Usually deformed feet and toes of chicks comes from either too high heat in the incubator and or too low humidity. Usually that first one is the culprit. There isn't a lot you can do other than some vitamins in the water to help strengthen the chick. Sometimes they do get better. If the chick does not look like it is suffering, you can keep it alive by dipping it's beak in the water a few times a day and sprinkling food around him so he doesn't have to struggle for it. If he looks like he might be suffering, you might need to put him down.