountered this issue before. As you can see by the pictures she is splayed out rather awkwardly. After I removed her from the coop she made it about 20 feet and then plop, that was it. A couple days ago at bedtime, she didn't want to climb the ramp to the upper part of the coop. So I put her in and she roosted on the branch closest to the floor.
Last night she stayed in the other coop I have in one of the nests under the rooster where 3 of the other chickens were. At first I thought maybe she was getting broody since she was staying on or near the nests. But now I don't know.
She is eating ok if I take her out and offer her food. I have given her plain yogurt and her normal feed. I do not know if she has laid an egg for the last few days, because they all lay in the same nest. As you can see from her bottom, it doesn't appear her poop has been normal.

I gave her a thorough exam of her feet and so forth and see no injuries.
Please any advice or information, suggestions let me know.

Thread 'Odd Behavior changes in mature Orpington hen' https://www.backyardchickens.com/threads/odd-behavior-changes-in-mature-orpington-hen.1675279/

 

[StinkyAcres]

Any heavy breathing or coughing? Have you introduced any new birds recently?

 

[StinkyAcres]

Am I correct that in the second photo her comb has purplish tips? That may point to a heart condition.

 

[want2know]

Any heavy breathing or coughing? Have you introduced any new birds recently?

no to all.

 

[want2know]

Any heavy breathing or coughing? Have you introduced any new birds recently?

no to all

 

[want2know]

No to all

 

[BlindLemonChicken]

Has she been vaccinated for Marek’s? Is it possible she got into anything toxic?

 

[want2know]

not that I am aware of

 

[want2know]

Am I correct that in the second photo her comb has purplish tips? That may point to a heart condition.

only two tops in that one photo

 

[BlindLemonChicken]

The curled up toes make me think vitamin deficiency but I am not at expert. Let me tag some people who are @Wyorp Rock @Eggcessive