Thanks for everyones advice - they seem to walk a little better this afternoon. We put a little cat food dish in there with water for them to drink and they of course have been taking turns bathing in it instead.
I will switch to shavings in the next couple of days.
What is the best thing to use on the floor of their brooder? I have day old ducks on paper towels right now but they seem to have a hard time gripping.