It seems like it's just the one hock fortunately. I'm trying to think of a way to help the hock. The curly toes can be somewhat of an easy fix. Here's a link to fixing curly toes. Even though it's with peafowl it's the same...
Welcome to BYC! I'm familiar with this problem, in peafowl though. Can you please take a picture of the hocks themselves. Hold the chick on its back securely and try to get a picture showing the hocks. Curly toes is an easier issue to correct than the hock problem. With peafowl and other birds...