I've been hatching ducklings every spring for a few years now and I very rarely have a duckling that can hold itself up and run around by the 2 hour mark. All they've ever known is the fetal position, they have no muscle strength to begin with and on top of that they have just spent a whole 24-48 hours hatching taking what little energy they had to begin with. They will sometimes shake, wobble and half of the time they will look like they're on deaths door for a few hours at the very least after hatch. That's also why it's important once they are moved to the brooder for them to be given a separate waterer with electrolytes and vitamins to help start building up their strength along with replenishing the energy loss at hatch.