What causes curled toes?

And, will a hen be able to walk with them curled?

One of my mixed breed chicks that we incubated has her toes curling to the side (it is the right foot and they are curling sideways to the right). She is 2 1/2 weeks old and gets around fine. I wonder though, if she'll lose the ability to walk on it as she gets older. Incidentally, I know not to hatch out any eggs from her in case it is a hereditary thing.

It could be a genetic thing or it could be that the humidity was off during hatching...
Either way, the chick should be fine...Slifer had only one straight toe on her feet and she got along fine. Instead of roosting she'd hunker down on their chair.

Can you try to reposition the toes and put them in sort of a cast using that "thick foam" type tape? I think someone described doing that recently for something else--just thought it might work for this one.

you can place the foot on a square of strong tape (duck tape for instance) and position the toes in the correct position and then another piece of tape on top (making sure the two pieces of tape are securely bound to each other in between the toes and cut to shape effectively forming a "shoe" (if this is not strong enough then you will hae to use a thin piece of carboard or such with it)... first though have a look at the two articles below...with this type of problem it is advised to give a supplement> (childrens liquid vitamins) of B vitamins @ 3 drops in beak for a week and then taper off...
https://www.backyardchickens.com/forum/viewtopic.php?id=2650

http://compepid.tuskegee.edu/syllabi/pathobiology/pathology/avianmed/chapter6.html
6.6 Riboflavin ( B2I) deficiency, Curl Toe paralysis
a. General consideration.
Riboflavin forms the active part of over a dozen enzyme systems in the body. Heat stable, water soluble compound. Riboflavin is present in milk by-products, alfalfa, grass meal, and liver, It is also synthesized by yeasts and bacteria.

b. Symptoms
1. Age: 3-4 weeks .
2. Action: Chronic.
3. Grow slowly, become weak and emaciated, their appetite is fairly good.
4. Diarrhea develops between the first and second week.
5. The chicks do not walk unless forced to do so, walk with the aid of wings curled inward. Paralysis also seen, drop wing, let muscle atrophied.
c. Lesions:
1. Atrophied thymus gland
2. Enlarged of the nerve, 4-5 times, due to swelling and edema.
3. Notched beak.
d. Treatment:
1. High riboflavin diet.
2. When the curled-toe deformity is long-standing, irreparable damage has occurred.