Thanks, I'm gonna have to try itCan be fixed fairly easily by making little cardboard or plastic shoes and attaching them with vet wrap. Just push the toes out flat & tape them down. Make your shoe as close to the size of the chicken's foot as possible so it doesn't trip over it. Could take anywhere from a couple days to a couple weeks to correct. Just unwrap & check feet every day or 2.
As for causes, could have been the flooring they were on in the brooder or just the way they hatched.
I agree 50% with Ed. It is most likely a result of 'incubation effects', but there can also be a genetic component to curled foot problems. The genetic defect is most likely to show up in inbred lines with a reduced gene pool.You can fix them but it is unnecessary as long as the chicken can walk and scratch. It is from incubation effects. Totally harmless and not hereditary