here is a good thread:Yes, I thought that's what was wrong in the first place. And for the second chick, I think it has clubbed feet.
https://www.backyardchickens.com/threads/peachick-with-slipped-tendon.1092979/
Read the whole thread, but pay special attention to this post:
https://www.backyardchickens.com/threads/peachick-with-slipped-tendon.1092979/page-2#post-16817050