Slipped tendon or other injury?

[h2olilee]

I got 4 baby chicks 4 days ago and one little buff brahma has been limping and holding it's right foot up a lot. I read a lot of information online about slipped tendons but I'm not sure that is it. I looked at the leg and joint very closely under a magnifying lamp and I couldn't see anything that looked like the pictures I saw online and when I felt the joint and rolled it between my fingers gently, I didn't feel anything that seemed out of place. And when I compared it to the other leg, I couldn't see any obvious differences. I'm hoping it's just a sprain, but if it is a slipped tendon, I would need to try to repair it right away. So I guess I'm just not sure what to do here. I have her separated from the others with a divider in the brooder and gave her a fuzzy mouse cat toy which she sleeps with for comfort. She is still eating and drinking ok. She does peep a lot like it's hurting her. Any suggestions on what I can do to help her is greatly appreciated!
Here's a picture of the two legs. It's the right one that's hurting her. I will try to post a video of her too.

 

[h2olilee]

Here's a short video of her...

 

[h2olilee]

So it is a week later and there have been times when I think she is getting better and then sometimes she seems in pain. She still gets up and walks, but with a limp- not putting much weight on the right leg. She lays down most of the time though. She can lift and lower the leg when hobbling about and I have even seen her stretch it out behind her when stretching. I have looked at the hock joint several times now and I still am not seeing a tendon that looks out of place or that moves at all with gentle pressure. Comparing with the other leg it seems in the same position to me. The joint is a bit red and swollen compared to the other leg. Is it possible she sprained the joint instead? Should I wrap the leg and put her in a sling to help it heal? Please, anyone have any advice to offer as to how I can help her, I really don't want to have to cull her!

 

[h2olilee]

Another thing that is worrisome with her is that in the week and a half I've had her, the other three chicks which I got at the same time, have doubled or even tripled in size and she is still tiny, doesn't seem like she's grown much at all. She is a buff brahma and I've read they are slow to mature, but I would think there would be some growth by now. The other chicks have exploded in their growth. She is eating (medicated chick starter) and drinking and gets excited about dried tubifex worms for a treat. I have electrolyte/vitamin/mineral in her water. I've also offered a dried egg food. Should I be giving anything else?

 

[Eggcessive]

In the video, it does look like it might be injured. Leg bone deformities are usually not able to be successfully treated unfortunately, so an injury might be preferred. Since she is not growing as rapidly, she probably hasn’t been eating and drinking as much as she needs.
I would probably get some vet wrap, and cut some thin strips, and try to splint her leg (pad it a little) but don’t get the wrap too tight. Change it frequently, maybe every other day, and move her leg some and replace it so her leg can grow.
Start chick vitamins either in her water or give some B complex crushed into her food. The chick chair or sling may help some, but she probably also needs to be out of it often to stretch and use her leg. Hopefully, she will be able to improve.
Sorry that no one saw your earlier posts until now.