head pulling

Please watch and let me know thoughts? Do I go ahead and just end this poor girls life? This has been going on for about a week. https://youtu.be/upnqRAoKrZQ This hen has changed quickly. Less than two weeks ago she was her usual full-feathered, sturdy self. Also the leader...

I have a hen that is a couple years old. Rescued/adopted from an animal sanctuary near me. In the mornings, when she comes out of her coop, I notice her body pulling to the right and left while her head stays in place. It happens repeatedly. She isn't doing it all the time. Her neck doesn't...